Design And Research On Structure Of There-axis Accelerometer Calibration Device

Vibration sensor is one of the indispensable important components inmodern industrial technology. Three-axis accelerometer used to measure theacceleration in space is finding wider and wider application in inertialnavigation, earthquake monitoring and weapon system testing, etc. There is nounified standard for the accelerometer calibration. The single axis accelerometercalibration method is adopted to calibrate sensitivities of three-axisaccelerometers one by one. This method is difficult to obtain the cross sensitivewhich reflect the coupling extent between the different axis and it takes a longtime. Researching and developing the calibration system which can excite threeaxis and calibrate them of three-axis accelerometers in the same time hasimportant theoretical and practical significance for the progress of thedevelopment of the three-axis sensor, inertial navigation, health monitoring andthe related industries.Design goal of the three-axis accelerometer calibration device is determined according to the domestic and foreign standards about theaccelerometer calibration, and according to performance parameters ofmainstream manufacturers’three-axis accelerometers. The realization scheme ofthe three-axis accelerometer devise is discussed. Decoupling structure based onthe aerostatic support technology is proposed, and the air cushion type of thedecoupling structure is determined.Physical model of the three-axis accelerometer device is created andimported to Adams. The virtual prototype model is set up and performed rigidbody dynamics analysis. Feasibility of the three-axis accelerometer devicescheme is verified.The structure sensitivity of key mechanical part workbench is analyzed,and the influence degree of the main structure sizes on workbench quality,maximum stress and strain is determined. The workbench structure is optimizedfor reduce its quality and the exciting force in the process of calibration.Decoupling precision of the three–axis accelerometer device is composedof exciting decoupling precision and fixture precision. The angle dimensionchain diagrams of exciting decoupling precision and fixture precision areestablished. The relationship between the parts’ form tolerance and thedecoupling precision is obtained by writing functions for each angle dimensionchain diagrams. The parts’ form tolerance is determined according standardsabout decoupling precision, and calculating decoupling precision when the partsare manufactured according5level precision. The key part workbench is always under three directions cyclic loading inworking process. Avoiding workbench’s fatigue damage and resonance byresearching its structure properties, analyzing its modal frequency and fatiguelife.The following conclusions are obtained by designing and researching thestructure of the three-axis accelerometer calibration device. The realizationscheme of the three-axis accelerometer devise is discussed and its feasibility isverified by performing rigid dynamic analysis. The quality and exciting force inworking process of workbench are reduced by optimization. The relationshipbetween the parts’ form tolerance and the decoupling precision is obtained.Decoupling precision is determined when the parts are manufactured according5level precision. Fatigue damage and resonance of workbench are avoided in itsall working life. These results of research and study of three-axis accelerometercalibration device lay foundation for subsequent physical prototype production,establishment and compensation of error modeling.