US Patent 7593796 Torque estimator for internal combustion engine

An apparatus for the determination of engine torque comprises a neural network receiving engine operational data, such as crankshaft rotation data, and providing an output corresponding to engine torque. The neural network may be, for example, a recurrent neural network (RNN) that is configured using training data obtained using a training process. By comparing a determined engine torque with an intended engine torque, for example determined from engine control input values such as throttle position, a useful engine diagnostic is obtained.