非平衡负载下轮式移动机器人的抗扰PID控制

在非平衡负载条件下,轮式移动机器人(WMR)的前进、转向速度耦合,影响着轨迹跟踪和避障等运动控制性能.为此,本文提出了一种基于抗扰PID(DR–PID)控制器的WMR速度调节主动抗扰(ADR)控制策略.首先,建立WMR的速度耦合模型,引入解耦矩阵减小静态耦合作用;然后,基于一类改进干扰观测器(DOB)控制方法,设计一种具有ADR能力的PID控制器,即DR–PID,用于WMR的速度分散调节.进一步,考虑高频增益不匹配/不确定性,分析闭环系统稳定性条件.所得结论揭示了PID控制器的抗扰机理;最后,在不平衡负载条件下开展WMR运动控制实验研究,实验结果验证了所提方法的有效性.

Disturbance rejection PID control of wheeled mobile robot under non-equlibrium load

Under the condition of non-equilibrium load,the coupling effect between the forward and steering speeds in the wheeled mobile robot(WMR)affects the motion control performance greatly,such as the trajectory tracking and obstacle avoidance.Therefore,this paper proposes an active disturbance rejection(ADR)control strategy for the speed tuning of WMR based on disturbance rejection PID(DR–PID)controller.Firstly,the speed coupling model of WMR is established to derive the decoupling matrix for static coupling reduction.Then,the design of PID controller with ADR capability,named DR–PID,is presented based on an improved disturbance observer control scheme.The DR–PID controller is utilized for the decentralized speed tuning in WMR.Furthermore,the closed-loop stability condition is investigated with the consideration of high-frequency gain unmatching/uncertainty.This result reveals the ADR mechanism of the standard PID controller.Finally,experimental study of WMR motion control is carried on with non-equilibrium load.The validity of the proposed method is verified by experimental results.