Testbench for IMU characterization and verification under combined vibration, rotation and temperature environments

Kurzfassung

Inertial Measurement Units (IMUs) are critical components in navigation systems, where their accuracy directly impacts mission success. While IMU technology has advanced significantly, characterizing their behavior under real-world operational conditions remains challenging, particularly when exposed to simultaneous vibrations, rotations, and temperature variations. This is especially relevant for space vehicles like launchers and interplanetary landers, which rely solely on navigation systems without hybrid solutions to correct errors caused by environmental factors.

Traditional testing methods have focused on identifying linear parameters such as scale factor and bias under static and isolated conditions. However, these approaches fail to capture nonlinear dynamic behaviors that occur in real-world operations. Existing high-order parameter estimation methods, such as those proposed in the IEEE 1293:2018 standard, are complex and to our assessment could be improved for routine use in space applications.

To address these limitations, we are developing a testbench at DLR Bremen that integrates testing capabilities under combined environmental conditions. This innovative test equipment not only enables the excitation of high-order effects that cannot be obtained by standard test equipment like rotation tables, but also provides 6-DOF displacement, velocity, and acceleration data that can be used for accurate characterization, with a reduced number of test cases which are similar to standard environmental tests already performed for aerospace systems. The system's ability to provide sufficiently exciting environmental conditions for each sensor axis supports observability of effects. The extensive inertial sensor characterization and high-fidelity modeling capability provided by such testbench have the potential to allow a more robust verification of navigation systems by use of high-fidelity sensor simulations validated by representative tests with real systems at representative scenarios. Besides that, they can facilitate the development of algorithms that aim to compensate for the combined dynamic and nonlinear environmental effects that detriment the sensor performance. This poster presents an overview of our testbench's capabilities and how its performance is verified. It also presents an example of application of the testbench and what benefits can be obtained with it. We aim to highlight its potential as a tool for advancing IMU characterization and fostering collaboration within the space community. Researchers and engineers are encouraged to reach out with their application ideas and needs, helping us improve the testbench's capabilities and further enhance European space project robustness.