Engine control system using an air and fuel control strategy based on torque demand

• US 6,298,824 B1
• Filed: 10/21/1999
• Issued: 10/09/2001
• Est. Priority Date: 10/21/1999
• Status: Expired due to Term

• Current Assignee: Woodward Governor Company
• Original Assignee: Brunswick Corporation
• Inventors: Suhre, Blake R.
• Primary Examiner(s): Kwon, John
• Application Number:
  US09/422,614
• Time in Patent Office: 719 Days
• Field of Search: 123/361, 123/406.52, 123/406.49, 123/406.47
• US Class Current: 123/406.49
• CPC Class Codes: F02D 2011/102 at least one throttle being moved only by an electric actuator
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/602 Pedal position
• CPC Class Codes: F02D 2200/703 Atmospheric pressure
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/32 of the low pressure type F02D41/3082 takes precedence

Abstract

A control system for a fuel injected engine provides an engine control unit that receives signals from a throttle handle that is manually manipulated by an operator of a marine vessel. The engine control unit also measures engine speed and various other parameters, such as manifold absolute pressure, temperature, barometric pressure, and throttle position. The engine control unit controls the timing of fuel injectors and the injection system and also controls the position of a throttle plate. No direct connection is provided between a manually manipulated throttle handle and the throttle plate. All operating parameters are either calculated as a function of ambient conditions or determined by selecting parameters from matrices which allow the engine control unit to set the operating parameters as a function of engine speed and torque demand, as represented by the position of the throttle handle.

Claims

1. A method for controlling the operation of an engine, comprising:

measuring an operating speed of said engine;

sensing a manually controlled command signal, said manually controlled command signal representing a magnitude of torque;

determining, as a function of said operating speed and said magnitude of torque, a quantity of fuel to be supplied to a cylinder of said engine for each cycle of said cylinder;

determining, as a function of said operating speed and said magnitude of torque, a desired quantity of air to be supplied to said cylinder of said engine for each cycle of said cylinder;

determining, as a function of said operating speed and said magnitude of torque, a timing of an activation of a sparkplug of said engine for each cycle of said cylinder, said sparkplug being associated with said cylinder;

calculating an actual magnitude of said quantity of air supplied to said cylinder of said engine;

comparing said actual magnitude of said quantity of air to said desired quantity of air;

determining an error magnitude of air between said actual magnitude of said quantity of air and said desired quantity of air; and

modifying said manually controlled command signal as a function of said error magnitude of air.

2. The method of claim 1, further comprising:

measuring the barometric pressure in the vicinity of said engine.

3. The method of claim 2, further comprising:

modifying said manually controlled command signal as a function of said barometric pressure.

4. The method of claim 1, further comprising:

measuring a temperature of air proximate said engine.

5. The method of claim 4, wherein:

said actual magnitude of air is calculated as a partial function of said temperature.

6. The method of claim 1, further comprising:

determining, as a function of said operating speed and said command signal, a volumetric efficiency of air being supplied to said cylinder.

7. The method of claim 6, further comprising:

modifying said actual magnitude of said quantity of air as a function of said volumetric efficiency.

8. The method of claim 1, further comprising:

measuring a throttle position; and

modifying said command signal when said command signal is generally equal to its maximum value and said throttle position is not generally equal to its maximum opened position.

9. A method for controlling the operation of an engine, comprising:

measuring an operating speed of said engine;

sensing a manually controlled command signal, said manually controlled command signal representing a magnitude of torque;

determining, as a function of said operating speed and said magnitude of torque, a quantity of fuel to be supplied to a cylinder of said engine for each cycle of said cylinder;

determining, as a function of said operating speed and said magnitude of torque, a desired quantity of air to be supplied to said cylinder of said engine for each cycle of said cylinder;

determining, as a function of said operating speed and said magnitude of torque, a timing of an activation of a sparkplug of said engine for each cycle of said cylinder, said sparkplug being associated with said cylinder;

measuring the barometric pressure in the vicinity of said engine;

modifying said magnitude of torque as a function of said barometric pressure;

measuring a throttle position; and

modifying said command signal when said command signal is generally equal to its maximum value and said throttle position is not generally equal to its maximum opened position.

10. The method of claim 9, further comprising:

measuring a temperature of air proximate said engine

calculating an actual magnitude of said quantity of air supplied to said cylinder of said engine as a partial function of said temperature of air proximate said engine; and

comparing said actual magnitude of said quantity of air to said desired quantity of air.

11. The method of claim 10, further comprising:

determining, as a function of said operating speed and said command signal, a volumetric efficiency of air being supplied to said cylinder; and

modifying said actual magnitude of said quantity of air as a function of said volumetric efficiency.

12. The method of claim 11, further comprising:

determining an error magnitude of air between said actual magnitude of said quantity of air and said desired quantity of air; and

modifying said manually controlled command signal as a function of said error magnitude of air.

13. A system for controlling the operation of an engine, comprising:

means for measuring an operating speed of said engine;

means for sensing a manually controlled command signal, said manually controlled command signal representing a magnitude of torque;

means for determining, as a function of said operating speed and said magnitude of torque, a quantity of fuel to be supplied to a cylinder of said engine for each cycle of said cylinder;

means for determining, as a function of said operating speed and said magnitude of torque, a desired quantity of air to be supplied to said cylinder of said engine for each cycle of said cylinder;

means for determining, as a function of said operating speed and said magnitude of torque, a timing of an activation of a sparkplug of said engine for each cycle of said cylinder, said sparkplug being associated with said cylinder;

means for measuring the barometric pressure in the vicinity of said engine;

means for modifying said magnitude of torque as a function of said barometric pressure;

means for measuring a temperature of air proximate said engine

means for calculating an actual magnitude of said quantity of air supplied to said cylinder of said engine as a partial function of said temperature of air proximate said engine;

means for comparing said actual magnitude of said quantity of air to said desired quantity of air;

means for determining, as a function of said operating speed and said command signal, a volumetric efficiency of air being supplied to said cylinder;

means for modifying said actual magnitude of said quantity of air as a function of said volumetric efficiency;

means for determining an error magnitude of air between said actual magnitude of said quantity of air and said desired quantity of air;

means for modifying said manually controlled command signal as a function of said error magnitude of air;

means for measuring a throttle position;

means for modifying said command signal when said command signal is generally equal to its maximum value and said throttle position is not generally equal to its maximum opened position.