JP6245842B2 - Vehicle collision prevention processing method, program and system - Google Patents

Description

  The present invention relates to a technique for communicating between traveling vehicles in order to prevent vehicle collisions.

  In recent years, traffic accidents are gradually decreasing, but preventing vehicle collisions remains a challenge. According to traffic accident statistics, many traffic accidents occur when a vehicle enters an intersection. Therefore, in order to prevent a traffic accident, it is effective to perform a collision prediction based on an intersection approach time of a vehicle, a prediction calculation, and the like, and issue a warning appropriately to the vehicle. In this regard, the following conventional techniques are known.

  JP 2004-240506 A discloses a vehicle-mounted device that can communicate with a server on the Internet via a mobile base station for each vehicle, and each vehicle-mounted device uses position-related information including the position of the host vehicle as a server. And the server determines whether each vehicle may collide with another vehicle based on the position related information and map data transmitted from each in-vehicle device, and The in-vehicle device that receives the alarm information obtains the risk of collision with another vehicle informed by the alarm information, and according to the risk, the alarm for avoiding the danger and the vehicle Disclosed is a safe driving support system that controls a running state.

  Japanese Patent Laid-Open No. 2005-234778 is based on outputs from a steering sensor, a vehicle speed sensor, a winker switch, and a navigation system, and determines whether the own vehicle has encountered another vehicle or the like by each encounter determination unit. The number of encounters is counted, and the registration determination unit registers the encounter situation in the road information database based on the number of travels and the counted number of encounters at a predetermined point. A system is disclosed that warns the driver when the host vehicle approaches a location registered in.

  Japanese Unexamined Patent Application Publication No. 2008-165604 discloses a wireless communication device that acquires position information and speed information from a traveling first vehicle, and a speed related to a second link related to the first link on which the first vehicle is traveling. A data collection unit for acquiring information, individual accidents in which positions on a plurality of maps and road features at each position are stored in association with each other, accident patterns in which accident information is classified and stored, and Based on the position information of the first vehicle, the road characteristics in the traveling direction of the first vehicle are acquired, the necessity of warning is determined with reference to the accident pattern, and when the warning is determined to be necessary, Disclosed is a system for providing a warning for a vehicle accident prevention to a driver based on the surrounding road conditions by including a warning determination unit that outputs an alarm to the in-vehicle device of the first vehicle.

  Even with these systems, it is possible to issue warnings to prevent car accidents that are effective to some extent, but when there are many vehicles close to the road, there are too many packets flying between the vehicles and they cannot be received. There is sex. Furthermore, even if received, the vehicle's built-in processor is generally powerless, and it may not be possible to guarantee that all combinations of related vehicle collision prediction calculations will be completed before the collision.

  Therefore, in the system described in Japanese Patent Application Laid-Open No. 2012-203478, the embedded processor, that is, the CPU first acquires the own vehicle traveling information and the own vehicle road information by the GPS receiving unit and the traveling state detecting unit, and the inter-vehicle communication unit The other vehicle traveling information and the other vehicle road information are acquired via the. Next, related information that affects the route of the other vehicle is acquired, and the weighting score of the accessibility is calculated for each other vehicle. Next, for each other vehicle, it is determined whether or not the weighted score is equal to or greater than a predetermined threshold, and the other vehicle that is equal to or greater than the threshold is specified as a driving support target vehicle. Exclude from the target vehicle. Accordingly, it is intended to accurately specify another vehicle to be a driving support target while reducing the required processing capacity.

  However, even in the system described in Japanese Patent Application Laid-Open No. 2012-203478, packet transmission / reception and related processing of the embedded processor are required even between vehicles with a low possibility of an accident, resulting in a considerable load on the embedded processor. It will be.

JP 2004-240506 A JP 2005-234778 A JP 2008-165604 A JP 2012-203478 A

  Accordingly, an object of the present invention is to provide a vehicle collision prevention processing technique that can be sufficiently processed even in a vehicle including an in-vehicle system having an embedded processor having a low processing capability.

