Research On Impedance Control Of 6-DOF Manipulator

Manufacturing industry is a developing subject of economy in our country. "China manufacturing 2025 strategy" has been proposed in 2015.The robotics is one of the priority development industries, and the robotic market was increased very rapidly during past years.As a kind of robots, manipulators applied very widely in the field of industrial production, air craft, military and daily life. In the currently industries, manipulators are often used to finish the tasks of trajectory planning. For the tasks which need physical contact, such as cutting,polishing, assembling and so on, manipulators should use compliance control. Therefore,compliance control is the hotspot and emphasis of research. In this paper, the research on compliance control strategy, especially the impedance control method has been taken. And the task of Chinese characters writing with force control has been finished by REbot-V-6R manipulator.Firstly, design and exploit the movement control and force signal acquisition systems of manipulator, and dispose the measured force signal. The hardware frame and movement pattern of REbot-V-6R manipulator is analyzed, and the movement control system is designed.Then the signal acquisition system of six dimensional force/torque sensor is designed. The noise of force signal is analyzed and determined that it is the Gaussian white noise. The noise signal is disposed with Kalman filter method. And the gravity compensation is carried.Secondly, study the trajectory planning method of manipulators. The kinematics models of 6-DOF manipulator is established, and the inverse kinematics with the modified Pieper method is solved. Then the interpolation algorithm of straight line, circular arc, and quadratic spline is studied. Trajectory planning experiments is carried, and the experiments result show that manipulator can track the position with high precision.Finally, study the impedance control method of manipulators. The simulated system is developed by Matlab/Simulink and Robotic Toolbox. The impedance controller based position and model reference adaptive controller are designed and experimented by manipulator. The experiments result show that model reference adaptive control method is robust for the environment with unknown stiffness. Position information of Chinese outline is extracted based True Type Font (TTF) vector fonts.The Chinese characters writing system with force control is designed, and force control in the process of Chinese characters writing is realized successfully.