A Study On The Motion Planning And Simulation For Mobile Robot Based On Improved RRT* Algorithm

Motion planning for mobile robot is the problem of how to design an appropriate control-input to make the system move from the starting point to the goal point safely and collision-freely.Nonholonomic constraints are widely present in the mobile robot system,like wheeled robots,space robots and so on.For this kind of robot,the limited range of motion caused by nonholonmic constraints should be taken into account in addition to the need of considering the configure-space constraints caused by obstacles.Therefore nonholonomic constraints have brought great challenges to the mobile robot motion planning problem.This paper is focused on solving motion planning problem for mobile robot under nonholonomic constraints.The specific research content as follows:(1)Introduced on the definition of nonholonomic constraints and how to establish the kinmatic model for non-complete system.The model of mobile robots under nonholonmic constaints are given for the research of motion planning algorithm follow-up.(2)The paper analyzed the Rapidly-exploring Random Trees(RRT)algorithm.Then,target on the complex and variability of operating environment,a new RRT*-based algorithm is proposed by combining the environmental constraints,vehicle constraints and kinematics constraints,rejected the bias in the original algorithm and sample insertion heuristic algorithm are introduced to increase the planning speed and quality greatly.(3)The Improved-Bidirectional Rapidly-exploring Random Trees(IB-RRT*)algorithm is verified by the test of probabilistic completeness,asymptotic optimality and rapid convergence,which ensure that the algorithm can quickly converge to the optimal path in theory.Finally,the validity,stability and correctness of this algorithm have been verified by a large of simulation experiments,it also verified the correctness of the theoretical analysis.And virtual reality technology is provided by ROS,establishing static and dynamic physical simulation platform in GAZEBO,to verify the practicability,real-time and accuracy of the algorithm in the mobile robot system,which ensure that the improved algorithm run in a variety of environments and situations.