JP2011164984A - Its simulation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately perform ITS(Intelligent Transport system) simulation even when vehicles whose corresponding ITS applications are different coexist. <P>SOLUTION: This ITS simulation system is configured to perform the simulation of an ITS system by making cooperate with each other a traffic flow simulator which simulates the motion of a vehicle, a communication simulator which evaluates information transmission possibility by communication, a position information simulator which simulates a GPS device, and a plurality of ITS simulators which simulate the operation of an ITS application, wherein correspondence information showing to which ITS application/communication system each vehicle is able to correspond is stored so as to be associated with the vehicle, and only when the vehicle corresponds to the application of an ITS application simulator, the information transmission possibility about the application and an application operation are simulated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique suitable for application to simulation of an ITS system.

In recent years, various applications such as road-to-vehicle communication and vehicle-to-vehicle communication have been studied as an ITS system (Intelligent Transport System). As an example of an ITS application, the vehicle position obtained by the GPS device is exchanged with surrounding vehicles, and when a danger such as an encounter collision or a rear-end collision occurs, the driver is warned or the driving is intervened to avoid the danger. To do.

  In order to verify the operation of an ITS application, it is necessary to conduct a demonstration experiment using several tens to several hundreds of vehicles in an actual traffic environment, but such an experiment is very large and requires time and cost. . Although verification by such a method is necessary at the final stage of development, it is not realistic to frequently perform such verification from the initial stage of development. Therefore, verification of the ITS application by simulation using a computer is indispensable.

  In order to evaluate an ITS application that uses communication, the ITS application simulation includes information on the micro traffic flow simulation that determines the vehicle position at each time, the radio wave propagation simulation that evaluates the radio wave reachability between the transmitting and receiving nodes, and communication. It is necessary to combine network simulation to evaluate whether it can be transmitted. The present inventors have developed an integrated platform that communicates with each element simulator, and has developed an integrated simulation system of a loosely coupled architecture that allows easy selection and exchange of each element simulator.

Toshiro Hamada et al., “Vehicle-to-vehicle communication simulation simulating real city environment with integrated simulator”, Dicomo 2008.

  By the way, various types of ITS applications have been proposed at present, and the number of types is expected to increase further in the future. As an example of the ITS application, there are an encounter collision prevention, a rear-end collision prevention, a right-hand accident prevention, an exchange of traffic jam information in a vehicle (and a route search based thereon), and the like. In addition, the communication method of wireless communication used for the ITS application is also different. In an actual environment, it cannot be assumed that all vehicles have the same in-vehicle device, and the corresponding application / communication method varies depending on the vehicle (in-vehicle device).

  Conventionally, it has not been possible to easily cope with the case where the applications that can be handled differ depending on the vehicle-mounted device. Therefore, an object of the present invention is to provide an ITS simulator system that enables simulation even in a situation where there are in-vehicle devices with different compatible applications.

  In order to achieve the above object, the present invention simulates the operation of the ITS system by the following means or processing.

The ITS simulation system according to the present invention includes:
A traffic flow simulator that simulates vehicle motion and determines the vehicle position at each time;
A communication simulator for evaluating the possibility of information transmission by communication between vehicles at the vehicle position determined by the traffic flow simulator;
A plurality of ITS application simulators that simulate the operation of the ITS application based on the vehicle position obtained by the traffic flow simulator and the possibility of information transmission obtained by the communication simulator, and determine the influence of the ITS application on the vehicle operation;
With
For each vehicle, storing correspondence information indicating whether or not each of the plurality of ITS applications simulated by the plurality of ITS application simulators corresponds to each vehicle,
At each time step, it is determined based on the correspondence information whether each vehicle is compatible with the plurality of ITS applications, and the communication simulator uses the communication simulator to evaluate the communication possibility of using the corresponding ITS application. Then, the operation of the ITS application is simulated using the result.

  As described above, the ITS simulation system according to the present invention stores the ITS application that each vehicle can handle. Based on this correspondence information, a simulation using each ITS simulator can be performed. Therefore, even in a situation where vehicles with different ITS applications that can be used are mixed, simulation can be performed appropriately.

