Engine ready detection using crankshaft speed feedback

• US 6,516,253 B2
• Filed: 12/05/2000
• Issued: 02/04/2003
• Est. Priority Date: 12/05/2000
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Burke, Stephen Richard, Kotre, Stephen John, Boggs, David Lee
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US09/729,872
• Publication Number:
  US 20020068998A1
• Time in Patent Office: 791 Days
• Field of Search: 701/22, 701/110, 477/7, 477/20, 123/436
• US Class Current: 701/20
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0652 Speed change rate
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/904 Component specially adapted for hev

Abstract

The present invention provides a method and system for determining “engine on” status in a Hybrid Electric Vehicle. A controller determines the engine is necessary and then checks the current “engine on” status. If the engine is not currently running, the controller proceeds to start the engine by commanding the generator to spin or “motor” the engine. The controller then starts fuel flow and spark within the engine to create combustion. A measuring device is then used to determine the crankshaft speed. The controller receives this measurement and determines whether the measured variations in crankshaft speed exceed a calibratable threshold. If the calibratable threshold is exceeded, combustion is determined to be occurring and the engine is on. The controller then turns on the “engine on” status flag.

Claims

1. A method of determining a vehicle “

engine on”

status comprising;

measuring crankshaft speed;

determining a variation in crankshaft speed;

comparing variation in crankshaft speed to a calibratable threshold;

determining if combustion is occuring.

2. The method of claim 1 wherein the vehicle is a Hybrid Electric Vehicle.

3. The method of claim 1 wherein a controller receives the measured crankshaft speed and compares the measured crankshaft speed variations to the calibratable threshold to determine if combustion is occurring.

4. The method of claim 1 further comprising the step of turning on an “

engine on”

status flag if the measured crankshaft speed variation exceeds the calibratable threshold.

5. A system to determine “

engine on”

status in a Hybrid Electric Vehicle comprising;

a controller;

a generator;

an engine; and

a measuring device to determine crankshaft speed,

wherein the controller starts the engine with a command to the generator to spin up the engine, and a command to start fuel flow to the engine and sparking within the engine.