  The present invention has been made to solve the above-described problems. A program for determining the possibility of an accident is generated in advance, and when the vehicle enters an intersection, the possibility of an accident is determined by simply executing the program. Processing is performed, and this preprocessing enables high-speed processing even with an embedded processor having low processing capability.

According to the present invention, the following is performed as pre-processing.
Extract major accident patterns at each intersection.
-Set an accident bit vector for each accident element list of the main accident pattern.
-Create a decision tree where the accident bit vector is a leaf node and the accident element is an internal node, and each internal node performs conditional branching based on the accident element value.
-Generate an accident possibility determination program from this decision tree and build it to create an executable file.

  Under the above-described advance preparation, the vehicle executes an accident possibility determination program before entering the intersection area, and acquires an accident pattern in which the own vehicle can be a constituent vehicle of the accident as an accident bit vector. At this time, parameters such as the approach direction to the intersection, vehicle operation, and traffic jam information are given to the program input. The vehicle operation is determined from the car navigation route, turn signal information, etc. before entering the intersection.

  Preferably, the accident possibility determination program calculates the predicted intersection arrival time from the distance to the intersection and the vehicle speed.

  The accident possibility determination program instructs execution of transmission packet generation and transmission processing and collision determination processing only when predetermined determination conditions are satisfied.

  In the transmission packet generation and transmission processing, a vehicle predicted to constitute an accident based on the determination by the accident possibility determination program is assigned a processing priority based on the accident bit vector and the intersection arrival prediction time. Add to information and send.

  The collision prediction calculation program compares the accident bit vectors of the vehicle pair packets with the logical product, and instructs to perform the collision prediction calculation for only the matched vehicle pairs.

  According to the present invention, only a vehicle that is predicted to constitute an accident transmits a packet, thereby reducing the number of packets and improving reception.

  In addition, by comparing the accident bit vectors with the logical product, the collision prediction calculation is performed only for the matched vehicle pair, and the others are instructed to be skipped, thereby reducing the overall processing amount and improving the overall performance. Can do.

  Furthermore, a high-risk packet is preferentially processed by preferentially processing from a vehicle pair with a short reach to the accident point.

It is a figure which shows typically signs that vehicles exchange packets between intersections, or exchange packets with a server. It is a figure which shows a plurality of vehicles near an intersection two-dimensionally. It is a block diagram of the hardware of a vehicle-mounted system. It is a block diagram of a functional element for performing processing concerning this invention. It is a figure which shows the flowchart of the process which prepares an accident possibility determination program for every intersection ID. It is a figure which shows the example of a main accident pattern. It is a figure which shows the example of the combined accident bit vector. It is a figure which shows the example of a judgment tree. It is a figure which shows the specific example of a main accident pattern. It is a figure which shows the motion of the vehicle relevant to the main accident pattern of FIG. It is a figure which shows the example of execution of an accident possibility determination program. It is a figure which shows the flowchart of the accident possibility determination process in a vehicle. It is a figure which shows the flowchart of the packet reception process in the vehicle by V2V. It is a figure which shows the example of the receiving vehicle data preserve | saved on the own vehicle. It is a figure which shows the flowchart of the packet reception process using a server.

  Embodiments of the present invention will be described below with reference to the drawings. It should be understood that these examples are for the purpose of illustrating preferred embodiments of the invention and are not intended to limit the scope of the invention to what is shown here. Further, throughout the following drawings, the same reference numerals denote the same objects unless otherwise specified.

  FIG. 1 is a schematic diagram showing how a plurality of vehicles 104, 106, 108 and 110 travel along an intersection 102 as a premise of the present invention. In FIG. 1, as indicated by reference numerals 112, 114, and 116, the vehicles 104, 106, 108, and 110 send packets to each other and perform a process for preventing a collision. In the following, communication between vehicles as shown in FIG. 1 is also referred to as V2V communication.

  Further, a server 120 and a packet communication network 122 are separately prepared. Preferably, the vehicles 104, 106, 108 and 110 skip packets via the packet communication network 122 as indicated by reference numerals 124 and 126. Thus, communication with the server 120 is performed.