In the present invention, the correspondence information further includes a communication method used by each vehicle for wireless communication.
In the communication simulator, it is preferable to evaluate information transmission possibility when communication of the ITS application supported by each vehicle is performed using the communication method indicated in the correspondence information.

  By doing so, it is possible to simulate communication in a communication system based on the implementation of the application corresponding to the vehicle.

  In the present invention, when a new vehicle is generated in the traffic flow simulator, it is preferable that the correspondence information is stored in association with the newly generated vehicle. For example, the proportion of vehicles that can be handled for each ITS application may be determined in advance, and the correspondence information may be determined at random according to the proportion.

  The present invention can also be understood as an ITS simulation method including at least a part of the above processing, or a program for realizing these methods. Each of the above means and processes can be combined with each other as much as possible to constitute the present invention.

  According to the present invention, simulation can be appropriately executed even when there are a plurality of vehicles having different ITS applications that can be handled.

It is a figure which shows the outline | summary structure of an ITS integrated simulator. It is a figure explaining cooperation of each element simulator in an ITS integrated simulator. It is an example of the data format of the corresponding | compatible information which stores the correspondence / non-correspondence to an ITS application and a radio | wireless communication system. It is a flowchart of the process which performs simulation of an ITS application and radio | wireless communication based on correspondence information.

<First Embodiment>
FIG. 1 is a diagram showing a functional configuration of an integrated simulator (ITS simulation system) capable of evaluating an ITS application using communication by linking element simulators. When simulating a phenomenon consisting of a plurality of elements, there is a method in which each element simulator is closely combined inside, but in this embodiment, a method in which element simulators that operate individually are loosely coupled is adopted. . In the loosely coupled architecture, an integrated simulation platform (hereinafter also referred to as ISP) 1 is prepared, and each element simulator is coupled by communication. The reason for adopting such a method is that the element simulator can be appropriately selected and exchanged according to the evaluation purpose.

  The integrated simulator according to the present invention uses the traffic flow simulator 9, the communication simulator 10, the position information simulator 11, and the ITS application simulator 12 as element simulators by the ISP 1. The traffic flow simulator 9 is a micro traffic flow simulator that determines the vehicle at each time by simulating the movement of the vehicle. The communication simulator 10 evaluates whether or not communication is possible between vehicles or between a vehicle and a roadside communication facility at each time when the position of the vehicle changes every moment, and evaluates whether information can be transmitted by communication. . The position information simulator 11 obtains positioning information acquired by the GPS device at each time point of each vehicle. The ITS application simulator 12 evaluates the influence on the vehicle operation by simulating the ITS application of the in-vehicle device or the roadside equipment. A plurality of ITS application simulators 12 are used, each simulating individual ITS application operations. Examples of the ITS application include safety meter applications such as encounter collision prevention and rear-end collision prevention, collection of traffic jam information and notification in vehicle-to-vehicle communication, route search using the notified traffic jam information, and the like.

  Note that the above-described element simulator may further include a plurality of simulators. For example, the communication simulator may include a radio wave propagation simulator and a network simulator.

  The ISP 1 includes an overall management module 2 that manages the cooperation of each element simulator, and various controllers (traffic flow controller 3, communication controller 4, position information controller 5, and ITS application controller 6) that control each element simulator. The ISP 1 includes a state data storage unit 7 that stores a state at each time step of each element simulator. The state data storage unit 7 stores the state of each vehicle (including various information in addition to position, traveling direction, speed, and acceleration). Further, the ISP 1 stores an ITS application and a wireless communication method that can be supported for each vehicle. The ISP 1 also includes an event data storage unit 8 that stores events that occur in the simulation (for example, sudden braking by the driver, start of collision avoidance control by the ITS application, occurrence of communication, etc.).

