Study On The Automatic Parking Method At The Non Side Marking Parking Lot

With the rapid development of science and technology,as well as the rapid increase of the number of automobiles in cities,it will become a new trend that automatic parking replace the traditional manual parking.Compared to manual parking,automatic parking has great advantages in safety,operation and accuracy and so on.The related researches now basically take the parking lots that have parking marks as the research object,and apply video positioning for automatic parking.However,in practice,there are a plenty of parking lots that have no parking marks,so this paper takes the parking lots that have no side parking marks as the research object.If there is no parking marks in a parking lot,there should be other references,and the direct references are the vehicles parking in front of or behind the automobile.If there are vehicles in front of and behind the automobile,it is difficult for a new driver to park a automobile.Therefore,this study mainly takes the automatic parking while there are vehicles in the front of and behind the automobiles as the research object.This thesis mainly analyzes parallel parking.When parking slowly,establish a vehicle motion trajectory equation by taking the edge of the parking space as the vertical direction to form a coordinate system,thus the running track of the vehicle is obtained.On the basis of the research,the planning scheme of taking the two equal arc as the running track and the previous four steps of the path planning scheme are analyzed.In view of the problems existing in the previous four step path planning,the paper designs a new algorithm to improve the scheme and refine the part which the original scheme is not involved in.The algorithm is not only convenient and easy to control,but also can overcome the shortcomings of the four steps scheme,which can lead the vehicles into the predetermined parking spaces more rapidly,safely and accurately.In order to apply the parking method described by the algorithm,the parking control process is also presented.According to the process of the project,the scheme of the control system is designed,which mainly consists of the main controller,electronic compass,ultrasonic detecter,photoelectric encoder,speed control device,steering control device,brake control device and other parts of the system.This thesis also puts forward a kind of low speed control method using fixed throttle and make use of the braking mechanism to adjust,which is used to match the speed control of parking needs.This method is simple and do not add additional hardware overhead system.While the whole system is not completed,in order to verify the effectiveness of the algorithm,the author apply two ways to verify: the first is the simulation program,and the second is applying manual control method according to a predetermined plan to verify.The basis of manual verification is to draw the corresponding spaces,calibrate several parking positions and observe the azimuth and other parameters of the electronic compass of the vehicles according to the specific parameters of the test vehicle and the calculation result.By doing these,the researchers can control the vehicles and judge whether the practical path is the same as the planning path.On the basis of the previous work,the thesis improves and refines the parking scheme.In summary,the thesis creates an effective way to parallel parking the vehicles slowly and proves the effectiveness of the algorithm on the premise of the detected data of the parking space detection system,and by taking the electronic compass azimuth control as the main basis and combining the path planning with the steering strategy and simulation as well as manual control.