Parallel Processing Robot Kinematic Scheme Design

Achieving stable machining is a difficult problem in large workspace robot field, this paper proposes a new 8-UPS parallel robot with 6 DOF as well as walking and machining ability. In machining mode, it equals to a traditional parallel robot, in walking mode it is a4 legs walking robot. It mainly from kinematics and inverse solution, workspace, mobile platform trajectory planning, singularity analysis, performance analysis to do kinematics analysis in machining mode; when the robot works in walking mode, the reseach mainly from configuration design, gait planning and kinematics analysis aspects.Firstly, the mechanism schematics of 8-UPS parallel robot and the coordinate system was established, researching the kinematic nature of this mechanism to get the positive solution model during processing period. Then, finishing the robot trajectory planning work in machining mode to get the posture transformation function, the planned joint trajectory can be converted to the Cartesian space track through positive solution. The next step is to give a searching method of the workspace of 8-UPS parallel mechanism, with this method, the workspace of 8-UPS parallel mechanism can be drawed, during reaserch how the rod length and the ratio between mobile and static platform impact the workspace,it is easy to find that the rod length will affect the maximum deflection angle of the mobile platform. Based on Jacobian matrix, the kinematic singular configuration was reaserched as well as its relationship with workspace.Secondly, the inverse kinematic model of 8-UPS Parallel robot under machining mode was established, and the rod length function was obtained. Based on the machining mode workspace, a robot design method was proposed, and the full performance indicator was used to help design the main parameters of the robot. Based on MATLAB, Simulink model was established to complete inverse kinematics simulation and get the rod length as well as drive speed variation of the 8-UPS parallel robot. Based on SolidWorks, 8-UPS model was established, with using Motion part according to the specified trajectory, kinematics simulation curve was obtained to help analyse the performance of the robot. At the end,interference checking process was proposed to help to check the interface between hinge and rods.Finally, under the walking mode, configuration design and gait planning were done to ensure stability of the robot during the walking period. During the walking period,kinematics analysis was done to obtain the key posture solution model of the parallel platform and the constraints of parallel platform, also obtain the robot joint angle and find the robot was stable under walking mode.