  The integrated simulator according to the present embodiment includes a central processing unit (CPU), a main storage device such as a RAM, an auxiliary storage device such as an HDD and a CD-ROM, an input / output device, and the like from the viewpoint of hardware. Consists of a computer. Each of the above functional units is realized by such a computer executing a program, but some or all of these functional units may be realized by a dedicated circuit. Note that it is also preferable that the integrated simulator is constituted by a plurality of computers or computers including a plurality of processors, and each element simulator is executed in parallel.

  The overall management module 2 receives the simulation parameters 13 including the simulation start time, end time, time of 1 time step, and the like, and starts the simulation. The simulation parameters 13 include the initial position of each vehicle, the performance of the equipment that each vehicle has, and the like. The input parameters are stored in a storage means (not shown). Correspondence information indicating whether or not a plurality of ITS applications are supported is stored for each vehicle. Such correspondence information is stored in association with the vehicle ID. The overall management module 2 uses the state data stored in the state data storage unit 7, the event data stored in the event data storage unit 8, and the map / terrain data stored in the map / terrain database 14 as a controller. The result is passed to each element simulator via, and the element simulation is executed, and the result is received. The calculation result by the element simulator is stored in the state data storage unit 7 and the event data storage unit 8. Interfaces 9a, 10a, 11a, and 12a for absorbing differences between element simulators are provided between the controller and each element simulator, and can be used without correcting the element simulator.

  The overall flow of the simulation in such an integrated simulator will be described with reference to FIG. First, the traffic flow simulator 9 simulates the vehicle operation based on the initial state, thereby calculating the position of each vehicle in the next time step. The position of each vehicle determined in this way represents the exact position of the vehicle in the simulation and does not include errors. Each ITS application simulator 12 extracts communication that occurs during one time step calculated by the traffic flow simulator 9 and passes it to the communication simulator 10 as a communication occurrence event. Note that a communication event does not occur from an ITS application simulator that is not compatible with a vehicle, and a communication event occurs only from an ITS application that is compatible with a vehicle. Whether or not the vehicle is compatible with the ITS application can be grasped by referring to the correspondence information described above. Further, the communication simulator 10 determines whether or not each communication included in the communication occurrence event can transmit information between the vehicles based on the accurate position of each vehicle. The position information simulator 11 obtains GPS positioning information obtained by the GPS device of each vehicle based on the accurate position of each vehicle. This GPS positioning information includes positioning errors in the GPS device. Position information including this error is position information exchanged by communication between vehicles. The ITS application simulator 12 simulates the operation of the ITS application between vehicles capable of transmitting information. Here, the ITS application simulator 12 simulates the operation of the ITS application using the vehicle position information including the error obtained by the position information simulator 11. Then, in consideration of the influence of the ITS application operation on the vehicle operation, the position of the vehicle at the next time step is calculated by the traffic flow simulator 9. Thereafter, the simulation of the ITS system is executed by repeating the above processing. Here, the description has been made so that the element simulators directly cooperate with each other. However, as described above, in the present embodiment, all data linkage is performed through the ISP 1.

  As described above, in this integrated simulator, it is possible to identify an ITS application supported by a vehicle (on-vehicle device) and perform a simulation by operating only the corresponding ITS application. Therefore, for example, an appropriate simulation can be easily performed even in an environment in which vehicles having different ITS application and wireless communication system support conditions coexist.

Hereinafter, a process for simulating the operation of an application different for each vehicle by the ITS simulation system will be described in more detail. First, the format of correspondence information indicating which ITS application and communication method each vehicle corresponds to will be described with reference to FIG. As shown in the figure, the correspondence information is roughly divided into an application simulator unit indicating which ITS application is supported and a communication simulator unit indicating which communication method is supported. In this example, there are five ITS applications, and 1-bit information 31 to 35 indicating whether each application is compatible or not is stored. As for the corresponding wireless communication system, 1-bit information 36 indicates whether there is a vehicle-mounted device, communication frequency (5.8 GHz, 700 MHz), communication protocol (RC005, 802.11p), multicast support (supported, not supported). ~ 39 are stored. Since this correspondence information represents which ITS application and communication method the vehicle can be used for, it is needless to say that other data formats may be adopted.

