A Design Of Flatness Measurement Instrument Based On2D Displacement Worktable

Flatness is an important evaluation index of the geometrical shape error forcomponents, the precision measurement is an important research subject. The traditionalmeasuring method of flatness is time consuming and less-automated, and the resultslargely relies on the experience level of testers, the workload of test and record is heavy,can’t meet the needs of industrial measurement.According to the actual engineeringbackground and the Natural Science Foundation of China " Research of Multi-scaleIntegration Measurement Method for Surface Texture ", and combines with the existingmeasuring methods, a set of flatness measuring instrument is designed. The sensor of themeasuring system is fixed, and the measured plane installed in two-dimensionalworktable rigidly.The worktable moves through the control program and then arrangemeasuring point and finish data collection. Each measured point data are input to theindustrial computer and stored in the database by data acquisition card, and thencomplete the data coordinate conversion in computer and evaluate the flatness error byusing least square method. The flatness error result can print in statements, show visuallyapparent in three-dimensional after coupled with OpenGL technology. The measuringsystem solves the problem of large amount of data, complicated calculation, lowprecision and complicated manual input data in the traditional flatness detection,provides the convenience for archiving and data backup.An inductive micrometer is designed, the sensor is calibrated and its error iscompensated. Then designs2D precision displacement worktable and studies the positiontracking performance of its equivalent two quality system. The feedforwardcompensation control is established to eliminate the influence of viscous friction onpositioning accuracy.The data among inductive micrometer, precision displacementworkbench and acquisition card in IPC is transmitted by using serial communicationprogramming technology. The interface circuit is designed and completes the debuggingbetween acquisition card and each of input and output channels. Analysis and compares the characteristics of each flatness assessment method anduses the least squares method based on regression principle as flatness evaluationmethods. The database is developed and designed by using C++Builder programmingenvironment and Access2007that can retain the original data and processing data so as toquery. A flatness measuring software is developed that can realize the coordinatesconversion and data processing, and the plane measurement has realized3D visualizationby using OpenGL technology. Comparing with dual-frequency interferometer by doingexperiment, it proves that the system is stable and reliable and with flexible operation,high precision, it fully meets the project requirements.