The response of the sensing axis provides information about the applied angular velocity.In driving loop control of the vibratory gyroscopes, the main target is to originate an oscillation along the vibrating axis with constant amplitude at its resonant frequency. Moreover, in order to obtain high efficiency in delivering energy from one axis to another, the resonant frequencies of both driving and sensing axes must be equal, which is also called mode-matching. However, for high-end applications such as the military, automotive, medical surgery, etc., micro-gyroscopes cannot not meet the performance demands due to the bias-drift which is a critical issue for high performance micro-gyroscopes. In other words, even in the absence of any input (angular velocity) the output of the micro-gyroscope is non-zero.

This offset, which is usually referred to bias-drift, is present in the measured signal. Bias-drift is a complex phenomenon which is a combination of time-, temperature- and disturbance-dependent behaviors [4]. The main consideration of the phenomenon is the effect of the temperature fluctuation of the environment. This effect is an important source error in MEMS gyroscopes and is the most discussed [5�C7]. Furthermore, the relation between the temperature bias-drift and Brownian noise was investigated in the literature [8]. Some neural network-based methods were also employed in the TBD modeling and compensation of fiber optic gyroscopes and proved satisfactory [9,10].

A systematic identification and compensation method was accomplished by a JPL micro-gyroscope [11], as well as the TBD of a micro-gyroscope was investigated in terms of the resonance frequency variation induced by temperature Brefeldin_A variations. In addition, temperature dependent characteristics and compensation methods were discussed in [12]. However, the aforementioned compensation system needed an additional thermal resistor to detect the environment temperature and it was based on a MCU and PC due to the complicated compensation algorithm. In [13], the temperature characteristics of the micro-gyroscope were investigated and two different methods were proposed. However, the proposed compensation method still needed an extra temperature sensor, A/D and D/A converter, making the whole system hard to integrate on a single chip. Although a temperature control method was proposed to operate the gyroscope under optimal temperature to overcome the different temperature model due to the manufacturing errors and the influences of the peripheral circuit, an additional thermoelectric cooler and power consumption problems were induced. To eliminate the need for an extra temperature sensor, temperature self-sensing is discussed in [14].