Duty cycle purge control system

Claim 1

A method of controlling a purge solenoid for a purge control system of an internal combustion, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 2

A method of controlling a purge solenoid for a purge control system of an internal combustion, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 7

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining whether the obtained duty cycle is about a predetermined minimum level; turning the purge solenoid OFF if the obtained duty cycle is about the predetermined minimum level; determining whether the obtained duty cycle is about a predetermined maximum level if the obtained duty cycle is not about the predetermined minimum level; turning the purge solenoid ON if the obtained duty cycle is about the predetermined maximum level; determining whether the internal combustion engine is operating at an idle condition; using the obtained duty cycle at a first predetermined frequency to control the purge solenoid if the internal combustion engine is operating at an idle condition; and using the obtained duty cycle at a second predetermined frequency to control the purge solenoid if the internal combustion engine is not at idle.

Claim 8

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining whether the obtained duty cycle is about a predetermined minimum level; turning the purge solenoid OFF if the obtained duty cycle is about the predetermined minimum level; determining whether the obtained duty cycle is about a predetermined maximum level if the obtained duty cycle is not about the predetermined minimum level; turning the purge solenoid ON if the obtained duty cycle is about the predetermined maximum level; determining whether the internal combustion engine is operating at an idle condition; using the obtained duty cycle at a first predetermined frequency to control the purge solenoid if the internal combustion engine is operating at an idle condition; and using the obtained duty cycle at a second predetermined frequency to control the purge solenoid if the internal combustion engine is not at idle.

Claim 10

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: calculating the duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML); determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value; using the result to obtain the duty cycle for the purge solenoid; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 11

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: calculating the duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML); determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value; using the result to obtain the duty cycle for the purge solenoid; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 12

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value; using the result to obtain the duty cycle for the purge solenoid; determining an output level of the purge solenoid based on the obtained cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 13

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value; using the result to obtain the duty cycle for the purge solenoid; determining an output level of the purge solenoid based on the obtained cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 15

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether the internal combustion engine is operating at wide open throttle; determining whether the internal combustion engine is operating in closed loop; calculating a duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML)if the internal combustion engine is not operating at wide open throttle or is operating closed loop; determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value and using the result to obtain the predetermined duty cycle for the purge solenoid; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit if DCINML is equal to the predetermined value; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; determining whether 02CNTR is more negative than a second predetermined limit if the simulated airflow is not outside of the predetermined operating range or engine vacuum is not below the predetermined limit; determined whether the internal combustion engine is operating in closed loop longer than a predetermined time limit if 02CNTR is not more negative than the second predetermined limit; sending a number of toggles from the oxygen sensor to an engine control unit; using more oxygen Sensor toggles per DCMULT increment if the internal combustion engine is operating in closed loop; using less oxygen sensor toggles per DCMULT increment if the internal combustion engine is operating in closed loop; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 16

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether the internal combustion engine is operating at wide open throttle; determining whether the internal combustion engine is operating in closed loop; calculating a duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML)if the internal combustion engine is not operating at wide open throttle or is operating closed loop; determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value and using the result to obtain the predetermined duty cycle for the purge solenoid; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit if DCINML is equal to the predetermined value; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; determining whether 02CNTR is more negative than a second predetermined limit if the simulated airflow is not outside of the predetermined operating range or engine vacuum is not below the predetermined limit; determined whether the internal combustion engine is operating in closed loop longer than a predetermined time limit if 02CNTR is not more negative than the second predetermined limit; sending a number of toggles from the oxygen sensor to an engine control unit; using more oxygen Sensor toggles per DCMULT increment if the internal combustion engine is operating in closed loop; using less oxygen sensor toggles per DCMULT increment if the internal combustion engine is operating in closed loop; determining an output level of the purge solenoid based on the obtained duty cycle of the purge solenoid; and controlling the purge solenoid to the obtained duty cycle.

Claim 17

A method of controlling a purge solenoid for a purge control system of an internal combustion, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a predetermined duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining whether the predetermined duty cycle is approximately a predetermined minimum level; turning the purge solenoid OFF if the predetermined duty cycle is approximately a predetermined minimum level; determining whether the predetermined duty cycle is approximately a predetermined maximum level if the predetermined duty cycle is not approximately the predetermined minimum level; turning the purge solenoid ON if the predetermined duty cycle is approximately the predetermined maximum level; determining whether the internal combustion engine is operating at an idle condition if the predetermined duty cycle is not approximately the predetermined maximum level; using the predetermined duty cycle at a first predetermined frequency to control the purge solenoid if the internal combustion engine is operating at an idle condition; and using the predetermined duty cycle at a second predetermined frequency to control the purge solenoid if the internal combustion engine is not operating at an idle condition.

