Error Calibration Research Of 5-UPS/PRPU PMT

The thesis discusses the basic error classification of parallel machine tools and existing calibrated methods of PMT. The paper also presents a calibrated method which systematically and comprehensively analyzes the spherical joints' (Huke joints') errors of moving(fixed) platform and legs' tolerance that is based on a novel 5-DOF parallel machine tool, and evaluates positioning of parallel machine tools.The basic error classification of the PMT is introduced, including static error and dynamic error mostly. The key of the precision analysis of the PMT is to establish cutting tools pose error model, and put forward the establishing idea of error model of the PMT. The thesis simply describes the existing kinematics calibrated methods of parallel machine tools.The constitutes and characteristics of the 5-DOF PMT are introduced. The degree of freedom of the mechanism is calculated using formula of the degree of freedom. Subsequently, the purpose of advanced calibration is explained,which is to minish terminal deferent error owing to fixed platform coordinate deviation. Methods and experimental processes of advanced calibration are described in details.The kinematic model of constraint limb is developed. According to the kinematic model of constraint limb, This thesis establishes the relation between terminal probe's core coordinate error and sensor parameter errors and the adjusted experiment model of PRPU limb. Experimental processes are described in details.The inverse kinematics solution of the PMT is given, and inverse solution of the driving limbs is also presented. According to the inverse solution model of PMT and methods of Hanqi Zhuang and Zvis.Roth , the measurement method of platform is developed. Experiments on the PMT are done by this method, and spherical joints' (Huke joints') errors and legs' tolerance of every leg using experiment data are calculated. At last positioning of parallel machine tools is measured.