The Application of Parametric Excitation in Resonant MEMS Gyroscopes

2014 ◽  
pp. 473-492
Author(s):  
Barry J. Gallacher ◽  
Zhongxu Hu ◽  
Kiran M. Harish ◽  
Stephen Bowles ◽  
Harry Grigg
Keyword(s):  
Parametric Excitation ◽  
Mems Gyroscopes

The Application of Parametric Excitation in MEMS Gyroscopes

2013 ◽  
Author(s):  
Barry J. Gallacher ◽  
Zhongxu Hu ◽  
Kiran Mysore Harish ◽  
Stephen Bowles ◽  
Harry Grigg
Keyword(s):  
Angular Velocity ◽  
Parametric Excitation ◽  
Signal To Noise Ratio ◽  
Parametric Amplification ◽  
Signal To Noise ◽  
Primary Mode ◽  
Harmonic Forcing ◽  
Mode Of Operation ◽  
Mems Gyroscopes ◽  
Secondary Mode

Parametric excitation, via electrostatic stiffness modulation, can be exploited in resonant MEMS gyroscopes. In the case of the Rate gyroscope, which is by far the most common type of MEMS gyro, parametric excitation may be used to amplify either the primary mode of the gyro or the response to the angular rate. Both approaches will be discussed. In the more complex mode of operation, known as “Rate Integrating” the output of the gyro is angle directly as opposed to angular velocity in the case of Rate gyro. In this rate integrating mode of operation parametric excitation does offer an effective energy control used to initiate, sustain the vibration and minimise damping perturbations. Parametric amplification of the primary mode of the rate gyroscope is presented and supported with experimental results. In this implementation parametric excitation is combined with external harmonic forcing of the primary mode in order to reduce electrical feedthrough of the driving signal to the sense electrodes. A practical parametric excitation scheme implemented using Digital Signal Processing has been developed to enable either amplification of the primary mode of the gyroscope or amplification of the response to the applied angular velocity. Parametric amplification of the primary mode of the gyroscope is achieved by frequency tracking and regulation of the amplitudes of the harmonic forcing and parametric excitation to maintain a desired parametric gain by closed loop PID control. Stable parametric amplification of the primary mode by a factor of 20 is demonstrated experimentally. This has important benefits regarding the minimisation of electrical feedthrough of the drive signal to the sense electrodes of the secondary mode. By taking advantage of the phase dependence of parametric amplification and the orthogonality of the Coriolis force and quadrature forcing, the response to the applied angular velocity may be parametrically amplified by applying excitation of a particular phase directly to the sensing mode. The major advantage of parametric amplification applied to MEMs gyroscopes is that it can mechanically amplify the Coriolis response before being picked off electrically. This is particularly advantageous for sensors where electronic noise is the major noise contributor. In this case parametric amplification can significantly improve the signal to noise ratio of the secondary mode by an amount approximately equal to the parametric amplification. Preliminary rate table tests performed in open loop demonstrate a magnification of the signal to noise ratio of the secondary mode by a factor of 9.5.

A Modification on Performance of MEMS Gyroscopes by Parametro-Harmonic Excitation

2010 ◽  
Author(s):  
Ali Pakniyat ◽  
Hassan Salarieh ◽  
Gholamreza Vossoughi ◽  
Aria Alasty
Keyword(s):  
Periodic Orbit ◽  
Parametric Excitation ◽  
External Rotation ◽  
Harmonic Excitation ◽  
Excitation Voltage ◽  
Mems Gyroscope ◽  
Mems Gyroscopes ◽  
Stable Periodic ◽  
Stiffness And Damping ◽  
Parameter Values

In this paper, parametric excitation for MEMS gyroscope proposed by Oropeza-Ramos, et al. [1–4] is examined and problems associated with this kind of excitation are shown. It is proved that origin has exponential stability for some sets of parameter values (including those considered in [1–4]). This stability is shown to be global for linearized system and local for the general nonlinear system. Hence, it is concluded that if there would be a periodic orbit, the system has difficulties reaching it. As a solution, a harmonic term to the parametric excitation is added and the new actuation is referred to as parametro-harmonic excitation. It is shown that there are some parameter values for which a stable periodic orbit exists. Finally, stability of periodic orbit of the linear parametro-harmonically excited MEMS gyroscope is analyzed based on Floquet Theory. Figures show that in the non-resonant driving frequencies, only stiffness and damping play important roles in the stability of periodic response and other terms like excitation voltage and imposed external rotation are of less influence on this stability. However, in the parametric resonant regions, not only stiffness and damping affect stability, but also excitation voltage is of great importance.

