Research On The Parallel Manipulator With The Redundant Input

Parallel manipulators offer obvious advantages over serial ones in applications where high stiffness, well accuracy, small inertia and well dynamic performance are predominant requirements. However, most of these manipulators have deficiencies, such as smaller workspace, lower dexterity and more complex models etc. In order to overcome some of the foregoing disadvantages, manipulators of this kind with redundancy was raised. At the same time, using redundancy not only increases the workspace, but also will help in coping with singularities and finally improves dexterity. So the redundancy parallel manipulators are being paid more and more attention. Compared with the general parallel manipulators, redundancy parallel manipulators posses higher structural stiffness, larger payload and better accelerating ability. From these aspects, we can see that it takes great importance to apply this redundancy parallel manipulators on an earthquake simulator.In this dissertation, a new type of redundancy parallel manipulator applied in the earthquake simulator is proposed and studied in the following fields. Solutions of direct and inverse position: Based on the direct position analysis of redundancy parallel manipulator, put forward a method of elimination and regression to get its direct position expression. That grounds the foundation for the future work. Singularity position: Analyzing the redundant parallel manipulators with a new concept of manipulability get two characteristics from that, and then on the base of that two characteristics greatly reduce the work required to decide if there is are singularity positions in its workspace. Workspace: Analyze the position workspace on condition that it is only under constraint of leg's length or of the sphere linkage and respectively give its position space sketch map to show the shape and size. Performance: Bring forward a new concept - "characteristic exponent" and conclude that the performance of this redundant parallel manipulators is identical on two sides of the plane y=-x. That it draws the same conclusion as another method that adopting manipulability Degree in analyzing this redundant parallel manipulator's performance proves its feasibility. And also elicit that it has the same performance as original position if it goes along with x-axis or y-axis, with the moving platform being kept parallel to the static platform. Simulation of the earthquake simulator: By the aid of AutoCAD and 3DMAX software, dynamically simulate the redundant parallel manipulators adopted by the earthquake simulator. It mtuitionally shows the movement path and function space and realizes the dynamic simulation vividly.