JP3040973B2 - Vehicle position detection method and vehicle emergency notification system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle position detecting method for detecting a vehicle position from data indicating a running history of a vehicle, and a vehicle emergency notification system for detecting a position of an accident vehicle by applying the method. It is intended to improve the vehicle position detection accuracy.

[0002]

2. Description of the Related Art In recent years, there has been a movement in Japan to standardize a vehicle emergency notification system in order to cope with frequent traffic accidents. In the event of a vehicle collision or accident, this system automatically reports vehicle emergency information to the center from an emergency notification device mounted on the vehicle, shortens the time it takes for the emergency vehicle to arrive at the accident site, Rescue more quickly,
This system has already been implemented in Germany.

The following functions are required for an emergency notification device mounted on a vehicle. (1) Communication function (communication with the center) It has a communication function similar to that of a mobile phone, and enables automatic switching between 9600 bps data communication and voice communication. (2) Position detection function (position detection of own vehicle) As vehicle position detection data, own vehicle position data such as GPS and gyro is recorded. (3) Emergency detection function (emergency detection of own vehicle) It has a collision sensor and a rollover sensor and detects what kind of accident has occurred. (4) Vehicle Emergency Information Notification Function (Emergency Notification to Center) An emergency notification is started by detecting a collision sensor or a rollover sensor, and the recorded vehicle position data is automatically transmitted. Manual notification by pressing the vehicle emergency information notification button is also enabled. (5) Power management function (controls the power supply of the emergency notification device) When an accident is detected, automatic switching to the auxiliary battery is performed to secure the power supply during the emergency notification.

When a vehicle equipped with the emergency notification device encounters an accident, the vehicle position data recorded in the emergency notification device is automatically transmitted to the center, and the center checks the position of the accident vehicle based on the data. And request that an emergency vehicle be dispatched.

[0005] Conventionally, a navigation device for displaying a traveling position of a vehicle has been provided with a navigation device similar to the emergency notification device.
It was proposed to have a location reporting function in the event of an accident,
For example, the apparatus is disclosed in Japanese Patent Application Laid-Open No. 5-5626.

However, in the vehicle emergency notification system, unlike a navigation device having a notification function, a database such as map data is stored and managed by the center, and is sent from an accident vehicle using this database. The location of the accident vehicle is specified on the center side based on the data.

In this case, the location of the accident at the center must be promptly and accurately performed to rescue the injured person as soon as possible. The data transmission time from the accident vehicle to the center is substantially on the order of 30 seconds excluding the time spent for network connection, and during this time, data enabling the location of the accident to be transmitted to the center.

[0008] A group including the inventors of the present invention has proposed a vehicle emergency notification system capable of responding to such a request. First, this system will be described.

In this system, as shown in FIG. 4, an emergency notification device 41 equipped with various sensors and communication means is mounted on a vehicle. And data is transmitted via the telephone line 88.

The emergency notification device 41 includes an angle sensor 47 such as a gyro for detecting the traveling direction of the vehicle, and a GPS antenna 65.
GPS to determine the position of the vehicle from the GPS data received at
A receiver 48, a rollover sensor 49 for detecting the rollover of the vehicle, a RAM 50 for recording data on the position of the vehicle while traveling, a flash ROM 51 for permanently storing data necessary for elucidating the cause of the accident, and an emergency Speed sensor connected to the notification device 41
54, a reverse 55, a crash sensor 56, a CPU 46 for detecting the occurrence of an accident based on information from the rollover sensor 49 and information from the rollover sensor 49 and controlling the operation of an automatic notification,
A modem 45 for modulating and demodulating data to be transmitted and received, and a control switching unit 44 for controlling switching to data transmission or voice communication,
A data / voice switching unit 43 for switching an input / output destination of data or voice to be transmitted / received, a mobile phone 42 performing a communication operation through an antenna 64, and power supply when an external battery 53 used in normal times cannot be used in an emergency or the like. Internal battery
52, and further, a speaker 62 and a microphone 63 that enable hands-free voice communication, an emergency button 60 that enables a manual emergency call, an LED 59 that displays an operation state of the emergency call device 41, and the like. Connected.