  FIG. 2 is a plan view of an example showing the possibility of an accident occurring at another intersection 202. As shown in the figure, there is a right turn waiting traffic jam train row 204 and a right turn waiting traffic jam train row 208 at the intersection 202. The vehicle 206 goes straight on Lane B and the vehicle 210 goes straight on Lane C.

  As can be seen, in this situation, there is a possibility that the leading vehicle in the congested vehicle row 204 waiting for the right turn and the vehicle 210 may collide, and the leading vehicle in the congested vehicle row 208 waiting for the right turn and the vehicle 206 may be in a collision accident.

  In order to determine the possibility of such a collision accident, it is necessary in the prior art to determine the possibility of collision by transmitting and receiving packets between a large number of vehicles at V2V. In some cases, the processing capability of relatively weak processors was exceeded. This is the problem to be solved by the present invention.

  Next, with reference to the block diagram of FIG. 3, the hardware of the in-vehicle system of the vehicle targeted by the present invention will be described. In recent years, in-vehicle systems are complex and large-scale systems connected to in-vehicle LANs such as CAN or FlexRay, but it is understood that only a part related to the present invention is shown here. I want.

  In FIG. 3, a CPU 304, a random access memory (RAM) 306, and a flash memory (SSD) 308 that is a nonvolatile memory are connected to a bus 302.

  The RAM 306 is used as a calculation work area for the CPU 304. The SSD 308 stores an accident possibility determination program 404 for each intersection ID, a packet creation / transmission program 408, a packet reception program 410, a collision prediction calculation program 412, and the like, which will be described later with reference to FIG.

  The bus 302 is further connected with a car navigation system 310, a sensor interface 312 for inputting data from the sensor group 314, and a communication device 316 for transmitting and receiving packets.

  Next, the functional configuration according to the present invention will be described with reference to the block diagram of FIG. In FIG. 4, a program selection routine 402 is prepared from an accident possibility determination program 404 for each intersection ID prepared in advance in relation to the intersection ID of the place indicated by the car navigation system 310. , And is preferably loaded into the RAM 306 as an accident possibility determination program 406. A method of preparing the accident possibility determination program 404 for each intersection ID will be described later with reference to the flowchart of FIG.

  The accident possibility determination program 406 receives various sensor data from the car navigation system 310 and the sensor interface 312, and in accordance with the determination based on those values, the packet creation / transmission program 408 performs packet processing with a predetermined priority. And the packet is transmitted by the operation of the communication module 316. The accident possibility determination program 406 particularly uses the input from the car navigation system 310 and the sensor interface 312 for the approach direction to the intersection, traffic jam information, car navigation route, turn signal information, and the like. The process of the accident possibility determination program 406 will be described later with reference to the flowchart of FIG.

  Based on the packet data received from other vehicles near the intersection by the packet receiving program 410, the collision prediction calculation program 412 performs collision analysis calculation with the vehicle concerned. The collision prediction calculation program 412 uses, for example, a technique described in Japanese Patent Application Laid-Open No. 2011-204124 or Japanese Patent Application Laid-Open No. 2010-095078, but is not essential to the subject of the present invention. The description is omitted. The processing of the packet reception program 412 will be described later with reference to the flowchart of FIG. 13 or FIG.

  The collision avoidance system 414 performs operations such as braking the engine to decelerate, operating the brake, issuing a warning message on the display, controlling the power steering, generating a warning sound, etc. For example, the techniques described in JP-A-11-29060, JP-A-11-353565, JP-A-2000-43741, and JP-A-2000-67396 are used. Since it is not essential to the subject of the present invention, the description is omitted.

  Next, processing for preparing the accident possibility determination program 404 for each intersection ID will be described with reference to the flowchart of FIG. This process is preferably automatically generated by a program using an accident pattern for each intersection created in advance from traffic accident information.

  In step 502, accident pattern data in a certain area is acquired. A certain area at this time is determined in advance, such as a municipality including a plurality of intersections.

  In step 504, an accident pattern (main accident pattern) having a high accident occurrence probability is extracted. At this time, a threshold value such as an accident occurrence probability is determined in advance.

