A Design For A6-DOF Stewart Platform And The Research Of The Application In The Optical Testing

Stewart platform is also called parallel hexapod system, Compare with the series connection system, parallel the error of the hexapod system is not accumulative, its position precision is higher than the series connection system. The driving device of the hexapod system can be placed on the base platform, that reducing the mass and the inertia of the movement parts, It’s benefit to the highly speed movement. It is widely used in the flight simulator, radar, industrial robots and parallel machine tool.Because of the inverse kinematics solution of the Stewart platform has a only solution, and it is a simple analytic form, we can control the position of the moving platform through the inverse kinematics solution. This paper gives out the inverse kinematics solution of the6-DOF Stewart platform based on homogeneous coordinate transformation. First establishes the coordinate system of the Stewart platform, defines3translational and3rotational variable quantities. Than gives the equation of inverse kinematics solution based on the principle of coordinate transformation. Also the equation of the inverse kinematics solution which the center of the rotation is not at the center of the platform is given out.The working place of the Stewart platform is given out through limit the ranges of the length of the pole, the limited angle of the hinge and based on the inverse kinematics solution.This paper designs a kind of six freedom degrees of a Stewart platform by the NX6.0software. The structure is designed according to the set of design requirement: Z axis ranges in150mm, XY axis ranges in300mm, position precision less than0.01mm.The structure of the Stewart platform and the connecting parts are designed. The NC system control the motor drive through the Umac controller. The structure of the platform and the connection way of the NC system are given out.This essay calculate the working place of the PI-M850Stewart platform. The position precision is tested the Stewart platform repeat accuracy by three coordinates measuring machine that verify the correctness of the mathematical model and the method of calculating the inverse kinematics solution. And the Stewart platform is used in the optical testing which lead out to be a good results.