Research On Interactive Control Of Humanoid Flexible Manipulator

With the continuous expansion of robot application scenarios,collaboration between human and robot has become a trend of robot development.Traditional industrial robots often need to be physically isolated from human,which limits the collaboration between human and robot.How to achieve human-robot communion has become a key issue.This thesis mainly focuses on interactive safety and compliance control of manipulator.First of all,based on the serial elastic actuator(SEA)joint,a collision experiment platform is built to explore the factors that affect the collision force,which can be conducted for the design of manipulator with multi-degrees.Then,position controller and teaching controller are designed for interactive compliance.The main contributions of this thesis are:1)Research on collision between human and robot is conducted.A human-robot collision model is constructed and a one-degree platform with SEA is designed.Influence to collision force of soft material's thickness,load inertia,collision velocity and joint striffness is explored.The results show that,increasing soft material's thickness,decreasing load inertia,collision velocity and joint stiffness can diminish collision force.Finally,analysis of the limitation of these efforts are given.2)Based on SEA's torque control,position controller for a humanoid flexible manipulator is designed.At first,a simple joint-independent PID controller is adapted.However,the integral part of the controller will weaken the interactive compliance.So a PID controller with gravity compensation is designed.The mass parameters of each link are identified by least squares method,and gravity compensation is added to PID controller as feedforward.At the same time,output of the integral part is limited.The position control effect is verified on the platform,and good interactive compliance is achieved.3)A teaching controller with gravity feedforward is designed.By compensating gravity at different positions,it can enable operators to drag the manipulator with small force.Experiment verifies that the controller works well on teaching and position reappearance.