Research On Precision Detection And Error Analysis Method Of Shaft Eccentric Parts

Industrial robots have been widely applied in multitudinous fields in recent years,and its related techniques are being obtained great attention.With the increasing demand of high-level techniques on industrial robots,the research and development of RV reducer has been restricted because of technical bottlenecks.Hence,the significant breakthroughs need to be imminently made on numerous new ideas,methods and theories.This paper does the following research on the detecting and handling error method of spline eccentric shaft--the core drive component of RV reducer that is widely used in various fields:To solve the problem that it is difficult to detect the eccentricity and phase angle of spline eccentric shaft with high-precision,a high-precision four-axis measuring machine has been manufactured in this paper.Renishaw XL laser measurement system is used to measure linear axis positioning error,and then method of modifying the NC code is adopted to achieve geometric error compensation.According to the experimental data,the compensated linear axis positioning accuracy has been reached sub-micron level.In order to improve the measurement accuracy of the four axis high precision measuring machine,the calibration of the rotary axis of the worktable is studied in this paper.The systematic errors of the mechanism are analyzed,and it presents a method to calibrate the parallelism error of worktable rotation axis and Z axis,the sensor probe eccentricity error,and the perpendicularity error of sensor measuring direction and worktable rotation axis.Then,the mathematical model of the error calibration is set up.At the same time,in view of the problem that the output signal current of the Renishaw trigger sensor is not enough to drive the controller’s I/O port,ar amplifying and inverting circuit is designed based on practical measurements to meet the design requirements in this paper.In this paper,roundness error and cylindricity error assessment algorithms of shaft parts inspection are discussed,and a square grid iteration algorithm is improved.This algorithm only needs to call the distance formula repeatedly and set the accuracy of error evaluation.After a simple judgment,the defined shape error can be obtained.A new method for detecting the error of eccentric axis and phase angle by the linkage of sensor and rotary shaft is introduced in which the sensor is fixed to the axis of motion.The contour data of the eccentric axis are collected and analyzed as it follows the axis motion of the eccentric axis,and the mathematical model of the error of eccentricity and phase angle are established by using the method of homogeneous coordinate transformation.In this paper,it is proved that this method can detect eccentricity and phase angle error with high accuracy through simulation and a large number of experiments.In the actual working conditions,problems of eccentricity and inclination occurred during loading and clamping the parts to be tested,so an error correction model with eccentric and inclined parameters of loading and clamping parts is established in this paper,which carries out the error correction for detecting cylinder,eccentricity and phase angle from the view of the algorithm.The results of calculation show that it is necessary and feasible to eliminate the errors of eccentricity and inclination.Finally,a system of axial eccentric parts error detection is developed in this paper,which realizes the visualization of error measurement.