1.1 Generalities Flashcards
(24 cards)
What is meant by autonomous vehicle?
An autonomous vehicle can have different meanings depending on the context and complexity:
- Trains: simplest scenario, they move along pre-defined routes, always know their position, and have no problems with traffic or pedestrians
- Utility vehicles (robots): more complex scenario, operate in confined locations, must estimate position accurately, have no predefined paths, and can experience environmental interference (people, obstacles, other vehicles)
- Self-driving cars: most complex scenario, require accurate position estimation, have no predefined paths, and experience heavy environmental interference
What does DDT mean according to SAE classification?
DDT (Dynamic Driving Task) comprises all real-time operational and tactical functions required to operate a vehicle in on-road traffic, excluding strategic functions like trip scheduling and destination selection. It includes:
- Lateral vehicle motion control via steering (operational)
- Longitudinal vehicle motion control via acceleration and deceleration (operational)
- Monitoring the driving environment via object and event detection, recognition, classification, and response preparation (operational and tactical)
- Object and event response execution (operational and tactical)
- Maneuver planning (tactical)
- Enhancing conspicuity via lighting, horn, signaling, etc. (tactical)
What does OEDR mean in SAE classification?
OEDR (Object and Event Detection and Response) refers to the DDT subtasks that include:
- Monitoring the driving environment (detecting, recognizing, and classifying objects and events)
- Preparing to respond when needed
- Executing an appropriate response to such objects and events to complete the DDT and/or DDT fallback
What does ODD mean in SAE classification?
ODD (Operational Design Domain) refers to the operating conditions under which a given driving automation system is specifically designed to function, including (but not limited to):
- Environmental restrictions
- Geographical restrictions
- Time-of-day restrictions
- Presence or absence of certain traffic or roadway characteristics
What does ADS mean in SAE classification?
ADS (Automatic Driving System) refers to the hardware and software that are collectively capable of performing the entire DDT on a sustained basis, regardless of whether it is limited to a specific operational design domain (ODD).
What does DDT Fallback mean in SAE classification?
DDT Fallback is the response by the user to:
- Perform the DDT or
- Achieve a minimal risk condition
after the occurrence of a DDT performance-relevant system failure, or upon operational design domain (ODD) exit, or the response by an ADS to achieve minimal risk condition under the same circumstances.
What is meant by “Minimal Risk Condition” in SAE classification?
Minimal Risk Condition is a stable, stopped condition to which a user or an ADS may bring a vehicle after performing the DDT fallback in order to reduce the risk of a crash when a given trip cannot or should not be continued.
What are the SAE automation levels?
The SAE automation levels are:
- Level 0 - No Driving Automation: driver performs the entire DDT
- Level 1 - Driver Assistance: system performs either lateral OR longitudinal control, driver does the rest
- Level 2 - Partial Driving Automation: system performs both lateral AND longitudinal control, driver monitors and supervises
- Level 3 - Conditional Driving Automation: ADS performs the entire DDT but user must be ready to intervene when requested
- Level 4 - High Driving Automation: ADS performs the entire DDT and fallback without expecting human intervention, but with limited ODD
- Level 5 - Full Driving Automation: ADS performs the entire DDT and fallback without expecting human intervention, with unlimited ODD
Describe SAE automation level 0
Level 0 - No Driving Automation:
- User Role: The driver (at all times) performs the entire DDT
- Automation Role: The driving automation system (if any) does not perform any part of the DDT on a sustained basis, although other vehicle systems may provide warnings or momentary emergency intervention
Describe SAE automation level 1
Level 1 - Driver Assistance:
-
User Role:
- Performs the remainder of the DDT not performed by the driving automation system
- Supervises the driving automation system and intervenes as necessary
- Determines when to engage/disengage the system
- Immediately performs the entire DDT when required or desired
-
Automation Role:
- Performs part of the DDT by executing either the longitudinal OR lateral vehicle motion control subtask
