Stress Testing for Performance Analysis of Orientation Estimation Algorithms

Abstract

Technological advancements have seen the spread of MEMS (Micro-electromechanical Systems) based sensors such as IMU (Inertial Measurement Unit) systems. The latter provide object orientation information in numerous applications such as smartphones, robotics, automotive, drones, and many others. In more detail, IMUs based on MEMS technology are characterized by small size, low power, and low cost. Technically, orientation information is provided by appropriate orientation estimation algorithms fed with quantities measured by MEMS sensors, such as acceleration, angular velocity, and magnetic field. A preliminary work pointed out that such MEMS sensors suffer significant drifts when they have to endure non-standard operating profiles in terms of thermal conditions. However, when considering very low-cost devices, the influence of temperature on the operation of orientation estimation algorithms still remains an important research gap in the literature. To deal with this important aspect, the paper proposes a specific test plan to analyze the performances of MEMS-based IMUs by considering a temperature stress test. Therefore, the effect of temperature was first analyzed on the individual sensors of the IMU (accelerometer, gyroscope, and magnetometer), then the effects of a very simple temperature compensation strategy were analyzed to highlight the importance of such step. Specifically, the effects of not compensating for temperature were studied considering a low-cost commercial IMU typically used in various fields of application. To better quantify such effects in practical applications, two wellknown orientation estimation algorithms (i.e., Complementary Filter and AHRS) typically fed by IMUs output have been considered. The experimental results obtained using the custom devices under test show that temperature compensation is necessary for the best performance of the analyzed orientation estimation algorithms.

Temperature Sensitivity Analysis of Inertial Measurement Unit Under Dynamic Conditions

“…As mentioned in the introduction section, an initial static assessment was conducted to evaluate the performances of multiple DUTs when the operating temperature is non-standard [33], [34]. Such previous studies pointed out unexpected and noteworthy temperature drifts on all the sensors embedded in the IMU.…”

“…To fill this gap, some preliminary research works available in [33], [34] carried out a static characterization of several MEMS IMUs under temperature stress tests, focusing on the correlation between the IMU's output and operating temperature. The previous papers pointed out a robust correlation measured across the IMU's sensor outputs for each axis orientation and each sensor under examination.…”

“…This is because the preliminary static characterization and the proposed dynamic test have been carried out on different IMUs. Thus, the uncorrelated behavior (in terms of sign and magnitude) of the sensors axes differs also depending on the specific device under test (for more test repetitions and more devices under static condition, see [33]- [34]). To further proceed the analysis, another phenomenon induced by the operating temperature on the tested IMU has been investigated.…”

Dynamic characterization of MEMS-based Inertial Unit under combined vibration stresses

“…Furthermore, the device also includes an additional temperature transducer that can be used for temperature compensation when the IMU is used under harsh thermal conditions (see for instance [19]- [20]).…”

Analysis of Inertial Measurement Units Performances Under Dynamic Conditions

“…In some previous studies, we proposed the analysis of MEMS-based IMU performances under vibration and temperature stresses and static conditions [24], [25], [26]. The proposed works aimed at analyzing the performances of the device considering the real scenario in which the system will be installed.…”