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Published on: February 18, 2021
From Light Pulses to Selective Enhancement: Performance Analysis of Event-Based Object Detection Under Pulsed
Leonard Haensel1,2, Torsten Bertram2
1Research Institute for Automotive Lighting and Mechatronics (L-LAB), Rixbecker Str. 75, 59557 Lippstadt, Germany.
Sensors (Basel, Switzerland)
|May 13, 2026
Summary
Pulse-width-modulated (PWM) headlights improve event-based camera detection for vulnerable road users. Optimal performance depends on specific PWM parameters, lighting, and target reflectivity, with cyclist detection being more robust than pedestrian detection.
Area of Science:
- Automotive lighting systems
- Computer vision for road safety
- Vulnerable road user detection
Background:
- Pulse-width-modulated (PWM) headlights can enhance nighttime event-based camera systems.
- Systematic optimization of PWM parameters for detecting vulnerable road users (VRUs) is not well-understood.
- Event-based cameras offer potential advantages in challenging lighting conditions.
Purpose of the Study:
- To systematically evaluate the impact of PWM headlight parameters on cyclist and pedestrian detection using event-based cameras.
- To identify optimal PWM settings for improved VRU detection under various driving conditions.
- To understand the influence of environmental factors and target characteristics on detection performance.
Main Methods:
- Simulated European New Car Assessment Programme (Euro NCAP) crossing scenarios.
- Varied PWM frequency, duty cycle, light distribution (low/high beam), ego-vehicle speed, and ambient lighting.
- Evaluated detection performance for cyclists and pedestrians against continuous illumination baseline.
- Assessed impact of retroreflective versus low-reflectivity surfaces and clothing.
Main Results:
- PWM headlight performance varied significantly, from substantial improvements to severe degradation compared to continuous light.
- High-frequency PWM with varied light distributions proved robust for cyclist detection.
- Low-frequency PWM with low beam caused significant degradation due to background noise.
- Pedestrian detection required high beam with street lighting; low beam failed universally.
- Simultaneous detection improvements for both cyclists and pedestrians were achieved with limited parameter combinations.
- Detection was optimal on retroreflective surfaces; low-reflectivity clothing reduced capability.
Conclusions:
- PWM headlight parameter tuning is critical for effective VRU detection with event-based cameras.
- Cyclist detection is generally more robust to PWM modulation than pedestrian detection.
- Future systems require target-specific optimization, considering reflectivity and environmental factors, to maximize safety benefits.
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