When we talk about fully autonomous vehicles, one of the most important things which makes it possible is ADAS systems, and without LIDAR technology, it is impossible to think about a self-driving car. Technology-wise ADAS systems can be classified as vision, RADAR, and LIDAR-based ADAS. This article will cover all about LIDAR technology for autonomous vehicles and why it is one of the most important technologies for future cars.
The automotive industry is booming, and everyday vehicle manufacturers are coming up with high-end applications to make driving luxurious and safe. In this regard, innovation in ADAS systems are also thriving, and vehicles are getting equipped with multiple sensors like camera, radar, image sensor, infrared sensors, ultrasonic sensors, and LIDAR sensors. Let’s know more about LIDAR-based ADAS systems.
What is LIDAR technology and how it works for automotive applications?
LIDAR, an acronym for (light imaging, detection, and ranging) is an active remote sensing technology that uses light waves (laser light) to scan and detect objects in the surroundings.
A LIDAR Sensor, while sending high-end laser beams in the environment, typically performs laser scanning or 3D scanning. The light waves emitted from the LIDAR sensor bounce back from the object in the surroundings and return back to the sensor. And by the time-speed and distance method, the distance of the object from the sensor is calculated. In a very high-speed action, a thousand times, LIDAR sensors repeat this action to detect the exact distance and dimensions of the surrounding objects.
LIDAR used in vehicles not just detects objects, but it helps in identifying the objects too. These sensors can replicate an exact image of the surroundings in an animated 3D map on the display screen of the vehicle’s infotainment system. And this is the best feature of LIDAR technology.
Why Self-Driving Cars need LIDAR Sensors?
ADAS systems in a vehicle are there to assist the driver in safe driving. Many times, driving becomes too difficult in poor visibility or blocked vision conditions. No ADAS sensor other than LIDAR is capable of seeing through objects, pitch dark, or dense fog. LIDAR technology in a vehicle gives a 360-degree view of the vehicle’s surroundings in a 3D map with high accuracy in real-time.
An autonomous vehicle, which requires high precision in taking the decisions for acceleration, braking, lane change, traffic lights/sign recognition, object detection and response to them, identifying roadblocks, adjusting driving patterns with respect to passing vehicles, and thousands of other preemptive actions must need LIDAR to perform accurately. LIDAR actually helps autonomous cars to handle all the discussed scenarios smoothly.
LIDAR Sensors for Cars
LIDAR sensors for the automotive application can be classified into many types depending on their technology, location, and Image type.
Electro-Mechanical LIDAR: Electro-mechanical LIDAR is the traditional scanning LIDAR system mounted on a vehicle and spin continuously at 360 degrees at high speed. These LIDAR systems are very expensive, bulky, and difficult to maintain.
Solid-State LIDAR: Solid-State LIDAR is a single-chip sensor that uses optical phased arrays and do not require any sensor movement like electro-mechanical LIDAR. On a solid-state LIDAR components like an emitter, receiver and processors are mounted on a single chip. This system sends out burst of laser photons in all directions and receives the same in different patterns after colliding with the surrounding objects. This super high-speed action is performed thousands of times per second and a high-end processor in the system record, analyze and process the data to show a 3D map of the surroundings.
Solid-state and Flash LIDAR sensors are the future of autonomous vehicles, and on the other end, electro-mechanical LIDAR is becoming obsolete. The latest small compacted LIDAR sensors can be placed in different locations in a vehicle like bumper and grille, headlight and taillight, roof and upper pillars, windscreen, and rearview mirrors.
Top 5 LIDAR Sensor Manufacturers:
2. Leddar Tech
How does LIDAR sensor work with other ADAS Sensors?
Other than LIDAR, there are camera and RADAR-based ADAS systems, and for a fully autonomous vehicle of level 5, all the sensors must complement each other.
On-board cameras used for vision-based ADAS are equally important as LIDAR sensors, as cameras using image processing techniques can see and detect colors i.e., traffic signs, lights, and texts, which is not possible with LIDAR sensors.
On the other hand, the RADAR sensors help in detecting the obstruction in the field of view of the vehicle. Short-range RADARs are capable of detecting objects up to 30 meters from the vehicle and assist features like blind-spot detection, rear collision warning, lane change assistance, cross-traffic alerts, and parking assistance. Long-range RADAR can detect objects to 200 meters and assist with Adaptive cruise control, Automatic Emergency Braking Systems, and other ADAS features. The only limitation of RADR is that it can detect objects but cannot identify them. It can trigger other sensors in a vehicle to notify the driver in case of object detection but cannot show what the object is, is it a tree, bicycle, car or person.
Here LIDAR sensors balance the limitation of the radar and camera sensors. LIDAR sees through the objects and identifies objects up to 250-300 meters.
So, the complete story is that the LIDAR sensors for ADAS applications are the latest trends in the automotive industry to assist drivers with accurate and precise driving experiences.