Research On Attitude Demodulation Of Rotating And Non - Rotating Carrier Based On MEMS Gyroscope

Non-driven structure silicon micromechanical gyroscope is a novel angular ratesensor based on Coriolis force effect without driven structure itself, which uses rotating ofrotating body as a spin-driven to sense pitching, yaw and spin angular rate of the rotatingbody. It can be widely used in gesture detection for high speed rotary body such as rollingmissiles. But this type of gyroscope can only output signals if both carrier’s spin and yaw(or pitching) are existed at the same time. Therefore it is not suitable for non-rotating flightcarrier. Furthermore, when the carrier spin rate is low, because output signals of this typeof gyroscope has loud noises, it is difficult to extract effective signals.Aiming at the above shortages of non-driven structure silicon micromechanicalgyroscope, this study proposes the solutions. A new type of silicon micromechanicalgyroscope was developed, and its output signals were analyzed. Meanwhile, signaldecoding algorithm was researched. This innovative work of the study includes thefollowing specific content:1. A new type of silicon micromechanical gyroscope was developed. It used a micromotor as rotating carrier to generate gyroscopic effect which was sensitive tovarious kinds of attitude information of rotating or non-rotating objects. Becausethe new type of gyroscope has more connected components，it causes more noiseinterference among output signals. So a lot of research were done about how toimprove the SNR and optimize the structure design.2. Through analyzing output signals of the new type of gyroscope and doing FFTalgorithm spectrum analysis to output signals and gravitational accelerometerreference signals, the relationships were gained between the motor drivingfrequency, carrier spin frequency, synthesized frequency of the two former andsynthesized angular vibration frequency of yaw and pitching.3. Signal decoding algorithm was studied for the new type of silicon micromechanicalgyroscope. And two decoding algorithms of yaw and pitching, spin angularvelocity (Envelope and orthogonal decomposition demodulation algorithm byusing phase difference and Hilbert transformation, or multiplication demodulationlow-pass filter algorithm) algorithm of rotating carrier’s were proposed, and Spinangular velocity of rotating carrier determination. 4. Based on above research, a novel of silicon micromechanical gyroscope prototypewas designed and implemented with small size DSP signal processing circuitswhich takes TMS320F2812as the core. And the prototype was tested by using thethree-axis turntable simulation rotation and non-rotating missiles. Test results show,the gyroscope can output three angular velocities (spin, pitching and yaw angularvelocity) which is sensitive at the same time directly in digital form to PC, and canalso be transformed to analog output signals by D/A and be monitored inequipments.