Development Of Supernumerary Robotic Limbs For Auxiliary

Supernumerary robotic limbs is a new type of wearable robot,which can cooperate with human in appropriate position and posture and assist the wearer to complete various operations.The external limb robot developed in this paper is mainly aimed at the two operating modes of auxiliary grasping and auxiliary support,and can avoid obstacles in the framework environment and human arm.According to two kinds of typical operation mode,two kinds of configuration of external limb robot are designed.The supernumerary robotic limbs adopts two three-degree-of-freedom mechanical arms as the main body of the robot,and USES the wire rope to decelerate,increase the moment and drive the span,and USES the wire rope to coupling drive the big arm joint and elbow joint of the mechanical arm.The robot control system is built by combining various sensors and controllers.The D-H parameter method is used to establish the kinematics model of the external limb manipulator,and the forward and inverse kinematics of the series and parallel models are solved by coordinate transformation and constraint equation.Newton-Euler equation is used to analyze the dynamics of the limb manipulator.The series kinematics and dynamics models are validated by Matlab robot toolbox.Aiming at the frame working environment and human arm,sphere bounding box and cylinder bounding box are used to simplify the model of obstacles and supernumerary robotic limbs.This paper analyzes the basic principle of the artificial potential field method,improves the artificial potential field method according to the needs of avoiding dynamic obstacles,and introduces the obstacle velocity factor into the potential field function.The repulsion force of the improved artificial potential field method is at the closest distance to the robot arm,and the resultant force is superimposed in the joint space,and the obstacle avoidance path is planned by using virtual work instead of potential energy gradient descent.The problem of manipulator falling into local minimum is solved by means of virtual target point.The configuration and structure design,kinematics and dynamics analysis,obstacle avoidance and path planning of supernumerary robotic limbs were integrated,and Matlab and V-REP were used for simulation of supernumerary robotic limbs.The kinematics and dynamics of the external limb manipulator are analyzed by grasping operation simulation.The function of the mechanical arm to compensate the human motion is analyzed through the simulation of support operation.The obstacle avoidance reliability of supernumerary robotic limbs mechanical arm is analyzed by simulation.Through the analysis of simulation verification,supernumerary robotic limbs can meet the design requirements.