Research On Design And Control Strategy Of Cable Driven Bionic Manipulator

The traditional industrial manipulators have acquired a great achievement.It has been extensively used in the field of manufacturing industry and service industry.Industrial robot has become a significant tool to realize manufacturing automation.It has the excellent attribute of high accuracy,high efficiency,high stability and so on.However,it also has the disadvantages of bloated joints,large size,heavy weight,large inertia and small load to weight ratio.Therefore,the traditional industrial robot shows great disadvantages in the process of human-robot interaction.To improve the safety of human-robot interaction,it is necessary to study some novel light-weight robot transmission modes.In this thesis,a six degrees of freedom bionic manipulator based on cable-driven technology is designed.Using flexible cable as the transmission mechanism,it can transfer force and motion along the preset path.Through the cable-driven traction mechanism,all driving motors can be placed on the base,which can effectively reduce the weight of the manipulator and improve the rapid response ability.The major tasks of this thesis are as follows:Firstly,the literature is reviewed to explain the research status and practical significance of cable-driven bionic manipulator.This thesis briefly describes the exploration process of cable-driven bionic manipulator technology at home and abroad,introduces the representative kinematics and dynamics modeling methods of manipulator,and sums up the research status of robot control methods.Secondly,the motion mechanism of human arm is analyzed to determine the overall design of cable-driven bionic manipulator and build up the experimental platform,which is divided into shoulder,elbow,wrist and flexible gripper.The shoulder adopts two degrees of freedom joint module,which can realize high torque output.The elbow adopts a special tension amplification mechanism,which can realize the rotation of single degree of freedom.The wrist is a quaternion joint,which has the rotation of three degrees of freedom.Thirdly,the kinematics model of cable-driven bionic manipulator is established.D-H method and screw method are used for forward kinematics analysis,and the advantages of screw method are verified by comparing the two modeling methods.The inverse kinematics solution is obtained based on Newton Raphson numerical iteration method.The workspace of the cable-driven bionic manipulator is analyzed by Monte Carlo method.Then,three common compliance control methods are studied,which are force and position hybrid control,impedance control and admittance control.The cable-driven bionic manipulator is simplified to a two degrees of freedom manipulator which only includes the forearm and the upper arm.This thesis focuses on the impedance control in Cartesian space,studies the impedance sliding mode control of two degrees of freedom manipulator with contact force,designs the impedance sliding mode controller and carries out the impedance control simulation experiment.Finally,the electric control system of cable-driven bionic manipulator is established by using model-based design(MBD)method,which includes servo driver,controller hardware,controller software and upper computer software.The reliability and stability of the designed manipulator are verified by simulation and physical motion test.