Design of the Bionic Rehabilitative Leg Based on the Passive Gait Biped

Abstract

The wearable assistive and rehabilitative leg is a complex mechanical device mounted with the underactuated joints based on the bionic mechanism. This device can ameliorate the movement function of the nerve and muscle system of the lower extremity. By applying the bionic control strategy and exerting force on the lower extremity of patients, the walking gait of normal human being can be simulated. The patients with leg deformity who need to be remedied can benefit from this method. The expense on medical treatment can be considerably reduced by this kind of device, which alleviates the burden on family and society economically. The walking stability controller is designed for researching the biped robots in 3D ( three-dimensional) space. By constructing the almost-cyclic Lagrange function, the biped robot dynamic system is decoupled into sagittal and lateral portions. Then the potential energy shaping and kinetic energy shaping controller is designed for the sagittal portion of under-actuated robot in 2D space , so that the stable walking gait and bionic characteristic gait can be obtained; the output zero dynamic controller is applied to control the lateral counterpart, which satisfies the dynamic decoupling conditions of the system. The simulation results show that the proposed method is effective.