The Degradation of Automotive Radar Sensor Signals Caused by Vehicle Vibrations and Other Nonlinear Movements

Abstract

As the demands on modern radar systems with respect to accuracy, reliability, and availability increase, a detailed assessment of the influence of nonlinear movements has become necessary. In particular, from the point of view of radar, different types of movements, such as any kind of acceleration, braking situation, or vehicle vibration, are essential parts of any traffic scenario. These unavoidable motions, in which the relative velocity changes within one measurement cycle, are called nonlinear movements. These nonlinearities contribute to intermediate frequencies, which are comparable to the extensively described nonlinearities of a frequency ramp. This additional contribution to the intermediate signal has a direct effect on the signal-to-noise ratio and thus on the accuracy and probability of target detection. This paper presents a study of various types of nonlinear motion and a detailed definition of the resulting parameters based on a variety of vehicle-based measurements. An advanced signal model of frequency-modulated continuous wave (FMCW) radar is introduced and verified in addition to a detailed mathematical description of spectral signal behaviour in sinusoidal motions and linear acceleration. The theoretical and experimental results in idealised point targets are transferred to real complex road users. Furthermore, by applying established automotive signal processing steps in the form of an ordered statistical constant false alarm rate (OS CFAR), the consequences of determining the noise level are also shown. In combination with the already introduced signal behaviour, these results enabled general description of the signal-to-noise ratio of nonlinear movements in complex traffic scenarios.

DNN-Based Estimation for Misalignment State of Automotive Radar Sensor

“…In the case of automotive sensor, the initial alignment may be distorted due to various external shocks and continuous vibration of the vehicle while driving [ 14 ]. In particular, because the radar sensor detects targets using radio waves if the vertical mounting angle is tilted and the transmitted signal is directed toward the ground or sky, sensing performance can be degraded [ 15 ].…”

Automotive Lidar and Vibration: Resonance, Inertial Measurement Unit, and Effects on the Point Cloud

“…Hau et al [9] simulated vibrations of an automotive chirp-sequence FMCW radar. This was followed by a more thorough study [10], where they developed the theory further and used a shaker to introduce sinusoidal movement.…”

Finite Impulse Response Filter-Based Track Formation for Preceding Vehicle Tracking Using Automotive Radars

“…An automotive radar is a system for detecting obstacles around a host vehicle on the road using microwaves. Currently, automotive radars have attracted increasing attention, and have been applied for tracking the position and velocity of preceding vehicles [1][2][3][4][5][6][7][8]. As many vehicles on the road are equipped with automotive radars, radar signals emitted from the radar of other vehicles may be detected by the receiver of the host vehicle.…”