Engine idle speed control
AssigneeOrbital Engine Company (Australia) Pty. Limited
InventorStuart Graham Price
Life of this patent
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Abstract
A method of controlling the idle speed of an internal combustion engine including, in response to the engine speed being below a predetermined level: determining the rate of change of the speed of the engine; selecting an idle entry set-point as a function of said rate; and initiating idle speed control of the engine on the basis of said idle entry set-point to thereby control the engine speed to a base idle speed.
Claims31
A method of controlling the idle speed of an internal combustion engine including, in response to the engine speed being below a predetermined level:
- determining the rate of change of the speed of the engine;
- selecting an idle entry set-point as a function of said rate;
- and
- initiating idle speed control of the engine on the basis of said idle entry set-point to thereby control the engine speed to a base idle speed.
A method according to any one of the preceding claims, wherein the rate of change of engine speed is determined once it has been established that an off-idle to idle transition is occurring in the operation of the engine.
A method according to any one of the preceding claims, wherein idle speed control of the engine speed is performed in a closed loop manner using an idle speed controller.
A method according to any one of the preceding claims, wherein the rate of change of the engine speed is determined as an idle entry gradient, the gradient increasing with increasing rate of change of engine speed.
A method according to any one of the preceding claims, wherein at least one high idle entry set-point and at least one low idle entry set-point speed are predetermined for use with the idle controller.
A method according to any one of the preceding claims, wherein during idle speed control of the engine, the engine speed may be controlled to follow predetermined engine speed set-point curves down to the base idle speed.
A method according to any one of the preceding claims, wherein the rate of change of engine speed is only calculated when the engine speed is between a predetermined range of engine speeds above the base idle speed.
A method according to any one of the preceding claims, wherein idle speed control of the engine is not initialised until there is zero demand on the engine.
A method according to any one of the preceding claims wherein the engine includes a direct fuel injection system, and the idle speed is controlled by varying the fuelling rate to the engine.
A method according to any one of the preceding claims, wherein the engine includes a dual fluid fuel injection system.
A method according to any one of the preceding claims, wherein the engine is controlled according to a fuel-led control system over at least part of its operating range.
An ECU adapted to control the idle speed of an internal combustion engine, including in response to the engine speed being below a predetermined level:
- determining the rate of change of the speed of the engine;
- selecting an idle entry set-point as a function of said rate;
- and
- initiating idle speed control of the engine on the basis of said idle entry set-point to thereby control the engine speed to a base idle speed.
Dependencies are inferred from the claim text.