Electronics and Semiconductors

New lidar technology is changing the automotive industry

18 December 2023
Autonomous self-driving vehicle with lidar technology. Source: RareStock/AdobeStock

Initially, scientists employed light-based measurement techniques to determine the density of the air at high altitudes by analyzing the strength of a searchlight beam's reflection. The time required for a light pulse to reach a cloud and return to the ground was then used to determine the cloud-base height. As a method of detecting distance, light detection and ranging (lidar) was first developed by Middleton and Spilhaus in 1953. But it wasn't until new technologies like Dennis Gabor's holography approach in 1945 and the laser in 1960 that the lidar principle as we know it today was introduced: it measures distances by determining how long it takes a laser pulse to travel from the source to the target and back.

It is now possible to say that we are making progress toward introducing completely autonomous vehicles onto our roads. Automobile industry giants are already equipping vehicles with autonomous capabilities via advanced driver-assistance systems (ADAS), allowing them to autonomously accelerate, steer and brake under the driver's watchful eye. Lidar is a crucial technology for the development of autonomous vehicles since it allows for the continuous improvement and introduction of new features like these. The primary role of automotive lidar lies in crafting intricate 3D maps of a vehicle's surroundings. These maps prove pivotal for autonomous vehicles to navigate and detect obstacles, pedestrians and other vehicles. Lidar collaborates with cameras and radar, furnishing a comprehensive view of the environment.

How does lidar technology work?

Lidar works by estimating the time it takes for a laser's light signal to travel from the source to its intended target and back again. The distance R to the target may be calculated using the speed of light c and the round-trip delay d (also called time of flight) of the emitted signal, as given by the following equation:

By changing the transmitted light's frequency, phase and intensity, and then timing how long it takes for the receiver to pick up on the modulation pattern, d may be determined. Time of flight must be determined independently for each location in order to construct a point cloud, which is a 3D model of the area surrounding the vehicle.

What makes up a lidar system?

The two main components of a lidar system are the laser rangefinder and the scanning system. The first part of the laser rangefinder is the laser transmitter, which uses a modulated beam of light to illuminate the target. A photodetector is also included, which processes the reflected photons optically and then converts them into an electric signal after photoelectric conversion. Third, it has optics, which concentrate the reflected signal onto the photodetector by collimating the emitted laser. Lastly, electronics are incorporated for signal processing to calculate the distance between the laser and the reflecting surface, depending upon the received signal. The scanning system, on the other hand, will direct laser beams in a variety of azimuths and elevations.

[Learn more about lidar technology on GlobalSpec]

How lidar is driving the automotive industry

Improvements in safety, navigation and vehicle autonomy are just some of the ways in which lidar is changing the car industry.

  1. Precise mapping: Lidar systems create detailed 3D maps of the vehicle's surroundings. This precision is crucial for accurate navigation, especially in complex urban environments.
  2. Obstacle detection: Lidar enables vehicles to detect and recognize obstacles in real-time. This is essential for avoiding collisions and ensuring the safety of passengers and pedestrians.
  3. Autonomous driving: The technology plays a pivotal role in autonomous vehicles. By providing a comprehensive and accurate view of the environment, lidar helps self-driving cars make informed decisions and navigate safely.
  4. Enhanced perception: Lidar works with other sensors like cameras and radar to improve overall perception. This multi-sensor method guarantees dependability across a wide range of driving circumstances, from low light to bad weather.
  5. Enhanced safety: The precise mapping and obstacle detection capabilities of lidar contribute to improved overall safety on the roads. ADAS efficacy benefits from lidar technology in the provision of capabilities such as emergency braking and lane-keeping assistance.
  6. Accident reduction: Lidar-equipped cars may help cut down on the number of accidents brought on by human error by improving obstacle recognition and providing other enhanced safety features.
  7. Adaptableness to various environments: The technology is versatile and can adapt to different environmental conditions, making it reliable in urban settings, highways and rural areas.
  8. Technological advancements: Ongoing advancements in lidar technology aim to make it more compact, cost-effective and robust. This will facilitate its integration into a broader range of vehicles, contributing to the widespread adoption of autonomous driving technology.

Conclusion

Automotive lidar technology deploys laser light for meticulous distance measurement. Within the autonomous driving domain, lidar stands as a vital sensing tool. These systems emit laser beams, gauging the time the light takes to bounce off nearby objects. The surge in its adoption within automotive contexts is notable, substantially amplifying the perceptual capacities of autonomous vehicles, particularly in challenging scenarios like low visibility or adverse weather conditions. Continuous advancements in this technology are directed toward augmenting performance, curbing costs and fortifying the reliability of autonomous driving systems.

To contact the author of this article, email GlobalSpecEditors@globalspec.com


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