CN104977560B

CN104977560B - Mobile device, localization method and alignment system

Info

Publication number: CN104977560B
Application number: CN201410136131.2A
Authority: CN
Inventors: 廖可; 伊红; 于海华; 王炜; 笪斌
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2014-04-04
Filing date: 2014-04-04
Publication date: 2017-12-05
Anticipated expiration: 2034-04-04
Also published as: CN104977560A

Abstract

A kind of mobile device, localization method and alignment system are disclosed, the mobile device includes：Positioned at N number of first wireless signal receiver of diverse location, it is configured as receiving the first wireless signal from the transmitting of another mobile device from different perspectives, wherein, N is the positive integer more than 1；Controller, it is configured as：According to the first wireless signal from the propagation rate for being launched into the N number of transmission time received by N number of first wireless signal receiver and the first wireless signal, N number of distance between another mobile device and N number of first wireless signal receiver is estimated；According to the known distance between N number of distance of estimation and N number of first wireless signal receiver, another mobile device is estimated positioned at the deflection angle with reference direction, wherein, reference direction is relevant with the position of N number of first wireless signal receiver；According to N number of distance of estimation, and the deflection angle of estimation, position of another mobile device relative to mobile device is obtained.

Description

Mobile device, positioning method and positioning system

Technical Field

The present disclosure relates to the field of wireless communications, and more particularly, to mobile devices, positioning methods, and positioning systems that facilitate positioning other mobile devices.

Background

In a meeting such as the exhibition industry, especially in scenarios where there is a need for on-site face-to-face communication, such as industry guidances, trade negotiations, technical forums, etc., the goal of most visitors is to find the location of people with matching interests on site and to communicate face-to-face, or even to achieve some business cooperation. However, in the face of many people, there is a problem that "where these interests match" is unknown, and therefore, the hit rate and efficiency of on-site communication is low.

Therefore, a technique for accurately locating the position of the other person is required.

Disclosure of Invention

According to an aspect of the present technology, there is provided a mobile device including: n first wireless signal receivers at different locations configured to receive first wireless signals transmitted from another mobile device from different angles, wherein N is a positive integer greater than 1; a controller configured to: estimating N distances between the other mobile device and the N first wireless signal receivers according to the N transmission times of the first wireless signal from being transmitted to being received by the N first wireless signal receivers and the propagation rate of the first wireless signal; estimating a deflection angle of the other mobile device from a reference direction according to the estimated N distances and known distances between the N first wireless signal receivers, wherein the reference direction is related to the positions of the N first wireless signal receivers; and obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle.

According to another aspect of the present technology, there is provided a positioning method for a mobile device to position another mobile device, including: causing N first wireless signal receivers located at different positions to receive first wireless signals transmitted from another mobile device from different angles, wherein N is a positive integer greater than 1; estimating N distances between the other mobile device and the N first wireless signal receivers according to N transmission times of the first wireless signal from being transmitted to being received by the N first wireless signal receivers and a propagation rate of the first wireless signal; estimating a deflection angle of the other mobile device from a reference direction according to the estimated N distances and known distances between the N first wireless signal receivers, wherein the reference direction is related to the positions of the N first wireless signal receivers; and obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle.

In accordance with another aspect of the present technique, there is provided a positioning system comprising: a coordinator configured to manage a plurality of mobile devices according to claim 1 in a network, and assign a mobile device ID number to each mobile device, and receive estimated distances and deflection angles between each mobile device and other mobile devices transmitted from each mobile device; a scheduler configured to sequentially instruct each mobile device to make an estimation of a distance and a deflection angle in accordance with the mobile device ID number; a mobile device as described in accordance with an aspect of the present technology is configured to send the estimated distance and yaw angle to a coordinator.

Drawings

Fig. 1 illustrates an example application scenario applying the techniques of this disclosure.

Fig. 2 shows a schematic block diagram of a mobile device according to an embodiment of the invention.

Fig. 3 shows an example flow diagram of a positioning method used by a mobile device to locate another mobile device according to another embodiment of the invention.

Fig. 4A shows a schematic diagram of a positioning system to which the positioning method of the present technology is applied, according to another embodiment of the present invention. Fig. 4B shows an exemplary hardware configuration block diagram of a mobile device to which the positioning method of the present technology is applied, according to another embodiment of the present invention. Fig. 4C shows an exemplary structural block diagram of an ultrasonic signal unit array of a mobile device to which the positioning method of the present technology is applied, according to another embodiment of the present invention.

FIG. 5 shows a timing diagram of exemplary steps performed by various components of a positioning system according to another embodiment of the invention.

Figure 6A shows a flow chart of example steps for latency correction by a transmitting mobile device and a receiving mobile device in accordance with another embodiment of the present invention. FIG. 6B shows the estimation of the time delay T in the step shown in FIG. 6A_UtUrAn example waveform of (a). Fig. 6C shows an example Radio Frequency (RF) signal physical layer frame structure.

Figure 7A shows a flow chart of example steps for a transmitting mobile device and a receiving mobile device to make received ultrasonic signals asynchronous with received RF signals according to another embodiment of the present invention. Fig. 7B shows noise waveforms of received ultrasonic signals and RF signals that may occur without the asynchronous mode shown in fig. 7A. Fig. 7C shows a correct waveform that can be obtained in the case of the asynchronous manner shown in fig. 7A.

Fig. 8 shows a flow chart of a method of locating another mobile device according to a preferred embodiment of the invention.

Fig. 9A, 9B, 9C and 9D show schematic diagrams of the principle of the deflection angle estimation of the method according to a preferred embodiment of the invention.

Detailed Description

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the specific embodiments, it will be understood that they are not intended to limit the invention to the embodiments described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. It should be noted that the method steps described herein may be implemented by any functional block or functional arrangement, and that any functional block or functional arrangement may be implemented as a physical entity or a logical entity, or a combination of both.

In order that those skilled in the art will better understand the present invention, the following detailed description of the invention is provided in conjunction with the accompanying drawings and the detailed description of the invention.

As shown in fig. 1, a mobile device (node) joins a local wireless network, and after finding interested nodes around the mobile device, the distance between the mobile device (node) and the interested nodes can be estimated (D shown in fig. 1)₁、D₂) And estimating the deflection angle (theta as shown in FIG. 1) between the present node and the node of interest₁、θ₂). Examples of typical usage scenarios are e.g. industry trade fairs, trade negotiations, technical forums, acquaintances, etc.

The mobile device 200 shown in fig. 2 includes: n first wireless signal receivers 201 at different locations configured to receive first wireless signals transmitted from another mobile device from different angles, where N is a positive integer greater than 1; a controller 202 configured to: estimating N distances between the other mobile device and the N first wireless signal receivers according to the N transmission times of the first wireless signal from being transmitted to being received by the N first wireless signal receivers and the propagation rate of the first wireless signal; estimating a deflection angle of the further mobile device from a reference direction based on the estimated N distances and known distances between the N first wireless signal receivers (and/or a geometric relationship of the positions of the N first wireless signal receivers and the further mobile device), wherein the reference direction is related to the positions of the N first wireless signal receivers; and obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle.

In this way, with N first wireless signal receivers 201 placed at different locations inside the same mobile device, a first wireless signal from another mobile device can be received from different angles, so that the distance and deflection angle of another mobile device with respect to the mobile device can be estimated using geometrical relationships. Note that the above-described deflection angle is based on a reference direction of the current mobile device, and the reference direction may be uniquely determined according to the positions of the N first wireless signal receivers. Accordingly, a user holding or wearing the mobile device can know a distance from a specific user holding another mobile device (e.g., other users having interest information matching the interest information of the current user) and a yaw angle from a known reference direction (e.g., a frontal direction, a face or head direction, etc.), so that the angle of the yaw angle can be easily turned and moved by the above-mentioned distance to find (or locate) the user holding another mobile device.

