The Automatic Emergency Braking (AEB) system’s effectiveness in handling Car-to-Car Rear Stationary (CCRS) scenarios is critical for preventing or mitigating rear-end collisions with stationary vehicles.
How AEB Works for CCRS Scenarios
- Detection:
- AEB systems use radar, cameras, or LiDAR to detect stationary objects, including vehicles, in the car’s path.
- Advanced systems can distinguish stationary vehicles from other objects (e.g., road signs or debris).
- Warning:
- If a stationary vehicle is detected ahead and a collision risk is imminent, the system issues visual, auditory, or haptic alerts to prompt the driver to take action.
- Braking:
- If the driver fails to respond in time, AEB automatically applies the brakes.
- The system reduces the speed to avoid the collision entirely or minimizes the impact by reducing crash severity.
Performance Factors
- Speed Range:
- The effectiveness of AEB in CCRS scenarios varies with speed.
- Most systems are optimized for low to moderate speeds (urban driving).
- High-speed scenarios may still result in collisions, but with reduced severity.
- Environmental Conditions:
- Poor weather (fog, heavy rain) and low light can reduce the detection accuracy.
- Modern systems equipped with infrared or thermal imaging improve detection in challenging conditions.
- System Calibration:
- The ability to detect stationary vehicles depends on the AEB system’s algorithm and sensor integration.
- Older or basic AEB systems may struggle to detect stationary objects reliably.
Key Metrics in CCRS AEB Performance
- Collision Avoidance: The ability to completely avoid rear-end collisions with stationary vehicles.
- Collision Mitigation: Reducing the impact force when a collision is unavoidable.
- Braking Distance: How early the system initiates braking relative to the stationary vehicle.
Industry Testing for CCRS AEB
Organizations like Euro NCAP, IIHS, and ANCAP evaluate vehicles for AEB performance in CCRS scenarios:
- Test Parameters:
- Vehicle speeds (e.g., 20–70 km/h).
- Detection accuracy for a stationary car.
- Reaction time and braking force.
- Scoring: High-performing vehicles earn safety ratings based on their ability to avoid or mitigate collisions.