There’s been no shortage of news in the field of next-generation automotive design from integrated device manufacturer ST Microelectronics lately, with product announcements related to safety-critical lighting, digital car-key system certification and road noise elimination. But perhaps the company’s most intriguing venture has to do with driver monitoring systems, a market ST said is growing at a rate of more than 10% per year.
A driver monitoring system (DMS) is designed to assess driver alertness with the goal of ensuring road safety, watching head movements to recognize signs of drowsiness and distraction. Earlier this year the company announced an automotive global-shutter image sensor as a tool for DMS design, noting the advantage of the global-shutter approach over a rolling-shutter scheme: Simultaneous exposure of all pixels to a scene simplifies synchronization with near-infrared (NIR) illumination, improving the illumination-subsystem budget. The sensor’s efficiency at NIR operation also enables it to be adequately illuminated by a low-power, non-visible LED emitter; operating outside the visible spectrum ensures consistent response in day or night driving, and in bright or overcast conditions.
ST’s recent product announcements include a hybrid sensor that extends monitoring capabilities beyond the space occupied by the driver alone and into the full vehicle interior. Source: ST MicroelectronicsOf course, the real proof of concept comes from actual system development. To that end, ST recently demonstrated its 1-LED driver monitoring system, developed cooperatively with human insight AI pioneer Smart Eye, at AutoSens Brussels 2022. According to a press release, the DMS combines Smart Eye’s expertise in driver monitoring algorithms and optical system design with ST’s VB56G4A imager.
The company has also announced a new hybrid sensor, the VD/VB1940, that puts both rolling- and global-shutter imaging into a single component, combining the sensitivity and high resolution of infrared sensing with high dynamic range (HDR) color imaging. That translates to monitoring capabilities that extend beyond the space occupied by the driver alone and into the full vehicle interior. As a result, all vehicle occupants are covered, allowing applications such as passenger safety-belt checks, vital-sign monitoring, child-left detection, gesture recognition and high-quality video/picture recording.
Both new sensors leverage ST’s in-house investment in 3D-stacked back-side illuminated wafer technology, which maximizes optical area and on-chip processing in relation to die size. According to the company, BSI-3D sensors are more sensitive, smaller and more reliable than the front-side illuminated (FSI) sensors used in a typical first-generation DMS.
Automotive markets have begun to respond to the possibilities of DMS; recently enacted legislation in Europe mandates DMS for all new car platforms in 2024, and for existing model platforms in 2026. In the U.S., the National Transportation Safety Board has recommended DMS for all semi-autonomous vehicles. A look at what’s been happening recently at ST Microelectronics seems to indicate that the company is already focused on equipping carmakers with the technologies required to move into the next generation of automotive design.
