Advanced steer-by-wire system for worlds longest busses

This article describes a novel automatic steering system for a 36.0m long double articulated bus equipped with four independent steer-by-wire axles. A model-based control design approach is proposed, which uses a kinematic vehicle model to design a train-like guidance system and a force-canceling that avoids excessive mechanical stress in the joints and the chassis. The control design generalizes the well-known Ackermann-steering system that performs well on available automotive electronic control units (ECU). Multi-body-system(MBS) simulations show that the proposed approach offers high tracking performance and low mechanical stress in the chassis of the vehicle. Furthermore, road tests with a true scale prototype vehicle confirm the simulation results. Very good test drive results show that the steering system for the first time enables the operation of very long buses even in urban areas.