Optimization Method Research Of Joint Torque For Redundant Space Manipulator

Redundant space manipulator can use its own redundancy to ensure that the terminal operation task is completed while optimizing performances of the system.In order to make space manipulator adapt to different operating tasks and improve the reliability of task execution,joint torque of space manipulator often requires optimizing.Joint torque optimization for space manipulator,on the one hand,can improve the safety of its working process and reliability of task execution,on the other hand,can make the manipulator reduce the required energy consumption while completing a prescribed operation task to change the situation that fuel is limited and difficult to supply for space manipulator in time to face.Therefore,optimization method research of joint torque for redundant space manipulator has important theoretical value and practical significance,and also has broad application prospects.Based on redundant space manipulator as the research object of this paper,hackling and sensitivity analysis of influence factors of joint torque for space manipulator during operation process,optimization method research of joint torque for space manipulator under no-load operating condition of rigid body and considering link flexibility,and that under a large load operating condition are carried out.The main research work is as follows:Firstly,hackling and sensitivity analysis of influencing factors of joint torque for space manipulator during operation process is carried out.By systematically combing,influencing factors of joint torque for space manipulator during operation process are mainly divided into motion parameters,its flexibility and terminal operating condition,and the three kinds influence factors hackled are analyzed.Then the sensitivity analysis of some typical influencing factors of joint torque is made with a single link flexible manipulator as an example.Secondly,optimization method of joint torque for space manipulator under low load operating condition is studied.An optimization algorithm of joint torque based on genetic algorithm is proposed,using seven times polynomial interpolation method to parameterize joint variables of space manipulator,obtaining optimization control parameters of genetic algorithm,and making the sum of each joint torque mean value for space manipulator minimal as the objective function;Based on the objective function and corresponding optimal control parameters,the operation path of the minimum sum of joint torque mean value for a manipulator is obtained using genetic algorithm to optimize and solve the operation trajectory of space manipulator.Simulation experiments show that compared with the traditional planning method of trapezoidal velocity and the optimization method making two norm of joint torque as an objective function,this method has a certain degree increase in the aspect of reducing sum of joint torque mean value.Again,the optimization method of joint torque for space manipulator considering link flexibility is studied.An optimization algorithm of joint torque for space flexible manipulator is proposed considering vibration suppression,using the assumed mode method to approximately describe bending deformation of the flexible link,and deriving the dynamic model of space flexible manipulator system based on Lagrange method.On the basis of decomposition of flexible manipulator dynamics equations,the manipulator's terminal vibration is restrained and joint torque is optimized at the same time by introducing Lagrange multiplier.The feasibility and effectiveness of the algorithm is verified through simulation experiments.Finally,optimization method of joint torque for space manipulator under large load operating condition is studied.A multi-objective optimization algorithm for space manipulator is proposed based on particle swarm optimization,making sum of joint torque mean value and the maximal joint torque and maximal joint angular velocity of space manipulator minimal as optimization objectives to solve,and using multi-objective particle swarm algorithm to optimize and solve the moving trajectory of the space manipulator.Compared with the single objective optimization algorithm making sum of joint torque mean value minimal,validity of the algorithm is verified by simulation experiments.