Kinematic error modeling and analysis of the loading device based on multi-body theory and stream of variation theory

Abstract

Because of some reasons such as machining error and assembly clearance, the loading device will produce kinematic error during movement. While kinematic error will have a great significance on the position accuracy of the loading device. For the above reasons, firstly, the topological structure of the loading device was described based on lower body arrays. The kinematic error matrices of adjacent parts in the loading device were obtained by multi-body system kinematic theory and homogeneous translation matrix (HTM). Then an improved error modeling method was put forward, which combined multi-body system theory with stream of variation theory. And the kinematic error model of the loading device was set up with this method. Numerical results could clearly display the error transformation and propagation among components. Finally, the effect of every kinematic error on final deviation was analyzed, and error sources of a greater effect on the final deviation were obtained. This method can provide a theoretical basis to improve the accuracy of the loading device.