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This paper presents a distributed control system framework for next-generation automotive control systems, in which various control units are connected with CAN bus. The framework is a software platform that performs communication between control units and invocation of application programs. The framework includes necessary functions for data transmission to meet end-to-end timing constraints in distributed control systems. Application programmers don't have to write any communication procedure but focus on developing application programs with appropriate API (Application Program Interface). The framework is based on driving force management and also OSEK, which is a standard real-time operating system (OSEK-OS) and a communication protocol (CAN) for automotive control. We are now applying our prototype framework to an adaptive cruise control system in our experimental vehicle.

This paper describes a longitudinal control method with an Adaptive Cruise Control (ACC) system using a wheel torque management technique. The wheel torque management technique can control vehicular speed by the following procedure without tuning parameters. First, the ACC module calculates a command speed from a desired headway distance and from output data of the radar sensor. Secondly, it calculates a required wheel torque to take the command speed, current speed and running resistance into consideration. Thirdly, the management module controls actuators based on the command wheel torque and characteristics of each vehicle. If the required wheel torque is positive, the management module orders adjustment of the throttle opening position and a change of the gear ratio in the automatic transmission. If the command wheel torque is negative, the management module activates the electronic brake in accordance with the magnitude of the command wheel torque.