| 摘要 |
<p>816.008 FUEL DEMAND ENGINE CONTROL SYSTEM An electrically controlled closed loop system for maintaining a desired air-fuel ratio within an internal combustion engine. An operatorpositioned accelerator commands a given fuel flow into the engine and the flow of air is controlled by means of a servo-actuated throttle plate. The commanded fuel flow and present position at the throttle plate are used to generate a basic command signal for controlling the servo motor to adjusting the position of the throttle plate. A gas detector or roughness sensor positioned in the engine is responsive to the actual air-fuel mixture in the engine which may be greater than or less than the desired air-fuel mixture and an error signal is generated which can be used to modify or correct the basic control signal in a closed loop manner for selectively adjusting throttle plate position to more precisely maintain a desired air-fuel ratio. While the present type of system has inherent acceleration enrichment since the fuel enters before the air flow increases, an undesirable condition of excessive enrichment may occur. The rate of change of commanded fuel flow is monitored to anticipate an impending undesirable condition of excessive enrichment and a transient control signal adjustment spike is generated to momentarily increase air flow to minimize the undesirable condition even before the gas detector or roughness sensor actually detects the existence of same. A closed loop governing system for metering the fuel flow may also be provided, if desired.</p> |
