JP2016038257A - Mobile terminal, map matching method, and map matching program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of map matching based on an autonomous navigation technique.SOLUTION: A mobile terminal according to the present invention has measurement means for measuring a current traveling direction and current position of the mobile terminal through autonomous navigation, and map matching means for mapping the current traveling direction on a map to the current travelling direction measured by the measurement means in the case where a cross point having an intersection angle that matches or approximately matches the amount of angular change in the current traveling direction after the amount of angular change based on temperature effects is excluded is present in close proximity to the current position.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a mobile terminal, a map matching method, and a map matching program.

  In recent years, navigation systems realized by mobile terminals such as smartphones have been widely used. Conventional navigation systems mainly use GPS to know the location of the terminal. However, in locations where radio waves from satellites cannot be received, such as in high-rise buildings and indoors, the position of the terminal is accurate. May not be measured.

  Therefore, a system using autonomous navigation (used together) has become the mainstream in recent years. In autonomous navigation, the position of the mobile terminal is measured by estimating the amount of movement and the amount of rotation angle from the initial position using an acceleration sensor and a gyro sensor.

JP 2009-285114 A JP 2009-139227 A

  However, in autonomous navigation, for example, when the angle or angular velocity of a mobile terminal is detected using a gyro sensor, there is an effect of temperature, etc., and even if it is not actually bent, the angle gradually increases and the correct traveling direction is determined. There are cases where it is not possible. For example, as shown in the matching trajectory of FIG. 1, even when a pedestrian is walking straight, it becomes a trajectory with an angle, so it is difficult to correctly determine whether or not the map is bent. is there.

  The present invention has been proposed in view of the above points, and an object thereof is to improve the accuracy of map matching by an autonomous navigation technique.

  In order to solve the above-described problem, the mobile terminal according to the present invention is configured to measure the current traveling direction and the current position of the mobile terminal by autonomous navigation, and the current state after eliminating the angle change amount based on the temperature effect. A map that maps the current traveling direction on the map to the current traveling direction measured by the measuring means when an intersection having an intersection angle that coincides with or substantially coincides with the angle change amount of the traveling direction is present in the immediate vicinity of the current position. Matching means.

  According to the embodiment of the present invention, it is possible to improve the accuracy of map matching by autonomous navigation technology.

It is a figure which shows the matching locus | trajectory of a prior art example. 1 is a diagram illustrating an example of a mobile terminal 1. FIG. It is a figure which shows the hardware structural example of the mobile terminal 1. FIG. FIG. 3 is a diagram illustrating an example of a software configuration of a mobile terminal 1. It is a flowchart figure which shows the example of a map matching process. It is a figure for demonstrating a specific process. It is a figure for demonstrating a specific process.

  Hereinafter, preferred embodiments of the present invention will be described.

[System configuration]
(Mobile terminal)
FIG. 2 is a diagram illustrating an example of the mobile terminal 1 according to the present embodiment. The mobile terminal 1 is a portable information terminal represented by a smartphone or a tablet terminal. Carried by a user (pedestrian). The mobile terminal 1 has a general-purpose web browser and a navigation application in advance. The mobile terminal 1 displays a map (map) 1b and a route 1c via a web browser or an application screen 1a.

  The mobile terminal 1 according to the present embodiment includes, for example, an acceleration sensor and a gyro sensor. The mobile terminal 1 uses an acceleration sensor and a gyro sensor to measure the distance and direction that the mobile terminal 1 travels from the starting point such as the starting point (autonomous navigation), and the current position and traveling direction of the mobile terminal 1 on the map To map. Thereby, for example, the current position and the traveling direction of the mobile terminal 1 are displayed on the map using the symbol 1d as shown in FIG.

(Hardware configuration)
FIG. 3 is a diagram illustrating a hardware configuration example of the mobile terminal 1 according to the present embodiment. As shown in FIG. 3, the mobile terminal 1 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an HDD (Hard Disk Drive) 14, as hardware configurations. An input device 15, a display device 16, a communication device 17, a voice input / output device 18, an acceleration sensor 19, and a gyro sensor 20 are included.

