ENGINE CONTROL UNIT USING SPEED DENSITY CONVERSION

• US 20130319377A1
• Filed: 06/05/2012
• Published: 12/05/2013
• Est. Priority Date: 06/05/2012
• Status: Active Grant

• Current Assignee: HONDATA Incorporated
• Original Assignee: HONDATA Incorporated
• Inventors: Stevens, Derek
• Granted Patent: US 9,091,224 B2
• Time in Patent Office: Days
• US Class Current: 123/480
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 2400/08 Redundant elements, e.g. two sensors for measuring the same parameter
• CPC Class Codes: F02D 41/04 Introducing corrections for particular operating conditions F02D41/14 takes precedence
• CPC Class Codes: F02D 41/182 for the control of a fuel injection device
• CPC Class Codes: F02D 41/40 with means for controlling injection timing or duration

Abstract

The present invention utilizes a speed density method for determining the cylinder air mass using volumetric efficiency (VE) based on engine speed and manifold pressure. The VE data contain the cylinder filling efficiency for various engine speed and manifold pressure values. The manifold pressure is then measured by a manifold absolution pressure (MAP) sensor. Using the speed density has the advantage that it is much less affected by pulsation in the intake system of the vehicle, and does not require a linear air flow past a sensor in the engine intake system.

Claims

1. A method for determining a duration of a fuel injector opening in a fuel injection system comprising:

measuring the air flow;

calculating cylinder air mass;

measuring a manifold pressure using a MAP sensor;

determine an injector duration using engine load and speed;

applying an air temperature compensation; and

returning the injector duration to the engine control unit.

2. The method for determining a duration of a fuel injector opening of claim 1, wherein the calculating cylinder air mass is based on the engine speed.

3. The method for determining a duration of a fuel injector opening of claim 1, further comprising an option for using the mass flow sensor in lieu of the MAP sensor.

4. A fuel injection system comprising:

a mass flow sensor for measuring the air intake;

means for determining the engine speed;

a processor for calculating a cylinder air mass;

a switch for determining an injector control using an air mass sensor and speed density;

a MAP sensor for measuring manifold pressure;

a look-up table for determining injector duration from engine load and engine speed;

a look-up table for determining a temperature correction;

wherein said processor utilizes the manifold pressure and engine speed to determine injector duration, and forward instructions for ECU control.

5. The fuel injection system of claim 4 further comprising an air mass versus injection duration table for determining injection duration using the mass flow sensor.

6. The fuel injection system of claim 4, further comprising means for adjusting the instructions based on one of the group comprising closed loop, cold enrichment, and acceleration enrichment.