Engine automatic stop/start mechanism

• US 9,181,915 B2
• Filed: 11/01/2011
• Issued: 11/10/2015
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: BAE Systems Controls Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Controls Incorporated (BAE Systems Plc)
• Inventors: Dupuy, James A.
• Primary Examiner(s): Chen, Shelley
• Application Number:
  US13/286,768
• Publication Number:
  US 20130054060A1
• Time in Patent Office: 1,470 Days
• Field of Search: 701/112
• US Class Current: 1/1
• CPC Class Codes: F02D 17/04 rendering engines inoperative or idling, e.g. caused by abnormal conditions dependent on lubricating conditions F01M1/22; dependent on cooling F01P5/14
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/604 Engine control mode selected by driver, e.g. to manually start particle filter regeneration or to select driving style
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02N 11/0822 related to action of the driver
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• 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 2200/023 Engine temperature
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/0801 Vehicle speed
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

An inventive system and method for managing vehicle power is presented. The novel technology provides a means to automatically shutdown a vehicle'"'"'s engine when conditions are such that engine power is not needed, reducing fuel consumption as well as lowering noise and emissions. A series of conditions are examined to determine whether engine power is needed and hence whether shutdown can be safely performed. The inventive system and method can also determine when power is again needed by the engine and can re-start the engine automatically at such times.

Claims

1. A method for performing automatic engine stop of a hybrid vehicle having a battery, the method comprising steps of:

determining whether the engine is in test mode;

determining whether the engine is in high idle;

determining whether automatic shutdown authorization is asserted;

determining whether a state of charge of the battery is above a predetermined charge limit;

determining whether the vehicle speed is less than a predetermined speed limit;

determining whether the vehicle speed has exceeded a predetermined minimum moving speed limit since the last automatic engine shutdown;

determining whether the engine has been running for at least a predetermined minimum engine run time limit;

determining whether engine coolant temperature is within a predetermined range;

determining whether generator power demand is less than a predetermined generator power demand limit;

determining whether the vehicle has been in drive for at least a predetermined minimum drive time since one of key on and engine start; and

performing the automatic engine stop when the engine is not in the test mode, the automatic shutdown authorization is asserted, and the state of charge of the battery is above the predetermined charge limit, unless at least one of;

(1) the engine is in high idle, (2) the vehicle speed is greater than the predetermined speed limit, (3) the engine coolant temperature is not within the predetermined range, (4) the generator power demand is greater than a predetermined generator power demand limit, (5) the vehicle has not been in drive for at least the predetermined minimum drive time since one of key on and engine start, and (6) either;

(a) the engine has not been running for at least the predetermined minimum engine run time limit, or (b) the vehicle speed has not exceeded the predetermined minimum moving speed limit since the last automatic engine shutdown.

2. A system for performing automatic engine stop, the system comprising:

a hybrid vehicle having an engine and a battery; and

a module operable to determine whether the engine is in test mode and whether the engine is in high idle and whether automatic shutdown authorization is asserted and whether a state of charge of the battery is above a predetermined charge limit and whether the vehicle speed is less than a predetermined speed limit and whether the vehicle speed has exceeded a predetermined minimum moving speed limit since the last automatic engine shutdown and whether the engine has been running for at least a predetermined minimum engine run time limit and whether engine coolant temperature is within a predetermined range and whether generator power demand is less than a predetermined generator power demand limit and whether the vehicle has been in drive for at least a predetermined minimum drive time since one of key on and engine start; and

wherein the module is further operable to perform the automatic engine stop when the engine is not in the test mode, the automatic shutdown authorization is asserted, and the state of charge of the battery is above the predetermined charge limit, unless at least one of;

(1) the engine is in high idle, (2) the vehicle speed is greater than the predetermined speed limit, (3) the engine coolant temperature is not within the predetermined range, (4) the generator power demand is greater than a predetermined generator power demand limit, (5) the vehicle has not been in drive for at least the predetermined minimum drive time since one of key on and engine start, and (6) either;

(a) the engine has not been running for at least the predetermined minimum engine run time limit, or (b) the vehicle speed has not exceeded the predetermined minimum moving speed limit since the last automatic engine shutdown.

3. A computer readable storage medium storing a program of instructions executable by a machine to perform automatic engine stop for a hybrid vehicle having an engine and a battery, the program of instructions being configured to provide steps comprising:

determining whether the engine is in test mode;

determining whether the engine is in high idle;

determining whether automatic shutdown authorization is asserted;

determining whether a state of charge of the battery is above a predetermined charge limit;

determining whether the vehicle speed is less than a predetermined speed limit;

determining whether the vehicle speed has exceeded a predetermined minimum moving speed limit since the last automatic engine shutdown;

determining whether the engine has been running for at least a predetermined minimum engine run time limit;

determining whether engine coolant temperature is within a predetermined range;

determining whether generator power demand is less than a predetermined generator power demand limit;

determining whether the vehicle has been in drive for at least a predetermined minimum drive time since one of key on and engine start; and

performing the automatic engine stop when the engine is not in the test mode, the automatic shutdown authorization is asserted, and the state of charge of the battery is above the predetermined charge limit, unless at least one of;

(1) the engine is in high idle, (2) the vehicle speed is greater than the predetermined speed limit, (3) the engine coolant temperature is not within the predetermined range, (4) the generator power demand is greater than a predetermined generator power demand limit, (5) the vehicle has not been in drive for at least the predetermined minimum drive time since one of key on and engine start, and (6) either;

(a) the engine has not been running for at least the predetermined minimum engine run time limit, or (b) the vehicle speed has not exceeded the predetermined minimum moving speed limit since the last automatic engine shutdown.