  The CPU 11 executes various programs and performs arithmetic processing. The ROM 12 stores a program necessary for startup. The RAM 13 is a work area for temporarily storing processing performed by the CPU 11 and storing data. The HDD 14 stores various data and programs.

  The input device 15 can be realized by a touch panel capable of detecting tap coordinates (touch coordinates) on the screen. The display device 16 is a display, and displays, for example, a map (map) 1b, a route 1c, and the like. In this case, the input operation is realized by a touch panel on the screen and a software key controlled by a program.

  The communication device 17 communicates with other devices via a network. The voice input / output device 18 is a device that performs voice input / output. For example, voice data for navigating a user is output.

  The acceleration sensor 19 is a device that measures the acceleration of the mobile terminal 1. It is used for measurement of the current position of the mobile terminal 1 (autonomous navigation). The gyro sensor 20 is a measuring instrument that detects the angle and angular velocity of the mobile terminal 1. It is used for measurement of the traveling direction of the mobile terminal 1 (autonomous navigation).

(Software configuration)
FIG. 4 is a diagram illustrating a software configuration example of the mobile terminal 1 according to the present embodiment. The mobile terminal 1 includes an autonomous navigation measurement unit 101, a map matching unit 102, and a storage unit 103 as main functional units.

  The autonomous navigation measurement unit 101 includes a step count measurement unit 101a and a traveling direction measurement unit 101b. Among these, the step count measuring unit 101a estimates the step count movement amount from the initial position based on the acceleration measured by the acceleration sensor 19, and measures the current position of the mobile terminal 1. Further, the traveling direction measuring unit 101b estimates the rotational angle amount from the initial position based on the angle and angular velocity measured by the gyro sensor 20, and measures the current traveling direction of the mobile terminal 1.

  The map matching unit 102 matches the current position and traveling direction of the mobile terminal 1 on the map based on the current traveling direction and current position of the mobile terminal 1 measured (positioned) by the autonomous navigation measuring unit 101. Thereby, for example, the current position and the traveling direction of the mobile terminal 1 are displayed on the map using the symbol 1d as shown in FIG.

  In the map matching unit 102 according to the present embodiment, the number of steps measuring unit 101a measures an intersection having an intersection angle that matches or substantially matches the amount of change in the angle of the current traveling direction measured by the traveling direction measuring unit 101b. If the current position is “near”, the current traveling direction on the map is mapped to the current traveling direction measured by the traveling direction measuring unit 101b.

  In the map matching unit 102 according to the present embodiment, the number of steps measuring unit 101a measures an intersection having an intersection angle that matches or substantially matches the amount of change in the angle of the current traveling direction measured by the traveling direction measuring unit 101b. If the current position is not “nearest” of the current position but is within “predetermined distance”, the current traveling direction on the map is mapped to the current traveling direction measured by the traveling direction measuring unit 101b and the current position on the map Are mapped onto intersections existing within a predetermined distance.

  The storage unit 103 stores various data used for map display and navigation, such as map data (map information) and NW data (node information, link information, road information, traffic information, POI information, etc.).

  Each functional unit is realized by a computer program executed on hardware resources such as the CPU 11, the ROM 12, and the RAM 13 of the computer constituting the mobile terminal 1. These functional units may be read as “means”, “module”, “unit”, or “circuit”.

  Moreover, you may have the route search part for searching the route | route from the departure place to the destination input by the user etc. When searching for a route, map data, NW (network) data, or the like stored in the storage unit 103 is used.

  Further, the functional configuration of the mobile terminal 1 is merely an example. The storage unit 103 or the like may be arranged on the external server side that can communicate with the mobile terminal 1.

[Information processing]
FIG. 5 is a flowchart showing an example of the map matching process according to the present embodiment. This will be described with reference to the drawings as appropriate.

  S1: First, the step count measuring unit 101a determines whether or not an acceleration change is detected by the acceleration sensor 19.

  S2: When a change in acceleration is detected in S1, the step count measurement unit 101a estimates the number of step movements based on the amount of change in acceleration from the initial position using the autonomous navigation technique, and measures the current position of the mobile terminal 1. (Autonomous navigation).

