Vehicle lane following achieved by two degree-of-freedom steering control architecture

The Advanced Driver Assistance Systems (ADAS) continue to grow rapidly in recent years. The ADAS can be divided into two categories: (1) vehicle lateral control assist whose actuation comes from power steering system, and (2) vehicle longitudinal control assist whose actuation comes from powertrain propulsion system and braking system. This paper proposes a two degree-of-freedom (2-DOF) controller architecture for an electric power steering system to achieve the function of the active steering angle control, integrated with upper-level supervisory control strategy implemented in lane following system (LFS). Also, we demonstrate its advantages over a one degree-of-freedom (1-DOF) controller structure. The vehicle dynamics with different active steering angle control architectures are analyzed to improve the angle control performance in lane following system. Furthermore, the active angle control algorithm was realized with an embedded-DSP and validated in a prototype vehicle.