There exist several difficulties in the design of monolithic high-shock three-axis accelerometer, such as high g overload, transverse overload and the cross coupling in three dimensions, etc. It is necessary to optimi...There exist several difficulties in the design of monolithic high-shock three-axis accelerometer, such as high g overload, transverse overload and the cross coupling in three dimensions, etc. It is necessary to optimize the sensitivity to improve the performance of the accelerometer. For the monolithic high-shock three-axis accelerometer, the complexity of the sensitivity optimization is that it should consider not only the sensitivity difference between different axes but also the elimination of cross-coupling outputs, together with the natural frequency, structural integrity and high g overload. In this paper, the optimization process for decreasing the difference of the sensitivities between different axes of a monolithic high-shock three-axis piezoresistive accelerometer with single sensing element is established. The optimization is conducted in the condition of 100000 g acceleration by two methods-the method based on the optimization module of ANSYS and the ACO (ant colony optimization) method. The comparison between un-optimized and optimized models proves the efficiency of the optimization methods. In addition, the optimization results show that the ACO method combined with the FEA (finite element analysis) is much more efficient than the method based on the optimization module of ANSYS for the structural optimization problem. And the ACO method can be widely used in the optimization problem of the sensing elements with complicated structure.展开更多
An integrated MEMS accelerometer has been designed and fabricated. The device, which is based on the piezoresistive effect, accomplishes the detection of three components of acceleration by using piezoresistors to com...An integrated MEMS accelerometer has been designed and fabricated. The device, which is based on the piezoresistive effect, accomplishes the detection of three components of acceleration by using piezoresistors to compose three Wheatstone bridges that are sensitive to the only given orientation. The fabrication of the accelerometer is described, and the theory behind its operation developed. Experimental results on sensitivity, crossaxis-coupling degree, and linearity are presented. The sensitivity of X, Y and Z were 5.49 mV/g, 5.12 mV/g and 4.82 mV/g, respectively; the nonlinearity of X, Y and Z were 0.01%, 0.04% and 0.01%, respectively; the crossaxis-coupling factor of X axis to Y axis and Z axis are 0.119% and 2.26%; the cross-axis-coupling factor of Y axis to X axis and Z axis are 0.157% and 4.12%; the cross-axis-coupling factor of Z axis to X axis and Y axis are 0.511% and 0.938%. The measured performance indexes attain accurate vector-detection in practical applications, and even at a navigation level. In conclusion, the accelerometer is a highly integrated sensor.展开更多
With the springing up of the MEMS industry,research on accelerometers is focused on miniaturization, integration,high reliability,and high resolution,and shares extensive application prospects in military and civil fi...With the springing up of the MEMS industry,research on accelerometers is focused on miniaturization, integration,high reliability,and high resolution,and shares extensive application prospects in military and civil fields.Comparing with the traditional single cantilever beam structure or ＂cantilever-mass＂ structure,the proposed structure of ＂8-beams/mass＂ with its varistor completely symmetric distribution in micro-silicon piezoresistive triaxial accelerometer in this paper has a higher axial sensitivity and smaller cross-axis sensitivity.Adopting ANSYS, the process of structural analysis and the manufacturing flow of sensing unit are showed.In dynamic testing conditions, it can be concluded that the axial sensitivity of x,y,and z are Sx-48μV/g,Sy = 54μV/g and Sz = 217μV/g respectively,and the nonlinearities are 0.4%,0.6%and 0.4%.展开更多
基金Supported by the "111" Project (Grant No. B08043)Foundation Program of National Key Lab for Electronic Measurement and Technology (Grant No. 9140C12040606060C12)
文摘There exist several difficulties in the design of monolithic high-shock three-axis accelerometer, such as high g overload, transverse overload and the cross coupling in three dimensions, etc. It is necessary to optimize the sensitivity to improve the performance of the accelerometer. For the monolithic high-shock three-axis accelerometer, the complexity of the sensitivity optimization is that it should consider not only the sensitivity difference between different axes but also the elimination of cross-coupling outputs, together with the natural frequency, structural integrity and high g overload. In this paper, the optimization process for decreasing the difference of the sensitivities between different axes of a monolithic high-shock three-axis piezoresistive accelerometer with single sensing element is established. The optimization is conducted in the condition of 100000 g acceleration by two methods-the method based on the optimization module of ANSYS and the ACO (ant colony optimization) method. The comparison between un-optimized and optimized models proves the efficiency of the optimization methods. In addition, the optimization results show that the ACO method combined with the FEA (finite element analysis) is much more efficient than the method based on the optimization module of ANSYS for the structural optimization problem. And the ACO method can be widely used in the optimization problem of the sensing elements with complicated structure.
基金supported by the National Science and Technology Cooperation Program of China(No.61011140351)
文摘An integrated MEMS accelerometer has been designed and fabricated. The device, which is based on the piezoresistive effect, accomplishes the detection of three components of acceleration by using piezoresistors to compose three Wheatstone bridges that are sensitive to the only given orientation. The fabrication of the accelerometer is described, and the theory behind its operation developed. Experimental results on sensitivity, crossaxis-coupling degree, and linearity are presented. The sensitivity of X, Y and Z were 5.49 mV/g, 5.12 mV/g and 4.82 mV/g, respectively; the nonlinearity of X, Y and Z were 0.01%, 0.04% and 0.01%, respectively; the crossaxis-coupling factor of X axis to Y axis and Z axis are 0.119% and 2.26%; the cross-axis-coupling factor of Y axis to X axis and Z axis are 0.157% and 4.12%; the cross-axis-coupling factor of Z axis to X axis and Y axis are 0.511% and 0.938%. The measured performance indexes attain accurate vector-detection in practical applications, and even at a navigation level. In conclusion, the accelerometer is a highly integrated sensor.
基金supported by the International Science & Technology Cooperation Program of China(No.61011140351)the National High Technology Research and Development Program of China(No.2011AA040404)the National Natural Science Foundation of China(No. 51075375)
文摘With the springing up of the MEMS industry,research on accelerometers is focused on miniaturization, integration,high reliability,and high resolution,and shares extensive application prospects in military and civil fields.Comparing with the traditional single cantilever beam structure or ＂cantilever-mass＂ structure,the proposed structure of ＂8-beams/mass＂ with its varistor completely symmetric distribution in micro-silicon piezoresistive triaxial accelerometer in this paper has a higher axial sensitivity and smaller cross-axis sensitivity.Adopting ANSYS, the process of structural analysis and the manufacturing flow of sensing unit are showed.In dynamic testing conditions, it can be concluded that the axial sensitivity of x,y,and z are Sx-48μV/g,Sy = 54μV/g and Sz = 217μV/g respectively,and the nonlinearities are 0.4%,0.6%and 0.4%.
