关节空间内工业机器人抗干扰轨迹跟踪控制

Trajectory Tracking Control for an Industrial Robot in Joint Space with Disturbance Rejection Technique

针对工业机器人在关节空间内轨迹跟踪精度差和易受集总干扰影响等问题,提出一种基于非线性扰动观测器的快速连续非奇异终端滑模控制策略。根据拉格朗日方程推导出四轴工业机器人的动力学模型,获得系统的输入输出关系。引入非线性扰动观测器对集总干扰进行估计与补偿,设计快速连续非奇异终端滑模控制器来加快系统状态量的收敛速率,提高关节空间内轨迹跟踪的精度。由李雅普诺夫稳定性理论证明了此控制器的全局稳定性。通过仿真案例与试验研究验证了所设计控制策略的有效性,结果表明:该控制器能有效抑制集总干扰影响,保证工业机器人轨迹跟踪的精度,具有一定的工程参考价值。

Aiming at the difficulty of poor trajectory tracking precision and susceptible to lumped disturbances in joint space control for an industrial robot, a fast-continuous nonsingular terminal sliding mode control strategy was proposed based on nonlinear disturbance observer. The dynamical model of a 4-DOF robot was modeled by using Lagrangian equation, by which the inputs and outputs of the system were obtained. A nonlinear disturbance observer was introduced to estimate and compensate the lumped disturbances. And a fast-continuous nonsingular terminal sliding mode controller was designed to accelerate the convergence of the system state variables, which could improve the trajectory tracking precision in joint space. Meanwhile, the global stability of the controller was proved by using Lyapunov theory. Some simulation cases and experiments were conducted to test the efficiency of the controller. The results show that the proposed controller can be used to retrain the lumped disturbances and to ensure the trajectory tracking precision, which has a project application value.