Design And Control Of Intelligent Bionic Leg Base On Hybrid Actuation

Intelligent Bionic Leg(IBL) has been an interesting research project in the fields of robotics, biomedical engineering and rehabilitation engineering in recently these years. Owing to battles, diseases, industrial injuries, traffic accidents, natural disasters and so on, millions of people have lost their lower limbs. They long for resuming their walking function by prosthesis urgently. However, IBL's excellent characteristic is that it can imitate the movement ways of human healthy leg and its walking speed can change naturally with the change of leg-amputee's walking speed. Therefore, The significance of this research is that it can help amputees to return to the mainstream society and lighten the burden of the society and their families.Up to today, most of intelligent prostheses(IP) are driven by passive and semi-active actuation which can not provide active driving torque so that they are limited to over-barrier and back off for amputees. External powered prosthesis can provide active driving power, but its practical application is very scarce because of high energy-consumption as well as large stiffness and inertia. In this paper, a hybrid actuation scheme combing magneto-rheological (MR) damper augmented with a DC motor, is proposed to improve the motion adaptation for intelligent prosthesis.Following the meaning, contents and methods of IP study, the mechanism and form of IP's test-bed, bionic design of hybrid-driven bionic leg, is given. And then using division modeling method, the kinematics and Lagrangian dynamics models of artificial leg and intelligent bionic leg in stance phase and swing phase are built. Next, the human normal gaits on all kinds of terrains are analyzed, modeling and control of DC motor and MR damper is presented. Base on a person walking gait characteristics, iterative learning control is utilized to follow the artificial leg, and this control algorithm is verified by the simulation in virtual prototyping platform. Finally, to highlight humanoid characteristics of hybrid-driven bionic leg by the analysis and simulation of the process of over-barrier and back off for human. In view of the complexity of the IP system, Pro/E, ADAMS and MATLAB/Simulink softwares are chosen to establish united simulation platform for BRHL study. Mechanism models of 4-bar hybrid-driven knee joint and semi-active ankle and simple BRHL are built in Pro/E. Then through Mech/pro interface proceeding, translate them into ADAMS to build virtual prototype and establish virtual environment. For control simulation, the modularity simulator of control algorithm is built in MATLAB/Simulink. Through ADAMS/Control interface, control algorithms can be simulated on virtual prototypes and control results can be displayed in three-dimensional animation. Kinematics and dynamics simulation can be expediently done on virtual prototypes. United simulation based on virtual prototypes can avoid the heavy works of manual programming of modeling and resolving, and reduce the study risk and shorten development period. This article is focus on the bionic design of hybrid-driven IBL and analysis of normal gait on the different terrains, and also procedure of the gait tracking, which will forms a solid foundation to the study of the IP.