On the other hand, the center 81 includes a telephone 82 for performing a communication operation, a modem 83 for modulating and demodulating data to be transmitted and received,
It has map data 85 stored in a database, a CPU 84 for judging an accident position and controlling each unit, an operation unit 87 operated by an operator, and a display unit 86 for displaying the accident position on the map. ing.

In this system, the running vehicle sequentially records its own vehicle position data in the RAM 50 of the emergency notification device 41,
When an accident occurs, the host vehicle transmits its own vehicle position data indicating the recorded traveling history to the center 81. In Center 81,
Map matching is performed using the received data to specify the location of the accident.

FIG. 3 shows a functional block diagram of the emergency notification device 41 for recording and transmitting the vehicle position data. This device processes signals received from GPS satellites and
A GPS processing unit 11 for generating data (G), a vector generation unit 12 for calculating a motion vector (V) of the vehicle from gyro data indicating a bearing and a vehicle speed pulse indicating a vehicle speed,
A position calculating unit 19 for obtaining a current position (P) using the GPS data (G) output from the S processing unit 11 and the vector data (V) output from the vector generation unit 12,
A ring buffer 13 for storing data (G), vector data (V) and current position data (P); a transmission data reading unit 16 for reading data to be transmitted from the ring buffer 13 when an accident occurs; A transmission data area 20 used as a temporary data storage area, a transmission unit 17 for transmitting read data to the center via an antenna 18, an accident detection unit 15 for detecting occurrence of an accident, and a GP
The control unit 14 controls the operations of the S processing unit 11, the vector generation unit 12, the position calculation unit 19, and the transmission data reading unit 16.

In this vehicle, radio waves from GPS satellites are received during normal driving, and the GPS processing unit 11 of the emergency notification device is used.
Processes the received signal, and reproduces the time and orbital elements and other reproduction data sent from the GPS satellites or the latitude / longitude data calculated based on the data at regular time intervals in the ring buffer 13 and the position calculation means 19. Output to

The vector generation unit 12 of the emergency call device
During traveling, a vector representing the moving direction and speed of the vehicle is calculated at regular intervals from data indicating the direction input from the gyro device and the vehicle speed obtained from the vehicle speed pulse, and the ring buffer 13 and the position calculating means 19 are calculated. Output to

The position calculating means 19 obtains the current position by making necessary corrections using the GPS data input from the GPS processing unit 11 and the vector data input from the vector generation unit 12, and stores the current position data in the ring buffer 13. Output to

Data to be input is sequentially and cyclically written to the ring buffer 13, and when data writing completes one cycle, newly input data is overwritten on data recorded one cycle before. For this reason, the ring buffer 13 always stores only the data that goes back a certain period from the current time.

In FIG. 3, the data recorded in the ring buffer 13 is represented by Gn, Vn, ‥, G1, V1, G0, V0 and P.
2n, P2n-1, ‥, and P0. G0, G
1, ‥, Gn (G0 is the oldest, Gn is the newest) is GP
The GPS data output from the S processing unit 11, V0,
V1, ‥, and Vn (V0 is the oldest and Vn is the newest) are vector data output from the vector generation unit 12,
P2n, P2n-1,..., P0 (P0 is the oldest and P2n is the newest) are the current position data output from the position calculating means 19. Here, the vector data and the GPS data are output alternately from the GPS processing unit 11 and the vector generation unit 12, and the current position data is output from the position calculation unit 19 at each output time of the vector data and the GPS data. FIG. If the measurement time interval between vector data and GPS data is different, the number of V data and G data held in the ring buffer 13 will be different.

When an accident occurs in the vehicle, an accident detection unit 15 including a collision sensor and a rollover sensor detects the accident based on the impact applied to the vehicle, the inclination of the vehicle body, and the like, and transmits the detection to the control unit 14. In response to this, the control unit 14
The processing unit 11, the vector generation unit 12, and the position calculation unit 19 stop outputting data to the ring buffer 13, and instruct the transmission data reading unit 16 to read data from the ring buffer 13. .

