Development Of The Data Acquisition System For Micro-inertial Devices Centrifuge Calibration And Dynamic Test

Precision centrifuge is the critical equipment, which supplys a simulated dynamicacceleration environment, used in determination the performance of inertial device. Theaccuracy of the physical simulation and test results will be directly affected by whetherthe output of the components under test can be collected accurately and in real-time.According to the development needs of micro inertial devices, I have completed thedevelopment of two sets of data acquisition system. One is used for the calibration ofinertial sensors through static centrifuge, and the other for the dynamic simulation testthrough dynamic centrifuge.According to the design specifications of the static centrifuge calibration testdata acquisition system, completed the system design and hardware selection. Usingdigital multimeter PXI-4071and multiplexer module PXI-2530effectively realize themulti-channel and high precision data acquisition system. The analysis of the systemmeasurement accuracy shows that the highest accuracy can reach to7digits and thecomprehensive measurement accuracy is better than10-4V order of magnitude.On the basis of the design specifications of the dynamic centrifuge simulation testdata acquisition system, especially the sampling synchronicity requirements, I havecompleted the system design and hardware selection. Use DAQ card PXI-6358,PXI-6221and the signal conditioning modules to realize the DAQ system, which cancomplete the acquisition of multi-channel analog signals and the standard g-valuereference signal. Using adapter module PXI-6584and programmable FPGA module,implement customized RS485/RS422communication and real-time analysis on theFPGA. At the same time write the timestamp to digital signal by FPGA module, whichfacilitates to provide accurate timenode at data processing anderror intercomparison, and ensure the digital signal acquisition and real-timesynchronization requirements. The analysis of the system measurement accuracy showsthat, the sampling time is no more than0.5ms, integrated measurement accuracy of thesystem is in10-3V order of magnitude, and the sampling point and the synchronism tothe centrifuge control system error is less than0.1ms.According to the different requirements of the two systems, utilize the LabVIEWplatform to complete the system software development. Assume modular program design method, design the channel parameter settings module, data acquisitionmodule, data analysis module, data access and playback module, which make thesoftware system reusability, scalability openness, easy to maintain, debug and update.In the dynamic test data acquisition system, I have solved the problem that two dataacquisition cards PXI-6221and PXI-6358share the common clocksource and startsynchronous acquisition. According to the differences in the format of data storage,have completed two software solutions respectively based on TDMS files and database.Took one certain type of micro-accelerometer as test object to do the calibrationtests, and compared the results from the newly developed static calibration dataacquisition system and the original data acquisition system based on KEITHLEY-2001,which validates the newly developed system not only has the same level of precision,but also has many advantages, such as more acquisition channels, larger storagecapacity, flexible parameter settings, powerful capability of data procession and higherperformance-price ratio. As the dynamic centrifuge host machine has not completed yet,the developed dynamic centrifuge simulation test data acquisition system can not bedebugged and actual tested.