DENSO has developed a new electronic control unit (ECU) for adaptive front lighting systems (AFS), which is approximately 70% smaller in volume compared to DENSO's conventional ECU for the AFS.
The new ECU is installed on the Toyota Estima, which was launched this month in Japan.
The AFS redirects low-beam headlamps individually in a horizontal direction in accordance with steering angle and vehicle speed.
As a result, this system can improve visibility during night time cornering, ensuring safer driving.
In 2003, DENSO developed the world's first AFS with Toyota Motor Corporation and Koito Manufacturing Co, Ltd.
DENSO reduced the size of the ECU by:
* Shifting the motor drive circuits that control headlamp direction, to the motors
* Adopting CAN (Controller Area Network) and LIN (Local Interconnect Network) communications for signal input and output, reducing the size of input and output connectors on the ECU
* Reducing the size of microcomputers and IC chips.
Adopting CAN and LIN communications also resulted in a smaller number of input and output wire harnesses, providing easy installation of the ECU.
In addition to its smaller size, the new ECU can provide more detailed light distribution control, depending on road conditions and vehicle speed, providing improved visibility.
Specifically, at the speeds of 30 kilometres per hour or more, the ECU can simultaneously redirect both the left and right headlamps.
At the speeds lower than 30 kilometre per hour, the swivel angle of the headlamp is controlled in accordance with the steering angle, regardless of the vehicle speed, thereby improving the visibility especially at intersections and sharp curves.
DENSO significantly reduced the cost for the new ECU through the size reduction and the standardisation of circuits.
DENSO's ECU for the AFS has an auto levelling function that controls the headlamps in a perpendicular direction. However, car manufacturers typically use an auto levelling ECU for models that do not have AFS, since the auto levelling ECU is less expensive than a conventional AFS ECU with the auto levelling function.