  Next, the ITS application operation for each vehicle will be described with reference to the flowchart of FIG. First, the traffic flow simulator simulates the operation of the vehicle (S11). Correspondence information is assigned to the vehicle newly generated by the traffic flow simulation at this time step (S12). For this allocation, for example, several types of vehicles with different ITS applications and communication methods are assumed, and the probability of occurrence is given as a simulation parameter for each type, and which type of vehicle is randomly selected according to this probability. Can be done by determining. The correspondence information assigned to the vehicle is stored in the ISP 1 in association with the vehicle ID.

  Next, each of the ITS application simulators determines whether or not each vehicle can handle an application handled by the simulator (S13). If the vehicle corresponds to an application handled by the simulator, a communication event that occurs during movement determined by the traffic flow simulator is extracted, and a packet is generated based on the implementation of the application simulator (S14). Then, the communication simulator determines whether or not the packet communication reaches the communication partner and information transmission is possible (S15). The ITS application simulator simulates the operation of the ITS application based on the information transmission possibility and the position information by the communication simulator. The operation of this ITS application is fed back to the traffic flow simulation at the next time step. Note that the location information used by the ITS application takes into account the GPS positioning error as described above, but the description thereof is omitted here for the sake of brevity.

1 Integrated simulation platform (ISP)
9 Traffic Flow Simulator 10 Communication Simulator 11 Location Information Simulator 12 ITS Application Simulator

Claims (6)

A traffic flow simulator that simulates vehicle motion and determines the vehicle position at each time;
A communication simulator for evaluating the possibility of information transmission by communication between vehicles at the vehicle position determined by the traffic flow simulator;
A plurality of ITS application simulators that simulate the operation of the ITS application based on the vehicle position obtained by the traffic flow simulator and the possibility of information transmission obtained by the communication simulator, and determine the influence of the ITS application on the vehicle operation;
With
For each vehicle, storing correspondence information indicating whether or not each of the plurality of ITS applications simulated by the plurality of ITS application simulators corresponds to each vehicle,
At each time step, it is determined based on the correspondence information whether each vehicle is compatible with the plurality of ITS applications, and the communication simulator uses the communication simulator to evaluate the communication possibility of using the corresponding ITS application. An ITS simulation system that simulates the operation of an ITS application using the result. The correspondence information further includes a communication method used by each vehicle for wireless communication,
The communication simulator evaluates information transmission possibility when communication of an ITS application supported by each vehicle is performed using a communication method indicated in the correspondence information. The ITS simulation system described in 1. 3. The ITS simulation system according to claim 1, wherein, when a new vehicle is generated in the traffic flow simulator, the correspondence information is stored in association with the newly generated vehicle. Computer
A traffic flow simulation process for simulating vehicle operation and obtaining the vehicle position at each time,
A communication simulation step for evaluating the possibility of information transmission by communication between vehicles at the vehicle position determined in the traffic flow simulation step;
Based on the vehicle position obtained in the traffic flow simulation process and the possibility of information transmission obtained in the communication simulation process, the operation of each of the plurality of ITS applications is simulated to determine the influence of the plurality of ITS applications on the vehicle operation. ITS application simulation process,
Run
Storing correspondence information indicating whether each vehicle corresponds to each of the plurality of ITS applications;
In the ITS application simulation step, it is determined based on the correspondence information whether each vehicle is compatible with the plurality of ITS applications, and the transmission possibility of communication used in the corresponding ITS application is determined in the communication simulation step. An ITS simulation method characterized in that the operation of an ITS application is simulated by using the result of the evaluation. The correspondence information further indicates a communication method used by each vehicle for wireless communication,
The information communication possibility when the communication simulation process communicates the communication of the ITS application supported by each vehicle using the communication method indicated in the correspondence information. 4. The ITS simulation method according to 4. 6. The ITS simulation method according to claim 4, wherein, when a new vehicle is generated in the traffic flow simulation step, the correspondence information is stored in association with the newly generated vehicle.

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