Contribution to the integrated control synthesis of road vehicles

A nonlinear vehicle model with 22 motion degrees of freedom, used for synthesis of the system autopilot, was described in the paper. It was demonstrated how a controller can be designed on the basis of such relatively complex dynamic model, ensuring simultaneous motion stability of the vehicle in longitudinal, lateral and vertical directions, as well as the stability of roll, pitch, and yaw dynamics of the vehicle about corresponding axes. Vehicle automatic control was realized at two hierarchical levels: tactical and executional. Proposed scheme of the distributed hierarchy control enables control of entire vehicle dynamics as a multibody dynamic system. Control has been synthesized in such a way that the system satisfies set criteria of dynamic behavior. The synthesized controller improves system motion caused by action of casual, external perturbations, and internal inertial and centrifugal forces which appear as a consequence of an inadequately adapted ride velocity to the road geometry. Also, necessary information for estimation of unknown time-variant parameters of the dynamic model and of tire-road interaction were briefly given in the paper. Simulation results were presented and analyzed for one example of characteristic trajectory with perturbation of type of an uneven and slippery road, as well as a wind gust.