Development Of Portable Integrated Dynamic And Static Test System For Aircraft Engine-Lower Computer

The aircraft engine dynamic and static test system which used for engine test-run and field test, has played a key role in engine fault detection, parameter analysis and accessory performance evaluation. Traditional bench test system uses a large number of analog circuits, and dynamic and static measurements are separated, these shortcomings make it unable to meet the requirements of mobility, efficiency and stability. Therefore, based on researching the sensor and PCB material carefully, the author makes use of measurement technology and the static and dynamic sharing technology, the portable integrated dynamic and static test system of aircraft engine is developed.Firstly, according to the technical requirements of the testing system, the characteristics of parameters and excitation signals are analyzed, and the overall design is made. Secondly, according to the knowledge of semiconductor physics, principles of thermocouple temperature measurement and cold junction compensation are analyzed, then the temperature detection circuit is designed according to the characteristics of the sensor. This paper proposes a new method of voltage controlled current source, and it uses OPA541 to design the temperature excitation circuit. According to the engine speed sensor characteristic and GaAs optocoupler principle, the circuit of rotating speed testing is developed using the method of MCU tests periods. Then, the PCB material impact on circuit performance is analyzed, including the influence of transmission lines and dielectric material on characteristic impedance, and the influence of copper foil thickness and substrate materials on heat dissipation. Finally, in order to reduce the error caused by the scale transformation, the method of two-step scale transformation by software is designed, and the function zero and full adjustments are achieved.The experimental results show that the designs of the hardware circuit and software program have met the design requirements and enhance the portable performance. The system reduces human consumption and engine life loss. The thermal design can effectively improve the heat dissipation capability of PCB and ensure the safety and reliability of the instrument in the appropriate temperature.