Motion Control Of Cable Driven Humanoid Arm

With the rapid development of medical technology,the life span of human beings has been extended,and the aging of the global population is increasing day by day.All countries in the world are focusing on service robots,especially in Europe,America,Japan and South Korea.At present,the main research hotspots of scholars in the field of robots are pattern recognition(image,sound and tactile information processing),autonomous movement,and intelligent operation.In this thesis,according to the current market demand and research hotspots,the robotic arm of the important task execution mechanism of the service robot is selected as the research object,and the cable is used as the transmission method to explore its design method and the characteristics of its kinematics and dynamics mechanism.This research is of great significance for improving the service quality of humanoid service robots.Using the cable as the transmission method,a humanoid seven-degree-of-freedom manipulator system was developed.By analyzing the physiological characteristics of the human arm,the configuration of the cable-driven humanoid robotic arm system is determined,divided into the shoulder,elbow,and wrist.The shoulders and wrists have the same degree of freedom,using the same three-free parallel mechanism(around,axis deflection,and rotation),and the elbow uses a one-degree-of-freedom tension amplification mechanism.In response to the task requirements of the cable-driven humanoid manipulator,the control system was designed.The electromagnetic interference of the strong current on the signal was fully considered during the design process.The hardware connection is all integrated plug-in design,reducing the complexity of system maintenance and improving the mobility flexibility.Analyze the kinematics of the elbow single-degree-of-freedom pure rolling mechanism,and from this evolved to the kinematics of the shoulder three-degree-of-freedom parallel mechanism.By establishing the global coordinate system of the cable-driven manipulator and using homogeneous matrix to represent the kinematics of shoulder,elbow and wrist,the overall mechanism kinematics is obtained.Using the unit quaternion to obtain the complete Jacobian of the three-degree-of-freedom parallel mechanism on the shoulder,and using the speed transfer characteristics between the connecting rods,the complete Jacobian of the cable-driven humanoid arm is obtained.According to the obtained complete Jacobian,the inverse kinematics of the rope-driven humanoid manipulator was obtained by Newton-Raphson numerical iterative method.Finally,based on the Newton–Raphson method,the dynamics of the rope-driven humanoid manipulator is obtained,and its correctness is verified by the ADAMS simulation model.The trajectory planning problem of the cable-driven anthropomorphic robotic arm is studied,and the joint trajectory with continuous space velocity and acceleration of the joint is constructed using cubic uniform B-spline curve.Based on kinematics and dynamics constraints,the construction trajectory is optimized with the three optimization goals of total movement time,energy saving and pulsation minimum,and an optimized mathematical model is established.Genetic algorithms are used to solve the mathematical model,which are simultaneously satisfied the better spatial trajectory of constraints.Using unit quaternion fixed attitude interpolation algorithm and spatial data point densification technology,spatial linear interpolation and circular interpolation experiments were designed to verify the motion performance of the prototype and the effectiveness of the algorithm.