US 7,127,337 B2Granted

Silent operating mode for reducing emissions of a hybrid electric vehicle

AssigneeGeneral Motors Corporation

InventorsAdam C. Bennett, William R. Cawthorne, Tung-Ming Hsieh, Gregory A. Hubbard

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Abstract

This novel silent operating mode for a hybrid electric vehicle (HEV) reduces noise and emissions compared to traditional HEV operating modes. It is a complementary series of software control functions that allows the vehicle to operate with reduced noise and emissions where specifically needed, while phasing-in engine power where allowed. The method utilizes an energy storage system budget associated with a modal quantity of energy allocated for the mode, and is adapted to automatically adjust the operation of the vehicle to accommodate deviations from the budgeted energy amount. The mode also adjusts the vehicle operation in conjunction with changes in the parametric conditions of the ESS.

Claims17

Dependent claims

A method of providing a silent mode of operation for a hybrid electric vehicle having a rechargeable energy storage system (ESS), comprising the steps of:

(1) transmitting a silent mode initiation request to a silent mode controller;
(2) comparing an actual value of at least one state parameter of the ESS that is indicative of the availability of the ESS for implementing the silent mode to at least one silent mode initiation limit value associated with the actual value, wherein if the actual value of the at least one state parameter compared to the associated at least one mode initiation limit value indicates that the silent mode is allowed, the method proceeds to step (3), and wherein if the actual value of the at least one state parameter indicates that the silent mode is not allowed, step (2) is repeated so long as the silent mode initiation request is being transmitted;
(3) transmitting a silent mode activation request to the silent mode controller;
(4) operating the vehicle in the silent mode using the silent mode controller, comprising designating an electric drive motor as a primary source of propulsion energy for the vehicle and designating an engine as a secondary source of the propulsion energy for the vehicle, wherein a modal quantity of energy in the ESS is allocated for use by the electric drive motor during the silent mode and the engine is used to make up the difference between the modal quantity of energy and a total vehicle propulsion energy requirement during the silent mode;
(4A) limiting an output power of the engine while the vehicle is in the silent mode to a silent mode output power limit that is less than a maximum output power of the engine, and,
(5) terminating the silent mode in response to the occurrence of a mode termination event.

3 more elements

A method of providing a silent mode of operation for a hybrid electric vehicle having a rechargeable battery, comprising the steps of:

(1) transmitting a silent mode initiation request to a silent mode controller;
(2) comparing a battery temperature to a mode initiation battery temperature limit value, wherein if the battery temperature is less than or equal to the mode initiation battery temperature limit value, the method proceeds to step (3), and wherein if the battery temperature is greater than the mode initiation battery temperature limit value, step (2) is repeated so long as the mode initiation request is being transmitted;
(3) precharging the battery prior to initiation of a silent mode;
(4) transmitting a silent mode activation request to the silent mode controller;
(5) operating the vehicle in the silent mode using the silent mode controller, comprising designating an electric drive motor as a primary source of propulsion energy for the vehicle and designating an engine as a secondary source of the propulsion energy for the vehicle, wherein a modal quantity of energy in the battery is allocated for use by the electric drive motor during the silent mode and the engine is used to make up the difference between the modal quantity of energy and a total vehicle propulsion energy requirement during the silent mode;
and
(6) terminating the silent mode in response to the occurrence of a mode termination event.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/686,175Filed 14 Oct 2003
Published: US 2005/0080523 A114 Apr 2005
Granted: 24 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

B60K 6/445
Series-parallel type: differential gearing distribution type
B60L 58/13
Responding to state of charge [SoC]: maintaining the SoC within a determined range
B60W 10/06
Including control of propulsion units: including control of combustion engines
B60W 10/08
Including control of propulsion units: including control of electric propulsion units, e.g. motors or generators