Development Of Control System For Horizontal Blade Measuring Instrument

As a key part of steam turbine and other equipments, blade has direct impact on the equipment performance and safety. For the complexity and diversity of blade root and blade crown and especialy the body shape of blade which is a free-fom surface in space, the work of measuring blade is definitely necessary and a great challenge. Although the common methods of balde measurement have certain advantages and space of application, but also have some shortcomings and limitations, therefore, to develop a dedicated blade measurement system with high precision and efficiency, economy and convenience is very necessary and the blade measurement system will have great practical value and market prospects.In this paper, the research of measuring principle of blade measuring system is firstly taken form the perspective of both hardware and software. And on this basis, the mechanical structure of blade measuring system is described in detail. The electrical control system is designed and the details of hardware are described.The general design and planning of measuring software system is presented. On the basis of analying the user requirements and function for the measuring software system, the four functional moudles of initialization moudle,data acquisition module,data analysis and precessing moudle,auxiliary moudle, for the measuring software systme, are planed, and gave details to the four functional moudles. Also, the frame of software is designed and the database management system based on Access is established.In initialization module, the instrument calibration algorithm based on four-point measurement of ball and the coordinate system established algorithm based on base-level measurement are proposed. In data acquisition module, an automatic generation method of measurement directive is put forth, and deep researches in the mechanism of geometric measurement mode and scanning measurement mode are taken. In the auxiliary moule, gave a emphasis on the simulation run of measuring code and its implementation. Also, establish the timer-based communication between software system and peripheral I/O devices.Finally, take DN56-type blade as an example of a test of measurement system developed in this paper, and verify its feasibility.The measurement system has been applied in a blade production plant, has been, and the practical application results also verify the feasibility of this measurement system.