Panasonic develops in-car driver drowsiness detection technology

Panasonic Corporation has developed a drowsiness-control technology for detecting and predicting a person’s level of drowsiness and allowing to stay comfortably awake.

This technology, which can help prevent drowsy driving, detects a driver’s shallow drowsiness at the initial state by accurately measuring the driver’s states without physical contact, including blinking features and facial expressions, etc. captured by an in-vehicle camera, and processing these signals using artificial intelligence.

Further, using measurement data from the in-vehicle environment, such as heat loss from the driver and illuminance, Panasonic’s new technology also predicts transitions in the driver’s drowsiness level. The technology also combines thermal sensation monitoring function, allowing the driver to stay comfortably awake while driving.

This new technology offers the following features:

  • Detects shallow drowsiness the driver is even unaware of by non-contact measurement of blinking features and facial expressions, etc.
  • Collects in-vehicle environment data to predict transitions in the driver’s drowsiness level.
  • Senses and monitors the driver’s level of thermal sensation, allowing the person to stay comfortably awake.

Conventional drowsiness-detection systems had difficulty in predicting transitions in drowsiness. Conventional anti-hypnotic stimulant systems use alarm sounds and vibrations to wake up users, which can make them feel uncomfortable.

(1) Detecting drowsiness by observing the blinking features

The system extracts an outline of the eyes (shown in the photo below) and monitors time-sequence shifts in blinking features by checking the opening between the eyelids (shown in the graphs below).

2. Collects in-vehicle environment data to predict transitions in the driver’s drowsiness level

Generally, people rarely become drowsy in a cool and bright environment, but can easily become drowsy in a warm and dim environment. Therefore, it is assumed that drowsiness depends on in-vehicle environmental factors, such as temperature and brightness. However, some people wear a lot of clothes while others wear less at the same temperature. Such variations in human behavior make it difficult to estimate people’s drowsiness based only on the ambient temperature.

Panasonic has conducted joint research with Chiba University, which revealed that heat loss from a person’s body is correlated with the person’s drowsiness after prescribed time elapses, regardless of how much clothes the person wears. Panasonic has also developed a contactless technology to measure heat loss from a person’s body with the company’s original infrared array sensor Grid-EYE [2]. In addition, the company has identified the effect of the elapsed time and the surrounding brightness, which is measured by an environment sensor, on a person’s level of drowsiness.

These results have made it possible to predict how a person’s current drowsiness can change by means of heat loss from the body (measured without contact) and the surrounding brightness.

An example of time-sequence drowsiness level estimates plotted on the assumption that the initial drowsiness level is 1

3. Senses and monitors the driver’s level of thermal sensation, allowing the person to stay comfortably awake

Adjusting room temperature or airflow based on an individual’s estimated level of drowsiness makes it easier to keep a person awake. However, a person would feel a cold when the room temperature is too low, which the level of thermal comfort would be disturbed. By applying our knowledge of thermal environments and physiology accumulated through research & development of indoor air conditioners and other products, Panasonic has developed, through joint research with Nara Women’s University, a technology to estimate the thermal sensation2. This technology can be used inside a vehicle, where the effects of airflow and others are significant. By applying the infrared array sensor Grid-EYE, an individual’s level of thermal sensation can be constantly monitored as an optimum means of controlling temperature, for example, an air conditioner. This allows a person to stay comfortably awake3.

Technology using an infrared array sensor to detect a person’s level of thermal sensation (sensing of warm and cold) without contact.
When a driver’s current drowsiness level is detected as high, a sound alarm or a command to rest is issued.

Source: Panasonic