Image measuring instrument on the method of reducing the error of three coordinate measuring machine

The method of image measuring machine to reduce the error of coordinate measuring machine. The coordinate measuring machine has a guiding mechanism, a length measuring element and a digital display device in three mutually perpendicular directions. There is a large table where the workpiece can be placed. The measuring head can be moved to the measuring position manually or automatically. At this time, a measuring device displays the coordinate value of the measuring point through the reading device and the digital display device. Coordinate measuring machines are used to measure the dimensions of workpieces, including the relationship between dimensions, such as length, symmetry, diameter, cylindricity, and other dimensions and geometric tolerances.

The coordinate measuring machine directly measures the original error of a single item by using a laser interferometer, etc., and can detect these error values u200bu200bwith high precision. The disadvantage is that the laser interferometer is expensive, the environmental conditions are harsh, and the operator's technical requirements are very high. Three coordinate measuring machine error detection methods can be divided into two categories: one is to use laser interferometer and other instruments to detect the single original error of the coordinate measuring machine; the other is to use physical reference detection such as ball column and ball panel to detect three types. Coordinates. Measure the overall error of the machine, and then decompose the original error. The important basis for decomposing the original error is that the CMM itself has good repeatability. Physical references such as the ball row and the ball board need to be verified by a laser interferometer, which places high requirements on the stability of the ball board itself. When the integral error is decomposed into a single error, a cross effect will inevitably occur, and the uncertainty of the original error obtained by the decomposition is greater than the uncertainty of the direct measurement (such as a laser interferometer). In addition, unlike the laser interferometer, the general step distance or ball pitch is difficult to be small, and it can continuously detect the error of the coordinate measuring instrument.