Abstract:
A variety of methods and arrangements for mitigating powertrain and accessory torsional oscillation through electric motor/generator control are described. In one aspect, working chamber air charge and crank position are determined prior to starting an engine. During the engine startup period, an electric motor/generator supplies a smoothing torque to at least partially cancel engine torque variations.
Abstract:
A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a dynamic firing level modulation manner. A smoothing torque is determined by adaptive control that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.
Abstract:
A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.
Abstract:
A variety of methods and arrangements for determining whether a high pressure exhaust spring is present in a cylinder of an internal combustion engine are described. For spark ignition engines, the electrical properties of the spark plug spark gap may be used to determine whether a high pressure exhaust spring is present.
Abstract:
A variety of methods and devices for controlling the operation of the intake and exhaust valves in an internal combustion engine during skip fire operation are described. In various embodiments, an exhaust valve monitor or other suitable mechanism is used to detect exhaust valve actuation faults. When an exhaust valve actuation fault is detected for a particular cylinder, the corresponding intake valve is deactivated (or not activated) in circumstances when it would otherwise be activated in order to prevent the intake valve from opening into a cylinder that contains high pressure combustion gases. The described approach is particularly beneficial when skip fire operation is combined with cylinder deactivation so that air is not pumped through the cylinders during the skipped working cycles.
Abstract:
A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.
Abstract:
A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a dynamic firing level modulation manner. A smoothing torque is determined by adaptive control that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.
Abstract:
A variety of methods and devices for controlling the operation of the intake and exhaust valves in an internal combustion engine during skip fire operation are described. In various embodiments, an exhaust valve monitor or other suitable mechanism is used to detect exhaust valve actuation faults. When an exhaust valve actuation fault is detected for a particular cylinder, the corresponding intake valve is deactivated (or not activated) in circumstances when it would otherwise be activated in order to prevent the intake valve from opening into a cylinder that contains high pressure combustion gases. The described approach is particularly beneficial when skip fire operation is combined with cylinder deactivation so that air is not pumped through the cylinders during the skipped working cycles.
Abstract:
A variety of methods and devices for mitigating power train vibration during skip fire operation of an engine are described. In one aspect, the slip of a drive train component (such as a torque converter clutch) is based at least in part upon a skip fire characteristic (such as firing fraction, selected firing sequence/pattern, etc.) during skip fire operation of an engine. The modulation of the drive train component slip can also be varied as a function of one or more engine operating parameters such as engine speed and/or a parameter indicative of the output of fired cylinders (such as mass air charge).
Abstract:
A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.