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US 10,641,234 B2Granted
Method for engine laser ignition system
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing a laser ignition system of an engine. In one example, a controller may operate the laser in a sealed cylinder hours after key-off. Then, the cylinder may be unsealed and a change in exhaust temperature may be correlated with laser functionality.
Claims20
A method, comprising:
- spinning an engine in reverse, unfueled, to establish a baseline intake air temperature and then sealing a cylinder at a position of negative valve overlap;
- operating a laser ignition device in the sealed cylinder;
- spinning the engine in reverse, unfueled, to unseal the cylinder;
- and
- diagnosing the laser ignition device based on a change in measured intake air temperature relative to the baseline intake temperature.
2 more elements
A method for an engine, comprising:
- operating the engine in a vehicle;
- operating the vehicle to drive in an autonomous driving mode;
- and while doing so:
- operating a laser ignition device in a sealed, unfueled engine cylinder after an engine key-off;
- during a first condition, comparing a measured exhaust temperature after the operating to a baseline exhaust temperature established via unfueled engine spinning;
- during a second condition, comparing a measured intake temperature after the operating to a baseline intake temperature established via the unfueled engine spinning and
- during both the first and second condition, diagnosing the laser ignition device based on the comparing.
4 more elements
An engine system, comprising:
- an engine including a cylinder;
- a laser ignition device coupled to the cylinder;
- an intake air temperature sensor coupled to an intake passage of the engine;
- an electric motor;
- and
- a controller with computer-readable instructions stored on non-transitory memory for:
- waking up a powertrain control module from a sleep mode when a threshold duration has elapsed following an engine key-off;
- spinning the engine, unfueled via the motor, to establish a baseline intake air temperature;
- sealing the cylinder by spinning the engine, unfueled via the motor, to a position where all cylinder valves are closed;
- operating the laser ignition device in the sealed cylinder for a duration;
- unsealing the cylinder by re-spinning the engine, unfueled via the motor, to a position where at least an intake valve is open;
- and
- diagnosing the laser ignition device by comparing an intake air temperature measured after the operating with the baseline intake air temperature.
10 more elements
Dependencies are inferred from the claim text.