  In step 506, the number of extracted major accident patterns is counted for each intersection, and the vector length is determined. Number of patterns = vector length.

  In step 508, as shown in FIG. 6, an accident bit vector in which each bit corresponds to one major accident pattern is set in each accident element list.

  In step 510, the table shown in FIG. 6 is searched for a match between the accident element lists, and those that match are combined by the logical sum of the accident bit vectors. As a result, the contents of the table as shown in FIG. 7 are obtained.

  In step 512, a decision tree is created from the table shown in FIG. 7 where the accident bit vector is a leaf node and the accident element is an internal node, and each internal node performs conditional branching according to the accident element value.

  In step 514, the ID3 algorithm is applied to the decision tree on the computer system to create a tree with few conditional branches. An example of the decision tree thus created is shown in FIG. The ID3 algorithm is well known, and refer to http://en.wikipedia.org/wiki/ID3_algorithm.

In step 516, a program code for performing a conditional branch with a switch statement is generated and built, and an execution file is created. An example of a switch statement generated in this way is as follows.
SetBitVec (0000); // initialization
switch (D) {
case Y:
switch (A) {
case Y:
ThirdStage1 ();
case N:
ThirdStage2 ();
}
case N:
switch (B) {
case Y:
ThirdStage3 ();
case N:
ThirdStage4 ();
}
}
ThirdStage1 () {
switch (B) {
case Y:
switch (C) {
case Y:
exit (0); // No
case N:
SetBitVec (0100);
}
case N:
switch (C) {
case Y:
SetBitVec (0001);
case N:
exit (0); // No
}
}
}
ThirdStage2 () {
switch (B) {
case Y:
switch (C) {
case Y:
SetBItVec (0011);
case N:
exit (0); // No
}
case N:
exit (0); // No
}
}
ThirdStage3 () {
switch (A) {
case Y:
switch (C) {
case Y:
exit (0); // No
case N:
SetBitVec (1100);
}
case N:
exit (0); // No
}
}
ThirdStage4 () {
switch (A) {
case Y:
switch (C) {
case Y:
exit (0); // No
case N:
SetBitVec (0100);
}
case N:
switch (C) {
case Y:
SetBitVec (1010);
case N:
exit (0); // No
}
}
}

  By applying steps 504 to 516 to past accident patterns in different regions, an accident possibility determination program 404 for each intersection ID is created.

  FIG. 9 is a diagram showing a table for more specifically explaining the accident element acquisition method. This assumes the situation of the vehicle as shown in FIG.

The accident elements in FIG. 9 are obtained as follows.
-Approach direction Obtained from map information and vehicle position information.
-Vehicle operation Car navigation system Use route information and turn signal information.
-Vehicle speed Obtained from the vehicle speed sensor information of the ECU.
− Congestion Use the traffic information used by the car navigation system.
The car navigation system receives traffic information using VICS (Vehicle Information and Communication System) and its own system.
-The head of the traffic is determined using the camera image information for confirming the front and the millimeter wave sensor. When it is determined from the sensor information that there is no vehicle ahead, it is determined that the vehicle is at the head of the traffic jam.
This is used to handle the head of the traffic separately, such as being unable to operate when in a normal traffic jam, so there is no possibility of an accident, but if you are at the head of a traffic jam waiting for a right turn, you can move to the right.

  FIG. 11 is a diagram showing an execution example of the major accident possibility determination program for vehicle B and vehicle C shown in FIG. In this figure, an accident bit vector such as 0100, 0001 or the like is given according to the condition at the bottom, or no accident bit vector is given depending on the condition.

  Next, with reference to the flowchart of FIG. 12, a description will be given of a process in which the system according to the present invention shown by the functional block of FIG.

  In step 1202 of FIG. 12, the system acquires the current position of the host vehicle from the car navigation system 310, and acquires the intersection ID of the area indicated by the car navigation system 310 based on the current position.

  In step 1204, the system reads out the corresponding accident possibility determination program from the accident possibility determination program 404 for each intersection ID in relation to the intersection ID acquired in step 1202 by the program selection routine 402. Is loaded into the RAM 306 as an accident possibility determination program 406.

