  This paper presents the comparison of two non-linear model-based control
strategies for autonomous cars. A control oriented model of vehicle based on a
bicycle model is used. The two control strategies use a model reference
approach. Using this approach, the error dynamics model is developed. Both
controllers receive as input the longitudinal, lateral and orientation errors
generating as control outputs the steering angle and the velocity of the
vehicle. The first control approach is based on a non-linear control law that
is designed by means of the Lyapunov direct approach. The second approach is
based on a sliding mode-control that defines a set of sliding surfaces over
which the error trajectories will converge. The main advantage of the
sliding-control technique is the robustness against non-linearities and
parametric uncertainties in the model. However, the main drawback of first
order sliding mode is the chattering, so it has been implemented a high order
sliding mode control. To test and compare the proposed control strategies,
different path following scenarios are used in simulation.
