Implementation of phase lead controller for lane following system based on identified vehicle lateral model

Vehicle lateral controllers are general designed based on a simplified lateral model, known as bicycle model. However, some of parameters of the bicycle model are difficult to estimate accurately such as cornering stiffness and moment of inertia. Furthermore, some expensive sensors are required for estimating these parameters such as GPS/inertial sensors, wheel force transducers. The paper studies a practical method for identifying lateral model and a phase lead controller implemented in a real vehicle is designed based on the identified model. The identified lateral model is in the form of a discrete-time transfer function, which is conducive to practical identification and digital controller design. The transfer function is derived from a bicycle model. The input and the output of the transfer function are the steering wheel angle and the lateral offset at a look-ahead distance respectively. The data for identification are provided by the electric power steering system and the lane detection system using a camera without the requirement of expensive sensors. The feedback signal of the controller is also based on the lane detection system. The identified model is validated successfully by the experimental data. The phase lead controller is carried out in a real vehicle and experiment results show that the phase lead controller works well.