Research On Structural Design And Control System Of Hybrid Power Assisted Robot

Hybrid power system is a new type of drive system that combines two or more drive systems with high power quality ratio,high efficiency and environmental friendliness.It is gradually popularized in the automotive field and is expanding its application in the field of robotics.The wearable power assisted robot is a kind of robot that realizes motion control through human-computer interaction.It has important and extensive application requirements in military defense,medical rehabilitation,agricultural transportation,industrial production and so on.The power-assisted robot for handling tasks is one of the important research directions.The goal is to reduce the muscle burden of the workers in the handling work during the repeated movements,and to improve the handling capacity of the human body to a certain extent.The key technologies involved include active joints that are consistent with the human body handling process,mechanical structures with unloading capabilities,intentional identification of the user's limb movements,and human-machine interaction motion control of the robot joints.This thesis focuses on the key technical problems of wearable mechanical structure design,hybrid system hardware platform design and handling task human-machine interaction motion control of hybrid power assisted robot.It uses theoretical analysis,semi-physical simulation and physical experiment.The paper mainly studies the following four aspects:(1)This paper designs the upper and lower limb attitude acquisition system to study the movement of the main joints in human body handling tasks.The thesis studies the movement and stress of the limbs,considers the individual differences,economy and safety,and designs a mechanical structure that can be adjusted in size and consistent with the human body movement and joint movement and can realize the weight reduction function.(2)In this paper,a hybrid drive control scheme for hybrid assisted robot is proposed for this system.A hybrid drive control system that combines upper limb pneumatic artificial muscle drive and lower limb brushless DC motor drive is designed and built.The design idea of flexible driving of upper limbs and rigid driving of lower limbs is realized.(3)This paper uses the self-made pressure-based flexible pressure sensing system to collect the contact force between the user and the hybrid assist robot arm.The paper designs an impedance controller to identify the stiffness damping coefficient.Through the simulation study,the lifting of the object phase assists the robot to assist the elbow joint of the user.(4)In this paper,the lower limb walking process is divided into swing phase and support phase.A semi-physical simulation platform was built for the swing phase,and the dynamic parameters of the lower limb hip and knee joints were identified,and the position control method based on the dynamic model was designed.The PD-based position control method is designed for the support phase,and the relevant simulation experiments are completed.