Abstract: Systems and methods for reducing noise or vibration generated by an internal combustion engine are described. An engine controller is arranged to operate the working chambers of the engine in a cylinder output level modulation manner A noise/vibration reduction unit actively control of a device that is not a part of the powertrain. The device is controlled in a feed forward manner to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a characteristic of the cylinder output level modulation operation of the engine.

Abstract: Systems and methods for reducing noise or vibration generated by an internal combustion engine are described. An engine controller is arranged to operate the working chambers of the engine in a cylinder output level modulation manner. A noise/vibration reduction unit actively control of a device that is not a part of the powertrain. The device is controlled in a feed forward manner to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a characteristic of the cylinder output level modulation operation of the engine.

Abstract: Systems and methods for reducing noise or vibration generated by an internal combustion engine are described. An engine controller is arranged to operate the working chambers of the engine in a cylinder output level modulation manner A noise/vibration reduction unit actively control of a device that is not a part of the powertrain. The device is controlled in a feed forward manner to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a characteristic of the cylinder output level modulation operation of the engine.

Abstract: Systems and methods for reducing noise or vibration generated by an internal combustion engine are described. An engine controller is arranged to operate the working chambers of the engine in a cylinder output level modulation manner. A noise/vibration reduction unit actively control of a device that is not a part of the powertrain. The device is controlled in a feed forward manner to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a characteristic of the cylinder output level modulation operation of the engine.

Abstract: Various methods and arrangements for operating a skip fire engine control system are described. In one aspect of the invention, a distinct firing sequence is determined for each bank of working chambers that is used to operate the bank in a skip fire manner. Each firing sequence uses a different firing fraction. In another aspect of the invention, a determination is made as to whether a firing sequence should be dynamically generated or selected from a set of predefined firing sequences.

Abstract: In one aspect, a system for reducing noise or vibration generated by an internal combustion engine is described. An engine controller is arranged to generate firing information suitable for operating the working chambers of the engine in a skip fire manner to deliver a desired amount of torque. A noise/vibration reduction unit is arranged to help reduce noise or vibration based on the firing information. The noise/vibration controller actively controls a device that is not a part of the engine to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a skip fire characteristic.

Abstract: A variety of methods and arrangements for controlling the operation of an internal combustion engine in a skip fire variable displacement mode are described. In general, a firing control unit determines working chamber firings during operation of the engine that are suitable for delivering a desired engine output. In one aspect, the firing control unit is arranged to isolate the generation of firing sequences having frequency components in a frequency range of concern and to alter the firing sequence in a manner that reduces the occurrence of frequency components in the frequency range of concern. In another aspect, a filter is arranged to filter a feedback signal to provide a filtered feedback signal that is used in the determination of the working chamber firings. In preferred embodiments, the frequency characteristics of the filter are variable.

Abstract: Various methods and arrangements for operating a skip fire engine control system are described. In one aspect of the invention, a distinct firing sequence is determined for each bank of working chambers that is used to operate the bank in a skip fire manner. Each firing sequence uses a different firing fraction. In another aspect of the invention, a determination is made as to whether a firing sequence should be dynamically generated or selected from a set of predefined firing sequences.

Abstract: A variety of methods and arrangements for controlling the operation of an internal combustion engine in a skip fire variable displacement mode are described. In general, a firing control unit determines working chamber firings during operation of the engine that are suitable for delivering a desired engine output. In one aspect, the firing control unit is arranged to isolate the generation of firing sequences having frequency components in a frequency range of concern and to alter the firing sequence in a manner that reduces the occurrence of frequency components in the frequency range of concern. In another aspect, a filter is arranged to filter a feedback signal to provide a filtered feedback signal that is used in the determination of the working chamber firings. In preferred embodiments, the frequency characteristics of the filter are variable. In various embodiments, the frequency characteristics of the filter vary as a function engine speed and/or a transmission gear ratio.

Abstract: Forward and Reverse Channel Automatic Repeat reQuest (ARQ) communication is described in which a Forward Channel Automatic Repeat reQuest (ARQ) session between a first unit and a second unit is performed, in which a command is send to the second unit to start a forward channel ARQ session, where the command includes a message length field specifying the length of an ARQ message to be sent by the first unit to the second unit. The second unit may refuse the command because of the length of the ARQ message.

Abstract: A method and apparatus for combined timing recovery, frame synchronization and frequency offset correction in a digital receiver is provided. In general, the present invention provides a pair of correlators that operate on a set of samples output by a discriminator. A positive correlator generates a positive correlation value and a negative correlator generates a negative correlation value. The positive and negative correlation values are used to determine frame synchronization, frequency offset and timing recovery values so that timing recovery, frame synchronization and frequency offset correction may be performed simultaneously.