Audi's advanced driver-assistance systems (ADAS) employ a combination of sensors, including laser scanners, or LiDAR, to achieve semi-autonomous capabilities like Traffic Jam Assist.
How Audi's laser scanner (LiDAR) works
- Emits light pulses: A fist-sized laser scanner, typically mounted in the front bumper, emits pulses of light in a fan shape across multiple vertical levels.
- Creates a 3D image: The light pulses, in the near-infrared spectrum and harmless to humans, are reflected by objects and return to the scanner. This creates a highly detailed, 3D static image of the vehicle's surroundings.
- Calculates distance and orientation: By measuring the time it takes for the light to return, the system can calculate the distance and orientation of other vehicles and obstacles. This "time-of-flight" measurement is similar to how radar functions.
- Detects objects early: The scanner's wide 145-degree horizontal view allows it to detect vehicles entering the lane early. It can also identify details about roadside structures like guardrails.
- Functions in adverse conditions: The scanner works in the dark and is equipped with a cleaning and heating system to remain operational in moderate snow or rain.
Key ADAS features using the laser scanner
On older high-end models like the A8, the laser scanner enabled more advanced functions by providing a more detailed understanding of the vehicle's surroundings.
- Traffic Jam Assist: In slow-moving traffic up to 40 mph, this system can take over accelerating, braking, and steering. It uses the laser scanner along with radar, ultrasonic sensors, and a front camera to track the vehicle ahead, follow lane markings, and maintain a safe following distance.
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Adaptive Cruise Control (ACC): The scanner works in tandem with radar and cameras to help maintain a set speed and distance from the vehicle in front.
The complete ADAS sensor suiteThe laser scanner is a specialized component that augments Audi's comprehensive ADAS suite, which gathers information from multiple sources.
- Laser Scanner (LiDAR): Creates a detailed 3D image of the area directly in front of the car, especially useful at lower speeds and in complex traffic situations.
- Radar: Long-range radar sensors, typically located in the front bumper, are used for adaptive cruise control and other forward-looking functions.
- Cameras: A windshield-mounted front camera helps recognize traffic signs, lane markings, and other objects.
- Ultrasonic Sensors: These short-range sensors are integrated into the bumpers and help with parking assistance and low-speed maneuvers.