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The Application of a Vibration Cancellation System to a Variable Displacement Engine

IP.com Disclosure Number: IPCOM000007400D
Publication Date: 2002-Mar-21
Document File: 1 page(s) / 128K

Publishing Venue

The IP.com Prior Art Database

Abstract

Variable Displacement Engines (VDEs) are being developed and manufactured for purposes of increasing automotive fuel economy. In VDEs, a subset of cylinders are deactivated during low power demand conditions such as idle, part throttle or steady state speeds. During high power demand conditions the subset of cylinders are reactivated and the VDE then operates on all cylinders. While the VDE is both at idle and in cylinder deactivation mode, alternating powerplant excitations may be at their highest levels. For standards of Noise, Vibration and Harshness (NVH) it is desired that vehicle occupants, especially the driver not notice when the VDE has changed (or is in transition between) operating modes. The VCS is designed to cancel or minimize excitations that could be felt by the driver or other vehicle occupants of those vehicles equipped with VDEs.

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The Application of a Vibration Cancellation System to a Variable Displacement Engine

Variable Displacement Engines (VDEs) are being developed and manufactured for purposes of increasing automotive fuel economy.  In VDEs, a subset of cylinders are deactivated during low power demand conditions such as idle, part throttle or steady state speeds.  During high power demand conditions the subset of cylinders are reactivated and the VDE then operates on all cylinders.  While the VDE is both at idle and in cylinder deactivation mode, alternating powerplant excitations may be at their highest levels.  For standards of Noise, Vibration and Harshness (NVH) it is desired that vehicle occupants, especially the driver not notice when the VDE has changed (or is in transition between) operating modes.  The VCS is designed to cancel or minimize excitations that could be felt by the driver or other vehicle occupants of those vehicles equipped with VDEs.

In the schematic of Figure 1, powerplant mounts are represented as springs.  According to the present invention, LHS and RHS VCS dampers are shown applied to frame rails.  Within packaging constraints, VCS dampers are located as close as possible to the powerplant mounts.

VCS dampers are feedback controlled by an electronic control unit with input from vibration sensors attached to the vehicle where vibration is a concern.  The electronic control unit actuates the dampers to generate an out-of phase excitation that cancels powerplant excitation as sh...