In one embodiment, the first wireless signal receiver may be an ultrasonic signal receiver. Since the ultrasonic wave is a wave whose propagation speed is a slow sound speed relative to the speed of light, the propagation distance can be estimated by measuring the time of propagation from transmission to reception and the sound speed, and therefore the ultrasonic wave is used as a preferable signal here. Of course, the present invention is not limited to this embodiment, and such a measurement of the propagation distance may be performed using other waves (e.g., acoustic waves).

In one embodiment, the controller 202 may be further configured to: (N-1) triangles connecting any two of the N first wireless signal receivers and the other mobile device are derived from the estimated distances and the known distances between the N first wireless signal receivers; obtaining the included angle of each vertex of the (N-1) triangles according to the (N-1) triangles; and obtaining an average value of N included angles between the connection line of the N first wireless signal receivers and the other mobile device and the reference direction according to the included angles and the reference direction, and taking the average value as the deflection angle.

Here, in order to make the estimated deflection angle more accurate and have smaller errors, it may be considered that in the above manner, in the case where more than two first wireless signal receivers can receive the first wireless signal transmitted from another mobile device, a more accurate deflection angle can be obtained by calculating an average value of the deflection angles in the case where any two first wireless signal receivers capable of connecting the first wireless signal and the another mobile device are triangularly shaped, and some errors due to transmission obstacles, signal attenuation, measurement errors, and the like can be eliminated.

In some embodiments, the reference direction may be: in a case where the N first wireless signal receivers are arranged in a circular arc shape, the reference direction is a normal direction of any one of the N first wireless signal receivers; in a case where the N first wireless signal receivers are arranged in a straight line, the reference direction is a vertical line direction of the straight line; and a preset direction which can be obtained from different positions of the N first wireless signal receivers. In summary, the reference direction can be uniquely derived from different positions of the N first wireless signal receivers, so that a user holding the mobile device can easily know which is the reference direction, and thus can know how to perform a yaw of the yaw angle. Of course, this is only a preferred embodiment, and in practice, the final estimated deflection angle may be obtained in other ways.

In one embodiment, the controller 202 may be further configured to: selecting a smallest distance of the estimated N distances between the other mobile device and the N first wireless signal receivers as a measured distance between the other mobile device and the mobile device.

Here, since a distance can be estimated for each time from when the first wireless signal is transmitted from another mobile device to when each first wireless signal receiver receives the signal, but the first wireless signal receiver and the another mobile device are generally in face-to-face opposition with the smallest estimated distance, in which case the condition of the transmission path between the first wireless signal receiver and the another mobile device is generally considered to be good, for example, the problem of signal transmission such as obstruction, scattering, diffraction, etc. is not likely to occur, it is considered that the estimated distance in this case is generally accurate because the signal transmission is closer to a straight line. Of course, this is only a preferred embodiment, and in practice, the final estimated distance may be obtained by averaging or other means.

In one embodiment, the mobile device may further include: a second wireless signal receiver configured to receive a second wireless signal transmitted from another mobile device substantially simultaneously with transmission of a first wireless signal from another mobile device, wherein a transmission rate V of the second wireless signal₂Faster than the transmission rate V of the first wireless signal₁(ii) a Wherein the controller is further configured to estimate a distance d between the other mobile device and each of the N first wireless signal receivers by the following formula (1):

wherein, T_UtUrIs the time delay of the first wireless signal from transmission to reception.

The second wireless signal receiver may be used with the first wireless signal receiver to make more accurate distance measurements. For example, the second wireless signal receiver may be a Radio Frequency (RF) signal receiver, which transmits a signal at a faster speed than the first wireless signal, so that a distance between the transmitting end and the receiving end can be calculated by a Time Difference of Arrival (TDOA) algorithm using propagation times of the two different speeds of the wireless signal from transmission to reception. Of course, the second wireless signal receiver may be a signal receiver propagating at other speeds, as long as the speed of the second wireless signal is different from the speed of the first wireless signal.

In one embodiment, the controller 202 may be further configured to: modifying each time delay T from transmission to receipt by each of the N first wireless signal receivers according to the first wireless signal according to equation (2) below_UtUr：

T_UtUr=Δt_UtRt+T_RtRr+Δt_Rr-T_UrRrEquation (2)

Wherein, T_UtUrIs the time delay, Δ t, of the first radio signal from transmission to reception_UtRtIs the time delay, T, of the transmission of the first radio wave signal and the transmission of the second radio wave signal_RtRrIs the time delay, at, of the second radio signal from transmission to reception_RrIs the time delay, T, of the second radio signal receiver processing the received second radio signal_UrRrIs the time delay of the reception of the first wireless signal and the reception of the second wireless signal.

Thus, more accurate time delay T of the first wireless signal from transmission to reception is obtained by considering various time delays_UtUrSo that a more accurate distance can be estimated by the propagation speed of the first wireless signal.

Wherein, in one embodiment,formula (3)

Wherein N is_preambleIs the number of bytes of the preamble in the physical layer frame structure of the second wireless signal; n is a radical of_lenthThe number of bytes of the data length in the physical layer frame structure of the second radio signal; n is a radical of_dataIs the number of bytes of actual data in the physical layer frame structure of the second radio signal; n is a radical of_CRCIs the byte number of the CRC checksum in the physical layer frame structure of the second wireless signal; the BaudRate is a transmission speed of data of the second wireless signal between the processing unit and the second wireless signal unit.

In one embodiment, the controller 202 may be further configured to: such that when one of the first and second wireless signal receivers is turned on, the other of the first and second wireless signal receivers is disabled and after the wireless signal is received by the one of the first and second wireless signal receivers, the other is turned on.

In this way, the first wireless signal receiver and the second wireless signal receiver are not always turned on, but are turned on asynchronously when needed, so that the possibility that any one receiver receives other interference signals or noise signals is reduced, and various wrong estimations caused by the received noise or wrong signals are avoided as much as possible.

In one embodiment, the mobile device 200 may further include: n first wireless signal transmitters, together with the N first wireless signal receivers at different locations, configured to transmit N first wireless signals to the another mobile device; a second wireless signal transmitter, together with the second wireless signal receiver, configured to transmit a second wireless signal to the other mobile device substantially simultaneously with the transmission of the first wireless signal. The N first wireless signal receivers located at different locations may also be configured to receive the first wireless signals transmitted from the N first wireless signal transmitters of the other mobile device from different angles. The controller 202 may be further configured to estimate a distance between each of the N first wireless signal transmitters of another mobile device and each of the N first wireless signal receivers of that mobile device based on each transmission time that a first wireless signal is transmitted from the N first wireless signal transmitters of the another mobile device to be received by each of the N first wireless signal receivers and a propagation rate of that first wireless signal; setting a shortest distance of the estimated distances as a measured distance between the mobile device and the other mobile device.

Here, in order to facilitate the internal arrangement, transceivers are generally arranged to simultaneously implement both functions of transmission and reception, so that N first wireless signal transceivers and possibly a second wireless signal transceiver may be arranged in each mobile device, so that, in the case where N first wireless signal transceivers also transmit first wireless signals in another mobile device, the N first wireless signal transceivers in the current mobile device may also respectively receive the first wireless signals transmitted from the N first wireless signal transceivers in another mobile device from various angles, and so that respective distances between the N first wireless signal transceivers in the current mobile device and the N first wireless signal transceivers in another mobile device may be estimated. In this case, the smallest distance can also be used as the measured distance between the mobile device and the other mobile device, because as mentioned above, the smallest distance usually means that the two first wireless signal transceivers are usually facing each other, so that the signal transmission process can be considered to be relatively smooth and not subject to interference or other propagation problems, and thus the distance thus estimated is usually considered to be relatively accurate.

