Research Of Active Compliant Technology And Application Software Development For Handling And Assembly Robot

Handling and Assembly is a major application area for industrial robots.The traditional position controlled robot is hard to deal with complex assembly process,furthermore,the risk of collision and security problems.Therefore,in order to meet the demand of force perception and reaction capability in handling and assembly process,the key technology of active compliant control of robot assembly and the development of application software are presented in this dissertation.Firstly,based on the analysis of the actual project requirements,all units of the system is introduced and the hardware connection and the communication is realized such as the real-time communication between the robot controller and the external PC,the acquisition of the sensor data and the control of gripper is solved.The KUKA KR16-2 industrial robot based on KRC4 controller and the six-dimensional force sensor and the electric gripper based on PC platform are established as the working platform.Secondly,the link-pole coordinate system of KR16-2 is established,then the D-H parameters is obtained and the kinematics model of the robot are calculated,the robot force jacobian matrix is calculated,which is the basis of force estimation.The robot coordinate system transformation problem is solved to transformate the motion describe from tool coordinate system to Base coordinate system of the robot.Thirdly,aiming at the requirement of position and pose adjustment during the peg-in-hole process,a reference point based 3-dimention model gravity compensation method is proposed and implemented.On this basis,the specific process of peg-in-hole assembly task is analyzed,the control strategy based on active compliant control method is put forward,and a typical peg-in-hole assembly is accomplished.Forthly,in order to meet the demand for compliant placement and avoid the use of expensive large range force sensor in relatively simple task,the robot aixs torque is estimated via motor torque,and the end-effector force is calculated by axis torque,then the gravity force and friction force is estimated and compensation of end-effector force be implemented.The sensorless active compliant handling task by estimation force is experimented.Finally,the PC-side operation software and robot-side control program are implemented.The feasibility of the active compliant handling and assembly system is verified by experiments,and the expected target is achieved.