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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.

The X-By-Wire (XBW) is one of the promising technologies for integrated vehicle dynamics control system for the next-generation. The system, in view of ECU architecture, combines multiple ECUs by a high-speed. In this, however, the failure of one ECU leads to system-wide failure. To avoid it, all the ECUs have to be fault tolerant, which is not a realistic solution in terms of cost. We propose a concept for a cost-effective and fault tolerant vehicle control architecture for real-time and scalable X-by-Wire systems. The concept is based on the Autonomous Decentralized Systems [1][2]. The features of the proposed concept are a shared data-field, self-operation, self-check, and self-backup. The proposed architecture will realize a fault-tolerant system without making all the subsystems fault-tolerant.

A new catalyzed hydrocarbon (HC) trap control system has been developed to reduce HC emission at cold engine start. The HC trap function changes according to its temperature, so it is important to optimize its temperature profile. To realize the best profile, the engine system was optimized with a thin wall exhaust tube, a thin wall HC trap and a new engine control, which controls ignition timing without engine stability deterioration. In a LA-4 mode test with some trial HC traps, the results showed good performance which met ULEV/SULEV standard.

An automotive powertrain control system using only one signal of the output shaft speed sensor has been investigated in order to lower the system costs and to simplify the calibration process A new smooth torque method after downshifting is described which is based on the differential value of automatic transmission output shaft speed The starting time of the engine torque control for restraining the torque fluctuation after downshifting can be detected accurately as a result of using the differential value The proposed engine torque control method is advantageous since it simplifies the calibration process for the data tables Moreover, it is possible to lower the cost of parts used in the automatic transmission control since speed and torque sensors are unnecessary The smooth torque control method was examined using a test vehicle and the same smooth torque after downshifting was obtained when the new method was employed

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.