Abstract: New algorithms for real-time estimation of the engine friction torque are developed. Engine friction torque can be estimated in a fuel cut-off state and at engine idle. New recursive and computationally efficient data-driven algorithms are developed for adaptation of the look-up tables. The algorithms make it possible to avoid driveability problems that could result from errors in estimating engine friction torque.

Abstract: Algorithms for real-time estimation of the engine friction torque in a vehicle powertrain are disclosed. Engine friction torque is estimated at start and at engine idle. Recursive and computationally efficient algorithms allow prediction of friction torque for a wide range of speeds and loads even with few new measured points by taking into account physical dependencies used for adaptation of the sites of the look-up tables (static maps). The algorithms make it possible to avoid drivability problems that could result from errors in estimating engine friction torque.