Development of car-crash accident simulator based on Petri nets and its application to anti-accident measures for dangerous points

(1)开发具有内置撞车风险的情节型模拟器：我们开发了用于交通拥堵分析及其对策的Petri-net交通模拟器（PETS）。在这一发展中，我们非常重视确保安全的交通流在道路网络中的任何地方，并建立了两种类型的机制，命名为自主和forcec型，在我们提出的交通流的Petri网表示。这些机制将通过连接所谓的杀手网而崩溃。在这里，我们开发了“令牌突然诞生”，“令牌淡出”和“令牌无标记”的杀手网。我们还开发了一个网络，检测和正常化的事故情况，并允许我们继续模拟。将这两类网与汽车交通网连接，可构成汽车碰撞仿真网，并可直接由PETS软件执行。(2)驾驶员行动过程子网络开发：为了细化安全机制的崩溃，我们首先考虑危险驾驶员的诞生 ...更多信息 并将其描述为与其在驾驶员行为过程网络中的强度相对应的彩色标记。其次，假设驾驶员可以根据环境判断采取紧急制动，并将新开发的驾驶员网络与行车子网的连接方式修改为将紧急制动既视为安全机构被破坏后的恢复，又视为后汽车发生危险。（3）追尾碰撞事故模拟结果：将两组驾驶员子网连接到代表130 × 200 m车道的车辆行驶子网，构成交通流网络。并在交通量为15辆/min、出生率较高的情况下，对追尾事故进行了仿真，结果表明，在仿真系统中，扩大最小汽车距和抑制加速欲望都有助于减少事故次数。我们还证明，如果我们成功地扩大驾驶员的谨慎，我们可以减少事故的数量显着。我们需要将我们的方法扩展到正面和右转的交叉口事故。我们还需要包括老年人和年轻司机的子网的特征。少

(1) Development of plot-type simulator with built-in car-crash risks :We have developed Petri-net traffic simulator (PETS) for traffic congestion analysis and its countermeasures. In this development, we paid much attention to ensure safety traffic flows anywhere in road network and built two types of mechanisms, named as autonomous and forcec type, in our proposed Petri nets representations of traffic flows. These mechanisms will collapse by connection of called killer nets. Here we develop nets of "suddenly birth of token", "fade-out of token", and "non-marking of token"as killer nets. We also develop a net that detects and normalizes accident situation and allow s us to continue simulation. Car-crash simulation nets can be constructed by connection these two type nets with car traffic nets and can directly be executed by our PETS software.(2) Development of Driver's Action Process Sub-net :To refine collapse of safety mechanisms, we first take into consideration of birth of risky oc … More casions at dangerous points and describe them as colored tokens corresponded to their intensity in driver's action process net. Secondly, we assume that driver could take emergency breaking according to circumstantial judgement and modify the connection of newly developed driver's net to car-running sub-net as taking emergency breaking both as recovery of broken safety mechanism and as occurrence of hazard for following cars. We also here include function of driver's caution in this process net(3) Results of Rear-end Collision Accident Simulation :We construct traffic flow net by connecting two set of driver's sub-net to car-running sub-net that represents a lane of 130〜200 m. And we do some simulation of rear-end crash accident, as assuming that the traffic volume is 15 (vehicle/min) and the birth rate of occasion is high, and show that expansion of minimum distance between cars and suppression of acceleration desire both contribute to reduce the means of number of accidents in our simulation system. We also demonstrate that if we success to expand driver's caution we could reduce the number of accident as remarkably. We need expand our method to head-on and right-turn accident at intersection. We also need include characteristics of elderly and young driver's sub-net. Less