非线性不确定机器人复合滑模非脆弱H_(∞)位/力控制

Composite Sliding Non-Fragile H_(∞)Position/Force Control for Nonlinear Uncertain Robot

针对非线性不确定机器人面临参数不确定性、控制器增益摄动及外界干扰的问题,在其终端受环境约束的情况下,提出一种基于多项式平方和(sum of squares,SOS)理论的复合滑模非脆弱H_(∞)(composite sliding non-fragile H_(∞),CSNH)位/力控制策略。首先,建立了机器人降阶动力模型和误差状态空间模型。其次,根据所提的复合位/力滑模面,基于Lyapunov稳定性理论设计一种具有H_(∞)扰动抑制的非线性变参数滑模非脆弱状态反馈控制器,给出控制器存在条件和求解方法。仿真结果表明,CSNH控制能够在不确定性和外部干扰作用下,使机器人快速、精确地跟踪位/力指令,体现出了良好的鲁棒性、抗干扰性及非脆弱性。

For the nonlinear uncertain robot faced with parameter uncertainty,controller gain perturbation and external disturbance,a composite sliding non-fragile H_(∞)(CSNH)position/force strategy based on SOS(sum-of-squares)theory is proposed when its terminal is constrained by the environment.Firstly,the reduced order dynamic model and error state-space model of the robot are established.Secondly,a nonlinear variable parameter sliding non-fragile state feedback controller with H_(∞)disturbance attenuation is designed based on Lyapunov stability theory according to the proposed composite position/force sliding surface,presenting the existence conditions and solution methods of the controller.The simulation results demonstrate that CSNH control can make the robot track the position/force commands quickly and accurately under uncertainty and external interference,showing good robustness,anti-interfere performance and non-fragility.