考虑非线性关节摩擦SCARA机器人模糊PID控制

Fuzzy PID control of SCARA robot considering nonlinear joint friction

为了使SCARA机器人在快速运动时具有较快的响应速度和较强的抗干扰能力,在传统PID伺服控制器的基础上,利用模糊理论将伺服控制器设计为模糊PID控制器。采用MATLAB软件对该模糊控制器进行仿真研究,分析对比两种控制器的性能指标和抗干扰能力。结果表明:在阶跃信号作用下,两种控制器均能较好地实现信号跟踪,但模糊PID控制器的超调量要小于传统PID控制器。当考虑周期外激励作用时,传统PID控制器出现振荡现象,而模糊PID控制器仍保持较好的信号跟踪;在五次多项式轨迹跟踪过程中,两种控制器均能有效地实现信号跟踪。当考虑非线性关节摩擦作用时,传统PID控制器轨迹跟踪出现偏移,而模糊PID控制器实际轨迹仍能保持与期望轨迹较好的一致性。

To improve the response speed and anti-jamming ability of the SCARA rotot when moving rapidly. Based on the tradi- tional PID servo controller,the fussy control theory was used to design the servo control as a fuzzy-PID controller. The fuzzy PID controller was studied with simulation on the MATLAB platform. The performance indexes and the anti-jamming abilities were an- alysed and compared between the two controllers. The results showed that, under the effect of step signal, two kinds of controllers could better accomplish signal tracking, while the overshoot of fuzzy PID controller was smaller than PID controller. When consid- ering the effect of periodic excitation, PID controller would occur oscillation, while fuzzy PID could still maintain a better signal tracking;In the process of five times polynomial trajectory tracking, two kinds of controllers could effectively accomplish. When considering the effect of nonlinear joint friction, PID controller trajectory tracking was offseting, but fuzzy controller actual trajecto- ry can still maintain to be consistent with the expected trajectory.