Adaptive transient fuel compensation for a spark ignited engine

• US 5,819,714 A
• Filed: 04/19/1996
• Issued: 10/13/1998
• Est. Priority Date: 10/30/1995
• Status: Expired due to Term

• Current Assignee: Temic Automotive of North America, Incorporated (Continental AG)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bush, Kevin J., Schumacher, Darren A.
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US08/636,729
• Time in Patent Office: 907 Days
• Field of Search: 123/673-675, 123/478, 123/480, 123/492, 123/493, 364/431.05, 701/103, 701/104
• US Class Current: 123/673
• CPC Class Codes: F02D 2041/141 using a feed-forward control element
• CPC Class Codes: F02D 2041/1415 using a state feedback or a state space representation
• CPC Class Codes: F02D 2041/1417 Kalman filter
• CPC Class Codes: F02D 2041/1418 Several control loops, either as alternatives or simultaneous
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 2041/1434 Inverse model
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/1402 Adaptive control
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration

Abstract

A method and system for adaptive transient fuel compensation in a cylinder of a multi-cylinder engine estimates fuel puddle dynamics for the cylinder by determining parameters of a wall-wetting model every engine cycle of the multi-cylinder engine. Fuel delivery to the cylinder is adjusted dependent on the estimated fuel puddle dynamics.

Claims

1. A method of adaptive transient fuel compensation for a cylinder in a multi-cylinder engine comprising the steps of:

continuously measuring one or more engine parameters of the multi-cylinder engine selected from the group of engine speed, engine load, and engine temperature, and providing a base variable dependent thereon;

estimating fuel puddle dynamics for the cylinder of the multi-cylinder engine by determining parameters of a wall-wetting dynamic model every per engine cycle of the multi-cylinder engine; and

combining the base variable and the estimated fuel puddle dynamics and adjusting fuel delivery to the cylinder of the multi-cylinder engine using a lead compensator with adjustable zero tuning and a fixed pole tuning while an estimate of a first wall-wetting parameter is small and a wall-wetting dynamics zero identified dependent on the first and a second wall-wetting parameters is invertible, and adjusting fuel delivery using a lead compensator with adjustable zero tuning and a fixed pole while the estimate of the first wall-wetting parameter is large, and adjusting fuel delivery using a lead compensator with adjustable zero tuning and a fixed pole while a wall-wetting dynamics zero, identified dependent on the first and second wall-wetting parameters, is not invertible.

2. A method of adaptive transient fuel compensation for a cylinder in a multi-cylinder engine comprising the steps of:

measuring one or more engine parameters of the multi-cylinder engine selected from the group of engine speed, engine load, and engine temperature, and providing a base variable dependent thereon;

estimating a first wall-wetting parameter indicative of a fraction of an amount of fuel injected that is retained on surfaces of an intake system for the cylinder of the multi-cylinder engine in accordance with the following relationship;

##EQU20## estimating a second wall-wetting parameter indicative of a fraction of an amount of fuel vaporized from the surfaces in the intake system for the cylinder of the multi-cylinder engine in accordance with the following relationship;

##EQU21## where;

k is an engine cycle index

u is a filtered value of fuel injected

y is a filtered value of measured fuel burned

v is a weighted covariance of exhaust gas sensor measurements

P₁ is an inverse of a weighted covariance of the estimate of c

P₂ is an inverse of a weighted covariance of the estimate of b_v

space="preserve" listing-type="equation">p(k)= b.sub.v (k)c(k)!'"'"'

space="preserve" listing-type="equation">y(k)=y(k)-y(k-1)+u(k-1)-u(k);

and

space="preserve" listing-type="equation">h(k)= (u(k-1)-y(k-1))(u(k-1)-u(k))!

adjusting fuel delivery to the cylinder of the multi-cylinder engine dependent on the provided base variable, the estimated first wall-wetting parameter and the estimated second wall-wetting parameter.