In one embodiment, the controller 202 may be further configured to: determining whether the other mobile device is located to the left or to the right of the reference direction by one or more of: if the distance between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is greater than the distance between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, it can be judged that the deflection angle is towards the right, and if not, the deflection angle is towards the left; or the deflection angle between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is larger than the deflection angle between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, so that the deflection angle can be judged to face the right, and otherwise, the deflection angle faces the left; or the number of the first wireless signal receivers with the estimated distance or deflection angle on the left side of the reference direction is less than the number of the first wireless signal receivers with the estimated distance or deflection angle on the right side of the reference direction, the deflection angle can be judged to face the right, and otherwise, the deflection angle faces the left; or judging whether the deflection angle is towards the left or the right and the like according to the geometrical relationship between the (N-1) triangles connecting any two of the N first wireless signal receivers and the other mobile equipment and the reference direction.

Here, in the case where the calculated deflection angle is an absolute value, it may be determined whether the other mobile device is located on the left side or the right side of the reference direction of the current mobile device node, thereby guiding the user holding the current mobile device node to deflect the above-calculated deflection angle to the left or the right to find the other mobile device and the user thereof. Of course, the manner of determining whether to face left or right is not limited thereto, and those skilled in the art can conceive other manners to find whether to face left or right by the arrangement of the first wireless signal receivers and the calculated distance and deflection angle. In addition, if the calculated deflection angle is already an angle value with positive and negative, it can be directly judged whether to face left or right according to the positive and negative without going through the above-described judgment step.

As such, according to various embodiments of the present invention, a first wireless signal from another mobile device can be received from different angles using N first wireless signal receivers 201 placed at different positions inside the same mobile device, so that the distance and deflection angle of the other mobile device with respect to the mobile device can be estimated using geometrical relationships, thereby positioning the other mobile device. In this way, the technology can directly locate any node by using the current node without any beacon node or external auxiliary parameter or facility and without traditional two or three nodes for locating a certain node.

The positioning method 300 includes: step 301, enabling N first wireless signal receivers located at different positions to receive first wireless signals transmitted from another mobile device from different angles, wherein N is a positive integer greater than 1; step 302, estimating N distances between the other mobile device and the N first wireless signal receivers according to the N transmission times of the first wireless signal from being transmitted to being received by the N first wireless signal receivers and the propagation rate of the first wireless signal; a step 303 of estimating, according to the estimated N distances and the known distances between the N first wireless signal receivers (and/or the geometrical relationship between the N first wireless signal receivers and the positions of the other mobile device), that the other mobile device is located at a deflection angle with respect to a reference direction, wherein the reference direction is related to the positions of the N first wireless signal receivers; and 304, obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle.

In this way, with N first wireless signal receivers placed at different locations inside the same mobile device, a first wireless signal from another mobile device can be received from different angles, so that the distance and the deflection angle of the other mobile device with respect to the mobile device can be estimated using geometrical relationships. Note that the above-described deflection angle is based on a reference direction of the current mobile device, and the reference direction may be uniquely determined according to the positions of the N first wireless signal receivers. Accordingly, a user holding or wearing the mobile device can know a distance from a specific user holding another mobile device (e.g., other users having interest information matching the interest information of the current user) and a yaw angle from a known reference direction (e.g., a frontal direction, a face or head direction, etc.), so that the angle of the yaw angle can be easily turned and moved by the above-mentioned distance to find (or locate) the user holding another mobile device.

In one embodiment, the first wireless signal receiver may be an ultrasonic signal receiver. Since the ultrasonic wave is a wave whose propagation speed is a slow sound speed relative to the speed of light, the propagation distance can be estimated by measuring the time of propagation from transmission to reception and the sound speed, and therefore the ultrasonic wave is used as a preferable signal here. Of course, the present invention is not limited to this embodiment, and such a measurement of the propagation distance may be performed using waves of other speeds.

In one embodiment, the positioning method 300 may further include: (N-1) triangles connecting any two of the N first wireless signal receivers and the other mobile device are derived from the estimated distances and the known distances between the N first wireless signal receivers; obtaining the included angle of each vertex of the (N-1) triangles according to the (N-1) triangles; and obtaining an average value of N included angles between the connection line of the N first wireless signal receivers and the other mobile device and the reference direction according to the included angles and the reference direction, and taking the average value as the deflection angle.

In one embodiment, the positioning method 300 may further include: selecting a smallest distance of the estimated N distances between the other mobile device and the N first wireless signal receivers as a measured distance between the other mobile device and the mobile device.

In one embodiment, the positioning method 300 may further include: causing the second wireless signal receiver to receive and transmit the first wireless signal from the other mobile deviceA second wireless signal transmitted substantially simultaneously from another mobile device, wherein the transmission rate V of the second wireless signal₂At the transmission rate V of the first wireless signal₁(ii) a Wherein the controller is further configured to estimate a distance d between the other mobile device and each of the N first wireless signal receivers by the following formula (1):

formula (1)

In one embodiment, the positioning method 300 may further include: modifying each time delay T from transmission to receipt by each of the N first wireless signal receivers according to the first wireless signal according to equation (2) below_UtUr：

T_UtUr=Δt_UtRt+T_RtRr+Δt_Rr-T_UrRrEquation (2)

Wherein, T_UtUrIs the time delay, Δ t, of the first radio signal from transmission to reception_UtRtIs the time of the first wireless signal transmission and the second wireless signal transmissionDelay, T_RtRrIs the time delay, at, of the second radio signal from transmission to reception_RrIs the time delay, T, of the second radio signal receiver processing the received second radio signal_UrRrIs the time delay of the reception of the first wireless signal and the reception of the second wireless signal.

Wherein, in one embodiment,formula (3)

In one embodiment, the positioning method 300 may further include: such that when one of the first and second wireless signal receivers is turned on, the other of the first and second wireless signal receivers is disabled and after the wireless signal is received by the one of the first and second wireless signal receivers, the other is turned on.

In one embodiment, the positioning method 300 may further include: causing N first wireless signal transmitters with the N first wireless signal receivers at different locations to transmit N first wireless signals to the other mobile device; causing a second wireless signal transmitter with a second wireless signal receiver to transmit a second wireless signal to the other mobile device substantially simultaneously with transmitting the first wireless signal. The N first wireless signal receivers located at different positions may also be caused to receive the first wireless signals transmitted from the N first wireless signal transmitters of the other mobile device from different angles. The distance between each of the N first wireless signal transmitters of the other mobile device and each of the N first wireless signal receivers of the mobile device may also be estimated based on each transmission time of a first wireless signal transmitted from the N first wireless signal transmitters of the other mobile device to be received by each of the N first wireless signal receivers and the propagation rate of the first wireless signal; setting a shortest distance of the estimated distances as a measured distance between the mobile device and the other mobile device.

In one embodiment, the positioning method 300 may further include: determining whether the other mobile device is located to the left or to the right of the reference direction by one or more of: if the distance between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is greater than the distance between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, it can be judged that the deflection angle is towards the right, and if not, the deflection angle is towards the left; or the deflection angle between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is larger than the deflection angle between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, so that the deflection angle can be judged to face the right, and otherwise, the deflection angle faces the left; or the number of the first wireless signal receivers with the estimated distance or deflection angle on the left side of the reference direction is less than the number of the first wireless signal receivers with the estimated distance or deflection angle on the right side of the reference direction, the deflection angle can be judged to face the right, and otherwise, the deflection angle faces the left and the like; or judging whether the deflection angle is towards the left or the right and the like according to the geometrical relationship between the (N-1) triangles connecting any two of the N first wireless signal receivers and the other mobile equipment and the reference direction.

