The Reseach On Path Planning Problem For Vehicle Navigation System

In the classic problem of vehicles path planning,the road traffic information,such as distance,fixed traffic management information,which can be known before path planning. This information is static path planning which does not change over time.In the classic problem of vehicles path planning,the road traffic information,such as distance,fixed traffic management information,which can be known before path planning.This information is static path planning which does not change over time.But distribution of traffic information of road net and traffic incident information in the actual vehicle path planning problems are real-time change.In recent years,with the development of communications and information processing technology and computer hardware,real-time information can be acquired rapidly. At the same time,it is possible of realizing vehicle routing arrangements.It creates the conditions for studying on dynamic programming,dynamic vehicle path planning problem has become a hot research.In the paper the route planning problem is transformed into a weighting path optimization problem whose objective function is the linear combination of path length and green time. The planned route is more fit for the different demands since the comprehensive weighted value is got by combining importance degree and spaciousness degree of the road.The problems of Car Navigation System are summarized and discussed,and the basic concepts and theories of static and dynamic optimal path planning are showed.Meanwhile,A dynamic path planning model is established and the right model solution is gotten according to the worthy.Firstly the static path planning Dijkstra algorithm and the dynamic path planning best time act mature method are discussed.But these two methods all have defects when solving dynamic path planning problems,therefore,the ant colony algorithm is introduced in this paper.The ant colony algorithm introduces the efficiency prior pheromone to update the strategy in real-time when solving the problem of dynamic path planning.Then the Greenshields model is used to deal with positive feedback and congestion induced by local optimum policy to analyze the path situation and combine with the ant colony algorithm to get optimal path.Finally,a improved ant colony algorithm which combines with hierarchical search algorithm is proposed to get the optimal path with the time least planning criteria.The mathod not only can effectively avoid the narrow and lots of traffic congestion also can plan the path length and shorten passage time according to the needs of people and the real-time road conditions.It is in line with the requirements of daily life.The experimental results show that improved ant colony algorithm is reasonable and effective to the optimal path.