Abstract
We present a novel linear observer with an extension dealing with polytopic uncertainties in a vehicle dynamic system to identify the side‐slip angle. The performance optimization issue is addressed by the minimization of H ∞ norm of the system considering the estimation error as an output and the steer angle as an input. Contrary to the standard robust optimal design approaches, we use a convex inner approximation technique to reduce the order of the observer and this enables us to derive suboptimal, fixed‐order, and efficiently practicable estimators. Moreover, the numerical examples performed on two‐track nonlinear model of the system are provided to illustrate the impacts of design parameters on the optimization results and the efficiency of the technique.