Research On Test Method Of Torsional Vibration On Transmission Shaft Of Tracked Vehicle

As the main force of the ground combat, tracked play an important role in the modern warfare. In the process of design for the power transmission system which provides energy for the moving vehicles, the inspection to the torsional vibration of the shaft system is inevitable. In the working process, the shafting torsional vibration will have a direct impact on the safety and reliability of the vehicle. Therefore, the measurement to the torsional vibration can not only provide a useful reference for the improvement and development of the vehicle, but also has a great significance to the monitoring of its operating condition.Torsional vibration is a kind of sports phenomenon caused by excitation torque fluctuations, whose expression form is high-frequency fluctuations with instantaneous speed and the changes to the torsion angle. The development status and a variety of measurement methods on the torsional vibration measurement are introduced in detail in this paper. Through the comparison analysis to the measuring method, combined with the limitations of tracked vehicle running environment and transmission shafting space, a set of test method which based on pulse testing principle and embedded volume grating sensor to obtain shafting torsional vibration is put forward. As a result, the torsional vibration test system is designed as well.A detailed analysis to the basic principles and design basis of the grating sensor is done in this paper. With finite element method, the characteristics are analyzed, and the input and output characteristic curves of the sensor are obtained, which verifies the correctness and feasibility of the sensor. On this basis, the sensor output pulse high precision testing circuit is designed. The circuit makes CPLD as the core, uses triggers to reduce the metastable and eliminate the effect of burr. At the same time, the finite state machine filter is used to eliminate the impulsive signal of high frequency jitter, to realize high precision measurement of the input pulse width. The Flash is used to storage the instantaneous speed and torsional angle changes. After that, the test data will be transferred through the USB interface to the host computer for data processing. According to the characteristics of non stationary signal, FFT is used to analyze the spectrum and power spectrum of the signal, which can extract the characteristic of the torsional vibration. The frequency domain analysis of the signal is carried out by using EMD.Finally, simulation experiment device has been built and related measurement experiments have been done. By measuring the pulse width of the simulated frequency and phase difference, and processing the measured signal to obtain the shaft torsional vibration characteristics. Through the analysis to the test result, the shaft torsional vibration, which verifies the reliability of the proposed test program.