Adjusted ignition timing for engine restart
AssigneeFord Global Technologies, LLC
InventorsDavid Ord, Brad VanDerWege, Joseph Thomas
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.
Claims20
A method for restarting an engine, comprising:
- responsive to a request for engine restart during an engine idle-stop,
- adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio in a cylinder and an estimation of a cylinder turbulence,
- wherein the estimation of the fuel-air equivalence ratio and the estimation of the cylinder turbulence is based on data inputted from a plurality of sensors after fuel is injected at one or more cylinders;
- and
- wherein the fuel is injected before at least one cylinder of the one or more cylinders reaches a predetermined number of degrees after top dead center.
A method for an engine restart event, comprising:
- detecting a low urgency request for engine restart based on one or more of a below-threshold demand for torque and a below-threshold exhaust system temperature;
- and
- responsive to detection of the low urgency request for engine restart,
- inputting data from a plurality of sensors;
- outputting an estimated fuel-air equivalence ratio and an estimated cylinder turbulence based on the data from the plurality of sensors;
- initiating spark at one or more cylinders positioned at a power stroke based on the estimated fuel-air equivalence ratio at a spark plug of each of the one or more cylinders and the estimated cylinder turbulence;
- and
- responsive to engine speed reaching a threshold speed,
- adjusting a timing of spark initiation at the one or more cylinders to a nominal timing.
An engine, comprising:
- a starting device coupled to a crankshaft of the engine;
- a plurality of cylinders, each of the plurality of cylinders including a spark plug and at least one fuel injector, wherein a piston position of each of the plurality of cylinders is adjusted based on rotation of the crankshaft;
- and
- a controller configured with executable instructions stored in non-transitory memory which, when executed during an idle-stop mode of the engine, cause the controller to:
- activate a starting device in response to detection of a low urgency request for engine restart;
- and
- assist the starting device to restart the engine by generating torque at one or more cylinders during a power stroke of the one or more cylinders,
- wherein the torque is generated by initiating spark at the one or more cylinders at a timing based on an estimated fuel-air equivalence ratio and an estimated cylinder turbulence;
- wherein an amount of the generated torque supplements an amount of torque provided by the starting device;
- and
- wherein the amount of torque provided by the starting device is less than an amount of torque provided by the starting device in response to detection of one of a medium urgency request for engine restart or a high urgency request for engine restart.
Dependencies are inferred from the claim text.