Study on the compensation for a quartz accelerometer based on a wavelet neural network

Abstract

In the position and azimuth determination system (PADS), the bias and scale factor of a quartz flexible accelerometer exhibit a non-ignorable drift after a quick turn-on and before the thermal balance is reached inside the system at different temperatures. To solve this problem, this paper presents a system compensation scheme. The multi-point temperature sensing experiment was repeated based on the realization of the hardware platform, and a wavelet neural network was used for the temperature compensation. Studies indicated that the selection of the temperature sensing points is one of the keys to achieve an effective compensation. Results show that the compensation scheme and algorithm increase the efficiency and reduce the preparation time; meanwhile the attitude precision can be improved to 8 arcsec, which meets the specification of the system.

Temperature characteristics and error compensation for quartz flexible accelerometer

“…Experimental results obtained in several days certify that the difference voltage ΔE can be well described by (5). By using Matlab, the difference voltage ΔE can be fitted perfectly.…”

“…Given certain acceleration, the accelerometer measurement values fluctuated considerably at different temperatures, resulting in degradation of accelerometer measurement accuracy. Moreover, several measurements show that the law under which the accelerometer output value varied with temperature can be given by (5). Equation (5) reflects a second order function, i.e., the output voltage is related with temperature and acceleration.…”

“…Studies prove that the more is robustness of K1 against temperature, the higher is the quality level of accelerometer. For some specific appli- cation such as spacecraft or satellite, the temperature instability K1 should not be exceed 0.1% in complete range of operating temperature [4,5] . However, the spacecraft is moving so fast that the external ambient temperature changes dramatically.…”

Method for Improved Performance of Fixed-Gain Self-Alignment in the Temperature Stabilizing State

“…The fine alignment needed to calculate the vertical attitude is performed after stabilizing the horizontal attitude through a coarse alignment of about 30 sec. Hence, it seems reasonable to analyze how the errors that occur during the temperature stabilizing state of the accelerometers affect the accuracy of self-alignment without the second-order terms in Equations (10)- (13). Equations (10) to (13) can be written in terms of an Inverse Laplace transform, as follows.…”

“…A direct method is to add a temperature control system [11]. Considering hardware feasibility, the compensation method using a mathematical model is commonly used in the accelerometer design [12,13]. Once accelerometers are assembled to an INS, this compensation method is not sufficient because the temperature environment is changed.…”