JPS62183231A - Id code collecting system - Google Patents

Abstract

PURPOSE:To exact an iD code from plural mobile bodies existing in a prescribed zone separately by providing a transmission means sending a call signal to a center device so as to eliminate the need for a means regulating the position of the mobile bodies. CONSTITUTION:For example, the transmission power of an antenna 22 is reduced to change the directivity into a characteristic A', then an iD code of at least a mobile body T1 is extracted. Thus, the power adjustment of the antenna 22 is required and the adjustment is executed by a control circuit 21. While the power adjustment is being increased sequentially, however, the iD code is not sent again for a prescribed time or a prescribed number of times of calls after the iD code is once sent. Then the center side completes a series of iD code collection within the time or number of times. The response control is executed in interlocking with the transmission control of the center side in this way, then it is possible to collect the iD codes of the plural mobile bodies existing in a prescribed zone separately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ID code collection method for collecting an identification (ID) code unique to a mobile body moving within a predetermined area from the mobile body.

[Conventional technology]

In this type of system, the mobile unit does not always output its own unique ID code, but generally transmits the unique ID code to each individual unit only when it receives a call signal from the center device. Therefore, the center device always outputs a paging signal towards a specific (limited) area, and when a mobile unit that has moved into the area receives the paging signal, it will receive its own ID code. Therefore, the center device receives the sent iD code.

[Problem that the invention seeks to solve]

The above method is based on the premise that there is only one individual that returns an iD code within the range where the center device outputs the calling signal.

In other words, if two or more individuals exist, two or more individuals will respond to a request at the same time, making it impossible for the center device to receive correct data and therefore unable to collect ID codes. The problem is that it disappears.

There is currently no effective way to solve this problem, and there are measures that only allow one individual to exist in a given area, such as passages or gates that prevent more than one individual from existing. Methods such as preparing equipment or sharpening the directivity of the calling signal to narrow the area to be detected have been taken. However, although such a method can be applied relatively easily to large moving objects, it is not suitable for small moving objects, and therefore, the current situation is that there is no suitable method at all for small moving objects.

This invention has been made in view of the above, and it is possible to separate the ID codes from a plurality of moving objects in a predetermined area and extract them from each other without providing special means for regulating the positions of the moving objects. The purpose is to do so.

[Means for solving problems]

The center device is equipped with a transmitting means for transmitting a paging signal, and the paging signal is controlled to be sent by gradually increasing the amplitude as time passes, while the mobile unit sends the iD code signal back to the center device. Each time a call is made, the transponder is controlled so as not to send out the iD code signal again until a predetermined time or a predetermined number of calls are reached. In addition, if it is a problem that the response sensitivity changes depending on the angle between the transmitting means and the transponder, a plurality of transmitting means may be provided so as to transmit the calling signals in different directions, and each of the calling signals may be The data are transmitted to each other in a time-division manner for a predetermined period of time.

[Effect]

An antenna for transmitting a calling signal for requesting an iD code is placed within a predetermined area, and the iD code is read from each individual within a certain range formed by this antenna. The output power of the calling signal from the antenna is gradually changed from small to dog, and the iD code is collected from a moving object at a closer distance to a moving object at a longer distance. On the other hand, when the iD code sending side outputs its own code signal, it does not respond until a certain period of time or a certain number of calls have elapsed, and the center side collects a series of iD codes within that time or number of calls. Complete the action.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows the structure of a transponder 1 and a center-side device 2 attached to a moving body (not shown). The transponder 1 has an antenna 11,
14. The switch element 12) is composed of a power supply 13, a control circuit 15, a transmission output circuit 16, etc., and the center side device 2 only shows one of the control circuit 21, antenna 22, 24, and received data processing device 26, and the others are omitted. .

A calling signal source is provided within the control circuit 21, and this provides an electromagnetic field change to the outside via an antenna 22 (or a loop coil as the case may be). Therefore, when a moving object (not shown) approaches or enters this electromagnetic field change area, the calling signal receiving antenna 11 (or coil in some cases) of the transponder 1 attached to the moving object picks up this electromagnetic field change. Convert to voltage signal. When this voltage signal reaches a level that activates (turns on) the switch element 12°, the power supply 13 is supplied to the control circuit 15 and the transmission output circuit 16 through this switch element 12, and the individual identification transmission function is activated. Control circuit 1 supplied with power supply 13
5 operates the switch element 12 to maintain its own power so that the switch element 12 remains on until the end of transmission of the individual identification code. The control circuit 15, which has secured the power supply, performs the individual identification (i
D) Output the code to the transmission output circuit 16. The transmission output circuit 16 consists of an oscillation, modulation, and power conversion section, modulates the carrier signal with the signal input from the control circuit 15, amplifies the power, and transmits it from the transmission antenna 14 as an electromagnetic wave. The electromagnetic waves output from the transmitting antenna 14 are received by the receiving antenna 24 of the center-side device 2 . The received electromagnetic waves are transmitted to the transponder 1 by the reception data processing device 23.
Demodulate and identify the iD code from. In this way, ID codes from mobile objects can be collected.

