Nez Alexis, Fradet Laetitia, Laguillaumie Pierre, Monnet Tony, Lacouture Patrick
PPrime Institute, CNRS - University of Poitiers - ENSMA, UPR 334, Robotics, Biomechanics, Sport and Health, Futuroscope, France.
PPrime Institute, CNRS - University of Poitiers - ENSMA, UPR 334, Robotics, Biomechanics, Sport and Health, Futuroscope, France.
Med Eng Phys. 2018 May;55:60-67. doi: 10.1016/j.medengphy.2018.03.002. Epub 2018 Mar 22.
Gyroscopes are now becoming one of the most sold MEMS sensors, given that the many applications that require their use are booming. In the medical field, gyroscopes can be found in Inertial Measurement Units used for the development of clinical tools that are dedicated to human-movement monitoring. However, MEMS gyroscopes are known to suffer from a drift phenomenon, which is mainly due to temperature variations. This drift dramatically affects measurement capability, especially that of cheap MEMs gyroscopes. Calibration is therefore a key factor in achieving accurate measurements. However, traditional calibration procedures are often complex and require costly equipment. This paper therefore proposes an easy protocol for performing a thermal gyroscope calibration. In this protocol, accuracy over the angular velocity is evaluated by referring to an optoelectronic measurement, and is compared with the traditional calibration performed by the manufacturer. The RMSE between the reference angular velocity and that obtained with the proposed calibration was of 0.7°/s, which was slightly smaller than the RMSE of 1.1°/s achieved by the manufacturer's calibration. An analysis of uncertainty propagation shows that offset variability is the major source of error over the computed rate of rotation from the tested sensors, since it accounts for 97% of the error. It can be concluded that the proposed simple calibration method leads to a similar degree of accuracy as that achieved by the manufacturer's procedure.
鉴于需要使用陀螺仪的众多应用正在蓬勃发展，陀螺仪现在正成为销量最大的微机电系统（MEMS）传感器之一。在医疗领域，陀螺仪可用于惯性测量单元，这些单元用于开发专门用于人体运动监测的临床工具。然而，已知MEMS陀螺仪会出现漂移现象，这主要是由于温度变化所致。这种漂移会极大地影响测量能力，尤其是廉价MEMS陀螺仪的测量能力。因此，校准是实现精确测量的关键因素。然而，传统的校准程序通常很复杂，并且需要昂贵的设备。因此，本文提出了一种用于执行热陀螺仪校准的简易协议。在该协议中，通过参考光电测量来评估角速度的精度，并将其与制造商执行的传统校准进行比较。参考角速度与通过所提出的校准获得的角速度之间的均方根误差（RMSE）为0.7°/秒，略小于制造商校准所实现的1.1°/秒的RMSE。不确定性传播分析表明，偏移变化是测试传感器计算出的旋转速率误差的主要来源，因为它占误差的97%。可以得出结论，所提出的简单校准方法可达到与制造商程序相似的精度。