As such, according to various embodiments of the present invention, a first wireless signal from another mobile device can be received from different angles using N first wireless signal receivers placed at different positions inside the same mobile device, so that the distance and deflection angle of the other mobile device with respect to the mobile device can be estimated using geometrical relationships, thereby positioning the other mobile device. In this way, the technology can directly locate any node by using the current node without any beacon node or external auxiliary parameter or facility and without traditional two or three nodes for locating a certain node.

As shown in fig. 4A, a positioning system 400 includes: a coordinator 401 configured to manage a plurality of mobile devices according to claim 1 in a network, and assign a mobile device id (identifier) number (identification symbol) to each mobile device, and receive estimated distances and deflection angles between each mobile device and other mobile devices, which are transmitted from each mobile device; a scheduler 402 configured to sequentially instruct each mobile device to make an estimation of a distance and a deflection angle in accordance with the mobile device ID number; a mobile device 403 configured to send the estimated distance and yaw angle to a coordinator.

In this way, under the coordination and scheduling of the coordinator 401 and the scheduler 402, the operations such as signal transmission and reception between the mobile devices 403 and estimation of the distance and the deflection angle can be performed more appropriately.

Fig. 4B shows a hardware structure of an internal example of the mobile device 403. For example, mobile device 403 may include: a processing unit U1 for controlling the behavior of the guiding mobile device node; a memory unit U2 for storing various results; a display unit U3 for displaying the result to the user; a power supply unit U4 for supplying power; the wireless transceiving module U5 is used for joining a wireless network and exchanging data through the wireless network; an ultrasonic signal unit array U6 for transmitting and receiving ultrasonic signals from different angles; a Radio Frequency (RF) signal unit U7 for transceiving Radio Frequency (RF) signals. For example, a typical example of the wtru U5 is a zigbee module having an omni-directional antenna, or any other wtru capable of establishing a wireless network.

Of course, U6 and U7 may be any two signal units other than ultrasonic and rf signals, and only two signals need to travel at different speeds in the same medium, so that the distance can be estimated by a time difference of arrival (TDOA) algorithm.

Note that possible hardware structures within the mobile device are shown here, but not all of the shown hardware elements are necessary for the present technique, and in fact only N first wireless signal receivers at different locations within the mobile device are needed to receive a first wireless signal transmitted from another mobile device from different angles, while other hardware elements are optional.

FIG. 4C shows a preferred example of the internal arrangement of the ultrasonic signal unit array U6. generally, if the ultrasonic beam's direction angle is α (α)<2 pi), the number of ultrasonic transceivers in the array is(n is an integer and n>1) For example, as shown in FIG. 4C, a typical value for the ultrasonic signal beam angle α is typically 120 degrees, in which case the number of ultrasonic transceivers in the array is 6 (g) ((C))) (i.e., N = 6) to ensure that any one ultrasound transceiver can receive signals transmitted from at least two different transceivers at a time from at least two different angles, which arrangement facilitates subsequent calculation of the deflection angle. And, it is assumed that the serial numbers of the ultrasonic transceivers are incremented in the clockwise direction, i.e., 1, 2, 3, … …, 6 in the clockwise direction. Of course, the presence of a total of 6 ultrasound transceivers in the ultrasound signal unit array U6 is merely an example, and in fact, the deflection angle can be calculated as long as there are at least 2 ultrasound transceivers capable of receiving ultrasound signals from another mobile device from at least 2 different angles.

Here, it is noted that there is no direct relationship between the total number of ultrasonic transceivers in the ultrasonic signal unit array U6 and the number of ultrasonic transceivers capable of receiving ultrasonic signals from another mobile device from at least 2 different angles, i.e., even if there are 6 ultrasonic transceivers, only 2 or 3 ultrasonic transceivers can receive ultrasonic signals from another mobile device from different angles at a time, because not all of the ultrasonic transceivers in the array can receive ultrasonic signals from a certain location at the same time due to the arrangement and orientation of the ultrasonic transceivers and the beam angle characteristics of the ultrasonic waves, and therefore, the present disclosure only needs to have at least 2 first wireless signal (e.g., ultrasonic) transceivers capable of receiving first wireless signals (e.g., ultrasonic waves) from another mobile device from at least 2 different angles, without limiting the total number of first wireless signal (e.g., ultrasound) transceivers, their arrangement shape, their beam angle size, whether their arrangement of first wireless signal (e.g., ultrasound) transceivers covers all angles, and so on.

Fig. 5 includes the steps of:

1) the coordinator: establishing a wireless network S111; sending the set of online mobile device nodes to the scheduler S112 along with the ID number of each node; sending a scheduling command to the scheduler, and starting a process S113 of one-time traversal and transmission; receiving a scheduling completion feedback signal from the scheduler, and stopping one-time traversal round-robin process S114; and receiving distance data and deflection angle data sent by the nodes, and updating a matrix formed by relative distances among the nodes and a matrix formed by relative deflection angles among the nodes S115.

2) A scheduler: joining the wireless network S121; receiving and updating the online node set and the ID number of each node from the coordinator S122; receiving a scheduling command sent by the coordinator, and starting a process S123 of traversing and sending for one time; in one traversal round-sending process, sequentially sending distance measurement commands to the nodes according to the sequence of the ID numbers of the nodes, and triggering the distance measurement function S124 of the nodes; and sending a scheduling completion feedback signal to the coordinator, and stopping the one-time traversal round-robin sending process S125.

3) A mobile device node: joining the wireless network S131; the node receiving the distance measurement command of the scheduler starts its own distance measurement function S132; the other nodes which do not receive the distance measurement command of the scheduler wait for the ultrasonic signal unit and the RF (radio frequency) signal unit to receive the ultrasonic signal and the RF (radio frequency) signal, so as to realize the distance measurement process and obtain initial distance values S2-S4; according to the distance initial value, completing the calculation process to obtain distance data and deflection angle data S5; and sending back the distance data and the deflection angle data to the coordinator, and updating a matrix formed by the relative distances among the nodes and a matrix formed by the relative deflection angles among the nodes S133.

Note that fig. 5 only shows the operational steps of the system in the presence of a coordinator and scheduler in the positioning system, but this is not necessary for the present technology, and in fact a mobile device of the present technology may implement the functionality of positioning another mobile device without a coordinator and scheduler.

FIG. 6A illustrates an example of latency correction by a transmitting mobile device and a receiving mobile device according to another embodiment of the present inventionFlow chart of the steps. FIG. 6B shows the estimation of the time delay T in the step shown in FIG. 6A_UtUrAn example waveform of (a). Fig. 6C shows an example Radio Frequency (RF) signal physical layer frame structure.

The flow chart shown in fig. 6A includes the steps of:

1) the mobile device node transmitting the signal, packaging the ID number of the node and the serial number of the ultrasound transceiver in the ultrasound transceiver array in an RF data frame S21; the node transmits the ultrasonic signal and the RF (radio frequency) signal S22 substantially simultaneously.

2) A mobile device node receiving signals, receiving ultrasonic signals and RF (radio frequency) signals S23; according to the above formula (3)Calculating the length S24 of the RF (radio frequency) physical layer frame according to the byte number of the RF (radio frequency) physical layer frame; comparing this frame length with the previous frame length S25; if the frame lengths are consistent (indicating that the received RF signal is correct), the delay T is estimated_RtRrS26; otherwise, the data is discarded, and the node transmitting the signal is required to complete step S2 again.

