The method of 1x asymmetry optical paths generating magnification error is employed in scale system
linear error compensation of universal tool microscope’s longitudinal coordinate.The
micro-displacements of scale iamges are achieved for compensation of scale linear error based on the
property of off-axis and out of focus and focal length inequality. The creative and ingenious optical
paths design is discribed in the paper . A detailed analysis of the principle of error compensation is
presented. Magnification error principle formula and defocus amount and off-axis aberration error
extension formula are also derived. The relationship between the calibration result and slope of formula
is obtained to benefit the analysis and application on-site.The influence caused by the change of
magnification parameters also are discussed in the paper. Indication error of one-meter longitudinal
coordinate can be achieved less than 2.5 um after compensation in using this method.
Using analyse method of state variable which is independent of system's inputs and outputs, the paper presents a method
to solve the difficult problem of dynamic measurement system modeling on a X-Y working table. Employing this
method, model on one guiding system of x-y working table is established. Transfer function of the model is calculated.
Signal transfer diagram between components of the system is also presented. The analysis results indicate that analyse
method of state variable is useful to modeling on complex system and helpful for understanding the information inside