eVTOL, UAS, and Now, Another UAM Acronym: LiDAR

When the UAM revolution takes off, there will be no shortage of acronyms. There’s already eVTOL (electric vertical take-off and landing vehicles), UAS (unmanned aerial systems), UAM (urban air mobility). Now add one more: LiDAR.

A 50-year-old technology, light detection and ranging (LiDAR) technology, is expected to play a key role in the development of urban air mobility. The “flying cars” will likely use photonics (the physical science of light generation, detection, and manipulation through emission, transmission, modulation, signal processing, switching, amplification, and sensing) and LiDAR to help navigate their way around urban skies.

The challenge has been minimizing the weight, size, and cost of advanced LiDAR technologies. LiDAR, which mechanically scans a vehicle’s surroundings, can provide a field view of 360° × 40° at a range of hundreds of meters. But it is expensive (costing thousands of dollars per unit) and relatively large and heavy, all characteristics counterproductive to building a car-sized vehicle intended to fly in the air as much as it will drive on terra firma, ideally autonomously.

Seeing LiDAR in a New Light

Voyant Photonics, a company founded in 2018 by Chris Phare and Steven Miller, visiting researchers at Columbia University’s Lipson Nanophotonics Group, raised US$4.3 million in 2019 to develop solid-state LiDAR technology (a microchip). This technology would be based on an optical phased array and a frequency modulated continuous wave (FMCW) LiDAR engine. The FMCW uses a bidirectional chirped 1550-nm CW laser with a frequency that changes over time. The difference between the outbound and inbound frequencies determines the distance of moving objects in the field of view as well as their velocity.

Equally valuable, the LiDAR engine consumes less than 1.8 watts of electricity and yields higher resolution sensing than LiDAR currently in use. This fingertip-sized chip, it turns out, will be very useful in everything from cellphones to 3D mapping (to within centimeters) for autonomous flying drones.

NASA is also developing LiDAR expected to be used in UAM. The NASA Ames Research and Armstrong Flight Research Centers have already tested a LiDAR system mounted on a jeep roof in August 2019. The survey route took the LiDAR around all vehicle-accessible areas at NASA’s Ames, Research Park, the perimeter road, the onsite wind tunnel, and the Roverscape (an 11,500 square meter facility used to test mobile robot locomotion, navigation, and operations, as well as simulations of planetary surface missions).

In an industry expected to be a US$3 trillion market by 2040, a tiny device, such as a LiDAR chip, could be a major player.