Sergiy Antonov

Unscented Kalman filter for vehicle state estimation

Vehicle dynamics control (VDC) systems require information about system variables, which cannot be directly measured, e.g. the wheel slip or the vehicle side-slip angle. This paper presents a new concept for the vehicle state estimation under the assumption that the vehicle is equipped with the standard VDC sensors. It is proposed to utilise an unscented Kalman filter for estimation purposes, since it is based on a numerically efficient nonlinear stochastic estimation technique. A planar two-track model is combined with the empiric Magic Formula in order to describe the vehicle and tyre behaviour. Moreover, an advanced vertical tyre load calculation method is developed that additionally considers the vertical tyre stiffness and increases the estimation accuracy. Experimental tests show good accuracy and robustness of the designed vehicle state estimation concept.

A new flatness-based control of lateral vehicle dynamics

This paper presents a new concept for vehicle dynamics control (VDC). The control of the longitudinal vehicle dynamics is not discussed, since we are assuming that it is much slower and weakly coupled to the lateral and yawing dynamics. The actuators are considered to be the traction and the braking torques of the individual wheels and only the standard sensors of the common VDC system are used. A modular interface to the subordinate wheel control system is provided by choosing the yaw torque as a fictitious control input. The VDC system is designed by means of a two degrees-of-freedom control scheme. It comprises a flatness-based feedforward part and a stabilising feedback part. The reference trajectory generation is introduced for the flat output which is given by the lateral velocity of the vehicle. Thus an advantageous kind of body side-slip angle control is provided with the standard VDC system hardware. Extensive simulation studies show excellent performance of the designed control concept.

Ein neuartiger Ansatz zur Querdynamikregelung von Personenkraftwagen (A New Approach to Lateral Dynamics Control of Passenger Vehicles)

Dieser Beitrag beschreibt einen neuen Zugang zur Querdynamikregelung von Personenkraftwagen. Um eine physikalisch interpretierbare Schnittstelle zu der untergeordneten Radregelung zu schaffen, wird das Giermoment um die Hochachse des Fahrzeuges als fiktive Stellgröße eingeführt. Es kann gezeigt werden, dass die Fahrzeugquergeschwindigkeit des nichtlinearen Einspurmodells einen flachen Ausgang des Systems repräsentiert. Das vorgeschlagene Konzept zur Querdynamikregelung basiert auf einer Zwei-Freiheitsgrad-Regelkreisstruktur mit einer flachheitsbasierten Steuerung der Fahrzeugquergeschwindigkeit und einer Stabilisierung des Trajektorienfehlersystems. Da mit diesem Regelungskonzept auch eine indirekte Regelung des Schwimmwinkels erreicht wird, bringt dieser Ansatz diverse Vorteile gegenüber der klassischen Gierratenregelung mit sich. Darüber hinaus wird die Parametrierung des Regelkreises durch den modellbasierten Entwurf deutlich erleichtert. Für die praktische Realisierung werden nur herkömmliche Mess- und Stellgrößen eines ESP®-Systems benötigt. Das Regelungskonzept wurde anhand von zahlreichen Simulationen mit einem detaillierten Fahrzeugmodell getestet. This paper presents a new approach to the lateral dynamics control of passenger vehicles. In order to establish a physically meaningful interface to the subordinate wheel control system the yawing torque of the vehicle is introduced as a fictitious control input. It is shown that the lateral vehicle velocity of the nonlinear single track model serves as a flat output of the system. The proposed concept for the lateral dynamics control relies on a two degrees-of-freedom control structure with a flatness-based feedforward control of the lateral vehicle velocity and a stabilizing feedback control of the corresponding trajectory error system. Since the control concept indirectly corresponds to the control of the vehicle´s body side-slip angle, it brings along some advantages compared to the classical yaw rate control. Moreover, the model-based approach extremely simplifies the controller parametrization. For the practical implementation of this control scheme only the standard equipment of an ESP®-system is required. The proposed control concept has been tested by means of numerous simulation studies with a detailed vehicle model.