Part 1 of this two-part article described the project goal and the overall characteristics of the car to be designed. Part 2 focuses on vehicle control systems as well as on the design and simulation methodology. In addition, it provides a project outlook
3.2 Vehicle Control System
The vehicle control system obtains information from various installed sensors. So the vehicle's dynamics in terms of acceleration, velocity, driven distance in longitudinal and lateral direction as well as yaw rate and GPS position is measured. Sensors for the accelerator and brake pedal as well as steering angle and steering angle rate indicate the driver's request.
The vehicle battery, power train and on-board electrical system are also equipped with many sensors to assess voltages and currents used for monitoring the systems operation and to calculate power flows for energy consumption analysis. Mechanical variables like wheels speeds, motor speed or motor torque are obtained via can bus from the related control units.
Vehicle Control System hardware
The E-Smart control system design is a hierarchic layout. A central rapid control prototyping unit takes responsibility for controlling the whole vehicle operation in all modes. The main control functions as power train control, charging control as well as monitoring and diagnosis are implemented on the central control unit. Using different type of digital, analogue, can and serial interfaces it can operate all devices. For this reason it is connected via two introduced main can buses to all relevant other control units and to diverse gateways which enable data transfer to further can buses and so further control units. The two main can buses are divided to an energy can and a drive can.
The energy can connects the central control unit with a further rapid control prototyping unit used for battery cell monitoring and as a gateway to the on-board charger control unit, the commercial battery management control unit, several converter modules measuring energetic variables and