In order to effectively control the working state of the gyroscope in drive mode, the drive characteristics of the micro electromechanical system （MEMS） gyroscope are analyzed in principle. A novel drive circuit for...
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In order to effectively control the working state of the gyroscope in drive mode, the drive characteristics of the micro electromechanical system （MEMS） gyroscope are analyzed in principle. A novel drive circuit for the MEMS gyroscope in digital closed-loop control is proposed, which utilizes a digital phase-locked loop （PLL） in frequency control and an automatic gain control （AGC） method in amplitude control. A digital processing circuit with a field programmable gate array （FPGA） is designed and the experiments are carried out. The results indicate that when the temperature changes, the drive frequency can automatically track the resonant frequency of gyroscope in drive mode and that of the oscillating amplitude holds at a set value. And at room temperature, the relative deviation of the drive frequency is 0.624 ×10^-6 and the oscillating amplitude is 8.0 ×10^-6, which are 0. 094% and 18. 39% of the analog control program, respectively. Therefore, the control solution of the digital PLL in frequency and the AGC in amplitude is feasible.
In order to research on the design and implementation of a modernized GPS civil signals simulation system,a brief review of the modernized GPS signals is introduced,including the signal structure and characteristics o...
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In order to research on the design and implementation of a modernized GPS civil signals simulation system,a brief review of the modernized GPS signals is introduced,including the signal structure and characteristics of L2C,L5 and L1C *** design and implementation of the main modules of the simulation system is described in *** simulation system is mainly composed of parameter setting,system initialization,signal generator,noise generator,disturbance generator,signal synthesis,low-pass filter,A/D conversion and *** simulation results based on Matlab are then presented,and the power spectral density（PSD） of all navigation signals is *** simulation system completes the physical layer simulation of a modernized GPS new civil signal and can provide a controllable signal source for designing and testing of modernized GPS civil receivers,especially for the signal processing algorithm design of the GPS software receiver.
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