The transmission data reading unit 16 includes a ring buffer 13
Out of the data held in the latest current position data (P2n), the oldest current position data (P0), and
All the GPS data and vector data are read out to the transmission data area 20, and these data are output to the transmission unit 17 in the following order.

First, the latest current position data, then
The GPS data and vector data are recorded in the order from the latest recording time, and finally the oldest current position data. That is, the order is P2n, Gn, Vn, ‥, G1, V1, G0, V0, P0. The transmitting unit 17 transmits this data to the center via the antenna 18 in that order.

By transmitting data in this order, even if the transmission is interrupted in the middle of data transmission, the center keeps the latest data of the own vehicle position (that is, the data of the accident position) and the nearby traveling data. The data indicating the history will arrive.

FIG. 5 (a) schematically shows data transmitted from the emergency notification device to the center. From the emergency notification device to the center, the current position data P of the last point 24
2n, Gn, Vn, Gn-1, Vn-1, ‥, Gk, Vk ‥, G1,
Data is transmitted in the order of V1, G0, V0, and the current position data P0 of the point 22. In the middle of this transmission, even if the transmission stops immediately after transmitting Vk, at the center, as shown in FIG. 5B, the current position data P2n, G
Data of n, Vn, Gn-1, Vn-1, ‥, Gk, Vk can be obtained.

When the center receives the data representing the travel locus from the emergency notification device, the center performs map matching with the map data to determine the final point 24.

When the data transmission from the emergency notification device is performed without interruption, the center executes the map matching with the point 22 in FIG. 5A represented by the current position data P0 as the initial position. I do.

Several methods are known for map matching, but the point is that the correspondence between the map data and the measured vehicle position data is sequentially examined to determine the final position on the map data. This is the processing to be performed.

For example, as shown in FIG. 6, a road (thick line) which enters a circle having a constant radius from a point 22 represented by the position data P0 on the map database is obtained, and a motion vector V0 and a motion vector V0 are obtained. Select a road that extends in the same direction, specify the adjacent positions 33, 34, 35 from point 22 on the road, and distance (difference) from those points 33, 34, 35 to point 22
Weight according to.

Next, the difference between the position moved from each of the positions 33, 34, 35 by the motion vector V0 and the position on each road adjacent to the position (the second proximity position) is determined, and the weight corresponding to the difference is calculated. Is cumulatively added for each road. Next, a difference between a position moved by the motion vector V1 from the second proximity position on each road and a position on each road (third proximity position) adjacent thereto is calculated, and a weight corresponding to the difference is calculated. Is cumulatively added for each road. By repeating these operations, the position corresponding to the final point 24 is specified on the road having the highest cumulative value of the weights.

In the course of this operation, when the position on the road deviates from the error range of the positioning position calculated using the GPS data, the road is excluded from the target of the matching, thereby improving the efficiency of the processing. , Matching accuracy can be improved.

When the data transmission from the emergency notification device is stopped halfway, the center returns to the vector V from the last point 24 in FIG. 5B represented by the current position data P2n.
The point 23 is determined by tracing n, Vn-1, .SIGMA., and Vk in reverse, and map matching is performed with the point 23 as a starting position, and a position on the road corresponding to the final point 24 is specified.

[0031]

However, since the starting point 23 of the map matching obtained by tracing the vectors Vn, Vn-1, .SIGMA., And Vk in reverse from the final point 24, the error of each vector is accumulated, May contain large errors,
It is expected that it is far from the location on the road. Therefore, when the map matching is executed from the start point 23, it becomes difficult to specify the final point on the road with high accuracy because the weights for the roads are dispersed.

The present invention addresses this problem, and provides a vehicle position detecting method capable of detecting the final position of a vehicle on a road with high accuracy using travel history data, and applying this method. It is another object of the present invention to provide a vehicle emergency notification system capable of accurately and quickly detecting the location of an accident vehicle.

