The Design Of A Three Finger Manipulator's Structure And Control System

Multi-finger manipulator is an intelligent robot end-effector which is comparatively commonly used in modern industry.Aiming to replace manual labor,it is generally cooperated with various robotic arms to apply to industrial processes such as processing,assembly and handling.It indicates an important research direction in the field of robotic,for the research,design and manufacturing of it involve lots of disciplines such as mechanics,materials,computers and automation.With the continuous development of industrial technology at this stage,people's requirements for multi-finger manipulators are getting higher and higher.The research and improvement of its structure and control system is regarded as focus for the reason that on the one hand,the mechanical structure,which directly affects the quality of the task execution,is the specific execution tool of various operation tasks,on the other hand,the control system is the processing center,which determines the way the manipulator performs the task.Therefore,this thesis focuses on these two aspects of a multi-finger manipulator.Firstly,the multi-finger manipulator applied in the process of parts assembly is taken as the research object.For the mechanical structure,combined the research status of multi-finger manipulators at home and abroad with required design indicators,the corresponding theoretical analysis is carried out to ascertain the finger type and manipulator style.The controlling difficulty of the manipulator is reduced through the linkage drive mode,while the underactuated mode drove by the DC servo motor is used to reduce the volume of the entire structure while ensuring the driving force.Then the whole mechanical structure of the manipulator is designed on this basis,including the design ideas and detailed design drawings of the main components.Secondly,it is significant to do the kinematics analysis and static analysis for the equivalent model of the designed manipulator to guarantee the smoothness and continuity of the finger movement trajectory.Furthermore,the parameters such as motion range and motion trajectory of the manipulator can be confirmed.At the same time,the grasping task is classified according to the difference of the target object,so as to do the grasping task planning,analyze of the its stability index and dexterity index,and verify and optimize the parameters of the manipulator.Thirdly,the design of the three-finger manipulator control system is studied,including research of compliant control algorithm so as analysis and design of the software and hardware principles.The joint position tracking control of the finger is performed by the force/position hybrid algorithm to realize the fingertip position control,and similarly finger impedance control based on system position is achieved based on the information provided by pressure sensors,to realize active compliance of the finger.Finally,the experiment to verify the parameter and the performance of the manipulator was carried out in sequence by joint debugging the prototype,the hardware and the software of the control system and the upper computer.The result shows that the designed manipulator operate better parameters than the design requirements,while the control system can not only make the manipulator to execute various gripping tasks through wired and wireless methods,but also make it possible to realize the required flexibility.