Positioning error modeling and compensation strategy of additive manufacturing equipment
Aiming at the widespread geometric and dimensional accuracy defects of additive manufacturing products,a modeling and compensation strategy for the position error of additive manufacturing machines was proposed based on the measured data of calibration sample augmentation point and the least square fitting method.Firstly,based on the widely used fuse forming equipment,an additive manufacturing test bench was built.Based on the test bench,a step pyramid calibration sample cluster was manufactured to establish the position error of the additive manufacturing equipment.The position of the center point(augmented point)and the distance to the vertical plane of each step were measured by a coordinate measuring machine.Secondly,based on the measured data and the kinematic chain-error transfer relationship,the equipment position error was characterized by low-order polynomial,and the parameters of the error model were estimated by least square fitting.At the same time,the initial error model was optimized according to the significance level of the estimated parameters.Finally,the position error compensation of the additive manufacturing equipment was carried out by using the optimized model combined with the modification of the stereo lithography file of the formed parts,and a brief size compensation method was proposed at the same time.The validity of the proposed error model and compensation method was verified by the forming processes of a new calibration sample cluster and real-world mechanical parts.The research results show that,comparing with the calibration sample cluster and the real-world mechanical parts manufactured without using error compensation,the maximum position error of the formed products after using the equipment position error compensation can be controlled below 300 μm,and the maximum relative dimensional error of the key features of the formed real-world mechanical parts is-2.4%after the comprehensive use of the equipment position and size error compensation.It meets the actual engineering needs,therefore the proposed error model and compensation method are proved to be effective.
万方数据
维普
