Along with the increasing number of vehicles, parking space becomes narrow gradually, safety parking puts forward higher requirements on the driver's driving technology. How to safely, quickly and accurately park the...Along with the increasing number of vehicles, parking space becomes narrow gradually, safety parking puts forward higher requirements on the driver's driving technology. How to safely, quickly and accurately park the vehiclo to parking space right? This paper presents an automatic parking scheme based on trajectory planning, which analyzing the mechanical model oftbe vehicle, establishing vehicle steering model and parking model, coming to the conclusion that it is the turning radius is independent of the vehicle speed at low speed. The Matlab simulation environment verifies the correctness and effectiveness of the proposed algorithm for parking. A class of the automatic parking problem of intelligent vehicles is solved.展开更多
In order to reduce the controlling difficulty caused by trajectory meandering and improve the adaptability to parking into regular lots,a versatile optimal planner(OP)is proposed.Taking advantage of the low speed spec...In order to reduce the controlling difficulty caused by trajectory meandering and improve the adaptability to parking into regular lots,a versatile optimal planner(OP)is proposed.Taking advantage of the low speed specificity of parking vehicle,the OP algorithm was modeled the planning problem as a convex optimization problem.Collision-free constraints were formalized into the shortest distance between convex sets by describing obstacles and autonomous vehicle as affine set.Since employing Lagrange dual function and combining KKT conditions,the collision-free constraints translated into convex functions.Taking the national standard into account,5 kinds of regular parking scenario,which contain 0°,30°,45°,60°and 90°parking lots,were designed to verify the OP algorithm.The results illustrate that it is benefit from the continuous and smooth trajectory generated by the OP method to track,keep vehicle's stability and improve ride comfort,compared with A*and hybrid A*algorithms.Moreover,the OP method has strong generality since it can ensure the success rate no less than 82%when parking planning is carried out at the start node of 369 different locations.Both of evaluation criteria,as the pear error and RMSE in x direction,y axis and Euclidean distance d,and heading deviation 6,are stable and feasible in real tests,which illustrates that the OP planner can satisfy the requirements of regular parking scenarios.展开更多
Parking is an important and indispensable skill for drivers. With rapid urban development, the automatic parking assistant system is one of the key components in future automobiles. Path planning is always essential f...Parking is an important and indispensable skill for drivers. With rapid urban development, the automatic parking assistant system is one of the key components in future automobiles. Path planning is always essential for solving parking problems. In this paper, a path planning method is proposed for parking using straight lines and circular curves of different radius without collisions with obstacles. The parking process is divided into two steps in which the vehicle reaches the goal state through the intermediate state from the initial state. The intermediate state will be selected from the intermediate state set with a certain criterion in order to avoid obstacles. Similarly, an appropriate goal state will be selected based on the size of the parking lot. In addition, an automatic parking system is built, which effectively achieves the parking lot perception, path planning and performs parking processes in the environment with obstacles. The result of simulations and experiments demonstrates the feasibility and practicality of the proposed method and the automatic parking system.展开更多
基金supported by the National Natural Science Foundation of China (61035004, 61273213, 61300006, 61305055, 90920305, 61203366, 91420202)the National Hi-Tech Research and Development Program of China (2015AA015401)+3 种基金the National Basic Research Program of China (2016YFB0100906, 2016YFB0100903)the Junior Fellowships for Advanced Innovation Think-Tank Program of China Association for Science and Technology (DXB-ZKQN-2017-035)the Project Funded by China Postdoctoral Science Foundationthe Beijing Municipal Science and Technology Commission Special Major (D171100005017002)
文摘Along with the increasing number of vehicles, parking space becomes narrow gradually, safety parking puts forward higher requirements on the driver's driving technology. How to safely, quickly and accurately park the vehiclo to parking space right? This paper presents an automatic parking scheme based on trajectory planning, which analyzing the mechanical model oftbe vehicle, establishing vehicle steering model and parking model, coming to the conclusion that it is the turning radius is independent of the vehicle speed at low speed. The Matlab simulation environment verifies the correctness and effectiveness of the proposed algorithm for parking. A class of the automatic parking problem of intelligent vehicles is solved.
文摘In order to reduce the controlling difficulty caused by trajectory meandering and improve the adaptability to parking into regular lots,a versatile optimal planner(OP)is proposed.Taking advantage of the low speed specificity of parking vehicle,the OP algorithm was modeled the planning problem as a convex optimization problem.Collision-free constraints were formalized into the shortest distance between convex sets by describing obstacles and autonomous vehicle as affine set.Since employing Lagrange dual function and combining KKT conditions,the collision-free constraints translated into convex functions.Taking the national standard into account,5 kinds of regular parking scenario,which contain 0°,30°,45°,60°and 90°parking lots,were designed to verify the OP algorithm.The results illustrate that it is benefit from the continuous and smooth trajectory generated by the OP method to track,keep vehicle's stability and improve ride comfort,compared with A*and hybrid A*algorithms.Moreover,the OP method has strong generality since it can ensure the success rate no less than 82%when parking planning is carried out at the start node of 369 different locations.Both of evaluation criteria,as the pear error and RMSE in x direction,y axis and Euclidean distance d,and heading deviation 6,are stable and feasible in real tests,which illustrates that the OP planner can satisfy the requirements of regular parking scenarios.
基金Supported by the National Natural Science Foundation of China(61473042,61105092,61173076)Beijing Higher Education Young Elite Teacher Project(YETP1215)
文摘Parking is an important and indispensable skill for drivers. With rapid urban development, the automatic parking assistant system is one of the key components in future automobiles. Path planning is always essential for solving parking problems. In this paper, a path planning method is proposed for parking using straight lines and circular curves of different radius without collisions with obstacles. The parking process is divided into two steps in which the vehicle reaches the goal state through the intermediate state from the initial state. The intermediate state will be selected from the intermediate state set with a certain criterion in order to avoid obstacles. Similarly, an appropriate goal state will be selected based on the size of the parking lot. In addition, an automatic parking system is built, which effectively achieves the parking lot perception, path planning and performs parking processes in the environment with obstacles. The result of simulations and experiments demonstrates the feasibility and practicality of the proposed method and the automatic parking system.