自由曲面打磨机器人非奇异终端滑模阻抗控制

Non-singular terminal sliding mode impedance control of free-form surface grinding robot

针对传统控制方法难以实现对复杂曲面高精度打磨问题,在笛卡尔坐标系下设计了基于非奇异终端滑模的复杂曲面打磨机器人阻抗控制方法。该方法首先根据系统的阻抗模型参数,将设定的打磨轨迹转化为机器人末端可执行的阻抗轨迹,然后设计了基于非奇异终端滑模的控制方法对该阻抗轨迹进行跟踪。对于滑模控制的抖振问题,采用指数趋近律对其进行削弱。基于Lyapunov理论对系统的稳定性进行了证明,仿真和缸体打磨实验结果显示,该方法能够在有限的时间内达到收敛状态且避免了控制奇异的现象,提高了控制系统的鲁棒性和精度。

In order to solve the problem that traditional control method is difficult to achieve high-precision grinding of complex surfaces,this paper designs the impedance control method of complex surface grinding robot based on nonsingular terminal sliding mode in Cartesian coordinate system.Firstly,according to the impedance model parameters of the system,the set grinding trajectory is transformed into the executable impedance trajectory at the end of the robot.Then a control method based on nonsingular terminal sliding mode is designed to track the impedance trajectory.For the chattering problem of sliding mode control,the exponential approach law is used to weaken it.The stability of the system is proved based on Lyapunov theory.Simulation and cylinder grinding experiment results show that the method can achieve convergence in a limited time and avoid the control singularity,and improve the robustness and accuracy of the control system.