Development Of A 2-D Coplanar Workbench For Z-axis Error Detection And Compensation

With the continuous improvement of the industrial level,the demand for the measurement of 3d surface morphology of parts is constantly increasing,and the measurement system is becoming more and more rigorous in its high precision and large range.In this paper,a high-precision Z-axis compensation two-dimensional worktable is designed.Adopt the structure design of common base plane,stepper motor with lead screw drive,grating ruler as feedback to achieve XY direction positioning.The inductance displacement sensor and optical crystal are used to compensate the Z axis.Based on the z-axis compensation table,a 3d contour measurement system with realtime compensation of z-axis is built by using the spectral confocal displacement sensor.The preparation of the lower position machine is realized by stm32,such as the control of the stepper motor,the reading and feedback of the grating ruler,and the reading of the displacement value of the inductance sensor.Through the vs2017 platform,c# is used to complete the development of the upper computer,which mainly communicates with the dispersion confocal controller and the lower computer,and synchronizes the spectral confocal sensor,inductance sensor and grating ruler when scanning,integrating the functions of motion,scanning and graphics display.After that,the z-axis compensation principle is discussed,and the z-axis compensation effect is tested by two-dimensional contour.Firstly,the measured contour is projected onto the horizontal surface,and then the data is filtered by gauss.The inductance sensor value is compensated to the measured value,and the compensated contour is obtained,which improves the measurement accuracy.At the same time,a spherical fitting method based on weighted least squares is also explored.Finally to set up the three-dimensional contour measurement system of three-dimensional contour measurement,the first test sensor plane is not parallel,features and movement of the ball 2 d contour test,then carries on the plane to plane mirror and standard steel ball and spherical measurement,through the compensation after the Z axis is obtained by comparing contour feature parameters on three-dimensional contours of higher precision.