Information Acquisition And Noise Error Processing Of High Accuracy Accelerometer

The inertial navigation system is composed of inertial elements such as gyroscopes and accelerometers as the core parts to obtain the various motion parameters of the carrier relative inertial space.Among them,the accelerometer as a direct measurement components,continuous measurement of the hull to obtain the acceleration,its accuracy will directly affect the resolution of the speed and latitude and longitude and other parameters of the accuracy,thus affecting the navigation system error.Therefore,we should do our best to improve the solution accuracy of acceleration parameters.Based on the shipboard inertial navigation equipment,the quartz flexible accelerometer with high resolution and high reproducibility and high stability is selected for the high resolution and wide dynamic range of the accelerometer information acquisition unit.Completed the corresponding acquisition circuit,and its noise error analysis and processing,testing shows that the acquisition program in line with the expected requirements.First,the design of the accelerometer information acquisition scheme is carried out.Based on the analysis of the working principle of the accelerometer,the two different data acquisition schemes of current frequency conversion and analog-to-digital conversion are compared and the advantages and disadvantages are pointed out.According to the high resolution,wide dynamic range and acceleration range of the acceleration parameters Real-time and other indicators of demand,we design the AD conversion acquisition program.Then,the design and completion of the accelerometer information acquisition circuit and its noise processing.In order to give full play to the performance of AD converter,the 31-bit high-precision analog-to-digital converter ADS1281 is as the core of acquisition circuit,and matching the corresponding pre-signal processing circuit.For the noise caused by various components in the acquisition circuit,hardware filtering circuit and digital filtering process are adopted to reduce the influence of the noise of the acquisition circuit to the system.As the same time,we take into account the layout and routing of printed circuit board(PCB)and the power system cooling,and also,digital signals and analog signals were isolated.Among them,the data read and digital filtering function are implemented by the inertial navigation system on the FPGA.Finally,the performance of the accelerometer acquisition unit was tested.According to "GJB1037A-2004",static stability,resolution and multi-point roll test in gravity field are designed.The test results show that the design meets the expected requirements.