NTN Corporation (hereafter, NTN) has developed the “MCU for Next-generation Steering” that has been adopted by Nissan Motor Company (hereafter, Nissan) in their Direct Adaptive Steering, and the product started to be released into the market in 2013.
Conventional steering systems transmit the driver’s steering input to the tires via a shaft. Direct Adaptive Steering transmits the driver’s steering input to the tires via electrical signals, so there is no mechanical link between the steering wheel and the tires. This means that the system is unaffected by undulations in the road surface, and allows for agile and precise steering operations.
Direct Adaptive Steering is able to detect malfunctions in the event that the system cannot function properly, and provides a backup mechanical link between the steering wheel and the tires.
The new “MCU for Next-generation Steering” developed by NTN ensures a backup mechanism for the Direct Adaptive Steering. With a compact layout consisting of an electromagnetic clutch and roller clutch, the electromagnetic clutch is energized when the Direct Adaptive Steering function is active to release the roller clutch, which in turn transmits steering input to the tires via electrical signals. If a malfunction is detected with the Direct Adaptive Steering, power to the electromagnetic clutch is turned off and the roller clutch is connected immediately to transmit steering input to the tires via a mechanical link. A high load capacity design ensures a high level of reliability when the mechanical link is active.
NTN is aiming for further market deployment of the “MCU for Next-generation Steering” with the functions above as a core technology product for next-generation steering systems.