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In recent years, integrated vehicle control systems have been developed to improve fuel economy and safety. As a result, engine control is shifting to torque-based systems for throttle / fuel / ignition control, to realize an engine torque demand from the system. This paper describes torque-based engine control technologies for SI (Spark Ignition) engine to improve torque control accuracy using a feedback control algorithm and an airflow sensor.

Most automatic transmissions are controlled in compliance with a predetermined program. Transient control during gear shift is also carried out according to a predetermined process. In this method a lot of labor is required to tune data tables. So we developed a tuning free system by feedback control using torque estimation technology and the experimental result is reported. Torque fluctuation during shift is detected and fed back to compare the torque reference, which is generated from the estimated torque itself. The engine torque is decreased by means of retarding the ignition spark advance, according to the comparison deviation. As a consequence of the feedback, the transient torque control is carried out without any tuning trouble, and better than usual torque fluctuation is obtained.

An automotive powertrain total control system using estimated output shaft torque has been investigated in order to enhance drivability and improve fuel economy. The system provides efficient control for both the engine and transmission which leads to an enhancement in drivability by reducing shocks during gear shifts. This paper describes a new smooth gear shift control method using the total control system. By use of the estimated output shaft torque, it is possible to detect accurately the fluctuation condition and the start time of the inertia phase, which are important factors affecting shock occurrence. Torque feedback, got from estimated torque, was applied to the control of engine output shaft torque during shifts. The optimum hydraulic pressure, also got from estimated torque, was applied to the clutch of the transmission during shifts.

An automatic transmission without a one-way clutch for a small sized, light weight automatic transmission is presented. The factor of torque fluctuation occurrence during shifting of the transmission increases so that the shifting is executed by controlling two wet clutches electronically in place of the one-way clutch and the wet clutch. Therefore, it is necessary to develop a new smooth gear shift control technology for clutch-to-clutch shifting on an automatic transmission without a one-way clutch. The control technology has desirable clutch-to-clutch shift control, learning control and robust control which apply to accurate signals obtained by an observation method. Smooth shifts during clutch-to-clutch shifting can be realized by recognizing clutch change-over time using a calculated acceleration and an input/output speed ratio of the transmission.