Asahi Kasei Corp developed a technology to calculate the pulse rate of an auto driver based on video shot by using a near-infrared camera.
The physical conditions of the driver are estimated based on the pulse rate. As a result, it becomes possible to control an air-conditioning system in accordance with the conditions and emit a warning sound when there is a risk of dozing off.
Asahi Kasei demonstrated the technology as a technology that contributes to improving comfort and safety at the time of driving at Automotive Engineering Exposition 2018, which took place from May 23 to 25, 2018, in Yokohama City, Kanagawa Prefecture, Japan.
One of the distinguishing features of the new technology is that it checks the "complexion" of the driver based on video shot by the camera by exploiting the fact that hemoglobin in the blood absorbs a large amount of green light.
When blood vessels are repeatedly expanded and contracted due to the movement of the heart, the amount of blood flowing in the face changes. In accordance with it, the brightness of the face in video changes. Therefore, when the number of brightness changes is counted, a pulse rate can be calculated.
It takes about eight seconds to measure the pulse rate of a driver. During that time, (1) face authentication, (2) measurement of brightness change and (3) calculation of a pulse rate are conducted.
"To obtain stable calculation results, data need to be accumulated for eight seconds and processed," Asahi Kasei said.
The current issue is that a calculation error is often caused by the movement of the driver's face at the time of driving a car, the vibration of an engine, etc. The company plans to solve this problem by enhancing processing capacity.