High-efficiency low-cost accelerometer-aided gyroscope calibration

Inertial measurement units (IMUs) are gaining popularity in several application fields, such as navigation, body motion monitoring and indoors positioning. Microelectromechanical (MEMS) accelerometers and gyroscopes are used for this purpose since they offer a reasonable price-performance trade-off. However, they still present several undesired characteristics in their output that should be compensated through proper device calibration. Although accelerometers are quite easy to calibrate, gyroscopes need more complex systems and equipment to achieve an accurate calibration. This paper shows a novel calibration system using simple equipment (a bike wheel as a turntable) designed for an IMU which is used for a knee telerehabilitation system and composed of a triaxial accelerometer and a biaxial gyroscope. MEMS Accelerometers are usually more accurate and offer better performance than MEMS gyroscopes. Thus, accelerometer data is used to help calibrate the gyroscope by applying a novel, simple, yet accurate set of maneuvers.