Research On Clearance Identification And Control Of Mechanical Arm System With Gear-driven

The robotic arm system plays an important role in the field of aerospace technology,especially in the field of space station construction and deep space exploration.The general robotic arm will use gears for transmission.However,the occurrence of gear gap will affect the control accuracy of the robot arm and reduce the performance of the system.Therefore,it is of great value to study the identification algorithm of the gear clearance and the control strategy of the robot arm system.Value and engineering applicability have been closely watched at home and abroad.This paper aims at the clearance identification of gear transmission and the controller design of the robot arm,and studies the aspects of gear meshing and collision,robot dynamics,controller design and simulation,and experimental verification.The research work is mainly conducted from the following aspects: :Firstly,according to the principle of gear meshing transmission,the mathematical model of the gear is obtained when the clearance is contained.Then,based on Hertz and the improved collision theory,the gear gap collision model is established.The mathematical model of the gear transmission fully describes the gear meshing.Based on the gap,the rotation function of the relative rotation of the gear is established.Then,the relationship between the embedded amount and the rotation function of the gear extrusion is obtained.Based on the collision model,the meshing transmission dynamic model including the gear clearanc e is obtained.This model is a gap recognition algorithm.Foundation.Then based on the simulation and experiment of single-joint mechanical arm,based on the mathematical models of gears and the models with gaps,a gap identification algorithm of gear transmission is proposed,namely the algorithm of small stimulus waveform gap recognition and the time-dependent phase identification algorithm,and then through the design simulation conditions.The algorithm is implemented and a single joint robotic arm test is performed to verify the accuracy of the gap recognition algorithm.Next we model the general space manipulator.The DH parameter matrix is used to describe the configuration of the manipulator,and the position and velocity equations of the connecting rod are deduced;then the dynamic equation of the system is established based on the Lagrangian equation,and then the dynamic equation of the manipulator with gear transmission is derived.The recursive idea gives the positive and negative dynamic solutions of the manipulator equation.Then based on the equations,the controller of the robotic arm is designed,and the design controller has certain robustness.The simulation of the controller is completed through the Matlab and Simulink solver,and the reliability of the robotic arm controller design is verified.Finally,based on the above theoretical basis,using MBsim simulation software and Simulink co-simulation,the controller is designed to calculate the torque control,torque feedforward control and PI robust control;and to carry out the test of the robot control,design the controller based on Labview.The use of NI equipment to complete the three-joint mechanical arm with gear control,simulation and test results show that the controller is designed to be able to better control the robot arm with clearance.