Wherein T is according to formula (2)_UtUr=Δt_UtRt+T_RtRr+Δt_Rr-T_UrRrTo obtain the time delay of the first wireless signal from transmission to reception. Wherein, Δ t_UtRtIs the time delay, T, of the transmission of the first radio wave signal and the transmission of the second radio wave signal_RtRrIs the time delay, at, of the second radio signal from transmission to reception_RrIs the time delay, T, of the second radio signal receiver processing the received second radio signal_UrRrIs the time delay of the reception of the first wireless signal and the reception of the second wireless signal.

As shown in fig. 6B, since in an actual situation, the transmission of the ultrasonic signal and the transmission of the RF (radio frequency) signal are not necessarily completely simultaneous, Δ t_UtRtDepending on the operating frequency of the processing unit and the transmission delay of the physical layer protocol of the RF (radio frequency) signal. Δ t_RrDependent on RF (radio frequency) signalsThe reception delay of the physical layer protocol. T is_UrRrThe accuracy of (c) depends on the accuracy of the processing unit timer (relative to the operating frequency of the processing unit). Because of the physical layer protocols involved, the protocol dependent transmit and receive delays are stable and the error is on the order of mus. Meanwhile, the frequency of the processing unit is generally in MHz, and the processing delay error is also in the mu s level. In the actually measured evaluation system,. DELTA.t_UtRt+Δt_RrPerhaps around 500 mus and this value is constant for a particular system. Therefore, in another embodiment, compensating and correcting this time delay in the form of a system constant is another way to improve the accuracy of the system.

Fig. 6C is a schematic diagram of a physical layer frame structure of an RF (radio frequency) signal. Typical RF (radio frequency) signals are 315MHz or 433 MHz. For 315MHz, the preamble is 8 bytes, the data length is 2 bytes, and the CRC checksum is 4 bytes. Generally, if the transmitted data is the serial number of the ultrasonic transceiver, the data is 1 byte. The baud rate for RF (radio frequency) signal transmission and reception is set to 9600 bps. Based on the above analysis, the length of the RF (radio frequency) physical layer frame is 15 bytes, according to equation (3), T_RtRrIs 12.5 ms.

Note that FIGS. 6A-6C only show the estimated (or corrected) time delays T at the transmitting node and the receiving node_UtUrTo achieve more accurate estimation of the delay T_UtUrAnd through a time delay T_UtUrExemplary operating procedures and principles for estimating distance, but this is not required by the present technique, in fact the delay T is not corrected_UtUrThe mobile device of the present technology may also perform the function of roughly locating another mobile device.

The asynchronous mode shown in fig. 7A includes the following steps:

1) the mobile device node that transmitted the signal selects one of its ultrasound transceivers in its ultrasound transceiver array and packages the serial number of this ultrasound transceiver into an RF (radio frequency) signal frame S31; transmitting the ultrasonic signal and the RF (radio frequency) signal substantially simultaneously through the selected one of the ultrasonic transceiver and the RF (radio frequency) signal unit S32; s31 and S32 are repeated in the order of the ultrasound transceiver serial number.

2) The mobile device node receiving the signal disables the RF (radio frequency) signal processing function and turns on the ultrasonic signal processing function S33; when the node receives the ultrasonic signal, the node records the moment, and forbids the ultrasonic signal processing function, and starts the RF (radio frequency) signal processing function S34; when the node receives the RF (radio frequency) signal, the node records the time, and starts the ultrasonic signal processing function, and disables the RF (radio frequency) signal processing function S35; calculating the time delay T between two recording moments_UtUr(ii) a If the time delay T_UtUrIs less than the time delay T estimated in the step S26_RtRr(this is only an assumption based on the magnitude relationship of FIG. 6B, and not a limitation), this delay T_UtUrWill be used in the next stage to calculate the initial value of distance S36 according to the formula:

d=T_UtUr×V_ultrasonicformula (4)

Wherein d represents the initial distance and T_UtUrRepresenting the time delay of the ultrasonic signal from transmission to reception, and V_ultrasonicRepresents the transmission rate of the ultrasonic signal;

thus, the distance initial value S36 is calculated; the sequence number of the ultrasonic transceiver is obtained from the RF (radio frequency) signal frame and the sequence number and the time delay correspondence are stored S37.

In this way, the ultrasonic signal receiver and the RF signal receiver are not always turned on, but are turned on asynchronously when needed, thereby reducing the possibility that any one receiver receives other interference signals or noise signals, and thus avoiding various erroneous estimations due to the reception of noise or erroneous signals as much as possible.

FIG. 7B is a graph of possible received signal noise waveforms when using TDOA range measurement: (a) an overlap of an Ultrasound (US) signal and an RF (radio frequency) signal; (b) absorption of RF (radio frequency) signals; (c) transmission, scattering and echo of the ultrasonic US signal. The overlap of the ultrasonic US signal and the RF (radio frequency) signal results from different nodes transmitting signals at the same time or nearly the same time. The asynchronous process described above can avoid this phenomenon. Signal absorption generally refers to absorption of RF (radio frequency) signals by metal or other materials in the actual environment. The transmission, scattering and echo are typically for ultrasound signals. In both cases (b) (c), the wrong pairing of the two signals results in a wrong T_UrRrThus, when the distance initial value is calculated according to equation (4), the result may be erroneous. In practical situations, especially the influence of human behavior and complex environmental factors, the noise waveform of the received signal may reduce the accuracy of the positioning, and even a specific node cannot be positioned.

FIG. 7C is the correct waveform of the received signal for TDOA range measurement after the asynchronous process described above: ultrasonic US signal reception and RF (radio frequency) signal reception. Because of the baud rate of the RF signal, it takes some time for the receiving node to finish receiving all the data of the RF signal and generate a reception completion beacon. This results in the ultrasonic US signal receiving the full beacon prior to the RF (radio frequency) signal receiving the full beacon.

As shown in fig. 8, the method includes: 1) s801, receiving an ultrasonic signal; 2) s802, receiving an RF signal; 3) s803, finishing time delay correction based on the received RF signal; 4) s804, making the received ultrasonic signal asynchronous with the received RF signal; 5) s805, estimating an initial value of the distance between two nodes; 6) s806, estimating a deflection angle, and 7) S807, obtaining a measurement distance; 8) and S808, calculating a matrix formed by relative distances among the nodes and a matrix formed by relative deflection angles among the nodes, and positioning the relative position of the specific mobile equipment node.

Of course, the steps described in fig. 8 are only examples and not limitations, and some steps, for example, steps S802 to S804, may be omitted, and the order of the steps may be changed according to circumstances. In addition, in step S804, instead of making the received ultrasonic wave signal and the received RF signal asynchronous, a hardware or software signal filtering method may be adopted to extract a correct signal waveform from a received combined waveform of a correct signal and a noise signal, which is not described in detail herein.

Fig. 9A is a schematic diagram of the transmission and reception of ultrasonic signals by the ultrasonic signal transceiver unit arrays in two nodes. A typical value for the ultrasonic beam angle is 120 degrees. In this case, the number of ultrasonic transceivers in the ultrasonic transceiver array is, for example, 6. As shown in fig. 9A, the ultrasonic transceiver 3 (i.e., serial number 3) of the transmitting node transmits an ultrasonic signal, which is received by the ultrasonic transceiver 1, the ultrasonic transceiver 2, the ultrasonic transceiver 5, and the ultrasonic transceiver 6 of the receiving node (for example, in the case of N = 6). The deflection angle of the connection line between the ultrasonic transceiver 3 of the transmission node and the ultrasonic transceiver 6 of the reception node with respect to the reference direction (note that, here, the reference direction assumes the normal direction of the ultrasonic transceiver 6 set as the reception node, i.e., the direction in which the ultrasonic transceiver 6 faces) can be calculated from the geometrical relationship of the triangles 326, 316, and 365 according to the following formula (the numerical meaning of the triangle: the ultrasonic transceiver serial number on the transmission node, the ultrasonic transceiver serial number on the reception node).

