基于改进型积分终端滑模控制方法的移动机器人轨迹跟踪设计与实验

为了使移动机器人获得高精度和快速收敛的跟踪性能,设计一种基于积分终端滑模和滑模观测器的轨迹跟踪控制方法.首先,考虑到移动机器人在实际运动过程中会受到地面湿滑、摩擦等原因引起的侧滑扰动的影响,建立其在该扰动影响下的运动学模型;然后,利用该动态模型设计滑模观测器来估计系统受到的扰动;接着,将估计的扰动值前馈至反馈控制器,用来抑制扰动对系统控制性能的影响,从而达到削弱抖振的目的;同时,基于跟踪误差设计积分终端滑模面,并结合滑模面和扰动估计设计新型积分终端滑模控制器;最后,基于Lyapunov稳定性理论对整个闭环系统进行稳定性分析.仿真实验结果表明,所设计的控制器具有更高的跟踪精度和更强的鲁棒性.

Trajectory tracking design and experiment of mobile robot based on improved integral terminal sliding mode control approach

To achieve the performance of high-precision and fast convergence for the trajectory tracking of a mobile robot, a trajectory tracking control method based on the integral terminal sliding mode and sliding mode observer(SMO) is addressed. Firstly, considering that the mobile robot would be affected by the side-sliding disturbance caused by the wet ground and frictions in the actual moving process, the kinematic model under the influence of the disturbance is established. Then, a sliding mode observer is developed using the dynamic model to estimate the disturbance of the system, and the estimated disturbance value is passed to the feedback controller to suppress the influence of the disturbance on the control performance of the system, so as to achieve the purpose of weakening the chattering. At the same time, an integral terminal sliding mode surface is devised on the basis of the tracking error, and integrating the sliding mode surface and disturbance estimations, a new integral terminal sliding mode controller is constructed. Finally, the stability of the whole closed-loop system under the present control method is also guaranteed using the Lyapunov stability theory. Simulation and experimental results show that the recommended controller has higher tracking accuracy and stronger robustness.