System for controlling engine crankshaft deceleration by limiting engine retarding torque
AssigneeCummins Inc.
InventorsGeorge L. Banta, III, Robert J. Layman, Martin T. Books, Greg A. Moore
Life of this patent
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Abstract
A system for controlling engine crankshaft deceleration in an internal combustion engine is operable to determine whether the engine is operating with low inertia, to monitor an operational status of an engine retarding device configured to produce an engine retarding torque for decreasing rotational speed of the engine crankshaft, and to limit the retarding torque produced by the engine retarding device if the engine retarding device is operational and if the engine is operating with low inertia.
Claims20
System for controlling deceleration of an engine crankshaft in an internal combustion engine, comprising:
- an engine speed sensor producing an engine speed signal indicative of rotational speed of the engine;
- a vehicle speed sensor producing a vehicle speed signal indicative of road speed of a vehicle carrying the engine;
- an engine retarding device configured to produce a retarding torque for decreasing rotational speed of the engine crankshaft;
- and
- a control computer configured to process the engine speed signal and the vehicle speed signal to determine an effective gear ratio of a transmission coupled to the engine and to determine that the engine is operating with low inertia if the effective gear ratio is greater than a threshold gear ratio value, the control computer further configured to control deceleration of the engine crankshaft when the engine retarding device is operational by limiting the retarding torque produced by the engine retarding device if the engine is operating with low inertia.
A method for controlling engine crankshaft deceleration in an internal combustion engine, the method comprising the steps of:
- monitoring an engine speed signal produced by an engine speed sensor operable to sense rotational speed of the engine;
- monitoring a vehicle speed signal produced by a vehicle speed sensor operable to sense road speed of a vehicle carrying the engine;
- computing an effective gear ratio as a function of the engine speed signal and the vehicle speed signal;
- determining that the engine is operating with low inertia if the effective gear ratio is greater than a threshold gear ratio;
- monitoring an operational status of an engine retarding device configured to produce a retarding torque for decreasing rotational speed of the engine crankshaft;
- and
- limiting the retarding torque produced by the engine retarding device if the engine retarding device is operational and if the engine is operating with low inertia.
Dependencies are inferred from the claim text.