Inter-vehicle Collision Warning And Communication Technology

Collision warning system is of great importance in the improvement of vehicle safety. Inter-vehicle short range communication is the basic technology for the cooperation between vehicles and is one of the key technologies in the development of platoon system. If inter-vehicle communication is integrated into conventional collision warning system, the precision of data collection can be upgraded and the function of the system can be expanded.Beginning with the conventional collision warning system (system without inter-vehicle communication), this paper makes a deep study on the collision warning algorithm. An algorithm based on the drivers' model is proposed to meet the requirements of both the availability of warning signal when in danger and the conformance with the drivers' feeling. Through simulation analysis and some experiments, the algorithm has proved to be effective in the situation when the vehicle ahead is still, moving or braking. Based on this algorithm, the whole collision warning system is designed when many other factors, such as the signal collection, the data processing and the human-machine interface are taken into consideration. Such system has a basic collision warning functional module. It can accomplish the warning mission with good performance. Moreover, it has the interface for data communication with which a more complicated system can be developed. The new system is divided into two function layers, which bring a good human-machine interface and an ability of function expansion.Another part of this paper is focused on the design of MAC protocol of inter-vehicle short range communication network. Wireless token ring is used in the net and problems in some situation are studied. For example, when the token ring is firstly established, when some new node wants to join the net, when some old node want to leave the net, and when some failure occurs in one node, the protocol should make the nodes adapt to the change and continue to work. The mechanism of the protocol is described in detail with finite state machine. The network performance is analyzed with the theory of queues. Combined with the application environment of vehicle platoon, how to build the platoon, how to control the car getting into or getting out of the platoon and how to keep communication within the platoon are discussed. Finally, the inter-vehicle short range communication network is integrated into the collision warning system. The logicality of the wireless token ring protocol and the effectiveness of the collision warning system based on inter-vehicle communication network are verified.