Method and apparatus for reducing engine cycling in hybrid electric vehicle

• US 6,624,527 B1
• Filed: 09/15/2000
• Issued: 09/23/2003
• Est. Priority Date: 09/15/2000
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Motor Company
• Inventors: Curran, Patrick Joseph, Crombez, Dale Scott, Napier, Steven Lee
• Primary Examiner(s): Waks, Joseph
• Assistant Examiner(s): GONZALEZ, JULIO CESAR
• Application Number:
  US09/663,515
• Time in Patent Office: 1,103 Days
• Field of Search: 290/40.C, 180/65.2, 318/139
• US Class Current: 290/40.00C
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60T 13/46 Vacuum systems
• CPC Class Codes: B60T 17/02 Arrangements of pumps or compressors, or control devices therefor
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 3/2013 using electric or magnetic heating means
• CPC Class Codes: F02D 2250/41 Control to generate negative pressure in the intake manifold, e.g. for fuel vapor purging or brake booster
• CPC Class Codes: F02D 41/0045 Estimating, calculating or determining the purging rate, amount, flow or concentration
• CPC Class Codes: F02D 41/024 to increase temperature of the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: F02N 11/0829 related to special engine control, e.g. giving priority to engine warming-up or learning
• CPC Class Codes: F02N 11/084 : State of vehicle accessories, e.g. air condition or power steering
• CPC Class Codes: F02N 2200/026 : Catalyst temperature
• CPC Class Codes: F02N 2200/0806 : Air condition state
• CPC Class Codes: F02N 2200/0807 : Brake booster state
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

A method and system that responds to non-propulsive needs of a hybrid vehicle by setting at least two thresholds related to engine support: one threshold to keep a running engine ON and a another threshold to turn the engine ON from an OFF state.

Claims

1. A method of reducing the number of times a main power unit of a hybrid electric vehicle is activated to support a plurality of auxiliary system of the vehicle during a given drive cycle comprising a sequence of the following steps:

determining the ON/OFF status of said unit;

if the unit is ON requesting that the unit be maintained ON until the value of an auxiliary system parameter exceeds a first threshold value wherein said first threshold value is a unit ON auxiliary system threshold value;

if the unit is OFF requesting that the unit be turned ON when the value of said parameter falls below a second threshold value wherein said second threshold value is a unit OFF auxiliary system threshold value;

setting said unit OFF auxiliary system threshold value when the status of said unit is OFF;

setting said unit ON auxiliary system threshold value when the status of said unit is ON; and

wherein said step of requesting that a unit ON status be maintained is performed if a predetermined parameter in any of said plurality of auxiliary systems is below respective unit ON auxiliary system threshold values, and said step of requesting a unit ON status is performed if a predetermined parameter in any of said plurality of auxiliary systems is below respective unit OFF auxiliary system threshold value.

2. The method of claim 1 wherein said auxiliary system is a brake booster vacuum system.

3. The method of claim 1 wherein said auxiliary system is an air conditioning and heating system.

4. The method of claim 1 wherein said auxiliary system is a purge vapor system.

5. The method of claim 1 wherein said auxiliary system is a catalyst system.

6. A method of reducing the number of times a main power unit of a hybrid electric vehicle is activated to support an auxiliary system of the vehicle during a given drive cycle comprising a sequence of the following steps:

determining the ON/OFF status of said unit;

determining whether the value of an auxiliary system parameter is within or outside a window defined by first and second threshold values, where said first threshold value represents a parameter value to be attained before a unit that is ON should be turned OFF and the second threshold value represents a parameter value at which it is desirable for a unit that is OFF to be turned ON;

requesting a change of status from OFF to ON if the value of the parameter falls below said second threshold value; and

requesting a change of status from ON to OFF if the value of the parameter is greater than said first threshold value.

7. A system for reducing the number of times a main power unit of a hybrid electric vehicle is activated to support an auxiliary system of the vehicle during a given drive cycle comprising:

means for determining the ON/OFF status of said unit;

means for determining whether the value of an auxiliary system parameter is within or outside a window defined by first and second threshold values, where said first threshold value represents a parameter value to be attained before a unit that is ON should be turned OFF and the second threshold value represents a parameter value at which it is desirable for a unit that is OFF to be turned ON;

means for requesting a change of status from OFF to ON if the value of the parameter falls below said second threshold value; and

means for requesting a change of status from ON to OFF if the value of the parameter is greater than said first threshold value.

8. The system of claim 7 further comprising:

means for setting said unit OFF auxiliary system threshold value when the status of said unit is OFF; and

means for setting said unit ON auxiliary system threshold value when the status of said unit is ON.