Target Grab Trajectory Planning And Design Of Control System For Mobile Manipulator

With the further development of industrialization and the expansion of the application field of robot technology,the mechanical arm fixed at a certain position has been unable to meet new demands.In many unstructured work environments,the fixed arm of the pedestal does not perform well.At this time,the arm needs to be movable.Therefore,the mobile robot arm can meet this need.The moving robot arm is usually composed of a robot arm and a moving platform,which combines the operability of the arm and the mobility of the moving platform,so that the operating space of the robot is greatly improved.The mobile robot arm designed in this paper consists of an omnidirectional moving trolley equipped with a seven-degree-of-freedom robot arm.The research content is as follows:First,the overall design of the mobile robot system is performed.According to the performance requirements of the manipulator,the overall structure of the seven-degree-of-freedom manipulator was designed,and the key components were selected.The main performance indicators of the mobile platform and the vision system design were also introduced.Second,kinematic analysis of the mobile robot arm.Mathematical models of the seven-degree-of-freedom manipulator and the mobile platform were established.For the manipulator,the simulation model of the manipulator was established by Matlab toolbox,and the working space of the manipulator was simulated by Monte Carlo method.In addition,the kinematic inverse solution of the manipulator based on the algebraic method of the arm angle parameter is also discussed.This method is compared with the common geometric method,and all feasible solutions can be obtained considering the joint limit.Then,study the robot arm target grab trajectory planning.The trajectory planning method of joint space and the trajectory planning method of Cartesian space are introduced respectively.For joint space trajectory planning,polynomial interpolation and PVT interpolation are introduced.For the trajectory planning of Cartesian space,the linear interpolation and circular interpolation methods in space are analyzed and the interpolation experiments are carried out respectively.Since the seven degrees of freedom have self-motion characteristics,the principle of mechanical arm interpolation from the motion field is also introduced and the self-motion interpolation experiment is carried out.For the obstacle avoidance problem in the process of grasping the manipulator,the RRT algorithm and its improvement method are introduced,and the simulation experiments are compared and analyzed.Finally,the ROS-based robotic arm simulation environment is built,and the robot arm obstacle avoidance algorithm simulation experiment is carried out to verify the feasibility of the RRT algorithm and its improved algorithm.The calibration of the vision system was carried out,including the calibration of the depth camera and the calibration of the hand-eye system.Finally,the PC software of the mobile robot arm was developed to realize the recognition and grabbing function of the mobile robot arm,and related experiments were carried out.