Hideaki Otsubo

Development of an electronically controlled four wheel drive system for FR vehicle with AT

Abstract A high-performance electronically controlled four wheel drive system was developed for a Front engine Rear drive (FR) vehicle with automatic transmission. This system consists of a center differential (torque split ratio is front: rear = 30:70 ), a linear solenoid valve, a hydraulic multi-disk clutch and a hydraulic control circuit. By regulating the hydraulic pressure on the clutch, the driving force distribution can be continously varied to the optimum ratio for the running condition of the vehicle, which is determined by wheel speed, yaw velocity and the steering wheel angle.

Robust Design Method for Automatic Calibration of Automatic Transmission Shift Control System

Recently, automatic transmissions have a problem whereby the calibration of control signals for the shift control system demands an enormous amount of time due to the increase in gear ratio. This study proposes the hierarchical and inverse directional design method in order to avoid a lot of trial and error in calibration. This method has two model-based processes: the first is the design of the target driving torque and the second is the control signals design based on the target. Through on-vehicle tests our proposed method has the same performance as the conventional one.

Development of robust servo system for synchronous shifting of a new compact five-speed automatic transmission

A novel compact five-speed automatic transmission was developed without the addition of a gear unit, using the same gear train as that of the four-speed automatic transmission, with two gear units connected in series for the multiplication of the gear ratios of individual gear units. A synchronous shift control technology was established to allow the synchronous shifting of two gear units in opposite directions despite the dynamic interference between them, using two-input/two-output robust servo controller. The design technique of the servo controller is described.<<ETX>>