| Nowadays, electricity industry is developing rapidly, the demand of dynamo equipments, such as steam turbine, water turbine, gas turbine and so on, is increasing day after day, so it is important to improve the quality of dynamo equipments. As the key part of those equipments, shape error of blade's surface has a great influence on the flow current lost,it is the reason that we put much emphasis on it. Blade is a kind of free form surface with many parameters and compound configuration. The surface contours differ from bottom to top at each section.At present, contact measurement is widely used, but non-contact measurement is developing rapidly. During the measurement of blade by coordinate measuring machine, the benchmark of design and measuring is not the same, so it is necessary to transfer the measuring model to the CAD model for comparison. Given transformation by hand consuming much time and energy, after research on some blade with special features, this thesis comes to conclusion: firstly adopting genetic algorithm to optimize the location of blade ,then matching two surfaces with least square algorithm, at this condition we can get high precision of registration comparing to using least square algorithm only.It is not enough only concerned with surface contour error when checking the quality of blade's surface. Making full use of the measured data form the CMM, more blade's surface quality indexes are raised. This blade checking system paves the way for improving efficiency of measuring and machining precision of the blade.This paper introduces the development of blade checking system based on UG as well as presents application examples in detail. It mainly includes the following aspects: the first is the registration of blade with genetic algorithm and least square algorithm; the second is the improvement of blade quality evaluation indices, raising new indices: lean error, bow error, twist error; the last is the interface design based on VC++6.0, UG/OPEN API and UIStyler. |
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