  S3: Next, the traveling direction measuring unit 101b determines whether or not the angle change is detected by the gyro sensor 20. If no angle change is detected in S3, the process proceeds to S4.

  S4: The map matching unit 102 maps the current position on the map to the current position measured in S2.

  S5: On the other hand, when an angle change is detected in S3, the traveling direction measurement unit 101b estimates the rotational angle amount from the initial position using the autonomous navigation technique, and measures the current traveling direction of the mobile terminal 1. .

S6: Here, the map matching unit 102 determines whether or not the angle change detected in S3 is affected by the temperature. Whether or not it is affected by temperature is determined by whether or not a flag to be described later is 1. That is, if flag ≠ 1, it is determined that the temperature is not affected, and the process proceeds to S7. On the other hand, when the flag = 1, it is determined that the temperature is affected, and the process proceeds to S8.

S7: When not affected by the temperature, the map matching unit 102 calculates the total angle change amount by summing (summing) the detected angle change amounts up to the past n. Note that n is an integer value that can be arbitrarily set by an administrator or the like, but may be set in proportion to the interval / frequency at which the step count measuring unit 101a detects a change in acceleration.

  S8: On the other hand, if the map matching unit 102 is affected by the temperature, the map matching unit 102 eliminates the effect of the temperature (considering the effect of the temperature), and sums up (total) the angle change amounts up to the past n. By doing so, the total value of the substantial angle change amount is calculated. That is, when the temperature is affected, the angle change amount is increased by the temperature influence. Therefore, in S8, after the angle change amount based on the temperature effect is eliminated by subtracting an angle change amount (X) corresponding to the temperature effect described later from the detected angle change amount up to the past n. The total value of the substantial angle change amounts is calculated.

  S9: Next, the map matching unit 102 determines whether the intersection having an intersection angle that coincides with or substantially coincides with the total value of the angular change amounts in the current traveling direction calculated in S7 or S8, and the autonomous navigation of the step count measurement unit 101a in S2. It is determined whether or not the current position is “nearest” of the current position.

  S10: If Yes in S9, the map matching unit 102 maps the current traveling direction on the map to the current traveling direction measured by the autonomous navigation of the traveling direction measuring unit 101b in S5.

  Here, S6 to S8 will be described in detail.

  Since the map data and NW data in the storage unit 103 include road information, intersection positions, intersections, intersection angles, etc., the map matching unit 102 first refers to the map data and NW data, A search is made as to whether or not an intersection exists in the immediate vicinity of the current position measured by the step count measuring unit 101a.

  In addition, when there is an intersection in the immediate vicinity of the current position, the intersection angle with the road where the current position is located (intersection angle at the intersection), and the intersection angle is an angle in the current traveling direction calculated in S7 or S8. It is determined whether or not the total amount of change matches or substantially matches. When there is an intersection that meets such a condition, the map matching unit 102 maps the current traveling direction on the map to the current traveling direction measured by the traveling direction measuring unit 101b.

  In general, for example, when an angle or angular velocity of a mobile terminal is detected using a gyro sensor, there is an influence of temperature or the like, and even if it is not actually bent, the angle gradually increases and the correct traveling direction may not be determined.

  For this reason, in this embodiment, although the traveling direction is measured by autonomous navigation, the crossing angle coincides with or substantially coincides with the total value of the angular variation in the traveling direction after eliminating the angular variation based on the temperature effect. The existence of the nearest intersection was confirmed. When there is an actual intersection, the pedestrian is likely to bend the intersection and the direction of travel measured by autonomous navigation is assumed to be correct, and the current direction of travel on the map is measured by autonomous navigation. To the current direction of travel. Thereby, the matching precision of the present advancing direction measured by autonomous navigation can be improved. Conversely, when such an intersection does not actually exist, it is unlikely that the pedestrian has turned a road without a road, and the traveling direction measured by autonomous navigation may not be correct.

