Odometry Estimation by Fusing Multiple Radar Sensors and an Inertial Measurement Unit

Tim Brühl, Tim Dieter Eberhardt, Robin Schwager, Lukas Ewecker, Tin Stribor Sohn, Sören Hohmann

Abstract: This paper presents a framework for odometry estimation in automotive application using six asynchronously operating millimeter wave radar sensors and a combination of gyroscope and accelerometer. Two different motion models are combined to estimate motion with three degrees of freedom. For this purpose, we propose a novel three-part radar filtering method for outlier detection: By analyzing uncertainties and system limits, sensor-specific outliers are detected and removed in the first filter. We introduce knowledge about the previous motion state by a status-quo-ante filter and hereby identify further false positive raw targets in the current measure which are not accessible from the previous state. Moreover, we suggest employing a downstream, resampling-based algorithm for additional outlier detection. Based on the filtered data, radar motion state estimation is performed by use of curve fitting methods. To fuse the radar odometry estimation with the acceleration and yaw rate measurements handling non-linearities, an Unscented Kalman Filter is used. The developed framework is evaluated with reference data in various scenarios. The results demonstrate that it accurately and robustly determines motion and position states even in radar-challenging scenes, such as environments with few radar targets or with heavy metal structures. Our method keeps up with common approaches such as wheel speed sensor odometry while outperforming it in terms of drift-impairment.