The Research And Achivement Of Path Planning Method For Intelligent Wheelchair

With the aggravation of the problem of the aging of the population,the proportion of elderly people who need to be taken care of is increasing,and with the increase in number of physical disability,at the present stage,taking care of elderly and disabled people become an urgent social problem.The emergence of intelligent wheelchair which provides means of transport for elderly and disabled,improves the quality of life of the elderly and the disabled.Path planning is the key content in the research of intelligent wheelchair.With a good path planning,the intelligent wheelchair could realize the automatic control better.The path planning of intelligent wheelchair includes three parts:environment modeling,localization and path planning algorithm.Among them,environmental modeling and localization is the basis of the path planning,and the algorithm is the core of the path planning.It is verified that a single path planning algorithm,which based on grid method,and ant colony algorithm both can plot a path as required.But,each algorithm has certain advantages and disadvantages.If the two algorithms are combined,the ant colony algorithm based on grid method is formed.It can not only be used to combine the advantages of both,but also make up for their shortcomings.And the results are obviously better than the single algorithm.Ant colony algorithm based on grid method can plan a better path,but there is a phenomenon that the path line contact to the vertex of obstacle grid,or the path is walking on both sides of the obstacle grid.Even if the barrier grid added the safety distance,the distance is not large.When the distance between the wheelchair and the obstacle is very close,the person in the wheelchair would believe that a collision occurs,which increase the psychological pressure to the user.In order to solve this problem,an improved method is proposed,which is used to carry out obstacle detection in the adjacent grids of the right direction and diagonal direction of the current grid,and formulate different path selection rules for the two cases,and avoid the obstacle edges and narrow area successfully,and the feasibility of the design is verified by experiments.Simulation experiments have been carried out in the MATLAB environment.The ant colony algorithm,the path planning algorithm based on the grid method,the ant colony algorithm based on grid method,and the improved algorithm have been simulated in the different environment and different position of same environment.The hardware and software flow chart of the intelligent wheelchair have been designed,which has been debugged in the intelligent wheelchair with the hardware module of AT91SAM9263.In order to improve the safety performance of the wheelchair,seven sets of ultrasonic module have been installed in a wheelchair to detect temporary obstacles.