Error Analysis And Compensation Of Large-range Profile Measurement Sensor

With the rapid development of science and technology, especially in the field ofindustry machining technology, the demand for large-range and high-precisionmeasurement on the workpiece surface is also becoming more and more pressing.Becauseof the features of large-range, high-precision and low requirement to the environment,stylus-type profilometer sensor is being widely used in the measurement of surface profile.However, because of the large curvature of many workpieces, it is difficult for traditionstylus-type profilometer sensor to provide large-range and high-precision measurementbecause of its non-linear error, which leads to the limitation of application anddevelopment. As a result, it is fundamentally important to analysis and compensate thenon-linear error of stylus-type profilometer sensor. The main content and work about theessay is below:Firstly, the mathematical model of the stylus-type profilometer sensor construction israised, the non-linear error is analysed, and the error relationship is also derived. Then,with the analysis of other aspects of error, the non-linear error is caused by many aspectsand all errors should be compensated. With further analysis, the non-linear error can bedecomposed into two directions: horizontal and vertical. And a method by usinghigh-precision vertical displacement worktable and standard workpiece is proposed. Withthe creation of error look-up table, the non-linear error can be compensated point-to-point,and the precision of measurement range of the sensor can be ensured.A large-range and high-precision vertical displacement worktable is designed, and amini laser rangefinder is also installed, which makes the worktable reach±0.5μm positionaccuracy in the range of20mm. A stylus-type profilometer sensor zero position sensingdevice is also designed, by using photoelectric close switch, the positioning accuracy ishigh.With the platform of C++Builder, the error compensation module interface of horizontal and vertical direction is designed. Various measurement parameters can beconveniently set, which makes the process of error compensation fast and efficient.Finally, by using HP5529A, the accuracy experiment of vertical displacementworktable and horizontal worktable is made; By measuring the surface profile of anglegauge block, cylindrical pin and steel ball, the feasibility of sensor non-linear errorcompensation method is verified.