Dead-beat control based thermal compensation for micromachined thermal gas gyroscope

Micromachined thermal gas gyroscopes take advantages of simple structure, low cost, high shock resistance, and large measurement range by using thermally driven gas stream instead of solid proof mass as moving and sensitive element compared with conventional silicon or quartz gyroscopes. However, they suffer from temperature susceptibility, which degrades performances of the gyroscopes. It is important to investigate thermal mechanism behaving in sensor and build an effective thermal compensation method to guarantee the sensor accuracy. In this paper, Finite-Element-Model (FEM) simulation method is used to study the thermal behavior and the relationship between the thermal drift of the gyroscope and the working temperature of the heaters that thermally drives gas motion is established. On this basis, we propose a real-time thermal compensation scheme based on Alternating Dead-Beat Control (ADBC). ADBC is used to alternatively modulate the heaters to implement fast, small-overshoot, and precise temperature control so as to keep the working condition of the sensor steady. Experiments validate that the thermal compensation scheme is effective to eliminate the temperature drifts in scale factor and zero bias of the sensor, meanwhile improves the gyroscope sensitivity. Predictably, the ADBC based compensation methodology can be applied for other thermal sensors (e.g. thermal accelerometers, thermal anemometers).