Specifically, as shown in fig. 9B, it is assumed that the transmitting nodeThe ultrasound transceiver 3 of the point and the ultrasound transceivers 1 and 6 of the receiving node form a triangle 316. Thus, the triangle 316 has three sides(distance between the ultrasonic wave transceiver 3 of the transmitting node and the ultrasonic wave transceiver 1 of the receiving node),(distance between the ultrasonic transceiver 3 of the transmitting node and the ultrasonic transceiver 6 of the receiving node) and(the distance between the ultrasound transceivers 1 and 6 of the receiving node, which is usually a known constant since the positions of these ultrasound transceiver units are known) and the angleThe geometrical relationship between the connecting line of the ultrasonic transceivers 1 and 6 of the receiving node and the angle between the ultrasonic transceiver 3 of the transmitting node and the ultrasonic transceiver 6 of the receiving node is as follows:

formula (5)

Wherein,d = T can be represented by formula (4)_UtUr×V_ultrasonicTo calculate (wherein, T_UtUrRepresenting the time delay of the transmission of the ultrasonic signal from the ultrasonic transceiver 3 of the transmitting node to the ultrasonic transceiver 1 of the receiving node),d = T can be represented by formula (4)_UtUr×V_ultrasonicTo calculate (wherein, T_UtUrRepresenting ultrasonic signals from transmitting nodesTime delay of transmission of the ultrasonic transceiver 3 to the ultrasonic transceiver 6 of the receiving node), andit is known that the connection line of the ultrasonic transceivers 1 and 6 of the receiving node and the angle between the ultrasonic transceiver 3 of the transmitting node and the ultrasonic transceiver 6 of the receiving node can be determined in this way

Thus, using the following formula (6)The angle of deflection of the connection line between the ultrasonic transceiver 3 of the transmitting node and the ultrasonic transceiver 6 of the receiving node relative to a reference direction (in this case, for example, the normal direction of the ultrasonic transceiver 6 of the receiving node) can be determined

Formula (6)

Here, the angle of deflection of the connection line between the ultrasonic transceiver 3 of the transmission node and the ultrasonic transceiver 6 of the reception node with respect to the reference direction is obtained by the triangle 316As shown in fig. 9B.

Similarly, in order to more accurately obtain the deflection angle of the connection line between the ultrasonic transceiver 3 of the transmission node and the ultrasonic transceiver 6 of the reception node with respect to the reference direction(but not necessarily) other triangles, such as 326 and365 respectively obtaining a deflection angleAnd averaged to obtain.

Specifically, the trilateral relationship of triangle 326 is as follows:

formula (7)

The trilateral relationship of triangle 365 is as follows:

formula (8)

At the same time, according to the above formula (6)To obtain the deflection angles under triangles 326 and 365, respectively

Then, the mean value of the deflection angles of the ultrasonic wave transceiver 3 of the transmission node and the ultrasonic wave transceiver 6 of the reception node from the reference direction is calculated according to the formula (9)

Formula (9)

After all the ultrasonic transceivers of the transmitting nodes are subjected to one-time traversal and round-trip ultrasonic signal transmission, the deflection angle is obtainedA matrix representing the transmitting nodeThe deflection angle of the connection line between each ultrasonic transceiver of the point and each ultrasonic transceiver of the receiving node from the reference direction, these values being used to calculate a matrix of deflection angle initial values, for example as follows:

in addition, as described above, an initial distance value can be obtained from the time delay of transmission and reception of the ultrasonic wave between each ultrasonic transceiver of the transmitting node and each ultrasonic transceiver of the receiving node, and is also listed as a matrix, for example, as follows:

where it is assumed that the upper right index is the serial number of the ultrasonic transceiver of the transmitting node, and the lower right index is the serial number of the ultrasonic transceiver of the receiving node.

The minimum value (non-zero) of the above two matrices (distance initial value matrix and deflection angle initial value matrix) is selected. Wherein the minimum distance initial value is used as the measuring distance between the transmitting node and the receiving node; the minimum deflection angle initial value serves as the deflection angle between the transmission node and the reception node (i.e., how many degrees the reception node is deflected to find the transmission node). Here, the selection of the minimum distance initial value and the minimum deflection angle initial value is merely an example, and is not a limitation, and is for selecting the distance initial value and the deflection angle initial value having the minimum transmission signal loss and error, so that more accurate distance and deflection angle can be obtained.

Here, since the deflection angle is relative to the reference direction (in this example, the normal direction of the ultrasonic transceiver 6 of the receiving node), assuming that the user holds the receiving node, the normal direction of the ultrasonic transceiver 6 is taken as the own frontal direction (for example, the user hangs the receiving node, the direction in which the receiving node is ahead is the normal direction (reference direction) of the ultrasonic transceiver 6, and for example, the user wears the receiving node, and the direction in which the head is ahead is the normal direction (reference direction) of the ultrasonic transceiver 6). In this case, knowing the yaw angle with respect to the reference direction, the user can easily know what yaw angle position the transmission node is located in the own frontal direction, so that the user finds the transmission node toward the angle of the yaw angle to the left or right.

Here, if the above estimated deflection angleIs an absolute value, and in one embodiment, the deflection angle may also be determined by one or more of the following waysShould be to the left or right (i.e., determine whether the line between the ultrasonic transceiver 3 of the transmitting node and the ultrasonic transceiver 6 of the receiving node is to the left or right of the normal to the ultrasonic transceiver 6 of the receiving node (counterclockwise or clockwise from the ultrasonic transceiver 6)):

the distance d between the ultrasonic receiver and the transmitting node next to the left side of the reference direction is greater than the distance d between the ultrasonic receiver and the transmitting node next to the right side of the reference direction, and the deflection angle can be determinedShould be to the right (i.e., clockwise) and, otherwise, to the left (i.e., counterclockwise) (as shown with reference to fig. 9C); or

The deflection angle θ of the ultrasonic receiver and the transmission node immediately to the left of the reference direction calculated as above is larger than the reference directionThe deflection angle theta of the ultrasonic receiver and the transmitting node which are close to the right side of the ultrasonic signal processing device can be judgedShould be to the right (i.e., clockwise) and, otherwise, to the left (i.e., counterclockwise) (as shown with reference to fig. 9C); or

The number of receivers having the estimated distance d or the yaw angle theta on the left side of the reference direction is smaller than the number of receivers having the estimated distance d or the yaw angle theta on the right side of the reference direction, and it can be judged that the yaw angle is presentShould be to the right (i.e., clockwise) and, otherwise, to the left (i.e., counterclockwise) (as shown with reference to fig. 9C); or

And judging whether the deflection angle is towards the left or the right and the like according to the geometrical relation between the (N-1) triangles connecting any two of the N ultrasonic receivers and the other mobile equipment and the reference direction.

Here, it is assumed that if the deflection angle is judgedShould it be right-facing (i.e., clockwise), the angle is deflectedSet to positive; if the deflection angle is judgedShould it be to the left (i.e., counterclockwise), the angle is deflectedSet to negative.

Of course, the above-mentioned manner of determining whether to face left or right is merely an example, and actually, through the known arrangement of the respective receivers and the various relationships between the distance matrix and the deflection angle matrix calculated above, it is conceivable to easily estimate whether the other mobile device node is facing left or right in the reference direction of the current mobile device node in other manners, which will not be described in detail herein.

