A Micro Oven-Control System for Inertial Sensors

This paper presents a modular and generic micromachined oven-control system for use with miniature micro-electro-mechanical system (MEMS) transducers. The micro-oven-controlled off-the-shelf commercial six-axis MEMS inertial measurement unit (IMU), Invensense MPU-6050, provides the lowest reported temperature-induced root of sum of squares bias errors of 62.71°/h and 1.920 mg from -40°C to 85°C for three-axis gyroscopes and three-axis accelerometers, respectively. The micro-oven control system provides thermal isolation from the surrounding environment using a micro-machined isolation platform, vacuum-sealing, and a metal package. In addition, a CMOS temperature sensor, a proportional-integral-derivative-based temperature control scheme, and least mean square and random forest compensation algorithms are utilized to reduce temperature-induced bias drifts of IMUs. The most stable axes achieve peak-to-peak bias drifts of 12.78°/h and 665.2 ug during a thermal-cycle test for gyroscopes and accelerometers, respectively. The oven's heater power consumption is <;125mW at the lowest temperature, -40°C. This oven-control system can be applied to a wide range of MEMS sensors to reduce performance degradation due to temperature variation.