The Study Of Measurement Correcting Techniques Of Linear Datum And Straightness Measurement

The straightness error measurement is the basic programme of basic geometric measurement and accuracy control, the linear datum is the key factor of the straightness error measurement. For its high stability and anti-jamming capability, the non-diffracting beam has been used for the linear datum of the straightness error measurement more often. To overcome the flaw that the optical linear datum are affected by the wandering distance, especially the angle wandering distance, and solve the big straightness error for the middle and long distance in the measurement of the optical linear datum, this article develops a correcting system of linear datum’s measurement based on the non-diffracting beam. Besides that aiming at the flaw that existed in the pole accounting method in the national standard, it provides pole directional search and iteration method for the straightness error evaluation, to improve the accuracy of the straightness error evaluation. The contents are specified in the following:(1)Based on the research status and the existed problems of the optical wandering exploration now, it develops a linear datum’s measurement correcting system of non-diffracting beam.①It raises the non-diffracting beam’s measurement correcting system general planning, and provides the non-diffracting beam’s wandering exploration and compensation theory and designs various mechanical devices required by the hardware system.②Based on the non-diffracting beam’s wandering exploration theory, it designs the synchronous controlling system which includes analyze synchronous controlling theory and provides the synchronous controlling method and designs the digital delay circuit and digital switch button according to the synchronous controlling demands.③Connected with the non-diffracting beam cross-section images’feature, it develops the image collecting and software handling system, to accomplish the image collection, parameter setting, the Bessel image center extraction, the wandering exploration and the accounting of the compensation datum. Finally it applies to the practical matters and accomplishes the functional test of the non-diffracting beam linear datum’s measurement correcting system.(2)To address the flaw of the pole accounting method of the national standard, it proposes the pole directional search and iterated least regional method evaluation method. At the time when it describes the positional search and iterated theory, and the mathematical model, it also develops the straightness measurement error handling software. The result of the straightness error data processing proves that the new pole search method possess the better completeness and a higher accuracy.