摘要:
A system and a method to control air flow during a transition in an internal combustion engine, in which intake valves are operated by more than one type of actuation device, is disclosed. Based on demanded engine torque, engine speed and transition type, throttle position and closing time of a randomly operable intake valve are determined such that a smooth transition can be accomplished.
摘要:
A method for controlling intake valves in an internal combustion with intake valves operated by more than one type of actuation device includes steps to accomplish smooth transitions among intake valve operating modes.
摘要:
A system and method for controlling a direct injection stratified charge engine during transitions between homogeneous and stratified operating modes position the throttle to a position corresponding to the desired operating mode to begin the transition and use valve timing control to provide a rapid change in air flow to traverse the gap between acceptable air/fuel ratios associated with the homogeneous and stratified modes. The invention reduces torque variations while improving engine performance by coordinating control of an electronic throttle and valve timing to reduce or eliminate step changes in fuel previously required to traverse the air/fuel ratio gap between modes. Primary reliance on air flow and fuel flow to reduce torque variations and improve driveability reduces reliance on spark timing and associated performance penalties.
摘要:
Various systems and methods are described for operating an engine in a vehicle in response to a driver performance/economy mode. One example method comprises delivering a first fuel to a cylinder of the engine from a first injector, delivering a second, different, fuel to the cylinder of the engine from a second injector, varying a relative amount of said first and second fuel as an operating condition varies; and adjusting delivery of at least said second fuel based on a driver-selected performance mode.
摘要:
Method and systems are provided for controlling a vehicle system including an engine that is selectively deactivated during engine idle-stop conditions. One example method comprises, adjusting a brake torque applied to a deactivated rotating engine after an engine restart request, the brake torque applied to slow the engine to at least a predetermined threshold speed without stopping the engine, and engaging a starter to the still rotating engine to increase the engine speed and restart the engine.
摘要:
A tunable bandpass filter (10) is provided. An RF signal is provided at an input of the tunable bandpass filter, and a level shifted control signal (V1, V2) inputted to the tunable bandpass filter (10) switches a first arrangement and a second arrangement of one or more tuning portions (15, 17-1, 17-2, 17-3) in or out of the tunable bandpass filter using a GaAs FET switch. The first arrangement is coupled to the second arrangement using an inductor (13). An RF signal having a desired predetermined frequency at an output of the tunable bandpass filter (10) is produced by the switching. The tuning portions include the GaAs FET switch (15), a first capacitor (17-1) connected at a first signal terminal of the GaAs FET switch and a second capacitor (17-2) connected between a second signal terminal of the GaAs FET switch and ground. Each of the tuning portions can be arranged in parallel with one another.
摘要:
Various systems and methods are described for operating an engine in a vehicle in response to a driver performance/economy mode. One example method comprises delivering a first fuel to a cylinder of the engine from a first injector, delivering a second, different, fuel to the cylinder of the engine from a second injector, varying a relative amount of said first and second fuel as an operating condition varies; and adjusting delivery of at least said second fuel based on a driver-selected performance mode.
摘要:
Methods and systems are provided for expediting engine spin-down in an engine that is shutdown during engine idle-stop conditions and restarted during restart conditions. In one example, the method comprises, during an automatic engine idle-stop, turning off spark, operating a first cylinder with a rich ratio of air to injected fuel richer than a rich flammability limit, operating a second cylinder with a lean ratio of air to injected fuel leaner than a lean flammability limit, and mixing un-combusted exhaust from the first and second cylinders with exhaust, the exhaust mixture being substantially stoichiometric.
摘要:
An engine system includes two spark plugs in a cylinder of an engine. The two spark plugs have different heat ranges in order to address pre-ignition, where only a first spark plug operates during a first condition, and only a second spark plug operates during a second condition.
摘要:
Various example approaches are described, one of which includes a method for adjusting relative delivery of liquid and gaseous fuel to a cylinder of the engine to effect rapid changes in cylinder air charge via changes in the displacement of fresh air by the gaseous fuel. In one particular approach, turbocharger lag is addressed by decreasing gaseous fuel injection while increasing liquid fuel injection to increase cylinder fresh air over and above any changes to fresh air via the throttle, wastegate, and/or turbocharger.