Vibration parameters of the physical quantities is how calibration

( 0002] Micro satellite propulsion system of small thrust measurement is usually used in quality - Spring - Damping second-order vibration system, and are usually owed damping system. After measuring system design and implementation, need through the experiment of measuring system standard, so as to obtain the measurement system of system parameters, including: static sensitivity, natural frequency and damping ratio. System parameter calibration is the basis of the line into the thrust measurement work, is crucial to the previous step.

( 0003] The common method to system parameter calibration include:

[ 0004] 1) For static sensitivity, the step response method is adopted, the standard quantity as step input signal, to obtain the steady-state output signal, step input and steady-state output linear fitting coefficient is the static sensitivity;

( 0005] 2) For the damping ratio, the step response method is adopted, using the maximum overshoot of system response and get the relationship between damping ratio and damping ratio or the free vibration method, using the logarithmic decrement for damping ratio;

( 0006] 3) For the inherent frequency, using the method of step response or free vibration method for system vibration period, using the inherent frequency rate of natural frequency and vibration cycle.

( 0007] System parameter calibration accuracy has direct influence on the thrust measurement results, at present most small thrust second-order vibration measurement system based on the above method for system parameter calibration, but did not make full use of the response of the system information, did not give the confidence interval of system parameters, will not be able to effectively assess the calibration precision of the system parameters. How convenient, effective and high precision in vibration system of two order system parameter calibration is a technical problem to be solved.