[0033]

Therefore, in the vehicle position detecting method of the present invention, when the final position of the vehicle is detected by using the data indicating the running history of the vehicle, map matching is performed to reverse the running route. Then, a past position on the road is obtained, and the past position is used as a starting position, and map matching for sequentially following the traveling route is performed to obtain a final position on the road.

In the vehicle emergency notification system of the present invention, the center implements the vehicle position detecting method using data indicating the running history sent from the accident vehicle to detect the accident position.

According to this method, it is possible to accurately obtain the starting position of the map matching for tracing the traveling route in the forward direction by the map matching for tracing the traveling route in the backward direction. It can be detected with high accuracy.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a vehicle position detecting method for detecting a final position of a vehicle using data indicating a running history of the vehicle. Selects the final position represented as the initial position, performs map matching that traces the traveling route in reverse, finds a past position on the road, and uses this past position as the starting position, maps the traveling route in order. Is performed to obtain the final position on the road. By performing backward map matching, the starting position of forward map matching can be accurately obtained.

According to a second aspect of the present invention, the map matching that traces the traveling route in reverse and the map matching that traces the traveling route in order are repeated a plurality of times until the final position on the road is specified. By repeating this, the accuracy of detecting the final position can be improved.

According to the third aspect of the present invention, when an accident occurs,
In a vehicle emergency notification system in which data for specifying the vehicle position is automatically transmitted from the accident vehicle to the center via a wireless line, the vehicle records data on the vehicle position cyclically while the vehicle is running, At the time of occurrence, part or all of the recorded data is transmitted to the center in the newest recording time, and the center selects the final position represented by the latest data in the received data as the initial position, Performing map matching that traces the traveling route in reverse to obtain a past position on the road, and starting with the past position as the starting position, performing map matching that sequentially traces the traveling route to determine the accident position on the road The position of the accident can be determined with high accuracy.

According to a fourth aspect of the present invention, the center repeats the map matching for tracing the traveling route in reverse and the map matching for sequentially tracing the traveling route a plurality of times until the accident location is specified. In addition, the accuracy of detecting an accident position can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The hardware configuration of the vehicle emergency notification system according to the present invention is the same as that shown in FIG. In addition, the emergency call device
When an accident occurs, as described above, the travel history data recorded in the buffer memory 13 is transmitted to the center in order from the latest data.

In the center, when the data transmission from the emergency notification device is stopped halfway, on the road using the final position data acquired up to that time, the vector data indicating the running history up to the final position, and the GPS data. The location of the accident.

At this time, the CPU 84 of the center detects an accident location on the road according to the procedure shown in FIG. FIG. 1A schematically shows a detection procedure at this time.

Step 1: As shown in FIG. 1 (a), the final position 24 corresponding to the final position data is set to the initial position, and each vector data is used in the opposite direction, and the traveling route is changed in the opposite direction. The road indicated by the last vector data received before the data transmission was stopped by performing map matching
Find position 25 on 27.

Step 2: Next, the position 25 is set as the start position, map matching is performed to follow the traveling route in the forward direction using the vector data in the forward direction, and the final position 24 is set.
The final position 26 on the road corresponding to is obtained.

Step 3: Evaluate whether the final position 26 on this road has been obtained with a high probability. This evaluation method differs depending on the map matching method. For example, when the map matching is performed by the method shown in FIG. 6 described above, the cumulative value of the weight of the road that has specified the final position 26 becomes a predetermined value. It can be evaluated by whether or not it exceeds.

If the accuracy is insufficient as a result of the evaluation,
Returning to step 1, the obtained final position 26 is set to the initial position, map matching is performed to trace the traveling route in the reverse direction, and then map matching is performed to trace the traveling route in the forward direction. This operation is repeated until a predetermined evaluation is obtained.

If a predetermined evaluation result is obtained, step 4: the obtained final position 26 is determined as the final position on the road.

