Off-the-shelf sensor vs. experimental radar -- How much resolution is necessary in automotive radar classification?

TL;DR

This study compares off-the-shelf and high-resolution automotive radars for road user detection, revealing that higher resolution significantly improves clustering performance, which enhances overall detection accuracy in autonomous driving systems.

Contribution

The paper provides a comprehensive evaluation of two radar generations, highlighting the impact of resolution on clustering and detection performance in automotive radar systems.

Findings

Next-generation radar improves clustering significantly.

Higher resolution enhances overall detection accuracy.

Performance gains mainly originate from better clustering, not classification.

Abstract

Radar-based road user detection is an important topic in the context of autonomous driving applications. The resolution of conventional automotive radar sensors results in a sparse data representation which is tough to refine during subsequent signal processing. On the other hand, a new sensor generation is waiting in the wings for its application in this challenging field. In this article, two sensors of different radar generations are evaluated against each other. The evaluation criterion is the performance on moving road user object detection and classification tasks. To this end, two data sets originating from an off-the-shelf radar and a high resolution next generation radar are compared. Special attention is given on how the two data sets are assembled in order to make them comparable. The utilized object detector consists of a clustering algorithm, a feature extraction module, and a recurrent neural network ensemble for classification. For the assessment, all components are evaluated both individually and, for the first time, as a whole. This allows for indicating where overall performance improvements have their origin in the pipeline. Furthermore, the generalization capabilities of both data sets are evaluated and important comparison metrics for automotive radar object detection are discussed. Results show clear benefits of the next generation radar. Interestingly, those benefits do not actually occur due to better performance at the classification stage, but rather because of the vast improvements at the clustering stage.