Conditionally Automated Driving, Basic Function - GF54.71-P-9904A
Model all (CAR)
with code 200 (Conditionally automated driving)
Overview
This document contains information on:
- General information
- Function requirements
- Function
- System components
- Status displays on steering wheel
General information
In conditionally automated driving SAE level 3, the DRIVE PILOT system can only take over driving under certain conditions. If DRIVE PILOT is active, the driver can then concentrate on peripheral activities, e.g. work, watching videos on the MEDIA display or using the InCAR Office. The driver must be ready to take control at all times, particularly in the event of a take-over request issued by the vehicle.
DRIVE PILOT regulates the speed and distance to the vehicle in front and it ensures that the vehicle remains in its lane. Unexpected traffic situations can also be detected and handled autonomously by means of an evasive maneuver within the lane or by braking maneuvers. For example, if other vehicles move into or out of the lane because an obstacle on the road has to be avoided or if the actions of another vehicle require maximum full-stop braking.
In order to detect important traffic and road conditions in a 360 degree field of view around the vehicle, DRIVE PILOT uses various sensors: radar, LiDAR (Lighting Detecting And Ranging), cameras, road humidity and ultrasonic sensors as well as microphones. The detection ranges of several sensors overlap each other. By merging the signals in the control unit, the sensors provide stable and redundant detection capability.
DRIVE PILOT also receives information on road geometry and route, route characteristics, traffic signs and any special traffic events (e.g. accidents or construction sites) from a digital HD map. This HD map is continuously updated through a back-end connection. The vehicle position is determined using a high-precision position determination system, which continuously compares the surroundings detected by sensors with map information, along with the satellite-based position finding, supported by correction data.
With conditionally automated driving SAE level 3, the steering and brake system as well as the on-board electrical system are redundant in design. The rear multifunction camera captures the area behind the vehicle and, together with the microphones in the vehicle interior, detects emergency vehicle warning lights and special signals from emergency vehicles. The driver display's camera keeps an eye on the driver at all times and it can detect if the driver is unable to take over the driving task again.
Function requirements
DRIVE PILOT can only be activated if a variety of different conditions are met.
Basically, these conditions are as follows:
- DRIVE PILOT is switched on in the multimedia system.
- The service is activated in the Mercedes me App and a cellular telephone system and Internet connection exist.
- Driving is on a freeway that is approved for the use of DRIVE PILOT.
- Operation is only permitted during the day, under dry conditions (only very low rainfall is permissible) and at temperatures above 4°C/39°F.
- The current vehicle speed is not above 60 km/h/40 mph, and the distance to the vehicle in front is adequate.
- The driving lights must be switched on (manual or automatic) and the windshield wipers must be set to automatic.
- No trailer operation or attached bicycle rack detected (through electrical connector).
- The driver camera is switched on and both eyes of the driver have been detected.
- The seat position is correctly adjusted so that the driver can reach the steering wheel and the pedals.
- No abrupt acceleration, braking or steering.
- The vehicle in front has been detected and is suitable.
- The detection ranges of the sensors and cameras are not concealed (free from dirt, ice or slush).
- The fuel/charge range of the vehicle is sufficient.
Function
The DRIVE PILOT function allows automated driving on structurally separated freeways with at least two lines, at a speed of up to 60 km/h. In high traffic volume, DRIVE PILOT follows a suitable vehicle driving immediately ahead and adapts the distance from the vehicle in front to match the speed of travel. The maximum permissible speed possible, irrespective of the traffic, is shown on the driver's display. The road characteristics, road events and traffic signs that lie ahead are evaluated by the system and automatically taken into account. DRIVE PILOT can also detect numerous critical traffic situations and react to them. If, for example, a vehicle driving a short distance ahead suddenly enters the vehicle's lane, DRIVE PILOT brakes or carries out an evading maneuver. To form an emergency corridor when speed decreases (e.g. in traffic jams) the vehicle moves either from the center of the lane to the edge of the lane or remains in the center of the lane, depending on the country involved. If necessary, DRIVE PILOT can brake the vehicle to a standstill at the outermost edge of the road.
DRIVE PILOT cannot autonomously change lanes or overtake other vehicles. A manual overtaking maneuver ends DRIVE PILOT. As soon as all requirements are met again, DRIVE PILOT can be reactivated. Manual intervention by the driver can, depending on the type and severity of the intervention involved, deactivate DRIVE PILOT or trigger a take-over-control request. DRIVE PILOT is deactivated as soon as the driver touches the steering wheel and presses a pedal while doing so. If the driver does not react to the take-over request within the maximum permissible time of 10 seconds, e.g. due to a medical emergency, emergency braking of the vehicle is initiated. The vehicle starts to brake and then comes to a standstill in the lane it is currently in; the surrounding traffic is warned by switching on the hazard warning light system. To ensure rescue personnel can access the vehicle as soon it comes to a standstill, the parking brake is applied, the Mercedes-Benz emergency call system is activated and the vehicle doors are unlocked.
System components
The conditionally automated driving SAE level 3 function is integrated into the driver assistance system control unit.
The system also includes the following components:
- LiDAR sensor (separately described subsystem)
The object data are merged with the long-range radar.
The lanes are detected together with the camera.
- Rear multifunction camera (separately described subsystem)
In combination with the interior microphones, this component has the task of detecting, e.g. priority vehicle warning lights and special signals from emergency vehicles.
- Moisture sensor
The moisture sensor is an acoustic/piezoelectric sensor used for the detection of swirled-up water in the wheel well.
- Driver camera
The driver display's camera detects the driver and his eyes. The driver must be able to take over control of the vehicle at any given time. If, for example, the driver falls asleep, turns backwards for too long or if the driver gets out of the driver's seat, DRIVE PILOT issues a take-over request.
- Self-learning HD map control unit
Along with the sensor data, a highly precise HD map provides on-line information over a backend connection about road geometry, route characteristics, traffic signs and special traffic events such as construction sites.
- Position determination control unit
Differential GPS (DGPS) is used to determine a precise vehicle position, down to the centimeter.
Vehicles equipped with DRIVE PILOT (code 200) have redundant steering and brake systems as well as a redundant on-board electrical system. If one of these systems malfunctions, the vehicle remains maneuverable in order to ensure a safe hand over to the driver.
Status displays on steering wheel
The operating status of DRIVE PILOT is indicated by the color of the status lamps on the steering wheel.
| Color of status lamps | Operating status |
|---|---|
| White | DRIVE PILOT is operational. |
| Turquoise pulsating | DRIVE PILOT is requested. |
| Turquoise | DRIVE PILOT is active. |
| Yellow | The road approved for DRIVE PILOT will end shortly. |
| Red pulsating | Take-over control request (activation of DRIVE PILOT not possible or malfunction has occurred) |
| Additional basic functions | |||
| Distance control, basic function | GF30.30-P-9903A | ||
| Intelligent driving control unit, basic function | GF30.30-P-9890A | ||
| LiDAR controller unit, basic function | GF54.71-P-9892A | ||
| Rear multifunction camera, basic function | GF54.71-P-9894A | ||
| Component part descriptions | |||
| Moisture sensor, component description | Model 223 | GF54.71-P-0012A | |
| Model 297 | GF54.71-P-0012D |