FIG. 1B shows a conventional method for obtaining the start position 23 by tracing the vector in reverse from the final position 24. In contrast, in the method of this embodiment, FIG.
As shown in (a), since the start position 25 is obtained from the final position 24 by map matching, the start position 25 can be obtained with high accuracy. As a result, the forward map matching starting from the start position 25 makes the final position on the road
26 can be detected accurately.

In this embodiment, this method has been described as a vehicle position detection direction when data transmission from the emergency notification device to the center is stopped halfway, but all data is transmitted from the emergency notification device to the center. Even in this case, the final position on the road, that is, the accident position can be obtained with high accuracy by using this method.

[0051]

As is apparent from the above description, the vehicle position detecting method of the present invention can accurately determine the final position of the vehicle on the road from the running history data of the vehicle.

Further, in the vehicle emergency notification system employing this vehicle position detecting method, the position of the accident can be quickly and accurately specified at the center, and the rescue of an injured person at the accident site and the processing of the accident can be performed quickly. .

[Brief description of the drawings]

FIG. 1 shows a vehicle position detection method (a) according to an embodiment of the present invention.
To explain the difference between the method and the conventional detection method (b),

FIG. 2 is a flowchart showing a procedure of a vehicle position detecting method according to the embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of an emergency notification device.

FIG. 4 is a block diagram showing a configuration of a vehicle emergency notification system.

FIG. 5 is a diagram showing travel history data transmitted to a center;

FIG. 6 is a diagram illustrating map matching.

[Explanation of symbols]

 11 GPS processing unit 12 Vector generation unit 13 Ring buffer 14 Control unit 15 Accident detection unit 16 Transmission data readout unit 17 Transmission unit 18 Antenna 19 Position calculation means 22 Start point 23 Start point due to transmission interruption 24 End point 32 Vector based on own vehicle position data 33 , 34,35 Location on the road 41 Emergency call device 42 Cell phone 43 Data / voice switching unit 44 Control switching unit 45 Modem 46 CPU 47 Angle sensor 48 GPS receiver 49 Rollover sensor 50 RAM 51 Flash ROM 52 Internal battery 53 External battery 54 Speed sensor 55 Reverse 56 Crash sensor 57 Brake 59 LED 60 Emergency button 62 Speaker 63 Microphone 64 Antenna 65 GPS antenna 81 Center 82 Telephone 83 Modem 84 CPU 85 Map data 86 Display section 88 Telephone line 89 Wireless line

Continuation of front page (72) Inventor Hiroyuki Maeda 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. (72) Inventor Takumi Yasushima 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama, Kanagawa Prefecture No. 1 Matsushita Communication Industrial Co., Ltd. (56) References JP-A-3-156315 (JP, A) JP-A-6-288780 (JP, A) JP-A 8-334342 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G08G 1/13 G01C 21/00 G08B 23/00-31/00

Claims (4)

(57) [Claims] 1. A vehicle position detecting method for detecting a final position of a vehicle using data indicating a running history of the vehicle, wherein a final position represented by the latest data in the data is selected as a starting position, and a driving route is selected. Is performed to obtain a past position on the road by performing map matching reversely, and the last position on the road is obtained by performing map matching that sequentially follows the traveling route using the past position as a starting position. Vehicle position detection method. 2. The map matching according to claim 1, wherein the map matching for tracing the travel route in reverse and the map matching for tracing the travel route in order are repeated a plurality of times until the final position on the road is specified. Vehicle position detection method. 3. A vehicle emergency notification system in which data for specifying a vehicle position is automatically transmitted from an accident vehicle to a center via a wireless line when an accident occurs. Data is recorded cyclically, and when an accident occurs, a part or all of the recorded data is transmitted to the center in the newest recording time, and the center is represented by the latest data among the received data. The final position is selected as the initial position, map matching is performed to trace the traveling route in reverse, a past position on the road is determined, and map matching is performed using the past position as the starting position to sequentially trace the traveling route. A vehicle emergency notification system, which is implemented to determine an accident location on a road. 4. The center according to claim 3, wherein the center repeats the map matching for tracing the travel route in reverse and the map matching for tracing the travel route in order until the accident location is identified. Vehicle emergency call system.