Development Of The Straightness Measurement System Of High-speed Elevator Rail

As a complicated system, elevator involves mechanical, electric and cybernetic technologies. The guide rail, which acts as the main source exciting lateral vibration of cabin, is a key part of an elevator. Many elements have great effects on the safety and comfort of elevators, among which the vibration factor is particularly significant. The performances of elevator, such as safety, comfort and speed, are determined by the quality of the guide rails in large degree. Therefore, the examination of guide rails has an important position in the installation adjustment, performance check as well as maintenance of elevators.Straightness measurement is one of the most basic and important item in the field of geometrical measurement, which is the basis of planar degree, parallel degree, orthogonal degree, coaxial degree and etc. Straightness measurement of the rail has some unique characters, such as the requirements of the long travel distance, numerous items, mass data, strict real time requirement, and work on-site. Traditional straightness measurements, such as leveling rules, gradienter, reinforcing wire, even though simple in detecting apparatus and adopted widely, are of certain limitation, low accuracy, low efficiency, and can't guarantee the performance. On the other hand, some other measuring devices cannot be widely used because of value. Under the support from Hangzhou Shenling Elevator Fittings Co.,Ltd, we take the straightness measurement of guide-way as object of research, and advance a new method based on digital image processing to measuring straightness on the premise of accuracy and economics.At the very beginning of the article is the analysis of the detecting requirements of the rail straightness, then combining with several common methods, we fix an assessment principle, further propose a systematic structure of the detecting equipment. As follows is the explanation of how and why we have chosen implements from two respects which are mechanical part and measurement-control part. Then, it is the introduction of system realization from two respects: the lower computer of data acquisition based on PLC, and the upper computer of data process based on LabVIEW method. We, next, provide some compensation method through the analysis of error sources, and provide a new way of the judgment of qualified criterion. At last, we use MSA method to verify some important indice such as migration, repeatability, reproducibility, stability, linearity and resolution and make the equipment into use.