漂浮基空间机器人关节轨迹跟踪的时延估计控制

Time-delay estimation control of joint trajectory tracking for free-floating space robots

针对漂浮基空间机器人系统出现的载体姿态及位置不受控问题,提出了一种基于时延估计的跟踪控制方法。该控制方法采取时延估计为主体框架,对不确定参数及动力学特性进行实时估计,获得不确定项的估计误差,并在控制设计方案中对误差进行补偿。首先根据第二类Language方程建立机器人动力学模型,并结合时延估计简化动力学模型;然后结合滑模变结构控制,对估计误差进行修正和补偿,同时进一步引入指数趋近律方法,能有效削弱滑模带来的抖振问题,进一步提高了系统的稳定性;利用Lyapunov函数在设定参数下,保证了闭环系统的渐近稳定性和鲁棒性能,最后通过仿真验证了该方案可靠。

Aiming at the uncontrollable attitude and position of the free-floating space robot system,a tracking control method based on time-delay estimation is proposed.In this control method,the time-delay estimation is adopted as the main frame,and the real-time estimation of the uncertain parameters and dynamic characteristics is carried out to obtain the estimation error of the uncertain terms,and the error is compensated in the control design scheme.Firstly,the dynamics model of the robot is established based on the Language equation of the second kind,and the dynamics model is simplified by combining with time-delay estimation.Then combined with sliding mode variable structure control,the estimation error is corrected and compensated.At the same time,the exponential approach law is introduced to effectively reduce the chattering problem caused by sliding mode and further improve the stability of the system.The asymptotic stability and robust performance of the closed-loop system are guaranteed by using Lyapunov function under set parameters.Finally,the reliability of the proposed scheme is verified by simulation.