Research On Optimum Structure And Control Characteristic Of Six-Degree Of Freedom Mechanical ARM In Series

Accuracy, responsiveness and stability are important index of performance of robot that depend on control characteristic of mechanical system and control structure and algorithms of control system. There are some deficiencies with industrial operative robot, for example, the bandwidth is not enough wide, the speed is limited and the accuracy is not enough high. Based on that, domestic and foreign researchers pay attention to control structure and algorithms. In light of that the industrial operative robot adopts serial and open-cycle layout, stiffness, inertia and damping of mechanical system are the key factors that restrict its control quality further improved. In order to improve the control quality of mechanical system furthest, this paper researches the configuration of driving components of each joint, the distribution of mechanical quality and the optimization of joint sustaining device in sequence with systematics viewpoint based on minimizing the mechanical inertia. On the basis of project "six-degree of freedom mechanical arm in series", the author optimizes the structure of mechanical arm further in order to improve the control characteristic. The main research work are as follows:The author has made dynamic analysis of each joint of mechanical arm, designed transmission form of each joint of mechanical arm intensively and completed the selection of all joints drives according to the inertia matching and dynamic computational results, bulided the platform of control system and completed all the design of control system mechanical arm.The author makes the kinematic analysis with D-H of the mechanical arm and acquires kinematic positive solution, kinematic negative solution and jacobi matrix. The author acquires the shape and the area of the workspace using MATLAB and determines the range of workspace, it provides necessary conditions for the optimum structure of the mechanical arm.The author builds kinetic equation of the base focusing on dynamic analysis and calculation. The control characteristic has been improved by enhancing rigidity of the support device of the base joint or reducing damping factor of the system. The author improves the control characteristic of elbow joint and shoulder joint by adopting two kinds of optimal scheme respectively that changing the riding position of the motor-reducer and settling balancing spring between the large arm and the forearm.The innovation point of this paper is embodied in that the author adopts appropriate and effective technical measures in transmission design and drive choices and quality configuration aimed at different joints of operative robot in order to improve the control quality of mechanical system and it creates good condition for improving the accuracy, response speed and stability of industrial robots.