In addition, if the deflection angle calculated in other ways is already an angle value with positive and negative, it is possible to directly judge whether to face left or right according to the positive and negative without going through the above-described judging step.

In addition, the above deflection angleIs based on the assumption that the reference direction is the normal direction of the ultrasonic transceiver 6 of the receiving node. Whereas, as shown in fig. 9D, if the reference direction is set to the normal direction of the ultrasonic transceiver 5 of the receiving node, it is possible to pass the deflection angle of the ultrasonic transceiver 6 of the receiving nodeTo the deflection angle of the normal direction (this is the current reference direction) of the ultrasonic transceiver 5 converted into the receiving nodeThe following formula may be used:

(ifFrom positive to negative to indicate orientation) or(ifTo the right (clockwise), is + ifTowards the left (counterclockwise) then is equation (10)

Similarly, if the reference direction is set to the normal direction of the ultrasonic transceiver 1 of the receiving node, the deflection angle of the ultrasonic transceiver 6 of the receiving node can be passedTo the deflection angle of the normal direction (this is the current reference direction) of the ultrasonic transceiver 1 converted into the receiving nodeThe following formula may be used:

(ifFrom positive to negative to indicate orientation) or(ifTo the right (clockwise), is + ifTowards the left (counterclockwise) then is equation (11)

Similarly, if the reference direction is set to the normal direction of the ultrasonic transceiver N of the receiving node, it is possible to pass the deflection angle of the ultrasonic transceiver 6 of the receiving nodeTo the normal direction of the ultrasonic transceiver N of the receiving node (thisAs the current reference direction) of the deflection angleThe following formula may be used:

(ifFrom positive to negative to indicate orientation) or(ifTo the right (clockwise), is + ifTowards the left (counterclockwise) then is equation (12)

Note here that the deflection angle of the conversionAnd the estimated deflection angle between the connection line between the ultrasonic transceiver 5 of the receiving node and the ultrasonic transceiver 3 of the transmitting node and the normal direction of the ultrasonic transceiver 5There are differences in meaning and value. The converted deflection angleActually, the deflection angle between the normal direction of the ultrasonic transceiver 5 and the line connecting the ultrasonic transceiver 6 (note that it is not 5) of the reception node and the ultrasonic transceiver 3 of the transmission node. But the angle of deflectionIs as aboveAnd the deflection angle between the connecting line of the ultrasonic transceiver 5 of the receiving node and the ultrasonic transceiver 3 of the transmitting node and the normal direction of the ultrasonic transceiver 5 is estimated according to the triangle principle. Of course, when the distance between the transmitting node and the receiving node is far, the difference can be ignored, namely the deflection angle of the conversionThe deflection angle, which can be estimated directly as described above, can be usedInstead of it. In the above-described embodiment, the deflection angle of the ultrasonic transceiver 6 through the reception node is adoptedThe deflection angle of the normal direction (in case of the reference direction) of the ultrasonic transceiver 5 converted into the receiving nodeWithout directly using the deflection angleIf, after the respective distances d and deflection angles θ have been calculated, the distance between the ultrasonic transceiver 6 of the receiving node and the ultrasonic transceiver 3 of the transmitting node is foundAnd deflection angleMinimum, as previously mentioned, the estimated distance between the two can be considered to be the minimum interferenceAnd deflection angleIs accurate and therefore even on the reference sideIn the case of a normal direction to the ultrasonic transceiver 6 which is not the reception node (for example, a normal direction to the ultrasonic transceiver 5 of the reception node), a relatively accurate deflection angle can be usedTo more accurately obtain the deflection angle between the converted direction and the reference directionOn the other hand, the ultrasonic transceiver 5 having the receiving node cannot receive an ultrasonic signal at all and hence cannot calculate the deflection angleIn this case, the deflection angle obtained by the above-mentioned method may be usedTo be converted into a deflection angle from a normal direction (reference direction) for the ultrasonic transceiver 5

In addition, if the converted deflection angleGreater than pi, i.e. requiring an angle greater than pi to be turned to the right (clockwise), in fact corresponding to a turn to the left (counter-clockwise)(resulting in an angle less than pi) where the user may grasp himself, or the display unit of the mobile device node of the present disclosure may give both options (i.e., rotate to the right (clockwise))Or to the left (anticlockwise)) Or directly giving a rotational selection of an angle smaller than pi; similarly, if the converted deflection angleLess than-pi (signed), i.e. requiring an angle greater than pi to be turned to the left (anti-clockwise), in fact corresponding to a turn to the right (clockwise)(resulting in a positive angle less than π) where the user may grasp himself, or the display unit of the mobile device node of the present disclosure may give both options (i.e., rotate towards the left (counterclockwise) (. Y.))I or to the right (clockwise)) Or a rotational selection giving directly a positive angle smaller than pi. This is contemplated by those skilled in the art and the specific process will not be described in detail herein.

In addition, the above embodiments describe the initial alignment of the respective deflection angles, e.g., of the respective triangles 316, 326, 365The final deflection angle is obtained by averagingThen deflecting the angle to a reference direction, e.g. toHowever, in another embodiment, the deflection angle to the reference direction, for example, may be performed firstIs rotatedBy converting and then repeating the conversion of eachAveraging to obtain the final deflection angle with the reference directionThis is contemplated by those skilled in the art and will not be described in detail herein.

In this manner, the deflection angle from the current reference direction can also be known, and optionally whether to face left or right as described above, which can help the user holding the receiving node to determine the relative position of the user holding the transmitting node to himself, thereby helping the user holding the receiving node to easily find the user holding the transmitting node (e.g., the user of interest, etc.).

Thus, the ultrasonic wave transceivers in different positions in the mobile equipment nodes are used for receiving ultrasonic wave signals from another mobile equipment node from different angles, and by estimating the distance initial value and obtaining the measured distance data and deflection angle data, the technology does not need any beacon node or external auxiliary parameters or facilities, does not need two or three traditional nodes to position a certain node, and can directly position any node by using the current node.

It is noted that advantages, effects, and the like, mentioned in the present disclosure are only examples and not limitations, and they are not to be considered essential to multiple embodiments of the present invention.

The block diagrams of devices, apparatuses, systems referred to in this disclosure are only given as illustrative examples and are not intended to require or imply that the connections, arrangements, configurations, etc. must be made in the manner shown in the block diagrams. These devices, apparatuses, devices, systems may be connected, arranged, configured in any manner, as will be appreciated by those skilled in the art. Words such as "including," "comprising," "having," and the like are open-ended words that mean "including, but not limited to," and are used interchangeably therewith. The words "or" and "as used herein mean, and are used interchangeably with, the word" and/or, "unless the context clearly dictates otherwise. The word "such as" is used herein to mean, and is used interchangeably with, the phrase "such as but not limited to".

The flowchart of steps in the present disclosure and the above description of methods are merely illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by those skilled in the art, the order of the steps in the above embodiments may be performed in any order. Words such as "thereafter," "then," "next," etc. are not intended to limit the order of the steps; these words are only used to guide the reader through the description of these methods. Furthermore, any reference to an element in the singular, for example, using the articles "a," "an," or "the" is not to be construed as limiting the element to the singular.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit embodiments of the invention to the form disclosed herein. While a number of example aspects and embodiments have been discussed above, those of skill in the art will recognize certain variations, modifications, alterations, additions and sub-combinations thereof.

The N operations of the method described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software components and/or modules including, but not limited to, a circuit, an Application Specific Integrated Circuit (ASIC), or a processor.

The N illustrated logic blocks, modules, and circuits may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an ASIC, a field programmable gate array signal (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may reside in any form of tangible storage medium. Some examples of storage media that may be used include Random Access Memory (RAM), Read Only Memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, and the like. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. A software module may be a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media.

