Development of an optical vehicle alert system for hybrid and electric vehicles

Electric and hybrid vehicles operating silently at low speeds pose a danger to pedestrians. Therefore, efforts have recently begun to integrate an Acoustic Vehicle Alerting System (AVAS) into vehicles to produce artificial sounds and ensure pedestrian safety. This study aims to develop an Optical Vehicle Alerting System (OVAS) that integrates with the vehicle's speed to enable individuals to detect vehicles. By processing speed data from vehicles via the Controller Area Network (CAN) communication line, various light patterns on the ground along the vehicle's route have been generated using different light sources in daylight conditions. Systems combining circular patterns obtained from arrays of light-emitting diodes (LEDs) emitting light at different wavelengths with linear warning systems obtained using laser sources have been compared. Vehicle simulation was conducted using a Data Acquisition (DAQ) device, and systems producing light based on lasers and LEDs were added to the test environment to measure light intensities and illumination profiles along the route. A warning pattern at 90 lux levels at a distance of 5 meters was generated on the ground along the vehicle's route using six LEDs with an output power of around 5 mW at a wavelength of approximately 505 nm. Additionally, it was shown that a dynamically changing linear warning pattern dependent on the vehicle's speed could be produced using three laser diodes operating at approximately 100 mW power at a wavelength of 532 nm. The adequacy of different light intensities and illumination profiles applied according to the changing vehicle speed for the vehicle warning system has been discussed. A general study demonstrating the applicability of optical vehicle alerting systems to various moving devices, including electric and hybrid vehicles, has been presented.