Novel FIB Use for Failure Analysis of MEMS Gyroscopes

2016 ◽  
Author(s):  
Nathan Wang ◽  
Saunil Shah ◽  
Camille Garcia ◽  
Vicente Pasating ◽  
George Perreault
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
New Techniques ◽  
Unique Challenge ◽  
Root Cause ◽  
Large Size ◽  
Mems Gyroscopes

Abstract MEMS samples, with their relatively large size and weight, present a unique challenge to the failure analyst as they also included thin films and microstructures used in conventional integrated circuits. This paper describes how to accommodate the large MEMS structures without skimping on the microanalyses needed to get to the root cause. Investigations of tuning folk gyroscopes were used to demonstrate these new techniques.

Stability of Ring-Type MEMS Gyroscopes Subjected to Stochastic Angular Speed Fluctuation

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Samuel F. Asokanthan ◽  
Soroush Arghavan ◽  
Mohamed Bognash
Keyword(s):  
Angular Velocity ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Damping Ratio ◽  
Operating Conditions ◽  
System Stability ◽  
System Response ◽  
Ring Type ◽  
Mems Gyroscopes ◽  
The Stability

Effect of stochastic fluctuations in angular velocity on the stability of two degrees-of-freedom ring-type microelectromechanical systems (MEMS) gyroscopes is investigated. The governing stochastic differential equations (SDEs) are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of largest Lyapunov exponents (LLEs) are employed for validation purposes due to lack of similar analytical or experimental data. The response of the gyroscope under different noise fluctuation magnitudes has been computed to ascertain the stability behavior of the system. External noise that affect the gyroscope dynamic behavior typically results from environment factors and the nature of the system operation can be exerted on the system at any frequency range depending on the source. Hence, a parametric study is performed to assess the noise intensity stability threshold for a number of damping ratio values. The stability investigation predicts the form of threshold fluctuation intensity dependence on damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear to have minimal influence on system stability.

A low-noise high-linearity interface ASIC for MEMS gyroscopes

2013 ◽  
Vol 34 (12) ◽  
pp. 125009
Author(s):  
Ran Fang ◽  
Wengao Lu ◽  
Guannan Wang ◽  
Tingting Tao ◽  
Yacong Zhang ◽  
...  
Keyword(s):  
Low Noise ◽  
High Linearity ◽  
Mems Gyroscopes

Concepts, Roadmaps and Challenges of Ovenized MEMS Gyroscopes: A Review

2020 ◽  
pp. 1-1
Author(s):  
Yuchen Wang ◽  
Rui Cao ◽  
Chong Li ◽  
Robert N. Dean
Keyword(s):  
Mems Gyroscopes

On the Parametric Excitation of Pendulum-Type Vibration Absorber

1961 ◽  
Vol 28 (3) ◽  
pp. 330-334 ◽  
Author(s):  
Eugene Sevin
Keyword(s):  
Energy Transfer ◽  
Numerical Solution ◽  
Parametric Excitation ◽  
Equations Of Motion ◽  
Vibration Absorber ◽  
Single Cycle ◽  
Linearized System ◽  
Nonlinear Equations Of Motion ◽  
Beam Oscillation ◽  
Energy Interchange

The free motion of an undamped pendulum-type vibration absorber is studied on the basis of approximate nonlinear equations of motion. It is shown that this type of mechanical system exhibits the phenomenon of auto parametric excitation; a type of “instability” which cannot be accounted for on the basis of the linearized system. Complete energy transfer between modes is shown to occur when the beam frequency is twice the simple pendulum frequency. On the basis of a numerical solution, approximately 150 cycles of the beam oscillation take place during a single cycle of energy interchange.

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