  Here, the term “nearest” means that the coordinates of the current position are superimposed on the position coordinates of the intersection, or the proximity in the case where the coordinates are almost superimposed although there is a slight deviation. In addition, “substantially coincidence” includes not only perfect coincidence but also approximately coincidence by an approximate value. By including the approximate match, it is possible to absorb a small error in the detected amount of change in angle.

  Further, the total value of the angle change amounts up to the past n calculated in S7 or S8 may be replaced with the angle change amount in the current traveling direction measured in S5. However, it is desirable to use the total value of the angle change amounts up to the past n. This is because an error is less likely to occur than the detected angle change amount in the current traveling direction. On wide roads and intersections, pedestrians may gradually turn left and right as they enter a right-left turn road in an arc from outside. In such a case, the amount of change in each angle is small, and it is difficult to detect that the pedestrian has turned left or right with only one amount of change in angle. On the other hand, roads and intersections with wide roads that cannot be detected with a small change amount of only one angle change amount by using the total value of the angle change amount for the past n pieces (n times until the angle is first converged) In this case, it can be detected that the pedestrian has turned right or left.

  FIG. 6 is a diagram for explaining specific processing of S6 to S8. FIG. 6A shows the angular trajectory of the mobile terminal 1 for each detected position n. FIG. 6B shows the matching locus of the mobile terminal 1 matched on the map for each position N at that time.

First, for example, a case where the measured current position is N ₅ in FIG. 6A will be described. The map matching unit 102 calculates the total value of the angle change amounts by summing (summing) the angle change amounts from the current position to the past n. Here, when n = 2, the map matching unit 102 sums up the angle change amounts at N ₅ , N ₄ , and N ₃ by, for example, the following equation.
Total value of angle change amounts at N ₅ , N ₄ , and N ₃ = (N ₅ angle−N ₄ angle) + (N ₄ angle−N ₃ angle) + (N ₃ angle−N ₂ angle)
However, as shown in FIG. 6 (a), the most recent current position N _5, the first place the intersection does not exist.

Therefore, in this case, since there is no intersection that matches the condition, the map matching unit 102 indicates the current traveling direction on the map at the current position N ₇ at the current position N ₅ as shown in FIG. 6B. No mapping is made in the current traveling direction measured by autonomous navigation (except in the case of S9 and Yes described later). In other words, since the pedestrian is not bent, the current traveling direction measured by autonomous navigation is ignored.

Next, as a second case, for example, a case where the measured current position is N ₆ in FIG. 6A will be described. The map matching unit 102 sums up the angle change amounts at N ₆ , N ₅ , and N ₄ .

As shown in FIG. 6 (a), the most recent current position N _6, the intersection is present. However, there is no intersection having an intersection angle that matches or substantially matches the total value of the angle change amounts in the current traveling direction.

Therefore, in this case, the map matching unit 102, since there is no intersection that matches the condition, as shown in FIG. 6 (b), at the current position N _6, the current traveling direction on the map, the current position N ₇ No mapping is made in the current traveling direction measured by autonomous navigation (except in the case of S9 and Yes described later). In other words, since the pedestrian is not bent, the current traveling direction measured by autonomous navigation is ignored.

Next, as a third case, for example, a case where the measured current position is N ₇ in FIG. 6A will be described. The map matching unit 102 sums up the angle change amounts at N ₇ , N ₆ , and N ₅ .

Then, as shown in FIG. 6 (a), in the immediate vicinity of the current position N _7, the intersecting angle that matches or substantially matches the angle variation of the total value of the current traveling direction (90 degrees or equivalent) (e.g., 90 degrees) There is an intersection with

Therefore, in this case, the map matching unit 102, since intersections that match the condition exists, as shown in FIG. 6 (b), at the current position N _7, the current traveling direction on the map, the current position N ₇ Maps to the current direction of travel measured by autonomous navigation. That is, since the actual pedestrian is turning at the intersection, the current traveling direction measured by the autonomous navigation is reflected on the map.

  Note that, in any of the above cases, the total value of the angle change amount is the total value of the substantial angle change amount after eliminating the angle change amount based on the temperature effect when it is affected by the temperature ( S8).

  Returning to FIG. 5 again, the description from S11 will be made.