- Disengages immediately upon driver request
Give an example of SAE level 1 system
Lane warning/keeping:
- A front-mounted camera detects vehicle position relative to the lane
- An ECU takes corrective actions
- Lane departure warning: if the vehicle approaches lane markings with turn indicator off, a warning is provided (e.g., the radio is turned off and a sound is emitted from the speaker in the direction the driver should turn)
- Lane keeping: if the car starts to drift off lane, the system takes corrective action by operating the steering wheel
Describe SAE automation level 2
Level 2 - Partial Driving Automation:
-
User Role:
- Performs the remainder of the DDT not performed by the system
- Supervises the system and intervenes as necessary
- Determines when to engage/disengage the system
- Immediately performs the entire DDT when necessary
-
Automation Role:
- Performs part of the DDT by executing both the lateral and longitudinal vehicle motion control subtasks
- Disengages immediately upon driver request
Give an example of SAE level 2 system
Adaptive Cruise Control \& Lane Keeping:
- The driver sets the desired speed
- The vehicle, using radar and/or camera:
- Measures the distance to the vehicle in front
- Controls speed to maintain safe distance
- Operates the steering to keep the vehicle in the center of the lane
- If the vehicle gets too close to the car in front, it warns in two stages:
- First with visual and acoustic signals
- Then with a short braking jolt. If necessary, the system will bring the car to a complete stop
Describe SAE automation level 3
Level 3 - Conditional Driving Automation:
-
User Role:
- When ADS is not engaged:
- Verifies operational readiness of the vehicle
- Determines whether to engage the ADS
- Becomes the DDT fallback-ready user when ADS is engaged
- When ADS is engaged:
- Is receptive to requests to intervene and responds by performing DDT fallback in a timely manner
- Is receptive to DDT performance-relevant system failures and intervenes in a timely manner
- Determines whether and how to achieve a minimal risk condition
- Becomes the driver upon disengagement of the ADS
- When ADS is not engaged:
-
Automation Role:
- When not engaged:
- Permits engagement only within its ODD
- When engaged:
- Performs the entire DDT within its ODD
- Determines if ODD limits are about to be exceeded and requests intervention if needed
- Detects system failures and requests user intervention
- Disengages an appropriate time after requesting intervention
- Disengages immediately upon user request
- When not engaged:
Give an example of SAE level 3 system
A vehicle capable of managing itself on a freeway journey, excluding on- and off-ramps and city driving. The vehicle can:
- Maintain safe distance from the vehicle in front
- Keep in lane
- Overtake
In hard-to-decide situations, handover to human driver is required.
Note: This solution was experimented with in 2012 by Google and abandoned because drivers were distracted and too slow to take control when needed.
Describe SAE automation level 4
Level 4 - High Driving Automation:
-
User Role:
- When ADS is not engaged:
- Verifies operational readiness of the vehicle
- Determines whether to engage the ADS
- Becomes a passenger when ADS is engaged (if physically present)
- When ADS is engaged:
- Need not perform the DDT or DDT fallback
- Need not determine whether/how to achieve a minimal risk condition
- May perform the DDT after the ADS reaches its ODD limit
- May request that the ADS disengage
- May become the driver after a requested disengagement
- When ADS is not engaged:
-
Automation Role:
- When not engaged:
- Permits engagement only within its ODD
- When engaged:
- Performs the entire DDT within its ODD
- May prompt the passenger to resume operation when approaching an ODD limit
- Performs DDT fallback and transitions automatically to a minimal risk condition when:
- A DDT performance-relevant system failure occurs
- A user requests it to achieve a minimal risk condition
- The vehicle is about to exit its ODD
- Disengages only after achieving a minimal risk condition or when a driver is performing the DDT
- May delay user-requested disengagement
- When not engaged:
Give an example of SAE level 4 system
A vehicle capable of completing an entire journey without driver intervention, even operating without a driver at all, but with some constraints:
- May be confined to a certain geographical area (geofenced)
- Could be prohibited from operating beyond a certain speed
- Still maintains driver controls like steering wheel and pedals for instances where a human may need to assume control
