Research On Signal Acquisition System For Quartz Accelerometers And Error Compensation Method

Accelerometer is one of the core components of the inertial navigation system, which is used for the acceleration signal that the sensitivity is proportional to the acceleration.While the accelerometer signal acquisition circuit is to convert the analog signal to digital signal,and the digital signal is sent to the FPGA chip for signal analysis and processing. The overall accuracy of an inertial navigation system is determined by the measurement accuracy of accelerometer itself, the acquisition accuracy of the accelerometer signal acquisition circuit and the data processing method in the FPGA chip. Compared with the aerospace, aviation and land use inertial navigation system, the marine navigation system has its own features. The ship's inertial navigation system has higher requirements for the accuracy of the accelerometer,and it needs the good repeatability and stability, but the bandwidth and dynamic range requirements are lower than other inertial navigation systems. Aiming at the marine inertial navigation system, this paper designs a new type of marine high precision quartz flexible accelerometer signal acquisition system, the overall accuracy of the system is improved by improving the sampling resolution of the system and establishing the error compensation model.Firstly, this paper compares the frequently used signal acquisition scheme, namely I/F conversion scheme and I/V conversion scheme (A/D conversion scheme), through the analysis of two kinds of scheme comparison, I/V conversion scheme can meet the demand of marine inertial navigation system, finally the ultra-precision ?-? analog-to-digital converter ADS 1281 is determined as the core of the accelerometer signal acquisition system, using digital isolation anti interference methods to ensure the system with high effective resolution.At the same time, the theory and the error of the quartz flexible accelerometer are modeled,and the effective and convenient temperature error compensation scheme is analyzed by establishing the error model.After the completion of the system design of the acquisition circuit and the temperature error compensation of quartz flexible accelerometer theory analysis and the scheming,the gained scheme is tested. After analysis and calculation, it can be concluded that the resolution accuracy of the signal acquisition board of quartz flexible accelerometer has achieved the design requirements. By the experimental results of the temperature error compensation scheme, the error compensation model can be proved that the error caused by the temperature variation of quartz flex accelerometer can be compensated effectively, and can ensure that the system has a good output accuracy in practical use..