  S11: If the map matching unit 102 is No in S9, this time, an intersection having an intersection angle that coincides or substantially coincides with the total value of the angle change amounts in the current traveling direction calculated in S7 or S8 is a step count measuring unit. It is determined whether the current position measured by 101a is “within a predetermined distance”.

  S12: If Yes in S11, the map matching unit 102 maps the current position on the map on the intersection searched in S11. Thereafter, the process proceeds to S10, and the current traveling direction on the map is mapped to the current traveling direction measured by the autonomous navigation of the traveling direction measuring unit 101b in S5.

  FIG. 7 is a diagram for explaining specific processing of S7 or S8 and S9, S11, and 12. In FIG. FIG. 7A shows an angular locus of the mobile terminal 1 for each detected position n. FIG. 7B shows a mapping locus of the mobile terminal 1 mapped on the map for each position N at that time.

For example, the case where the measured current position is N ₇ in FIG. 7A will be described. In S6, the map matching unit 102 sums up the angle change amounts at N ₇ , N ₆ , and N ₅ .

However, as shown in FIG. 7 (a), the most recent current position N _7, the first place the intersection does not exist. Therefore, in S9, the map matching unit 102, an intersection having a crossing angle that matches or substantially matches the sum of the current traveling direction of the angle variation is determined not to exist in the immediate vicinity of the current position N _7, the process proceeds to step S11 .

Next, in S11, the map matching unit 102 determines whether or not an intersection having an intersection angle that matches or substantially matches the total value of the angle change amounts in the current traveling direction exists within a predetermined distance of the current position. . As shown in FIG. 7 (a), the intersection with cross angle that matches or substantially matches the sum of the current traveling direction of the angle variation is present within a predetermined distance of the current position N _7.

Therefore, in this case, in S12, the map matching unit 102, since intersections that match the condition exists, as shown in FIG. 7 (b), at the current position N _7, the current position on the map, searching in S11 Map on the specified intersection. That is, the current position on the map is moved and changed on the intersection searched in S11.

Also, advances over the S12 to S10, the map matching unit 102, as shown in FIG. 7 (b), at the current position _{N 7,} the current traveling direction on the map, as measured by the autonomous navigation in the current position _{N 7} Map the current direction of travel.

As a result, as shown in FIG. 7 (b), the current position N _7, as well located at the intersection on the map, the current traveling direction is in a state the vehicle has turned at an intersection (right direction).

  As described above, in the present embodiment, first, the existence of the nearest intersection having an intersection angle that matches or substantially matches the total value of the angle change amounts in the current traveling direction is confirmed. However, if such an intersection does not actually exist immediately before, but such an intersection actually exists within a predetermined distance, there is a possibility of an error in the current position measured by the autonomous navigation of the step count measuring unit 101a. There is. That is, in reality, although there is an intersection where a pedestrian is bent, there is a deviation in mapping due to an error in the measured current position. Therefore, in this case, the traveling direction on the map is mapped to the traveling direction measured by the traveling direction measuring unit 101b, and the current position on the map is not the current position measured by the step count measuring unit 101a but within a predetermined distance. Map on the intersection searched from the range. Thereby, not only the current traveling direction measured by autonomous navigation but also the matching accuracy of the current position measured by autonomous navigation can be improved.

  It should be noted that within the predetermined distance can be arbitrarily determined by the manager or the like as appropriate based on the maximum range of errors that can be measured by the step count measuring unit 101a.

  S13: On the other hand, if the map matching unit 102 is No in S11, the map matching unit 102 determines that the flag ≠ 1 and the total detected angular change amount for the past n (calculated in S7) is predetermined. It is determined whether or not the angle is exceeded. When the predetermined angle is affected by the temperature, the predetermined angle is a value corresponding to an angle change amount resulting from the temperature effect. It is a value set in advance from experience values or an average value of past angle changes.

  S14: If Yes in S13, the map matching unit 102 determines that it is affected by temperature, and sets a flag indicating that it is affected by temperature to 1 (flag = 1). There is no intersection that matches the total angle change amount within the specified distance, and an angle change amount equivalent to or greater than the angle change amount that can occur due to temperature effects is detected. This is not due to the person turning around the intersection or being detected with a slight error, but actually due to the effect of temperature.