Claim 18

A method of controlling a purge solenoid for a purge control system of an internal combustion, said method comprising the steps of: determining whether predetermined conditions are right for duty cycling the purge solenoid; turning the purge solenoid OFF if predetermined conditions are not right for duty cycling the purge solenoid; obtaining a predetermined duty cycle for the purge solenoid based on a duty cycle flow (DCFLOW) if predetermined conditions are right for duty cycling the purge solenoid; determining whether the predetermined duty cycle is approximately a predetermined minimum level; turning the purge solenoid OFF if the predetermined duty cycle is approximately a predetermined minimum level; determining whether the predetermined duty cycle is approximately a predetermined maximum level if the predetermined duty cycle is not approximately the predetermined minimum level; turning the purge solenoid ON if the predetermined duty cycle is approximately the predetermined maximum level; determining whether the internal combustion engine is operating at an idle condition if the predetermined duty cycle is not approximately the predetermined maximum level; using the predetermined duty cycle at a first predetermined frequency to control the purge solenoid if the internal combustion engine is operating at an idle condition; and using the predetermined duty cycle at a second predetermined frequency to control the purge solenoid if the internal combustion engine is not operating at an idle condition.

Claim 23

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether the internal combustion engine is operating at wide open throttle; determining whether the internal combustion engine is operating in closed loop if the internal combustion engine is not operating at wide open throttle; turning the purge solenoid OFF if the internal combustion engine is operating at wide open throttle or is not operating in closed loop; calculating a duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML); determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result of DCINML is not equal to the predetermined value and using the result to find the predetermined duty cycle for the purge solenoid; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit if DCINML is equal to the predetermined value; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value and using the result to find the predetermined duty cycle for the purge solenoid if 02CNTR is not more negative than the first predetermined value; determining whether the engine is operating in closed loop longer than a predetermined time limit if the simulated air flow is not outside the predetermined operating range; sending a number of toggles from the oxygen sensor to an engine control unit; using more oxygen Sensor toggles per DCMULT increment if the engine is operating in closed loop; using less oxygen Sensor toggles per DCMULT increment if the engine is operating in closed loop; determining an output level of the purge solenoid based on the predetermined duty cycle of the purge solenoid; and controlling the purge solenoid to the predetermined duty cycle.

Claim 24

A method of controlling a purge solenoid for a purge control system of an internal combustion engine, said method comprising the steps of: determining whether the internal combustion engine is operating at wide open throttle; determining whether the internal combustion engine is operating in closed loop if the internal combustion engine is not operating at wide open throttle; turning the purge solenoid OFF if the internal combustion engine is operating at wide open throttle or is not operating in closed loop; calculating a duty cycle flow (DCFLOW) based on a simulated engine airflow and a duty cycle initial multiplier (DCINML); determining whether DCINML is equal to a predetermined value; multiplying the calculated DCFLOW by at least one predetermined factor to find a result of DCINML is not equal to the predetermined value and using the result to find the predetermined duty cycle for the purge solenoid; determining whether a simulated air flow is outside of a predetermined operating range or engine vacuum is below a predetermined limit if DCINML is equal to the predetermined value; determining an 02CNTR value based on feedback from an oxygen sensor; determining whether 02CNTR is more negative that a first predetermined limit if the simulated air flow is outside of the predetermined operating range or engine vacuum is below the predetermined limit; decrementing a duty cycle multiplier factor (DCMULT) if 02CNTR is more negative than the first predetermined limit; multiplying the calculated DCFLOW by at least one predetermined factor to find a result if DCINML is not equal to the predetermined value and using the result to find the predetermined duty cycle for the purge solenoid if 02CNTR is not more negative than the first predetermined value; determining whether the engine is operating in closed loop longer than a predetermined time limit if the simulated air flow is not outside the predetermined operating range; sending a number of toggles from the oxygen sensor to an engine control unit; using more oxygen Sensor toggles per DCMULT increment if the engine is operating in closed loop; using less oxygen Sensor toggles per DCMULT increment if the engine is operating in closed loop; determining an output level of the purge solenoid based on the predetermined duty cycle of the purge solenoid; and controlling the purge solenoid to the predetermined duty cycle.