Start with the sensors, then design the rest: How Zoox built its robotaxi

Source: Ars Technica

Introduction

These days the hype is all about AI and robots, but almost a decade ago the tech du jour was self‑driving. You couldn’t swing a lanyard at CES for the latter half of the last decade without hitting a robotaxi; post‑COVID, the number of startups has shrunk, but the technology has definitely matured. In the right cities—San Francisco and Austin, Texas, spring to mind—you might see dozens of sensor‑festooned vehicles among the downtown traffic.

The pod‑like robotaxis belonging to Zoox stand out. Other robotaxi developers are retrofitting existing vehicles like Hyundai Ioniq 5s with sensors and the computing power necessary for self‑driving. Zoox, which was bought by Amazon in 2020, did that with its test fleet, but as it starts to offer ride‑hailing services—currently in Las Vegas and San Francisco—it’s doing so with a purpose‑built design that looks like it just drove off the set of a big‑budget sci‑fi production.

“A robotaxi is not a car; it’s not a human‑driven vehicle, and the requirements are wildly different, although it has to live in that world,” explained Chris Stoffel, director of robot industrial design and studio engineering at Zoox.

Sensor Placement and Coverage

It all starts with the sensors, each perched on a little ledge projecting from the top four corners of the robotaxi’s body. From up there, each has an unobstructed, high‑level view, giving the Zoox robotaxi good situational awareness, particularly straight ahead. “Because we don’t have a traditional hood, we’ve optimized our frontal coverage in a way that would be nearly impossible on a retrofitted vehicle,” said Zoox director of sensor engineering Ryan McMichaels.

Zoox’s robotaxi has a friendly, welcoming design.
Credit: Zoox

Bidirectional Symmetrical Design

The robotaxi doesn’t care whether it’s coming or going, thanks to its symmetrical, bidirectional design. The advantages are tantalizing for a vehicle that’s summoned on demand: there’s no need for a three‑point turn, and with its symmetrical steering axles it achieves unparalleled agility. Because both axles have the same degrees of steering, the Zoox robotaxi can “crab walk” far more effectively than the GM Hummer EV performing its party trick.