  S15: Further, the map matching unit 102 stores the total value (calculated in S7) of the detected past n angle change amounts as the angle change amount X corresponding to the temperature influence. If the angle change amount is detected regardless of whether the pedestrian is turning around the intersection, the detected angle change amount is exactly the angle change amount corresponding to the temperature influence.

[Summary]
As described above, although the mobile terminal 1 according to the present embodiment measures the traveling direction by autonomous navigation, it confirms the existence of the nearest intersection having an intersection angle that matches or substantially matches the total value of the angle change amounts in the current traveling direction. I made it. When there is an actual intersection, the pedestrian is likely to bend the intersection and the direction of travel measured by autonomous navigation is assumed to be correct, and the current direction of travel on the map is measured by autonomous navigation. To the current direction of travel. Thereby, the matching precision of the present advancing direction measured by autonomous navigation can be improved.

  In addition, the mobile terminal 1 according to the present embodiment confirms the existence of the nearest intersection having an intersection angle that matches or substantially matches the total value of the angle change amounts in the current traveling direction. However, when such an intersection does not actually exist in the immediate vicinity, but such an intersection actually exists within a predetermined distance, the traveling direction on the map is set to the traveling direction measured by the traveling direction measuring unit 101b. In addition to mapping, the current position on the map is mapped not on the current position measured by the step count measuring unit 101a but on an intersection searched from a range within a predetermined distance. Thereby, not only the current traveling direction measured by autonomous navigation but also the matching accuracy of the current position measured by autonomous navigation can be improved.

  As described above, according to the mobile terminal 1 according to the present embodiment, it is possible to improve the accuracy of map matching by the autonomous navigation technology.

  The present invention has been described with reference to preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments, various modifications and changes may be made to the embodiments without departing from the broad spirit and scope of the invention as defined in the claims. Obviously you can. In other words, the present invention should not be construed as being limited by the details of the specific examples and the accompanying drawings.

1 Mobile terminal 11 CPU
12 ROM
13 RAM
14 HDD
DESCRIPTION OF SYMBOLS 15 Input device 16 Display apparatus 17 Communication apparatus 18 Voice input / output device 19 Acceleration sensor 20 Gyro sensor 101 Autonomous navigation measurement part 102 Map matching part 103 Storage part

Claims (5)

Measuring means for measuring the current traveling direction and current position of the mobile terminal by autonomous navigation;
If an intersection having an intersection angle that coincides with or substantially coincides with the angle change amount in the current traveling direction after eliminating the angle change amount based on the temperature effect, the current traveling direction on the map is determined. Map matching means for mapping in the current traveling direction measured by the measuring means;
A mobile terminal characterized by comprising: The angle change amount in the current traveling direction is
A total value of a plurality of angle changes measured most recently by the measuring means;
The mobile terminal according to claim 1. The map matching means includes
When an intersection having an intersection angle that coincides with or substantially coincides with the angle change amount of the current traveling direction does not exist in the vicinity of the current position but is within a predetermined distance, the current traveling direction on the map is measured by the measuring unit. Mapping the current position on the intersection and mapping the current position on the map onto the intersection;
The mobile terminal according to claim 1 or 2. Mobile terminal
Measurement procedure for measuring the current traveling direction and current position of the mobile terminal by autonomous navigation;
If an intersection having an intersection angle that coincides with or substantially coincides with the angle change amount in the current traveling direction after eliminating the angle change amount based on the temperature effect, the current traveling direction on the map is determined. A map matching procedure for mapping the current traveling direction measured by the measurement procedure;
The map matching method characterized by performing. On the computer,
Measuring means for measuring the current traveling direction and current position of the mobile terminal by autonomous navigation;
If an intersection having an intersection angle that coincides with or substantially coincides with the angle change amount in the current traveling direction after eliminating the angle change amount based on the temperature effect, the current traveling direction on the map is determined. A map matching program for functioning as map matching means for mapping in the current traveling direction measured by the measuring means.

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