Papers by Keyword: MEMS Gyroscope

Abstract: In order to decrease the temperature error of MEMS gyroscopes, a mitigation method based on gyroscope array was proposed. Angular rate of MEMS gyroscope fluctuates dramatically with the change of gyro temperature when gyroscope starts up. The temperature characteristic error of MEMS gyroscope has become one of the major errors in the practical application. A mitigation method for temperature error was presented based on MEMS gyroscope array utilizing high correlation of temperature errors in the same batch of MEMS gyroscopes. This method was designed to improve environmental adaptability and shorten the startup time of MEMS based inertial measurement unit. Experimental results showed that the method was feasible and effective.

Abstract: MEMS gyroscope can be used in various field such as stabilization, controlling and guiding, navigation and so on. Bias variation over temperature is the key performance in MEMS gyroscope. The encapsulation moisture has great influence on the bias variation of MEMS gyroscope.By experiments on gas recharged, roast temperature, die attach adhesive and encapsulation shell, method to depress the encapsulation moisture is obtained. By DPA, the encapsulation moisture of sensing element encapsulated by the reformative method can be reduced to less than 1000 ppm, and the performance on temperature of MEMS gyroscope is improved.

Abstract: The output signal of the free-drive three-axis MEMS gyroscope used in Spinning Projectiles contains rolling is sine period signal. In order to demodulate the yawing and pitching angular rates, extracting the fringe phase information is needed. It is difficult to realize the phase demodulation of single signal. To solve this problem, reference signal is provided. The phase of the gyroscope is extracted by computing the phase difference. Then, three methods of phase difference measurement are introduced and simulated by MATLAB. According to the signal feature, the contrastive analysis of measurement error is made and the maximal precision of measuring method for phase difference is obtained. The last part is the analysis of performance.

Abstract: A novel noise reduction algorithm combined with compressive sensing (CS) and lifting wavelet transform (LWT) is proposed in this paper. This algorithm can overcome the limitations of traditional noise reduction methods based on Kalman filtering and wavelet threshold filtering. The characteristics of wavelet time-frequency distribution of the microelectromechanical system (MEMS) gyroscope are discussed to illustrate the demerit of the classical filtering methods. Noise reduction algorithm of MEMS gyroscope signal is studied in detail by combining CS theory with lifting wavelet transform. De-noising effect, time-consumption of computation as well as traditional CS reconstruction algorithms are analyzed. The results show that the signal reconstruction algorithm of conventional matching pursuit (MP) greedy algorithms contains more glitches and computation time-consumption, the basis pursuit de-noising (BPDN) algorithm is better and it has advantages of high computational efficiency and ease of implementation.

Abstract: In engineering application, the nonlinearity effect of the environment noise is inconsistent with the successive starting state of MEMS gyroscope which will induce the random drifts. It manifests as the weak nonlinearity, non stability and slow time varying which cannot be compensated by the conventional method. In order to overcome the problems of the great random drift error model established based on the time series for MEMS gyroscope and the non Gaussian noise, the method of Iteration Unscented Kalman Particle Filter (IUKPF) is proposed in this paper. This method is based on the Particle Filter combing the Unscented Transformation (UT) with Iteration Kalman Filter (IKF), and it solved the instability of the precision for the conventional filtering methods and the degradation for the weight of the particle filter. The filtering result shows that the method of IUKPF can effectively restrain the random drift error under nonlinear and non Gaussian noise. The standard deviation for the output noise of MEMS gyroscope has decreased 81.9% by IUKPF which verifies the efficiency and superiority of this method.

Abstract: This paper presents one kind of digital closed loop control system of MEMS (Micro Electro-Mechanical Systems) vibratory gyroscope, particularly concentrating on the sense mode of MEMS gyroscope. The controller consists of a sine wave source realized by CORDIC algorithm, multiplication demodulators, some low-pass filters and force feedback rebalance module. Compared with the open loop sense system of gyroscope, the closed loop sense system has larger measurement range and wider bandwidth. Besides, the sine wave source realized with CORDIC algorithm can save hardware resources. The digital system is demonstrated on a PCB with a FPGA on it. The test results show that the measurement range of the closed loop system can be increased to 3 times by the open loop, and the bandwidth can be extended to 262Hz from 27Hz of the open loop system.

Abstract: The influence of temperature’s variation upon the resonant frequency and damping of the Micro-Electro- Mechanical-System (MEMS) gyroscope’s silicon structure in the vacuum package is investigated in this article. The gyroscope’s working principle and the dual-mass decoupled gyroscope structure are introduced, the drive and sense modes’ frequencies are analyzed. The ideal models of resonant frequency and damping are established and the dominate elements of impacting the resonant frequency and damping are Young Modulus, air viscosity coefficient and ambient pressure respectively. The experiments and the results proved that the frequency model works well, and the damping model only can simulate the tendency because of the air getter’s influence.

Abstract: To estimate the flight attitude angles of Guided Projectile rapidly and accurately to realize the precise control, angular motion equations and MEMS gyroscope measurements were used to build the state equation and the measurement equationcombined withthe ballistic priori knowledge. Based on the unscented kalman filter for nonlinear system, an approach of estimating the attitude angles of Guided Projectile was proposed. Taking a certain type of Guided Projectile as an example, the data of triaxial angular velocities with the measurement noise was considered as the output signal of MEMS gyros, and considered the calculated ballistic data as the ballistic priori knowledge. Through the approach proposed in this paper, the above were used to obtain the estimates for attitude angles. The results indicate that, it’s feasible to obtain the attitude angles by angular motion equations and gyros. On account of the actual random noise signal of gyros, the accuracy of the estimated attitude angles can meet the requirement of trajectory control system for Guided Projectile.

Abstract: In recent years, Gyro stabilized and tracking platform has been widely used in the guidance, airborne, ship-borne, the military area and civil area such as the weapon, missile seeker, sensing detection, public security fire control, environmental monitoring. In order to improve line of sight stabilization precision of the Infrared Guidance equipment to ensure the stability of the seeker pinpoint the maneuvering target, we do some researches about the essential technologies in the stability and precision of gyro. This paper developed a set of new stable platform used of MEMS gyro device based on the infrared detection system, in view of the zero shift stability for MEMS gyro, with the key technologies for the gyro signal analysis and processing of theoretical research and experiment.

Abstract: In recent years, Gyro stabilized and tracking platform has been widely used in the guidance, airborne, ship-borne, the military area and civil area such as the weapon, missile seeker, sensing detection, public security fire control, environmental monitoring. In order to improve line of sight stabilization precision of the Infrared Guidance equipment to ensure the stability of the seeker pinpoint the maneuvering target, we do some researches about the essential technologies in the stability and precision of gyro. This paper developed a set of new stable platform used of three MEMS gyro devices based on the seeker of infrared detection system, in view of the zero shift stability for MEMS gyro, with the key technologies which are Kalman filtering and data fusion processing of theoretical research and experiment on the gyro signal.