Simultaneous Obstacle-avoidance Motion Planning Approach For Dual Arm Robot In Complex Environment

To solve the problem of possible collision between the dual arm robot and obstacles during its motion in a complex working environment,a new obstacle avoidance approach based on improved RRT algorithm is proposed.First,the motion planning for the main arm is conducted to avoid the existing static obstacles in the working environment,and a feasible motion trajectory as well as the status of each joint angle are obtained.Then the main arm is regarded as dynamic obstacles to the second robot arm,and the obstacle map is updated accordingly.At each s tep,the position of the main arm is treated as a dynamic obstacle for the motion planning process of the second arm,so as to prevent the second arm from collision with either the static obstacles in the environment and the dynamic main arm.Also,to impr ove the search efficiency of the algorithm,strategies of nodes-pruning as well as setting of target area are adopted,where the algorithm is terminated if the distance between the manipulator's end position and the goal point is within a prescribed tolera nce.Based on MATLAB program simulation experiments,a Solidworks virtual prototype is built and imported into Adams for simulation experiment studies,demonstrating the effectiveness and feasibility of the algorithm.This dissertation mainly contains following aspects:Modeling.The D-H method is adopted to mathematically model the two manipulators.The model of obstacles is also established in the work space of the dual-armed robot.MATLAB simulation.The improved RRT algorithm is applied in the MATLAB software.Firstly,a collision-free path of the main arm is obtained.Afterwards,the main arm at each moment is regarded as a dynamic obstacle during the motion planning of the driven arm,and a feasible motion path is obtained.When the two robotic arms reach the target location,two feasible paths are obtained with the algorithm.ADAMS simulation verification.A dual-arm robot model is established in the Soliworks software and leaded in ADAMS software.A virtual prototype of the dual-arm robot is created after setting the dual-arm robot's movement and driving mode.The angle path of each manipulator arm joint motion angle is extracted after the algorithm,and which is set as the driving function of the virtual prototype.The angle path is verified in established the simulation environment.Experiment platform verification.The single-chip microcomputer is applied to control the motion of the two robot arms simultaneously.The data of each joint angle obtained by the algorithm is imported,and the value of proposed algorithm in practical application is proved in the comparison result of physical verification and simulation.