On the design of linear virtual sensors for low cost vehicle stability control

The design of linear direct virtual sensors (DVS) to estimate yaw rate for vehicle stability control systems is investigated. The obtained DVS is stable and it can be used in a large range of operating conditions. It is shown how the use of closed-loop collected data and a suitable choice of the measured variables in sensor design improves the estimation accuracy. The effectiveness of the proposed DVS design is demonstrated by its employment in an existing yaw rate feedback loop, based on an active front steering actuator and designed using internal model control techniques. Robust stability is guaranteed in the presence of model uncertainty and of the DVS. In particular, the presented study shows that the DVS technology can be conveniently taken into account to replace physical sensors to obtain low cost stability control solutions for application on A and B segment cars.