Abstract: This invention relates to an apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter. Provided is an open loop fuel controller comprising a detector arranged down stream of a catalyst for detecting rich breakthrough; a catalyst model having an estimator for estimating a stored oxygen level in the catalyst; a comparator for comparing an estimated stored oxygen level with a plurality of predetermined thresholds; demand adjusting means for adjusting an air fuel ratio demand in dependence upon a received signal from said comparator and upon a received signal from said detector. A method of open loop fuel control is also provided.

Abstract: This invention relates to a method and apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter. The invention provides a controller for requesting an air fuel ratio according to a switching value derived from an estimated oxygen storage value of a catalyst, in which the controller is arranged to perform the following steps a) request a maximum ratio of air to fuel when the switching value is less than a first threshold; b) gradually decrease the requested air to fuel ratio from said maximum ratio; c) request a minimum ratio of air to fuel when the switching value is greater than a second threshold; and d) gradually increase the requested air to fuel ratio from said minimum ratio.

Abstract: This invention relates to an apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter. Provided is an open loop fuel controller comprising a detector arranged down stream of a catalyst for detecting rich breakthrough; a catalyst model having an estimator for estimating a stored oxygen level in the catalyst; a comparator for comparing an estimated stored oxygen level with a plurality of predetermined thresholds; demand adjusting means for adjusting an air fuel ratio demand in dependence upon a received signal from said comparator and upon a received signal from said detector. A method of open loop fuel control is also provided.

Abstract: This invention relates to an engine torque controller for spark ignition internal combustion engines and more specifically for direct injection engines. The invention provides a torque controller and a method of controlling torque for an engine in which torque is controlled in dependence upon a filtered difference signal where the filtered difference signal is the difference between a desired torque signal and a signal representing an estimate of the current torque.

Abstract: This invention relates to a method and apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter.

Abstract: This invention relates to an engine torque controller for spark ignition internal combustion engines and more specifically for direct injection engines. The invention provides a torque controller and a method of controlling torque for an engine in which torque is controlled in dependence upon a filtered difference signal where the filtered difference signal is the difference between a desired torque signal and a signal representing an estimate of the current torque.

Abstract: The present invention relates to an apparatus (1) and a method for quantifying the net torque (28) produced by an internal combustion engine, for example, in a motor vehicle. Nominal gross engine torque (2) and expected torque losses (17,19,21) associated with the engine (102) are estimated. Estimated net torque (28) from the gross engine torque (2) and expected torque losses (17,19,21) are calculated.

Abstract: An apparatus and a method for controlling engine speed in a motor vehicle engine (9) by an engine management system (1) with an engine control output (8,46). The engine management system (1) provides the following operations. A driver demand controller (38) responsive to an accelerator pedal (12) provides a first control signal (40) representative of a target engine speed. A cruise speed controller (22) responsive to a cruise control setting and vehicle speed provides a cruise signal (28). An idle speed controller (30) provides an idle signal (32). A combined idle-cruise speed controller (36) provides a second control signal (42) representative of a target engine speed which is responsive to the greater of the cruise signal (28) and idle signal (32). The greater of the first (40) or second (42) signals is selected to control (8,46) engine speed.