It is assumed that the received data processing device 23 is composed of, for example, a microcomputer, and also includes demodulation, amplification, shaping circuits, and the like.

However, if a plurality of mobile objects TI+T2*T3 exist within the radio wave area A of the antenna 22 as shown in FIG. As mentioned above, ID codes cannot be collected because all mobile units respond at the same time.

However, if we reduce the transmission power of the antenna 22 and make the directivity characteristic like A', at least the iD of T1
You can see that the code can be extracted.

For this purpose, it is necessary to adjust the power of the antenna 22, and this adjustment is performed by the control circuit 2 in FIG. 1 or 2.
It will be held at 1. However, while the power adjustment is gradually increased from small to large, once the mobile device sends the iD code, it should not send it again until a certain period of time or a certain number of calls have elapsed. It is necessary to. This is to avoid, for example, when the transmitted radio waves are adjusted to have a directivity that can cover the mobile body T2 in FIG. This is a treatment for

Furthermore, since the response sensitivity changes depending on the angle between the antenna 11 for receiving the calling signal and the antenna 22 for transmitting the calling signal, and the detection distance characteristic also changes depending on the angle, it is not possible to arrange a plurality of antennas 22. desirable. Third
Figure (a) shows an example in which two antennas are arranged, such as antennas 22 and 22'. In this case, the antennas 22, 22' are driven alternately as shown in FIG. AT,
'...AT6' is made to increase sequentially as time passes.

By doing this, A2 e A2'# A4+ A4' in the same figure (a) is obtained using the two antennas 22 and 22'.
+ A6 + A, 6' calling signal areas that change sequentially can be formed.

The above-mentioned response control on the transponder side to the transmission control by the center side device is performed by the control circuit 15, and the control operation is shown in time charts in FIGS. 4, 5 and 5. FIG. That is, FIG. 4 shows an example in which the answering device returns a response signal to a calling signal from the center side device and then does not send out an iD code for a certain period of time, and FIG. is an example in which no iD code is sent. Further, FIG. 6 is an example in which the calling cycle is faster than that in FIG. 5. In these figures, (a) shows the calling signal S, and (b) shows the response signal R. Therefore, by performing such response control together with transmission control on the center side, it becomes possible to separately collect ID codes from a plurality of mobile objects existing within a predetermined area.

Note that although an example in which two antennas are installed in orthogonal directions has been described above, the number and arrangement of antennas can be adjusted depending on the size of the individual, the number of individuals existing within a predetermined area, etc. Further, the present invention can be widely applied to general technical fields where it is necessary to collect the above-mentioned ID codes.

〔Effect of the invention〕

According to this invention, the center side device is provided with an antenna for transmitting a paging signal, and the paging signal is transmitted with the amplitude gradually increasing over time, while the answering device side
Every time a D code signal is sent back to the center device, the ID code is not sent again until a predetermined time or a certain number of calls are reached, so even if there are multiple mobile objects within a predetermined area, their iD This provides the advantage that the codes can be retrieved separately from each other.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining the relationship between antenna directivity and a moving object, and FIG. An explanatory diagram for explaining the antenna and its operation, FIG. 4 is a time chart showing an example of adjustment operation in the transponder, FIG. 5 is a time chart showing another example of adjustment operation in the transponder, and FIG. 6 is a time chart showing another example of adjustment operation in the transponder. It is a time chart which shows yet another example of the adjustment operation in a responder. Code explanation 1...Responder, 11, 14, 22, 22', 2
4... Antenna, 12... Switch element, 13... Power supply, 15.21... Control circuit, 16... River/transmission output circuit, 23・・・・・・
Reception data processing device. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki---Ichitomi 2 Figure 3

Claims (1)

[Scope of Claims] 1) A call signal is transmitted from a center side device to a moving body that moves within a predetermined area and has a transponder that receives a call signal from the outside and returns a unique identification (iD) code signal. In the iD code collection method, the center device is provided with a transmitting means for transmitting a paging signal, and the paging signal is sent out with the amplitude gradually increasing as time passes. At the same time, each time the transponder sends an iD code signal back to the center side device, it controls not to send the iD code signal again until a predetermined period of time or a certain number of calls is reached. ID from multiple mobile objects in
iD characterized by separating codes from each other and taking them out
Code collection method. 2) In the iD code collection method according to claim 1, a plurality of the transmitting means are provided so as to transmit a calling signal in different directions, and each of the calling signals is time-shared by a predetermined period of time. An iD code collection method characterized by controlling each transmission means so that the ID code is transmitted according to the method.