基于未知动态估计器的下肢外骨骼漏斗控制  

Unknown system dynamic estimator-based funnel control for lower limb exoskeleton

作　　者：宋鹏 张文豪 武明英 冯博琳 SONG Peng;ZHANG Wenhao;WU Mingying;FENG Bolin(Northwest Institute of Mechanical&Electrical Engineering,Xianyang 712099,China)

机构地区：[1]西北机电工程研究所,陕西咸阳712099

出　　处：《兵器装备工程学报》2024年第S01期345-351,共7页Journal of Ordnance Equipment Engineering

基　　金：陕西省青年人才托举计划项目(20230126)。

摘　　要：针对下肢外骨骼在运动控制中由于不可测干扰导致的暂稳态收敛性能恶化问题,提出了一种基于未知动态估计器的下肢外骨骼漏斗控制方法。在干扰辨识与补偿方面,将摩擦干扰、外部环境干扰和参数不确定性视为总体干扰,通过对系统可测状态进行滤波操作,结合不变流形定理构造了未知动态估计器(USDE),实现了系统扰动的在线估计。在暂稳态收敛性能约束方面,通过在髋膝关节控制回路设计漏斗变量,保证了跟踪误差暂稳态收敛特性的先验调节,并利用Lyapunov理论分析了所提控制方法的稳定性。仿真对比及计算结果表明:与传统自抗扰控制方法(ADRC)相比,所提方法下髋膝关节维持着与ADRC相似的控制量消耗,但稳态跟踪精度可达0.0054、0.0072,相比ADRC下的0.0574、0.0333大幅提升,且所提方法暂态收敛时间缩短近一倍。Aiming at the deterioration problem of transient and steady-state convergence process of the lower limb exoskeleton in control motion due to unmeasurable disturbances,an unknown system dynamic estimator-based funnel control for the lower limb exoskeleton was proposed.In terms of the identification and compensation for lumped disturbances,by deeming the friction interference,external environment disturbances,and parameter uncertainty as the lumped disturbances and imposing filtering operations upon the measurable states,the unknown system dynamic estimator(USDE)was constructed to online estimate the system perturbations with combining the invariant manifold theorems.For the convergence configurations in transient and steady-state,the funnel variables were introduced in the hip and knee subsystem,enabling the convergence performance for tracking errors as a prior,and the Lyapunov function was utilized to verify the stability of the proposed control method.Simulations and calculation results showed that:Compared with the traditional active disturbance rejection control(ADRC),the proposed method maintained a similar degree of control consumption,yet the steady-state precision could be regulated to 0.0054 and 0.0072,which were significantly improved compared to 0.0574 and 0.0333 under ADRC,additionally,the convergence time of the proposed method was nearly doubled.

关 键 词：未知动态估计器 轨迹跟踪 漏斗控制 下肢外骨骼 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]