关键词: 轨迹跟踪控制, 模糊控制, 滑模面, 趋近律, 抖振

Abstract: To improve the trajectory tracking control performance of SCARA robot, a sliding mode control strategy based on nonsingular terminal sliding mode surface and the improved fast reaching law is proposed. A fast nonsingular terminal sliding mode surface is designed, which can converge to equilibrium point under arbitrary initial state and the convergence speed is faster than the traditional terminal sliding surface. The reaching law of improved sliding mode control can restrain the chattering effectively whilst also guaranteeing fast approaching, and with the use of hyperbolic tangent function instead of the traditional symbol function, the high frequency chattering is eliminated effectively. Furthermore, a fuzzy control method is utilized to adjust the parameters of the reaching law, improving the torque impact problems caused by too big initial state error. Simulation results which is based on SCARA robot model show that the tracking performance is good, the output torque is smooth.

Key words: trajectory tracking control, fuzzy control, sliding surface, reaching law, chattering