  In step 1206, the system acquires accident factors such as vehicle position and speed from the car navigation system 310 and the sensor group 314.

  In step 1208, the system obtains the intersection ID of the next intersection from the intersection information, vehicle position information, and speed information, and in step 1210, determines whether each value in the accident element list or the intersection ID has been updated. To do. Otherwise, the process returns to step 1206.

  In step 1210, when the system determines that each value in the accident element list or the intersection ID is updated, the system executes the accident possibility determination program 406 in step 1212, and the obtained accident bit vector is stored in the RAM 306, for example. Save to.

  In step 1214, the system determines whether a bit is present in the accident bit vector. Here, referring to the example of FIG. 11, the fact that a bit stands in the accident bit vector means that even one bit is included in the bit string.

  If the accident bit vectors are all 0, the process returns to step 1206. If a bit is set in the accident bit vector, in step 1216, the system calculates an intersection arrival prediction time from the current position of the vehicle and the distance to the intersection, and obtains a processing priority according to the intersection arrival prediction time.

  Next, in step 1218, the system calls the packet creation / transmission program 408 to create a packet with vehicle ID information, ECU information, intersection ID, accident bit vector, intersection arrival prediction time, and processing priority added. In step 1220, the communication module 316 transmits the packet.

  Next, the processing of the packet reception program 410 in FIG. 4 will be described with reference to the flowcharts in FIGS. 13 and 15.

  Each of the processes in FIGS. 13 and 15 corresponds to a different embodiment, FIG. 13 is a process using V2V, and the process in FIG. 15 is a process using the server 120.

  First, from the case of processing by V2V, in step 1302 of FIG. 13, the packet reception program 410 determines whether or not the accident bit vector of the host vehicle is standing. If not, the packet reception program 410 continues to wait in step 1302.

  When the accident bit vector of the host vehicle is set, the packet reception program 410 stores the received packet in a queue for each processing priority in step 1304, and performs the processing from step 1306 to step 1312 below with the priority. Process in descending order.

  In step 1306, the packet reception program 410 determines whether or not the received packet and the intersection ID of the host vehicle match, and if not, returns to step 1304.

  If the received packet and the intersection ID of the own vehicle match, the packet reception program 410 stores the accident bit vector and the estimated arrival time at the intersection on the own vehicle or updates data in step 1308 for each vehicle. The data is, for example, as shown in FIG.

  In the next step 1310, the packet reception program 410 calculates the logical product of the accident bit vector of the host vehicle and the stored accident bit vector. For example, when the accident bit vector of the host vehicle is 100, the logical relation with the accident bit vector 101 of the vehicle ID 3 in FIG. 14 is true (100 & 101 = 100). If it is determined in step 1312 that it is zero, the process returns to step 1304. If it is not zero, in step 1314, the collision prediction calculation program 412 starts collision analysis calculation with a vehicle whose logical product is not zero.

  As an example of collision analysis calculation, for example, vehicle position information and vehicle speed information are communicated with each other (for example, every 100 msec), and the intersection approach time is calculated from the position information and vehicle speed information. The warning information is presented to the driver by voice, display, seat belt hoisting, etc. You may make it control a vehicle directly, such as decelerating.

  Next, the case of processing using the server 120 will be described. In step 1502 of FIG. 15, the packet reception program 410 stores the received packet in a queue for each processing priority, and the following steps 1504 to 1514 are performed. Processes are processed in descending order of priority.

  In step 1504, the packet reception program 410 searches whether the intersection ID of the received packet exists in the data on the server. Data on the server is a table of data including an intersection ID, a vehicle ID, an accident bit vector, and an intersection arrival time, as indicated by reference numeral 1508. This data is preferably placed in the main memory (not shown) of the server 120.

  In step 1506, the packet reception program 410 saves the accident bit vector of the received packet together with the vehicle ID and the intersection ID on the server 120.

  In step 1510, the packet reception program 410 determines whether or not there is matching intersection ID data in the search in step 1504. If not, the process returns to step 1502.

