A novel design of force to rebalance control for a hemispherical resonator gyro (HRG) based on FPGA is demonstrated in this paper. The proposed design takes advantage of the automatic gain control loop and phase lock loop configuration in the drive mode while making full use of the quadrature control loop and rebalance control loop in controlling the oscillating dynamics in the sense mode. First, the math model of HRG with inhomogeneous damping and frequency split is theoretically analyzed. In addition, the major drift mechanisms in the HRG are described and the methods that can suppress the gyro drift are mentioned. Based on the math model and drift mechanisms suppression method, four control loops are employed to realize the manipulation of the HRG by using a FPGA circuit. The reference-phase loop and amplitude control loop are used to maintain the vibration of primary mode at its natural frequency with constant amplitude. The frequency split is readily eliminated by the quadrature loop with a DC voltage feedback from the quadrature component of the node. The secondary mode response to the angle rate input is nullified by the rebalance control loop. In order to validate the effect of the digital control of HRG, experiments are carried out with a turntable. The experimental results show that the design is suitable for the control of HRG which has good linearity scale factor and bias stability.
References
[1]
Rozelle, D.M. The Hemispherical Resonator Gyro: From Wineglass to the Planets. Spaceflight Mech 2009, 134, 1–26.
[2]
Dzhandzhgava, G.I.; Bakhonin, K.A.; Vinogradov, G.M.; Trebukhov, A.V. Strapdown Inertial Navigation System Based on a Hemispherical Resonance Gyro. Gyroscop. Navigat 2010, 1, 91–97.
[3]
Stripling, W.W.; Lynch, D.D.; Baskett, J.R. Hemispherical Resonator Gyro: Principle, Design, and Performance. Proceedings of Symposium Gyro Technology, Stuttgart, Germany, 22–23 September 1992.
[4]
Loper, E.J.; Lynch, D.D.; Stevenson, K.M. Projected Performance of Smaller Hemispherical Resonator Gyros. Proceedings of Positon Location and Navigation Symposium Plans 86, Las Vegas, NV, USA, 4–7 November 1986.
[5]
Loveday, P.W. Analysis and Compensation of Imperfection Effects in Piezoelectric Vibratory GyroscopesPh.D. Thesis. Virginia Polytechnic Institute and State University, Blacksburg, VA, USA, 1999.
[6]
Matthews, A. Vibratory Rotation Sensor with Scaning-Tunneling-Transducer Readout. US Patent 5,712,427 1998.
[7]
Lynch, D.D. HRG Development at Delco, Litton, and Northrop Grumman. Proceedings of The Anniversary Workshop on Solid-State Gyroscopy, Yalta, Ukraine, 19–21 May 2008; pp. 19–21.
[8]
Lynch, D.D.; Matthews, A.; Varty, T. Innovative Mechanization to Optimize Inertial Sensors for High or Low Rate Operations. Proceedings of Symposium Gyro Technology, Stuttgart Germany, 16–17 September 1997.
[9]
Matthews, A.; Bauer, D.A. Hemispherical Resonator Gyro Noise Reduction for Precision Spacecraft Pointing. Proceedings of 19th Annual AAS Guidance And Control Conference, Breckenridge, CO, USA, 7–11 February 1996.
[10]
Matthews, A.; Bauer, D.A. The Hemispherical Resonator Gyro for Precision Pointing Applications. Proc. SPIE 1995, 2466, doi:10.1117/12.211500.
[11]
Zhbanov, Y.K. Amplitude Control Contour in a Hemispherical Resonator Gyro with Automatic Compensation for Difference in Q-Factors. Mech. Solid 2008, 43, 328–332.
[12]
Zhbanov, Y.K.; Zhuravlev, V.P. Effect of Movability of the Resonator Center on the Operation of a Hemispherical Resonator Gyro. Mech. Solid 2007, 42, 851–859.
[13]
Shatalov, Y.M.; Joubert, S.V.; Coetzee, C.E. The Influence of Mass Imperfections on the Evolution of Standing Waves in Slowly Rotating Spherical Bodies. J. Sound Vibrat 2011, 330, 127–135.
[14]
Shatalov, Y.M.; Coetzee, C. Dynamics of Rotating and Vibrating Thin Hemispherical Shell with Mass and Damping Imperfections and Parametrically Driven by Discrete Electrodes. Gyroscop. Navigat 2011, 2, 27–33.
[15]
Loveday, P.W.; Rogers, C.A. The Influence of Control System Design on The Performance of Vibratory Gyroscopes. J. Sound Vibrat 2002, 255, 417–432.
[16]
Loveday, P.W.; Rogers, C.A. Modication of Piezoelectric Vibratory Gyroscope Resonator Parameters by Feedback Control. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 1998, 45, 1211–1215.
[17]
Lynch, D.D.; Coriolis, Vibratory. Gyros. Proceedings of Symposium Gyro Technology, Stuttgart Germany, 15–16 September 1998.
[18]
Lynch, D.D. Vibratory Gyro Analysis by the Method of Averaging. Proceedings of The 2nd Saint Petersburg International Conference on Gyroscopeic Technology and Navigation, St. Petersburg, Russia, 24–25 May 1995.
[19]
Park, S. Adaptive Control of a Vibratory Angle Measuring Gyroscope. Sensors 2010, 10, 8478–8490.
[20]
Park, S.; Tan, C.-W.; Kim, H.; Hong, S.K. Oscillation Control Algorithms for Resonant Sensors with Applications to Vibratory Gyroscopes. Sensors 2009, 9, 5952–5967.
[21]
Dzhashitov, V.E.; Pankratov, V.M. Mathematical Models of the Thermoelastic Stress-Strain State, Temperature, and Technological Errors of a Wave Solid State Sensor of Inertial Information. J. Mach. Manufact. Reliab 2010, 39, 248–255.
[22]
Shatalov, M.; Roux, J.D.P.L.; Koch, F. Estimation of Vibratory Gyroscope Parameters with Data Derived from the Vibrating Element. Proceedings of Symposium Gyro Technology, Stuttgart Germany, 17–18 September 1996.
[23]
Fox, C.H.J. Vibrating Cylinder Rate Gyro: Theory of Operation and Error Analysis. Proceedings of Symposium Gyro Technology, Stuttgart Germany, 20–21 September 1988.
