Fixed time-step drivetrain observer for embedded automotive applications

This article proposes a technique for fixed timestep state observation of automotive gear transmissions containing multiple friction elements like clutches and brakes. As adaptive time-step methods are not feasible for embedded control, the solution of model equations containing friction elements is a major challenge. The suitability of the proposed approach for a complex gear transmission comprising multiple friction elements is demonstrated by modeling and fixed timestep simulation. Based on that model, a fixed time-step proportional integral state observer is derived, that permits embedded execution at execution rates of common automotive control units.