Research On Measurement System Of The Blade Of Complex Surface

Blades are widely used in turbines, steam turbines, aircraft engines, windturbines and other equipment for the exceptional dynamic performance. Special alloymaterial and high-quality processing quality assure that blades can work in hightemperature, high pressure, high corrosion and other harsh environments for long term.With the development of the level of industrialization, aerospace, water conservancyand electricity put forward higher quality and quantity requirements for blades.Intelligent and precision manufacturing institute of Jilin University developedthe non-contact three coordinate measuring machine for blades measuring and studyon the measurement system for blisk. Based on the completed non-contact threecoordinate measuring machine, this paper achieve the measurement of a single turbineblade, while study the error analysis and precision calibration for the measurementsystem. This paper study the blisk measurement from system hardware design,hardware selection, mathematical modeling, measurement path planning and otheraspects.The single blade has many methods to measure for its open structure. This paperpresent the structure and hardware system of the non-contact CMM which is used tomeasure the turbine blade. The hardware includes servo motors, motion control card,rails, laser displacement sensors, PC, cabinet and so on. The software control andmeasurement process are described. The software required to control each axismovement of the machine, obtain the laser displacement sensor data, output and storethe coordinate values.This paper presents the two-dimensional ball plate detection method for the error detection of the non-contact three coordinate measuring machine. The error model isestablished for the non-contact three coordinate measuring machine. The final errorvalues are calculated according to the errors of each axis detected by the laserinterferometer and compared with the error values detected by the two-dimensionalball plate detection method in this paper. The measurement accuracy of non-contactCMM can be calibrated by comparing these two methods.In the study of blisk measurement, the structure of measurement system isdetermined by the difficulty of controlling the implementation process, cooperationwith the processing side, installation and debugging. Based on the structure ofmeasurement system, the appropriate measuring head and probe system is selected byconsidering every aspect of the application and system parameters.The blisk is animportant component of aviation engine, and its level of machining and measuringwill directly affect the development of the aerospace industry. This paper investigatesthe on-line measurement of single blade of the blisk. The section lines and controlpoints to be measured are determined by using the empirical formula and feature pointextraction algorithm of B spline. The global interference problem is solved bydividing the measurement area and calculating the sector inference-free domain. TheCATIA simulation is conducted to validate the correctness of the path planningalgorithm for measurement. The measuring path planning plays an important role inimproving the measuring efficiency, reducing the cost of measurement, and increasingthe intelligence of measurement.