Nissan's ProPilot '2.0' 360-degree sensing system.

Yokohama - Nissan is sticking to its guns on self-driving technology that uses radar sensors and cameras, but not lidar or light-based sensors, and this they put down to high costs and limited capabilities.

The Japanese carmaker unveiled updated self-driving technology a month after Tesla Chief Executive Elon Musk called lidar "a fool's errand", berating the technology for being expensive and unnecessary.

Nissan, which wants to have its self-driving cars on city streets by 2020, has long shunned lidar, a relatively new technology for cars, which has recently been the subject of an influx in investment by many of its rivals.

"At the moment, lidar lacks the capabilities to exceed the capabilities of the latest technology in radar and cameras," Tetsuya Iijima, general manager of advanced technology development for automated driving, told reporters at Nissan's headquarters.

"It would be fantastic if lidar technology was at the level that we could use it in our systems, but it's not. There's an imbalance between its cost and its capabilities."

Iijima unveiled Nissan's own latest self-driving technology, which enables hands-free driving in single lanes on highways on predefined routes.

The technology, to be released in Japan later this year, uses radar and sonar sensors along with cameras to compile the three-dimensional mapping data required for cars to "see" their surroundings.

Apart from sonar, side radar and around-view monitoring cameras, Nissan said it has developed a "tri-cam" that focuses on three points to the front and sides of the vehicle to capture a wide area of view.

Tesla also relies on cameras and radars for its self-driving technology.

Nissan wants to add its self-driving technology to more of its affordable models to boost sales and recover from a profit slump. When reporting earnings earlier this week, the automaker said it had hit "rock bottom" in the aftermath of a financial scandal involving its ousted Chairman Carlos Ghosn.

Fool's errand?

Lidar is currently used by companies such as General Motors, Ford and Waymo as carmakers and tech firms race to develop self-driving cars.

Lidar technology uses light-based sensors that fire roughly 1 million laser pulses a second as it collects measurements that are analysed and processed into 3D models and maps.

More than $1 billion (R14.3bn) in corporate and private investment has been pumped into some 50 lidar startups over the past three years, according to a Reuters analysis in March of publicly available investment data.

Still, it is a technology in flux.

Initially using bulky spinning devices placed on the roof of cars, lidar developers have transitioned to more compact solid-state devices that can be mounted on other parts of a car. These now sell for less than $10 000 (R143 000) in limited quantities, and are widely expected to eventually sell for as little as $200 (R2860) in mass production.

Reuters