Search Results

Conventional steering system has a mechanical connection between the driver and the front tires of the vehicle, but in steer-by-wire system, there is no such a connection. Instead, actuators, positioned in the vehicle's front corners receive input from the control module and turn the front wheels accordingly. In steer-by-wire system, steering wheel is an important part that not only transfers driver's steering input to the controller but also provides a road feedback feeling to the driver's hand. Thus the reactive torque actuator, providing road feedback, plays an important role in steer-by-wire system. In conventional steer-by-wire-system, a motor was used as a reactive torque actuator. But using motor has some disadvantages such as an oscillatory feeling, and improper and potentially dangerous acceleration of the steering wheel by the motor when driver's hands are released from steering wheel abruptly.

This paper describes the modeling of dual hybrid electric vehicle drivetrain and proposes a hybrid control system for controlling the drivetrains. In dual hybrid electric drivetrains, the energy from the engine passes through the planetary gear set and is split into the generator and motor paths. A complete dual hybrid electric drivetrain system model is developed. The modeling process is discussed for each of the major components of dual hybrid electric drivetrain, such as planetary gear transmission, gasoline engine, motor, generator and vehicle dynamics. Integrated nonlinear model and effects of parameter variations are also studied. The hybrid control system which is a discrete-event system interacting with a continuous-state system, is suitable for modeling and control of the systems that have state jumps and dynamics changes. In this paper, on/off state of engine is treated as a discrete state of HEV system and, velocities and torques, etc., as continuous states.