The methods disclosed herein comprise one or more acts for implementing the described methods. The methods and/or acts may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and/or use of specific actions may be modified without departing from the scope of the claims.

The functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions on a tangible computer-readable medium. A storage media may be any available tangible media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other tangible medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. As used herein, disk (disk) and disc (disc) includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

Accordingly, a computer program product may perform the operations presented herein. For example, such a computer program product may be a computer-readable tangible medium having instructions stored (and/or encoded) thereon that are executable by one or more processors to perform the operations described herein. The computer program product may include packaged material.

Software or instructions may also be transmitted over a transmission medium. For example, the software may be transmitted from a website, server, or other remote source using a transmission medium such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, or microwave.

Further, modules and/or other suitable means for carrying out the methods and techniques described herein may be downloaded and/or otherwise obtained by a user terminal and/or base station as appropriate. For example, such a device may be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a CD or floppy disk) so that the user terminal and/or base station can obtain the various methods when coupled to or providing storage means to the device. Further, any other suitable technique for providing the methods and techniques described herein to a device may be utilized.

Other examples and implementations are within the scope and spirit of the disclosure and the following claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard-wired, or any combination of these. Features implementing functions may also be physically located at N locations, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, "or" as used in a list of items beginning with "at least one" indicates a separate list, such that a list of "A, B or at least one of C" means a or B or C, or AB or AC or BC, or ABC (i.e., a and B and C). Furthermore, the word "exemplary" does not mean that the described example is preferred or better than other examples.

Various changes, substitutions and alterations to the techniques described herein may be made without departing from the techniques of the teachings as defined by the appended claims. Moreover, the scope of the present disclosure and claims is not limited to the particular aspects of the process, machine, manufacture, composition of matter, means, methods and acts described above. Processes, machines, manufacture, compositions of matter, means, methods, or acts, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or acts.

Claims

1. A mobile device, comprising:

n first wireless signal receivers at different locations configured to receive first wireless signals transmitted from another mobile device from different angles, wherein N is a positive integer greater than 1;

a controller configured to:

estimating N distances between the other mobile device and the N first wireless signal receivers according to the N transmission times of the first wireless signal from being transmitted to being received by the N first wireless signal receivers and the propagation rate of the first wireless signal;

estimating a deflection angle of the other mobile device from a reference direction according to the estimated N distances and known distances between the N first wireless signal receivers, wherein the reference direction is related to the positions of the N first wireless signal receivers;

obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle; and

a second wireless signal receiver configured to receive a second wireless signal transmitted from another mobile device substantially simultaneously with transmission of a first wireless signal from another mobile device, wherein a transmission rate V of the second wireless signal₂Faster than the transmission rate V of the first wireless signal₁；

Wherein the controller is further configured to estimate a distance d between the other mobile device and each of the N first wireless signal receivers by:

<mrow> <mi>d</mi> <mo>=</mo> <mfrac> <mrow> <msub> <mi>T</mi> <mrow> <mi>U</mi> <mi>t</mi> <mi>U</mi> <mi>r</mi> </mrow> </msub> <mo>&times;</mo> <msub> <mi>V</mi> <mn>1</mn> </msub> <mo>&times;</mo> <msub> <mi>V</mi> <mn>2</mn> </msub> </mrow> <mrow> <msub> <mi>V</mi> <mn>2</mn> </msub> <mo>-</mo> <msub> <mi>V</mi> <mn>1</mn> </msub> </mrow> </mfrac> <mo>,</mo> </mrow>

2. The mobile device of claim 1,

the controller is further configured to:

obtaining N-1 triangles connecting any two of the N first wireless signal receivers and the other mobile device according to the estimated distance and the known distances between the N first wireless signal receivers;

obtaining the included angle of each vertex of the N-1 triangles according to the N-1 triangles;

and obtaining an average value of N included angles between the connection line of the N first wireless signal receivers and the other mobile device and the reference direction according to the included angles and the reference direction, and taking the average value as the deflection angle.

3. The mobile device of claim 1, wherein the reference direction comprises at least one of:

in a case where the N first wireless signal receivers are arranged in a circular arc shape, the reference direction is a normal direction of any one of the N first wireless signal receivers;

in a case where the N first wireless signal receivers are arranged in a straight line, the reference direction is a vertical line direction of the straight line;

predetermined directions that can be derived from different positions of the N first wireless signal receivers.

4. The mobile device of claim 1, wherein the controller is further configured to:

selecting a smallest distance of the estimated N distances between the other mobile device and the N first wireless signal receivers as a measured distance between the other mobile device and the mobile device.

5. The mobile device of claim 1, wherein the controller is further configured to:

according to the following formulaCorrecting each time delay T from transmission to reception by each of said N first wireless signal receivers in accordance with the first wireless signal by the following equation_UtUr：

T_UtUr＝Δt_UtRt+T_RtRr+Δt_Rr-T_UrRr,

Wherein, T_UtUrIs the time delay of the first wireless signal from transmission to reception,

Δt_UtRtis the time delay of the first radio signal transmission and the second radio signal transmission,

T_RtRris the time delay of the second radio signal from transmission to reception,

Δt_Rris the time delay for the second radio signal receiver to process the received second radio signal,

T_UrRris the time delay of the reception of the first wireless signal and the reception of the second wireless signal.

6. The mobile device of claim 1,

the controller is further configured to:

such that when one of the first and second wireless signal receivers is turned on, the other of the first and second wireless signal receivers is disabled and after the wireless signal is received by the one of the first and second wireless signal receivers, the other is turned on.

7. The mobile device of claim 1, wherein the controller is further configured to determine whether the other mobile device is located to the left or right of the reference direction by one or more of:

if the distance between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is greater than the distance between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, it can be judged that the deflection angle is towards the right, and if not, the deflection angle is towards the left; or

The deflection angle between the first wireless signal receiver next to the left side of the reference direction and the other mobile device is larger than the deflection angle between the first wireless signal receiver next to the right side of the reference direction and the other mobile device, so that the deflection angle can be judged to face the right, and otherwise, the deflection angle faces the left; or

If the number of the first wireless signal receivers having the estimated distance or deflection angle on the left side of the reference direction is smaller than the number of the first wireless signal receivers having the estimated distance or deflection angle on the right side of the reference direction, it can be judged that the deflection angle is towards the right, and if not, the deflection angle is towards the left;

and judging whether the deflection angle is towards the left or the right according to the geometrical relation between the reference direction and N-1 triangles connecting any two of the N first wireless signal receivers and the other mobile equipment.

8. A positioning method for a mobile device to position another mobile device, comprising:

causing N first wireless signal receivers located at different positions to receive first wireless signals transmitted from another mobile device from different angles, wherein N is a positive integer greater than 1;

obtaining the position of the other mobile equipment relative to the mobile equipment according to the estimated N distances and the estimated deflection angle;

receiving a second wireless signal transmitted from another mobile device substantially simultaneously with transmitting a first wireless signal from another mobile device, wherein the second wireless signalTransmission rate V₂Faster than the transmission rate V of the first wireless signal₁；

Wherein the distance d between the other mobile device and each of the N first wireless signal receivers is estimated by:

9. A positioning system, comprising:

a coordinator configured to manage a plurality of mobile devices according to claim 1 in a network, and assign a mobile device ID number to each mobile device, and receive estimated distances and deflection angles between each mobile device and other mobile devices transmitted from each mobile device;

a scheduler configured to sequentially instruct each mobile device to make an estimation of a distance and a deflection angle in accordance with the mobile device ID number;

the mobile device of claim 1, configured to send the estimated distance and yaw angle to a coordinator.