Mohsen Lakehal-ayat

ROBUST YAW CONTROL DESIGN WITH ACTIVE DIFFERENTIAL AND ACTIVE ROLL CONTROL SYSTEMS

Abstract A simple robust yaw controller for the nonlinear single-track model is designed, making use of active differential and active roll control systems. Robustness is studied for uncertainties in several model parameters, namely the vehicle longitudinal velocity, the road adherence coefficients and the hand wheel angle. Constructive nonlinear dynamics are employed for the controller design. The controller parameters are selected by solving an optimization problem. Stability of the solution is guaranteed by constraints that ensure a minimal distance between the nominal operating point and a stability boundary in the space of uncertain parameters.

The yaw torque influence of active systems and smart actuators for coordinated vehicle dynamics controls

This article presents the capability of several active systems and smart actuators to control the vehicle yaw motion for various driving situations. A control concept allowing for a centralised coordination of multiple actuators is described. The additional yaw torque generated through system control interventions is determined taking account of the vehicle side slip angle and the lateral acceleration. Analysis results are illustrated for the active front steering and brake system, active differential and active anti-roll bars. The developed control concept is based on a centralised yaw torque allocation algorithm. The concept comprises the coordination of the considered active systems and the identification of required interventions to control the vehicle yaw motion. A sine with dwell time open-loop manoeuvre is utilised to illustrate the stability and agility improvement achieved by the centralised and coordinated control strategy.

Beobachtung von Fahrzeugzuständen der Querdynamik mit integrierter reibwertschätzung

Regelungssysteme fur die Fahrdynamik beruhen auf Informationen uber den aktuellen Fahrzeugzustand. Wahrend viele Daten direkt aus Sensorsignalen gewonnen werden konnen, lassen sich wichtige Grosen wie die Fahrzeugquergeschwindigkeit und der zugehorige Strasenreibwert nicht mit der vorhandenen Sensorik erfassen und mussen uber einen Beobachteransatz ermittelt werden. Diese Zustandsschatzung wurde in mehreren Projekten zur integrierten Fahrdynamikregelung am Ford-Forschungszentrum in Aachen erfolgreich eingesetzt.

Adaptive Kalman filter-based yaw rate estimation using accelerometers and wheel speed sensors

This paper presents a kinematic yaw rate estimator which combines measurements obtained from a pair of accelerometers and ABS wheel speed sensors of the non-driven wheels. The Extended Kalman Filter methodology has been used for realization of this sensor fusion-based estimator. The estimator adapts to variations in reliability levels of individual sensors. The estimator performance is validated and corresponding estimation errors are analyzed by computer simulations for different driving maneuvers.Copyright

State estimation of the vehicle lateral dynamic with integrated estimation of the friction between tyre and road

Control systems for vehicle stability require information about the actual vehicle state. While many states can be obtained from sensor signals, some important states, like the lateral velocity and the corresponding tyre-road friction have to be reconstructed by a vehicle state estimator, comprising of a simplified vehicle model. The efficiency of the developed vehicle state estimator has been proven in several projects for integrated vehicle dynamics control at the Ford Research Centre in Aachen.