Coherent lidar for ride-hailing autonomous vehicles

TL;DR

This paper explores the advantages, challenges, and technological solutions for implementing coherent lidar systems in autonomous ride-hailing vehicles, focusing on optics, laser power, and signal processing innovations.

Contribution

It provides a comprehensive analysis of the technical hurdles and proposes integrated approaches for low-cost, high-performance coherent lidar systems suitable for autonomous vehicles.

Findings

Coherent lidars offer velocity measurement and interference immunity advantages.

Achieving required points per second and fields of view involves high laser power and advanced optics.

Photonic integration can enable low-cost, high-power coherent lidar solutions.

Abstract

Coherent lidars promise a number of advantages over traditional time-of-flight lidars for autonomous vehicles. These include the direct measurement of target approach velocities via the Doppler effect, and near-immunity to interference from other lidars and sunlight. Furthermore, coherent lidars are compatible with a variety of solid-state beam steering technologies such as optical phased arrays, which may enable low-cost and compact lidars. In this manuscript, we discuss the headwinds facing the adoption of coherent lidar for autonomous ride-hailing vehicles and how they can be addressed. On the optics side, we explore how one can achieve the points per second and fields of view required for autonomous vehicles, and the resulting laser power requirements. We then discuss how these power levels could be achieved by co-packaging high-power semiconductor lasers and amplifiers with photonic integrated circuits, the preferred approach for low-cost coherent lidars. On the signal processing side, we discuss how to robustly disambiguate multiple returns in realistic environments and affordably meet the compute requirements.