Design And Simulation Of A Hip Assist Exoskeleton

Exoskeleton is a special type of robot that wears on human to assist wearer's movement and is widely used in the field of medical rehabilitation.Because of increasingly aging population,more and more researchers focus on the research of exoskeleton,hoping to assist the elderly in movement and rehabilitation training.This paper focused on the exoskeleton that assist the wearer's hip joints.The research includes hardware systems,human-robot physical interface and control algorithms.According to the kinematic characteristics of the hip joint,the key components such as motors and bearings were selected.In order to reduce the overall weight,the links and fittings of exoskeleton use carbon fiber and aluminum alloy.And then the motor drive system,power supply system and communication system were designed.In the human-robot physical interface,a flexible and controllable airbag unit was designed to reliably connect the wearer and the exoskeleton.The airbag unit can be divided into two parts:a silicone airbag and a sensor.The airbag can adjust its shape to adapt the irregular surface of the human body and ensure the comfort of the wearers under the premise of reliable connection.The sensor is based on liquid metal.Liquid metal was embedded in the silicon and its resistance changed with the deformation of the airbag.The volume and direction of deformation can be detected by the sensor.As the basis of exoskeleton control,the dynamics modeling of exoskeleton based on Lagrangian method is firstly carried out and the parameter identification algorithm and joint control of exoskeleton are theoretically analyzed and established in the simulation environment to verify their reliability.Finally,an exoskeleton assist control strategy is proposed based on zero-force control,central pattern generator and impedance control and verified on the simulation platform.