Workspace And Athletic Performance Analysis Of Lower-mobility Parallel Machine Tool

Parallel Machine Tool has been an important development direction of machine tool,because it has many advantages such as its high ratio of stiffness to mass, fast response,higher machining accuracy and environment adaptability. In our county, although domesticscholars and designers have gotten some research fruits, there is still a great gap compared tothe level of the developed countries. One of the factors which limit the development ofParallel Machine Tool is the small workspace. We can analyze of the athletic performance inthe workspace of Parallel Machine Tool and change the structural parameters to improve theParallel Machine Tool development.3-TPT Parallel Machine Tool as research object, based on inverse position analysis ofthe machine, inverse and direct position analysis of the parallel locking mechanism, to searchthe workspace and consider the influence of the structural parameters and athleticperformance in the workspace. Optimizing the athletic performance to make the volume ofthe effective workspace bigger is the target. The details are as bellow:（1）Building the coordinate system based on the structural characteristics, inverseposition analysis of the machine, inverse and direct position analysis of the parallel lockingmechanism, Jacobian matrix of the machine, velocity and acceleration equation all can beworked out.（2）The workspace of3-TPT Parallel Machine Tool is described by MATLAB softwarebased on the method of numeric. Adopting the indicators of operable degree to study thesingularity of the machine and adopting the condition numbers of the Jacobian matrix to studythe motor dexterity of the machine. The MATLAB is used for simulation.（3）The effective workspace of the3-TPT Parallel Machine Tool is given to optimizethe rod length, parallel locking mechanism and hinge point position. The volume of theeffective workspace is bigger.（4）Compared the actual workspace and the theoretical workspace to prove thetheoretical workspace is correct. The actual workspace can be worked out by indirectmethod.