Describe SAE automation level 5
Level 5 - Full Driving Automation:
-
User Role:
- When ADS is not engaged:
- Verifies operational readiness of the vehicle
- Determines whether to engage the ADS
- Becomes a passenger when ADS is engaged (if physically present)
- When ADS is engaged:
- Need not perform the DDT or DDT fallback
- Need not determine whether/how to achieve a minimal risk condition
- May request that the ADS disengage and may achieve a minimal risk condition after disengagement
- May become the driver after a requested disengagement
- When ADS is not engaged:
-
Automation Role:
- When not engaged:
- Permits engagement of the ADS under all driver-manageable on-road conditions
- When engaged:
- Performs the entire DDT
- Performs DDT fallback and transitions automatically to a minimal risk condition when:
- A DDT performance-relevant system failure occurs
- A user requests it to achieve a minimal risk condition
- Disengages only after achieving a minimal risk condition or when a driver is performing the DDT
- May delay a user-requested disengagement
- When not engaged:
Give an example of SAE level 5 system
A vehicle capable of complete hands-off, driverless operation under all circumstances:
- This is the level where there are no provisions for human control: no steering wheel, no pedals, no joysticks
- Vehicle is unconstrained geographically and theoretically able to travel at all speeds safely
- Functions through advanced software and vehicle-to-vehicle and vehicle-to-environment communications
What are the main functional blocks of a self-driving car?
The main functional blocks of a self-driving car are:
-
Sensors: components that allow the autonomous vehicle to take in raw information about the environment
- GPS/Inertial Measurement Unit (IMUs)
- Cameras
- LiDAR
- Radar
-
V2X (Vehicle-to-Everything):
- V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure)
- Enable the vehicle to communicate with other machine agents in the environment
- Information from traffic lights, warnings from other cars, etc.
-
Actuators: components responsible for controlling and moving the system
- Steering
- Braking
- Acceleration
- Suspension
-
Perception: ability to understand what the raw information from sensors means
- Enables the car to understand whether an object is another car, a pedestrian, or something else
-
Planning: ability to make decisions to achieve higher-order goals
- Determines what to do in a situation (stop, proceed, slow down)
- Combines information about the environment with policies and navigation knowledge
-
Control: process of converting intentions from the planning system into actions
- Tells the actuators the necessary inputs to achieve desired motions
What is the function of sensors in a self-driving car?
Sensors are the components that allow the autonomous vehicle to take in raw information about the surrounding environment. The main types of sensors include:
- GPS/IMUs (Inertial Measurement Units): provide information about the vehicle’s position and movement
- Cameras: capture images of the surrounding environment
- LiDAR: use lasers to create 3D maps of the environment
- Radar: detect objects and measure their speed and distance
What is meant by V2X in a self-driving car?
V2X (Vehicle-to-Everything) refers to technologies that allow the autonomous vehicle to communicate with other agents in the environment. It includes:
- V2V (Vehicle-to-Vehicle): communication between vehicles, such as warnings from oncoming cars
- V2I (Vehicle-to-Infrastructure): communication with infrastructure, such as information from traffic lights
These technologies enable the vehicle to receive and send information that can improve safety and efficiency of autonomous driving.
What is the role of actuators in a self-driving car?
Actuators are the components of a machine responsible for controlling and moving the system. In a self-driving car, the main actuators include:
- Steering: controls the direction of the vehicle
- Braking: slows or stops the vehicle
- Acceleration: controls the speed of the vehicle
- Suspension: manages the comfort and stability of the vehicle
Actuators translate the commands from the control system into physical actions that change the vehicle’s behavior.
What is meant by perception system in a self-driving car?
The perception system refers to the ability of the autonomous vehicle to understand the meaning of raw information coming from sensors or V2V components.
For example, it enables the car to understand from a given picture frame whether a certain object is another car, a pedestrian, or something else entirely.
