Dynamic Detection Method for Blade Tip Clearance of Aero-Engine in Assembled State Based on Linear Structured Light

Aero-engine blade tip clearance (BTC) is one of the most important parameters that have decisive influence on engine performance. Thus, it is a typical inspection indicator during engine assembly. With the higher demand for consistency of engine performance, the measurability of BTC is required to be much more accurate and dynamically. However, the traditional BTC detection method in the assembly process is restricted to lower accuracy, inability of complex structures and lack of dynamic measuring capability. This paper introduces a visual BTC measuring system based on structured light, which can directly measure the clearance between rotor and stator casing by observing its position from the engine principle axial direction. A special laser generator is designed to project structured light to the surfaces of blade and casing. Simultaneously, the light is captured by the industrial camera. Compared to the traditional methods, the BTC in whole circumferential phase can be measured rather than single phase. Meanwhile, the proposed method is not influenced by casing deformation and installation errors. Finally, the feasibility and capability of the system is verified by simulation experiment.