Research On The Signal Feedback And Error Correction Circuit Of Silicon Micro-Gyrpscope

The Silicon Micro-Machined Gyroscope that is an important MEMS inertial sensor is small in volume, light in weight,low in cost and high in reliability, which has great use value and application prospect for both civil and military requirements. Therefore, the study of silicon micro-gyroscope control technology is important to improve the accuracy of the gyroscope.(1)The design, analysis and simulation of the closed-loop drive circuitryAnalysis the necessary of closed loop control in the drive mode of micro-gyroscope, in the drive control mode, using phase-locked loop (PLL) control system to achieve real-time tracking drive frequency and automatic gain control (AGC) system to provide a stable driving vibration amplitude. Construct the PLL and AGC control model, through the simulation to analysis the dynamic characteristics of the control system. Design and implement the control system, and the experiments are given to verify the correctness and applicability of the drive circuitry.(2) Research and optimizing of quadrature error correction technologyThe formation and manifestation of quadrature error are analyzed. The negative stiffness is used to eliminate the quadrature error. Construction of the quadrature error loop control model, the simulation and the experiments results show that the quadrature error correction system can effectively counteract the coupling stiffness, suppress the quadrature component from detection signal.(3) Sense close loop design and bandwidth expandingThe sense open and closed loop detection is designed and analyzed. The close loop is used in the paper, the simulation and experiment of closed-loop control can be seen effectively improve the performance of gyroscope. This paper focuses on the closed loop control system of silicon micro-gyroscope.(4) Research and simulation of frequency tune technologyDue to poor micro fabrication tolerances, the resonant frequency of the sense mode is difference to the drive mode. In this paper the electrostatic tuning capability is used to eliminate the frequency difference. When the drive mode and sense mode work in the same resonant frequency called Modal matching state. In this state the system significantly improve the sensitivity and the signal to noise ratio of the system.(5)The design of digital circuitThe hardware circuitry is designed based on the silicon micro-gyroscope measurement and control circuits. The FPGA chip is the core of the control system and the digital programming algorithms, including DCO, digital PI, digital filter and control software algorithms is achieved through the FPGA processing platform. Implementation the final control circuit based on the FPGA and high-performance ADC, DAC as the core of the hardware monitoring.(6) Tests and analysisComplete the debug of each circuitry module, and the performance of silicon micro-gyroscope is detailed test, through the performance test verified the correctness of the hardware circuit which designed in this paper. The use of quadrature correction, the closed-loop detection and frequency tuning technology, the static and dynamic performance of gyroscope is greatly improved. The experiment indicate that the control circuit enhance the performance greatly, and achieve the desired goal, which laid the foundation for further research and application.