07 Technologies III - New Trends in Active Safety: Communication and Automation Flashcards
Wireless communication
- may help active safety when visibility is limited because the information about the approaching vehicles may be acquired without line of sight.
- is essential for platooning (cooperative, automated, ACC), for instance to coordinate how vehicles should join or leave the platoon
What are Cooperative Systems?
Cooperative systems are intelligent transportation systems, that rely on wireless communication to enable data exchange. Intelligent transportation systems are HW and SW implementations which utilize intelligent technologies to improve safety, and mobility (including fuel efficiency). Intelligent (and communication) technologies include information (SW), communication, and electronic technologies (HW). Intelligent in-vehicle transportation systems addressing safety are active safety systems. Cooperative systems addressing safety are often referred as cooperative safety
systems or cooperative safety applications
What are Cooperative Systems? Two types
V2V
V2I (I2V)
Multipath Propagation
Multipath Propagation: Signal travels multiple paths from transmitter to receiver.
Path Differences: Vary in amplitude (strength) and phase (timing).
Receiver’s Limitation: Receives a single signal as the sum of all paths.
Challenge: Large differences between paths → harder to decode original information.
Fading
Multipath Effect: Signal at receiver differs from signal sent by transmitter.
Interference:
* Constructive/destructive interference causes signal variation.
* May lead to fading (amplitude changes).
Challenge: Fading can make the signal hard for the receiver to interpret.
SWOT analysis - Automated Driving
Strengths:
* Automated vehicles will not get high, drunk, or sleepy.
* Driving is not a task all humans enjoy at all times.
* Automated vehicles can work 24/7 with ”low” wage.
weakness:
* Automated vehicles will not use glances, gestures, or voice to show their intent.
* Automated vehicles may have hard time empathizing with other road users (to predict their behavior).
* Automated vehicles are not legal in most countries (today).
* Automated vehicle cost a lot of money (today).
opportunities:
* Increase safety (less human errors)
* Reduce congestion (more parking spaces)
* Increase personal mobility
* Decrease driver load
* Enable drivers to do other tasks than driving
threats
* The problem may be too complex to solve in a mixed environment.
* Automated vehicles may introduce new types of crashes (hard to predict)
* Transition of control are necessary and may result in mode confusion.
* Humans are not good at monitoring.
* It is hard to prove that automated vehicles are safe(r)
Communication challenges
- Multipath Propagation
- Fading, shadowing
- Inter-symbol Interference
- Spectral Limitation
- Limited Energy
- User Mobility
Limited Energy
Context: Communication for mobile users (e.g., road-users) often relies on batteries.
Importance: Lower power consumption benefits users (less weight, longer battery life, reduced charging time).
Challenge: Lower power → weaker signals → more vulnerability to interference and noise.
Solution: Reliable low-power communication needs optimized hardware (e.g., amplifiers) and software (e.g., signal processing).
User Mobility
Challenge: Moving users face increased issues with fading and shadowing compared to stationary users.
Road-User Context: Road-users are typically in motion, making these challenges more frequent.
Network Transition: Movement may require switching networks or cells (e.g., in mobile-phone communication).
Engineering Solution: Maintaining communication during transitions demands engineering of processes like:
Discovery
Handshaking
Spectral Limitation (DSRC)
Wireless Basics: Uses electromagnetic waves with different frequencies.
Simultaneous Use: Different frequencies = minimal interference.
Bandwidth Limit: Too many signals → interference → communication failure.
