| Path planning is the core problem facing all mobile robots. This involves a number of problems like along which path and at what speed to come to the destination, how to perform the real-time planning within a designated time frame, how to ensure that the robots will follow these plans without going against their own kinetics, how to detect and avoid collisions, and how to set the system parameters. After decades of research and practice, a large amount of research has been accumulated in path planning of mobile robot, but there are still plenty of problems to intensive study. After decades of research and practice, a large amount of research has been accumulated in path planning of mobile robot, but there are still plenty of problems to intensive study.RoboCup, i.e., robot world cup soccer games. Small size league soccer league is one of the principal games of RoboCup that requires high real-time level and therefore offers an ideal platform for researches on real-time path planning. In this paper, some key issues relating to path planning are investigated and experimented. The obtained results can not only be applied to various competitions of RoboCup, but also be used to solve the problems of robotics. Consequently, the study will provide both significant theoretical and practical value. The obtained results can not only be applied to various competitions of RoboCup, but also be used to solve the problems of robotics. Consequently, the study will provide both significant theoretical and practical value.The innovative research has been performed to the following aspects:1) In practice, a linear chain list is often used by competition teams to store obstacles. Before collision test, the obstacle data are pretreated with a round bounding box for the robots and KD tree structural storage for the obstacles. By combining bounding box method with space-based segmentation algorithm, a collision test method based on KD tree and round bounding box is proposed, which reduces the number of bounding box collision tests, relieves the complexity of the algorithm and accelerates the obstacle test rate.2)Modified algorithms based on stochastic path planning like ERRT, CRRT, DRRT and MP-RRT are used by leading small size RoboCup league teams and all involve replanning of the path by RRT when there is a material change in the target point. However, as RRT planning has a high randomicity level, there have been cases when the planning was materially overtime and could not meet the real timeliness of small size RoboCup league. This shows certain probability of inability to meet the real timeliness of the system.3) To ensure sound kinetic property of the robots, the PI parameter setting of the four-wheel synergic movement of small-size RoboCup soccer teams is studied, a new automatic Intelligent PI parameter setting algorithm of the four-wheel synergic movement is proposed based on genetic algorithm, and the chromosome coding and decoding method, fitness function and genetic operator involved in the algorithm. Experiments show that this algorithm achieves higher system operation stability and parameter setting efficiency than conventional robot setting algorithms.4) To solve the safety of robots against potential collision with obstacles during operation, the type of obstacles in small-size RoboCup games as well as collision-related kinematics of robots is investigated, and a dynamic kinetics planning algorithm is designed, based on which the collision potential for robots during their movement is tested on real-time basis, and where there is a risk to collision, the acceleration of the robot exposed to collision in the present controlled period is corrected to avoid real-time collision. |
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