Development of a New High Speed Cable-Based Planar Parallel Manipulator

cable;parallel manipulator;Mechanical Engineering

Sun, Nan Nan

University of Waterloo

关键词: cable;    parallel manipulator;    Mechanical Engineering;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/6605/1/Sun_NanNan.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

Industrial robots and automation technology have advanced rapidly in the last several decades. Newtypes of manipulators that uses parallel mechanisms are becoming more popular due to their high speedand high stiffness. This thesis focuses on a sub-class of parallel manipulators that uses cables to replacerigid links for further increase in speed. The design strategies in this study were expanded from researchworks by Khajepour. Behzadipour, and Edmon Chan. This thesis presents analysis and development of anew cable-based planar parallel manipulator that is based on a previous prototype built by Edmon Chan.The new manipulator design added a new rotational DOF to the end-effector, and the number ofcables are doubled in order to increase the stiffness. New methods for kinematics and dynamics analysisare formulated to make the procedure more systematic. A new mathematical formulation for stiffnessmatrix of the end-effector is presented. The resultant stiffness matrix is equivalent to the stiffness matrixformulated by Behzadipour. Additional stiffness analysis is conducted on valid range of stiffnesscalculation and comparison of different cable configurations. A multi-objective optimization problem isformulated in order to search for the best set of design parameters for the manipulator, and it is solvedwith an exhaustive complete search method.A physical prototype of the manipulator is modelled and manufactured with the help of partners fromConestoga college. Experiments with the manipulator show that more powerful motors are needed to runthe robot at full speed. Motor torque measurements show that the dynamics analysis of the manipulator isvalid. Stiffness of the manipulator is measured by applying external force to the end-effector, and it isshown to be strong. The manipulator is able to demonstrate a sort and pick-and-place operation at 60cycles per minute while running at 70% of the maximum speed, with an acceleration of 2.8 g and velocityof 4 m/s.