Analysis Of Kinematics And Mechanics For 3-SPR Parallel Rescue Robots

The rescue robots play an increasingly important role in disaster relief. Now manyrescue robots have been designed and manufactured at home and abroad, and the mainpart of many of them is the serial mechanism. These robots are mainly used for detection,search, transmission of information, and other auxiliary work or demolition operations,but they are easy to hurt people, cause the collapse, and cause a disaster again in thedemolish process. Actually, their rescue capabilities cannot meet the practicalrequirements in disaster relief. Therefore, it is a very important theoretical and practicalsignificance to study the parallel rescue robot.This paper analyzes a parallel rescue robot. It is composed of a rescue car, 3-SPRparallel mechanism, gripper grab mechanisms. This robot can be used in the rescue workof the earthquake, housing collapse, and can also be used for fire, radiation and otherdangerous rescue. The position relations between the gripper grab mechanism and theparallel mechanism is established, the principle of rescue is explained, and theperformance of workspace, kinematics, statics, dynamics and coordinated of movement issystematic analyzed.Based on the geometry constrains existing in the rescue robot, the gripper coordinatesystems are established, and the forward and reverse analytic position model of the rescuerobot can be deduced by using the vector method. The workspace is obtained using CADvariable geometry. And the analytical model of velocity is gained by the motionalrelations of rigid bodies. The analytical model of acceleration is derived by the derivativerelationship between the velocity and acceleration.According to the force balances of the gripper grab mechanism and the dualitybetween the velocity and force of PM, the statics model can be established. Combinedwith the D’Alembert’s principle and the principle of virtual work, the dynamics model canbe established. The simulation model of the parallel rescue robot can be built by CADsoftware, and then the kinematics, statics, and dynamics can be simulated.The coordinated motion, among the gripper grab mechanisms, between the gripper grab mechanisms and the parallel mechanism, is analyzed. The driving relationship amongthem is established and several cases are particularly analyzed. And the coordinatedmotion is simulated, and the relationship between the position and force is derived.