AV Perception
What is AV Perception?
AV Perception refers to how AV see and understand its surrounding.
Why Perception is important for AV?
AV must be able to continuously observe its surrounding accurately.
The AV need to know what is on the road.
Eg: local: Curb, obstacles, intersections, etc.
This is to navigate AV through streets and cities.
How can AV achieve this action?
Sensors are installed all around the vehicle.
Type of sensors
Self-sensing
Localisation
Surrounding-sensing
It is to measure the current state of the vehicle.
It is used to measure vehicle velocity, Inertial Measurement Unit (IMU) to measure acceletation
It is to determine the vehicle's exact location on the map.
Eg: It uses GPS to determine the vehicle's geographic location.
It is to help the vehicles to see and understand its surroundings.
Camera; to see the environment.
Considerations
Accuracy
Resolution
Sensitivity
Dynamic Range
Perspective
Active VS Passive
Timescale
Output or Interface technology
Commonly available measurements
Wheel speed
Measured by hall effect sensors, that produces a digital signal that is proportional to speed.
Vehicle Dynamic state
Yaw rate, lateral acceleration, longitudinal acceleration
Driver Inputs
Throttle pedal position, Brake pedal position, turn signals, headlights, steering wheel position
AV Perception
Brake Pressure
Master Cylinder or each wheel of the vehicle
This is measured using diaphragram or silicon piezoelectric sensor.
Engine and Exhaust varibles
Coolant Temperature, Engine speed, O2 levels, NOx levels and spark plug firing timing.
IMU measures the vehicle's acceleration, angular rate, orientation of the body using accelerometers
Accelerometers is to measure the linear acceleration
Gyroscope measure rotational rate
Magnetometer is to measure the direction, strength or relative charge of magnetic field
It uses GNSS
It help to check the state of driver
The driver's vigilance, drowsiness, fatigue, boredom
LIDAR: it uses light detection to measure the distance.
RADAR: it uses radio waves to determine the range, angle or velocity of the object.
RADAR and LIDAR works the same, but RADAR use radio waves while LIADAR use laser
Ultrasonic sensor: It uses ultrasonic waves to measure distance of an object by sending signals and receive an echo.
Image processing sensor: detect and convey information used to make an image