某空间伸杆机构的摩擦补偿及反步自适应控制

A Friction Compensation and Adaptive Back-Stepping Control for a Space Deployable Boom

面向某新型大伸展(收拢比)、高载荷(自重比)伸缩式空间伸杆机构的实际应用需求,研究其低速伸展过程中摩擦力矩补偿及其反步自适应控制方法。考虑伸杆伸长量等各种因素引起的摩擦力矩变化,将其等效描述为摩擦变化系数的影响,由此得到Lu Gre改进模型的摩擦表征。在此基础上,设计基于摩擦力矩补偿的反步自适应控制器,以补偿和抑制模型不确定性和摩擦影响。最后通过仿真校验表明,该方法不依赖精确的动力学模型,能够在保证鲁棒性的前提下有效提高系统控制性能。

In order to satisfy the requirement for a novel deployable boom characterized by small stowed volume,light weight and a large magnification ratio,the friction compensation and back-stepping control method in the low velocity deployment process are studied. Firstly,the various friction torques in the deployment process of the boom is described by the effect of friction coefficients; then,an improved Lu Gre friction model is deduced to describe the friction characteristics of the boom. On the basis of that,an integral back-stepping adaptive control method is proposed to compensate the friction and suppress the model uncertainties. Finally,Simulation results show that the developed control method does not rely on the exact dynamics model and can ensure robustness to improve the system tacking accuracy further.