Research And Application Of External Force Estimation And Control Methods For Manipulators

In recent years, with the sustained growth of the robot intelligent level, the application area of robot have extended form the simple tasks, such as welding and handling to the tasks which need to interact with the environment, such as grinding, polishing and assembly. When robot perform those tasks, involving interaction with the environment, pure motion control schemes are not suitable. Therefore, the research on robot force/position control methods can expand the scope of application of the robot to a great extent.By reading a large number of literatures, this thesis analyses the domestic and foreign research situation of force control, and then specializes the key technologies of the robot force control, including the research of external force estimation, impedance control and direct teaching. The main work and achievements are as follows:Firstly, considering the drawbacks of conventional force sensors, a method of estimating end-effector force based on H∞ filting is proposed, a two-link manipulator model is established based on SimMechanics in MATLAB/Simulink, and the effectiveness of the proposed algorithm is verified through the simulation.Secondly, an indirect adaptive impedance control is proposed, and a force estimator which is researched in chapter 2 is added to the control structrue, the related simulation experiments are conducted.Thirdly, compliance tracking control based on position and based on velocity which can make manipulator move along the direction of external force. The performance of the control methods is evaluated through experiments.Fourthly, a direct teaching system based on St?ubli industrial robot is developed, which implements the compliance tracking control, and the system software is programmed by VAL3. The path data collected during the robot teaching process is compressed by the Douglas-Peucker algorithm, and the performance of the proposed algorithm is evaluated through the teaching experiment.Finally, the work of this thesis is summarized, and some prospects for the futrue research work are put forward.