LiDAR Controller Unit, Basic Function - GF54.71-P-9892A

Model All (CAR) 

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 
  • Lane recognition 
  • Object recognition 
  • Spray and precipitation detection 
  • Blockage detection 
  • Detection range determination 

General 

LiDAR stands for "Light detection and ranging" and it is a visual measuring method for the spatial location and measurement of distances to objects.

The surrounding area is scanned here with IR light beams and mapped in a virtual 3D format as a point cloud. Three-dimensional information about the shape and surface properties is derived from the surrounding objects that, in particular, are required for conditionally automated driving. Where moving objects are involved, the direction of movement can also be determined.

This then clearly recognizes where an object is moving to. In combination with object classification (e.g. pedestrian, lane marking, etc.), a high degree of certainty is achieved.

The LiDAR controller unit is located in the front center of the radiator trim and basically consists of the following components:

• Infrared laser unit
• Light detector unit
• Motor and mirror unit
• Electronic analysis and control electronics (control unit)
• Auxiliary heater heating element

The range of the LiDAR sensor is approx. 180 m and the detection range is approx. 120° (horizontal) with an opening angle of approx. 10° (vertical).

The laser operates with a wavelength of 905 nm.

Important note:

The LiDAR controller unit uses a Class 1 laser system: If the housing is opened or if it is damaged, laser beams may damage the retina.

Function requirements 

• Calibration procedure successfully completed
• No blockage detected

Function 

The LiDAR controller unit sends pulsated infrared light pulses over two rotating mirrors that are then reflected from objects (e.g. road users, obstacles or lane markings). The receiver detects the reflected pulses and uses them to determine the position of the target object through calculation of the laser pulse flight time. The controller unit then creates a 3D map of the surrounding area in front of its own vehicle. Vehicle dynamics signals (wheel speed, steering angle, lateral and longitudinal acceleration, etc.) are also used to determine the movement of the vehicle.

The following functions are also implemented in the evaluation and control electronics of the LiDAR controller unit:

Lane recognition 

The lane markings are recognized on both sides of its own lane and their course.

Object recognition 

Stationary objects and moving objects in the field of view are detected.

Spray and precipitation detection 

It is detected here if vehicles driving in front in the sensor's field of view form any spray or if any precipitation or snow restricts the sensor's detection range.

Blockage detection 

It is detected here if any dampening on the front of the sensor (e.g. though dirt) prevent object recognition and the detection of lane markings from achieving their performance levels.

Detection range determination 

The possible detection range in which a reference target can be detected is determined.

The LiDAR controller unit also heats or cleans the sensor front in order to alleviate the effects of dirt, ice or snow. A self-monitoring function is run at the start or cyclically during operation. The heating element is located as a vapor-deposited heater wire on the front side and prevents any fogging of the optics. For cleaning purposes, a telescopic nozzle located above the sensor is supplied with washer fluid by the LiDAR cleaning system pump. The telescopic nozzle and the spray nozzle are heated.

The LiDAR controller unit is connected to the vehicle's network architecture via Ethernet.

The following information and requests are primarily sent to the driver assistance systems control unit:

• Information:
  • Lane data
  • Object data (object size, object type, object direction of motion, distance)
  • Weather conditions
  • System status (incl. diagnosis information)
• Requests:
  • LiDAR sensor cleaning system pump
  • Warning and information messages

Function restrictions: 

• Curvatures with a radius of < 150 m.
• Lane width > 4.20 m.
• Dazzle through very low sun in the immediate detection range.
• Heavily soiled, scratched or damaged cover panel.

	Component descriptions
	LiDAR controller unit, component description	Model 223	GF54.71-P-9893A
		Model 297	GF54.71-P-9893D
	Spray nozzle heater, component description	Model 223	GF82.35-P-5002A
		Model 297	GF82.35-P-5002D
	Spray nozzle hose heater component description	Model 223	GF82.35-P-5003A
		Model 297	GF82.35-P-5003D