A variable structure passivity control method for elastic joint robots based on cascaded high-order state estimation  

作　　者：ZHANG JieXin NIE PingYun ZHANG Bo 

机构地区：[1]State Key Laboratory of Mechanical System and Vibration,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai200240,China

出　　处：《Science China(Technological Sciences)》2024年第2期395-407,共13页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.91648112,52375506)。

摘　　要：Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction system.However,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure control.This method ensures the tracking error converges in a finite time,even when the system faces uncertainties.The method also preserves the passivity of the system.Moreover,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity signals.This observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation channels.In particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot interaction.The effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.

关 键 词：motion control elastic joint robot finite-time convergence high-order system state estimation physical human-robot interaction 

分 类 号：TB18[一般工业技术] TP242[自动化与计算机技术—检测技术与自动化装置]