Study On Mechanism Design And Dynamics Simulation Of Parallel Robot

With its advantages of small tracking error,fast running speed and strong running ability with heavy load,parallel robots have been widely used in industrial production sites,especially in the processing of light objects such as lens handling,food packaging and medical supplies packing.A large number of applications of high-speed parallel mechanisms have greatly reduced the problems of low efficiency and high investment cost in simple manual operations such as sorting,packing and handling.In this thesis,a high-speed parallel robot is designed to meet the main requirements of industrial production.The main operation objective of this mechanism is to realize the picking and placing operation.Firstly,the main structure and basic motion law of the mechanism are introduced,and then the kinematics equation of the mechanism is obtained by using geometric principle and vector operation,and the simplified mechanical structure model of the parallel robot is built by using Simscape module in MATLAB.Then,the correctness of the kinematic theory is verified,and the reachable task space and its three views of the parallel robot are drawn by Monte Carlo method under Angle constraints.The LCI performance index was calculated by the condition number of Jacobian matrix,and the LCI performance index diagram of the cross section of the task space was drawn,so the singularity of the mechanism was analyzed.Secondly,the trajectory planning of the parallel robot is very important for the robot terminal platform to complete the operation task with high precision.Therefore,this thesis carried out mathematical theoretical derivation and numerical simulation analysis for the application of 4-3-4,3-5-3,4-5-4 and 4-3-3-4 polynomial interpolation methods in motion trajectory respectively.The results show that the motion curve planned by 4-3-3-4 polynomial interpolation method is smoother,and the goal of lower energy consumption in motion process is realized.In order to achieve the goal of shortening the movement time of the mechanism,an improved particle swarm optimization algorithm was used to optimize the movement time of the 4-3-3-4 polynomial interpolation method.Then,the sparrow optimization algorithm is applied to the trajectory planning process of mechanism for the first time in this thesis,and better optimization results are obtained.Finally,the virtual work principle is used to solve the basic dynamic equation of the mechanism,and the research goal is achieved.After that,the PID control method is used to complete the accurate tracking of the target path and achieve a high precision,which has important reference value for the work of the industrial processing field robot.