Design and Comparison of Robust Nonlinear Controllers for the Lateral Dynamics of Intelligent Vehicles

This paper focuses on the lateral control of intelligent vehicles; the aim is to minimize the lateral displacement of the autonomous vehicle with respect to a given reference trajectory. The control input is the steering angle, and the output is the lateral error displacement. We present here an analysis of commonality of three lateral nonlinear adaptive controllers. The first controller is a higher order sliding-mode controller (SMC). The second controller is based on the immersion and invariance (I & I) principle. The design of this controller led us to prove a very strong stability criterion of the closed-loop system for all controller gains chosen to be positive. Thereafter, some interesting characteristics of passivity of the systems were proved following this development. Hence, the third controller is a passivity-based controller (PBC), an adaptive PI controller based on the feedback of a passive output. To validate our control laws, tests have been performed on SCANeR Studio, a driving simulation engine, according to several real driving scenarios. A comparison of these different controllers is made to highlight the advantages and drawbacks of each control approach in lateral tracking of a reference trajectory.