Resonant frequency detection and adjustment method for a capacitive transducer with differential transformer bridge.

The capacitive transducer with differential transformer bridge is widely used in ultra-sensitive space accelerometers due to their simple structure and high resolution. In this paper, the front-end electronics of an inductive-capacitive resonant bridge transducer is analyzed. The analysis result shows that the performance of this transducer depends upon the case that the AC pumping frequency operates at the resonance point of the inductive-capacitive bridge. The effect of possible mismatch between the AC pumping frequency and the actual resonant frequency is discussed, and the theoretical analysis indicates that the output voltage noise of the front-end electronics will deteriorate by a factor of about 3 due to either a 5% variation of the AC pumping frequency or a 10% variation of the tuning capacitance. A pre-scanning method to determine the actual resonant frequency is proposed followed by the adjustment of the operating frequency or the change of the tuning capacitance in order to maintain expected high resolution level. An experiment to verify the mismatching effect and the adjustment method is provided.

[1]  Li Gan,et al.  Actuation to sensing crosstalk investigation in the inertial sensor front-end electronics of the laser interferometer space antenna pathfinder satellite , 2011 .

[2]  Jun Luo,et al.  Capacitive position measurement for high-precision space inertial sensor , 2009 .

[3]  W. J. Weber,et al.  Progress in the development of a position sensor for LISA drag-free control , 2001 .

[4]  Virginio Sannibale,et al.  Readout system and predicted performance of a low-noise low-frequency horizontal accelerometer , 2006 .

[5]  P. Touboul,et al.  Capacitive detection scheme for space accelerometers applications , 1999 .

[6]  C. Speake,et al.  Capacitive sensing for drag-free satellites , 1997 .

[7]  R. V. Jones,et al.  REVIEW ARTICLE: The design and some applications of sensitive capacitance micrometers , 1973 .

[8]  W. J. Weber,et al.  Position sensors for LISA drag-free control , 2002 .

[9]  Larry K. Baxter,et al.  Capacitive Sensors: Design and Applications , 1996 .

[10]  Luo Jun,et al.  Excitation Frequency Effect of Differential Capacitance Transducer for Equivalence Principle Test , 2004 .

[11]  P. Touboul,et al.  Accelerometers for CHAMP, GRACE and GOCE space missions: synergy and evolution , 1999 .

[12]  Daniele Bortoluzzi,et al.  Position sensors for flight testing of LISA drag-free control , 2003, SPIE Astronomical Telescopes + Instrumentation.

[13]  Li Gan,et al.  LTP IS FEE Sensing Channel: Front-End Modeling and Symmetry Adjustment Method , 2012, IEEE Sensors Journal.

[14]  Jadranka Marasovic,et al.  EMC in electronic system developed to support measurements in space environment , 2012, SoftCOM 2012, 20th International Conference on Software, Telecommunications and Computer Networks.

[15]  Pierre Touboul,et al.  Electrostatic space accelerometers for present and future missions 1 1 Based on paper IAF.96.J1.02 p , 1999 .