Pmac Card Aero-engine Labyrinth Gap Measurement System

The technique of labyrinth seal is a conventional non-contact sealing technology, which is widely used in aeroengine. The clearance of labyrinth is related to capability of a aeroengine. So it is necessary to accurately measure the clearance of labyrinth in the process of devising, ameliorating, producing and maintaining engines. The study on measuring the clearance of labyrinth now is at the infant stage at home. This paper studies an accurate measuring system based on PMAC motion controller's structure, which can be used to measuring the clearance of labyrinth.The main researches of this paper are as followings. Based on the analyses of various method and labyrinth seal of aeroenginethe characteristics of, reflecting light intensity measurement was selected. A fiber-optic sensor which satisfied the measure accuracy of the system and the system of data measurement system, including PCI high-speed data acquisition card, amplifier, A/D convension and so on,were designed. The hardware structure of the system was determined. With PMAC motion controller's structure as the core, the system is a precise motion controll's system which was consist of dual CPU frame with PMAC and IPC as the up-down computer and BAYSIDE's NANOMOTION motor. According to the test data and the characteristics of system's hardware structure, the principle and the method to auto-calibrate the labyrinth measurement system was determined. a the PID control principle about PMAC motion controller's structure and the PID parameter setting of PMAC in the system were put forward in detail. Finally, the software of the system was programmed, including the non-real-time software of upper computer and the real time software of lower computer. The upper computer software is developed by means of VC++6.0 including PMAC parameter setting PMAC motion control system's auto-calibration of system and the data collection and information processing of clearance of labyrinth. The lower computer software is finished mainly by using the built-in function library of PMAC controlier's structure in the VC++6.0 environment. the program of real time motion was progrsmmed using PLC language.The captive test and the results of analysis indicated that the principle of this system was clear and the structure of this system was simple.The measurement accuracy of this system achieved the requirements of measuring the clearance of labyrinth.