考虑执行器饱和补偿的移动机器人自适应积分滑模控制

Adaptive integral sliding mode control of mobile robot with actuator saturation compensation

针对存在执行器输入饱和约束、模型参数不确定性以及外部扰动等因素影响下的移动机器人跟踪控制问题,提出一种考虑执行器饱和补偿的移动机器人自适应积分滑模控制方法。利用双曲正切函数对执行器输入饱和约束作近似处理,并将系统动力学模型表示为仿射系统形式。将执行器输入饱和约束的近似处理误差、模型参数不确定性以及系统外部扰动扩张为一个新的状态,进而设计扩张状态观测器对系统总和扰动进行估计,在此基础上设计系统自适应积分滑模控制器,从而改善普通滑模控制中抖振突出的问题,保证系统的跟踪控制性能。对所提控制方法进行了仿真验证,结果表明,所提控制方法在执行器输入饱和约束、模型参数不确定性以及外部扰动等因素影响下能够保证跟踪误差快速稳定收敛。

In this paper,an adaptive integral sliding mode control method considering actuator saturation compensation is proposed for the tracking control of mobile robot with actuator saturation constraint,model parameter uncertainties and external disturbances.Firstly,the hyperbolic tangent function is used to approximate the actuator input saturation constraint,and the system dynamics model is expressed as an affine system form.Then,by taking the approximate processing error of actuator input saturation constraint,model parameter uncertainties and external disturbances as a new state variable,the extended state observer is designed to estimate the total disturbance of the system.Based on that,an adaptive integral sliding mode controller is designed for the system.Thus,the problem of chattering in common sliding mode control is improved,and the tracking control performance of the system is guaranteed.Finally,the simulation of the proposed control method is carried out.The simulation results show that the tracking errors can converge to zero fast and stably under the influence of actuator input saturation constraint,model parameter uncertainties and external disturbances.