Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: A noise cancellation system for a vehicle includes an excitation device mountable to a vehicle body component. The excitation device is operable to produce a low frequency response of the vehicle body component.

Abstract: A noise cancellation system for a vehicle includes an excitation device mountable to a vehicle body component. The excitation device is operable to produce a low frequency response of the vehicle body component.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: A two-stage stiffness driveshaft includes a hollow cylinder having first and second ends and a hollow cylinder stiffness. An inner shaft having first and second ends and an inner shaft stiffness extends through the hollow cylinder. The inner shaft's first end and the hollow cylinder's first end are engaged via a rotational clearance fit. The inner shaft's second end is rotationally fixed to the hollow cylinder's second end to permit the inner shaft's first end to twist through a predetermined angle relative to the inner shaft's second end. The inner shaft's stiffness defines the driveshaft's first-stage stiffness, while the combined stiffness of the inner shaft and the hollow cylinder defines the driveshaft's second-stage stiffness. A damping element positioned between the inner shaft and the hollow cylinder controls variation in torque transmitted by the driveshaft and generates gradual transition between the first-stage stiffness and the second-stage stiffness.

Abstract: A two-stage stiffness driveshaft includes a hollow cylinder defined by a longitudinal axis, a first end, a distal second end, and a hollow cylinder stiffness. The driveshaft also includes an inner shaft extending through the hollow cylinder along the longitudinal axis and defined by a first end, a distal second end, and an inner shaft stiffness. The first end of the inner shaft is engaged with the first end of the hollow cylinder via a rotational clearance fit. The second end of the inner shaft is rotationally fixed to the second end of the hollow cylinder such that the first end of the inner shaft can twist to a predetermined angle with respect to the second end of the inner shaft. The inner shaft stiffness defines a first-stage stiffness of the driveshaft, and the inner shaft stiffness and the hollow cylinder stiffness together define a second-stage stiffness of the driveshaft.

Abstract: A two-stage stiffness driveshaft includes a hollow cylinder defined by a longitudinal axis, a first end, a distal second end, and a hollow cylinder stiffness. The driveshaft also includes an inner shaft extending through the hollow cylinder along the longitudinal axis and defined by a first end, a distal second end, and an inner shaft stiffness. The first end of the inner shaft is engaged with the first end of the hollow cylinder via a rotational clearance fit. The second end of the inner shaft is rotationally fixed to the second end of the hollow cylinder such that the first end of the inner shaft can twist to a predetermined angle with respect to the second end of the inner shaft. The inner shaft stiffness defines a first-stage stiffness of the driveshaft, and the inner shaft stiffness and the hollow cylinder stiffness together define a second-stage stiffness of the driveshaft.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: An engine active motion control system for controlling engine dynamic torque includes an engine that generates a first dynamic torque. A first module selectively initiates generation of a second dynamic torque about an axis of rotation of a crankshaft of the engine in a direction opposite that of the first dynamic torque generated through the crankshaft.