  If there is matching intersection ID data in the search in step 1504, in step 1512, the packet reception program 410, for all the data having the matching intersection ID, Compute the logical product of the accident bit vector.

  If it is determined in step 1514 that the packet reception program 410 is zero, the packet reception program 410 returns to step 1502; Start.

  The accident bit vector shown in FIG. 11 and the like is as short as 3 bits. However, this is merely an example of the description, and in fact, it is generally longer, such as several tens of bits or more. Note that this is a bit string.

  Although the present invention has been described according to the specific embodiment, the present invention is not limited to the specific embodiment shown, and can be implemented by any vehicle type, any in-vehicle system hardware and software. Will be understood by those skilled in the art.

120 Server 310 Car navigation system 404 Accident probability determination program 408 for each intersection ID Packet creation / transmission program 410 Packet reception processing program 412 Collision prediction calculation program

Claims (6)

A method of determining the possibility of collision between vehicles by computer processing,
Extracting major accident patterns for each intersection,
Setting an accident bit vector for each accident element list of the main accident pattern;
A step of creating a decision tree in which a condition branch is caused by an accident element value at each internal node with an accident bit vector as a leaf node and an accident element as an internal node;
A step of generating an accident possibility determination program from the decision tree and creating an executable file by building it
An extracting step comprising:
In response to the approach of the vehicle to the intersection, the accident possibility determination program using as a parameter a plurality of accident elements including the approach direction of the intersection, vehicle operation, vehicle speed, traffic congestion status, and the head of the traffic jam in relation to the vehicle Obtaining an accident bit vector for determining the possibility of an accident at the intersection;
Determining whether it is necessary to transmit a packet based on the accident bit vector ;
Setting a processing priority for the packet;
And accidents bit vectors obtained from the packet from other nearby vehicles of the intersection, and calculating a logical association of accidents bit vector of the vehicle, the accident bit vector is written in the bit string, Calculating the logical relevance is calculating a logical product of the accident bit vectors , and determining that the logical relevance is is that the logical product is not zero; and
In response to being determined to have the logical relevance, the vehicle has a step of performing a collision prediction calculation between the vehicle and the other vehicle according to the processing priority set in the packet.
A method of determining the possibility of collision   The method of claim 1, wherein the step of calculating the logical relevance is performed by packet communication between vehicles.   The method of claim 1, wherein performing the collision prediction calculation is performed by a server in communication with a vehicle within a predetermined distance from the intersection. A system for determining the possibility of collision between vehicles by computer processing,
A means to extract major accident patterns for each intersection,
Means for setting an accident bit vector in each accident element list of the main accident pattern;
A means for creating a decision tree for conditional branching according to an accident element value at each internal node, with an accident bit vector as a leaf node and an accident element as an internal node;
Means for generating an accident possibility determination program from the decision tree and creating an executable file by building it
Means for extracting, comprising:
In response to the approach of the vehicle to the intersection, the accident possibility determination program using as a parameter a plurality of accident elements including the approach direction of the intersection, vehicle operation, vehicle speed, traffic congestion status, and the head of the traffic jam in relation to the vehicle Means for obtaining an accident bit vector for determining the possibility of an accident at the intersection;
Means for determining the necessity of packet transmission based on the accident bit vector ;
Means for setting processing priority on the packet;
And accidents bit vectors obtained from the packet from other nearby vehicles of the intersection, and means for calculating a logical association of accidents bit vector of the vehicle, the accident bit vector is written in the bit string, Means for calculating the logical relevance is to calculate a logical product of the accident bit vectors , and the determination that the logical relevance is present is that the logical product is not zero;
In response to being determined to have the logical relevance, the vehicle has a means for performing a collision prediction calculation between the vehicle and the other vehicle according to the processing priority set in the packet.
A system that determines the possibility of collision. The system of claim 4 , wherein the means for calculating the logical relevance is performed by packet communication between vehicles. The system of claim 4 , wherein the means for performing the collision prediction calculation is performed by a server communicating with a vehicle within a predetermined distance from the intersection.

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