ZMP Theory-based Gait Planning and Model-Free Trajectory Tracking Control of Lower Limb Carrying Exoskeleton System

Abstract

A virtual prototype design and corresponding mathematical model analysis is presented. To obtain a stable and smooth synthesized gait, the zero-moment-point (ZMP) theory and three spline interpolation method have been combined and applied. A novel data-driven model free control strategy, called Time-Delay Estimation based intelligent PID (TDE-iPID) combined with Equivalent Sliding Mode Control (TDE-iPIDESMC), is developed for the trajectory tracking of the planned gait. To demonstrate the effectiveness of the proposed planning gait and controllers, the exoskeleton system is implemented on the co-simulation platform composing of Adams and MATLAB/Simulink. The corresponding cosimulation results show better performances than the compared classical PID and TDE-iPID methods.

Simulating human–machine coupled model for gait trajectory optimization of the lower limb exoskeleton system based on genetic algorithm

“…26 These methods can be classified into off-line, online, and a combination of both. The off-line trajectory method mainly includes using mathematical expression 16,27 and recorded human motion data. 28 Like the biped robots, zero-momentpoint method 16 are used as stability criteria.…”

“…The off-line trajectory method mainly includes using mathematical expression 16,27 and recorded human motion data. 28 Like the biped robots, zero-moment-point method 16 are used as stability criteria. In Biagiotti and Melchiorri, 29 the study shows that the planned gait trajectory is much like the physiological gait trajectory of healthy humans.…”

“…Usually, it is necessary to establish a kinematic and dynamic model of a robot system. Denavit–Hartenberg (DH) parameter method 16,17 is a popular way to describe the relationship between components in a robot system when analyzing the forward and inverse kinematic. The main idea of this DH method expresses the position and attitude of the target object in the same coordinate system by vector operation.…”

“…In the studies of the literature, 25 a biped robot simulation with several different configurations is established in MATLAB. Compared with the mathematic methods, 16 physics-based methods 20 can get rid of the matters caused by complex mathematic differential equations. Moreover, in the process of designing real electromechanical systems, a physics-based method provides researchers with tremendous design creativity and flexibility.…”

Toward a model-free feedback control synthesis for treating acute inflammation

“…This new viewpoint in control engineering has been successfully illustrated in many concrete casestudies (see, e.g., the references in[34], and[1,2,3,4,17,21,43,47,49,50,52,53,54,57,55,66,72,81,82,87,88,89,90,91,94,95]). Some of the methods have been patented and some have been applied to life sciences[35,43,47,57,81].…”