Design Of 6-DOF Collaborative Robot ARM And Kinematic Analysis

It has been decades for development of industrial robotic arms at home and abroad,but the collaborative robotic arm has made great progress due to its unique advantages.The collaborative robotic arm is equipped with the capability of force sense,differing from traditional robotic arms which are surrounded by fences.It is suitable for an open environment where robots and workers work together.The collaborative robotic arms nowadays usually use motor current to control the joint torque,which realize the contact safety between humans and robotic arms.However,this way is still lack of safety especially when the load increases.This text is aimed at designing a collaborative robotic arm with joint torque feedback function and increasing the robotic arm's safety.After doing investigation on the collaborative robotic arm,this text designs a collaborative robotic arm consisting of integrated joints.The scheme of 3 consecutive parallel joints is adopted while designing the structure.This satisfies the PIPPER rule which assures the analytical solution of inverse kinematics.While designing the integrated joints,the torque sensor?harmonic reducer?frameless motor?position sensor and brake are integrated into one joint,making it modularized.After estimating the mass of each joint and links,this text calculates the static and dynamic moments of each joint.The reducers and motors are selected according to this.At last,the strength check of the joint shell and links are done to guarantee the reliability of the design.The DH model of a cooperative manipulator is established based on the fixed coordinate system postposition method.The positive kinematics is induced based on the DH model.This text adopts the algebraic method to realize the robotic arm's inverse kinematics.In motion planning,this text adopts the method based on sinusoidal acceleration and deceleration.At the same time,this text fulfills the robotic arm's trajectory planning based on the line,arc and fixed point.Finally,all algorithms are fulfilled and simulated in MATLAB.To realize the motion control of the robotic arm,this text adopts the distributed master-slave control architecture.The master controller makes the trajectory planning and completes the inverse kinematics.It writes the six joints' position values obtained by interpolation to disk files.Joint drivers use PID algorithm to realize closed-loop control of position loop,making the joint adjusted to the given input value in each servo cycle.The CAN bus protocol architecture is used for communication between master and slave.Finally,this text fulfills the single joint and the robotic arm's trajectory motion experiments.Single joint trajectory tracking experiment indicates the joint has good tracking performance.By experiment of the robotic arm's triangle trajectory motion,it indicates the correctness of kinematic algorithms and control system's design.This text successfully sets up a cooperative robotic arm research platform for the laboratory.