Millimetre-wave radar innovation could cut traffic accidents

The millimetre-wave radar technology makes it possible to detect objects outdoors in poor visibility conditions, such as night, rain and snow, as well as against the sunlight, unlike optical and infrared cameras and laser sensors.

Traffic monitoring sensors would be installed at intersections to alert drivers to the presence of pedestrians and bicycles up to 40m ahead even at night-time and under bad weather conditions that hinder visibility.

Panasonic says it has overcome the difficulties with conventional millimetre-wave radar technologies and can detect humans and cars simultaneously in spite of the fact that the human body reflects extremely weak radar signals compared with a car.

The company is claiming to achieve high-detection performance with a range resolution of less than 50cm and an angular resolution of 5 degrees, which enables the system to detect pedestrians and vehicles.

Two new element technologies were developed for this application. A coded pulse modulation technique that employs a newly designed code sequence for pulse radar method improves sensitivity to achieve a longer detection range and pick out small objects that have weak radar reflection.

Also an adaptive antenna technique combines radar beam-forming transmission and adaptive array antenna reception with a signal processing algorithm for estimation of target direction, thereby achieving high angle resolution even with a smaller antenna compared with conventional one.

Some cars are already fitted with radars that measure distance to the vehicle in front, but these cannot detect a human body with high resolution because of its weak radar reflection.

Panasonic developed the system with support from a Japanese government research programme, and will demonstrate it at a conference in Yokohama this month.