Crankshaft rotation control in a hybrid electric vehicle

• US 20020093202A1
• Filed: 01/16/2001
• Published: 07/18/2002
• Est. Priority Date: 01/16/2001
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Tamai, Goro, Richey, Dennis T., Hoang, Tony T., Downs, Robert Charles
• Granted Patent: US 6,453,864 B1
• Time in Patent Office: Days
• US Class Current: 290/40.00R
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: F01M 5/02 Conditioning lubricant for aiding engine starting, e.g. heating
• CPC Class Codes: F02D 2041/0092 Synchronisation of the cylinders at engine start
• CPC Class Codes: F02D 2041/0095 Synchronisation of the cylinders during engine shutdown
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02N 19/005 Aiding engine start by starting from a predetermined position, e.g. pre-positioning or reverse rotation
• CPC Class Codes: F02N 2019/007 using inertial reverse rotation
• CPC Class Codes: F02N 2019/008 the engine being stopped in a particular position
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/917 with transmission for changing gear ratio

Abstract

A method of controlling engine crankshaft motion in a hybrid electric drive system having an internal combustion engine and a motor-generator operatively connected to a crankshaft of the engine is disclosed. The steps include monitoring the crankshaft position, forecasting a crankshaft stall position; comparing the forecast stall position with a target range; and if the forecast crankshaft stall position is outside the target range, operating the motor-generator to modify the forecast stall position to be within the target range. These steps properly position the crankshaft for re-initiating engine start-up. The method further includes the steps of calculating an effective lube interval time once the crankshaft speed is zero; comparing the effective lube interval time to a critical time; and if the effective lube interval time is greater than the critical time, pulsing the motor-generator to rock the crankshaft for a pulse time to redistribute a lubricant film.

Claims

1. A method of controlling engine crankshaft motion in a hybrid electric drive system having an internal combustion engine and a motor-generator operatively connected to a crankshaft of the engine, comprising the steps of:

monitoring the crankshaft position;

forecasting a crankshaft stall position;

comparing the forecast stall position with a target range; and

if the forecast crankshaft stall position is outside the target range, operating the motor-generator to modify the forecast stall position to be within the target range.

2. The method of claim 1, wherein the step of operating the motor-generator further includes one of the following steps:

applying a preloading torque to the crankshaft in the direction of crankshaft rotation; and

applying regenerative braking to slow the crankshaft to stall within the target range.

3. The method of claim 2, further comprising the steps of:

after operating the motor-generator, monitoring the crankshaft speed;

if the crankshaft speed is zero, comparing the crankshaft stall position to the target range; and

if the crankshaft stall position is outside the target range, operating the motor-generator to modify the crankshaft stall position to be within the target range.

4. The method of claim 3, further comprising the step of:

after the crankshaft speed is zero, calculating an effective lube interval time;

comparing the effective lube interval time to a critical time; and

if the effective lube interval time is greater than the critical time, pulsing the motor-generator to rock the crankshaft for a pulse time to redistribute a lubricant film.

5. The method of claim 4, wherein the step of calculating the effective lube interval time further comprising the steps of:

monitoring engine coolant temperature;

monitoring engine oil pressure; and

monitoring how long the crankshaft speed is zero without motor-generator pulsations.

6. The method of claim 5, further comprising the step of:

summing the pulse times.

7. The method of claim 6, further comprising the step of:

comparing the summed pulse time to a maximum time; and

if the summed pulse time is greater than the maximum time, discontinuing further pulsing of the motor-generator.

8. A method of controlling engine crankshaft motion for lubrication redistribution in a hybrid electric drive system having an internal combustion engine and a motor-generator operatively connected to a crankshaft of the engine, comprising the steps of:

monitoring crankshaft speed;

if crankshaft speed is zero, calculating an effective lube interval time;

comparing the effective lube interval time to a critical time;

if the effective lube interval time is greater than the critical time, pulsing the motor-generator to rock the crankshaft for a pulse time to redistribute a lubricant film.

9. The method of claim 8, wherein the step of calculating the effective lube interval time further comprising the steps of:

monitoring engine coolant temperature;

monitoring engine oil pressure; and

monitoring how long the crankshaft speed is zero without motor-generator pulsations.

10. The method of claim 9, further comprising the step of:

summing the pulse times.

11. The method of claim 10, further comprising the steps of:

comparing the summed pulse time to a maximum time; and

if the summed pulse time is greater than the maximum time, discontinuing further pulsing of the motor-generator.