System for controlling operation of an internal combustion engine

• US 6,135,918 A
• Filed: 05/20/1999
• Issued: 10/24/2000
• Est. Priority Date: 06/18/1998
• Status: Expired due to Term

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Bellinger, Steven M., Shutty, John V.
• Primary Examiner(s): Ta, Khoi Q.
• Application Number:
  US09/315,722
• Time in Patent Office: 523 Days
• Field of Search: 477/107, 477/110, 477/120, 477/124, 477/901, 701/94, 74/335
• US Class Current: 477/111
• 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 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02D 41/023 in relation with the gear ratio shifting conjoint control for improving gear change B60W30/19
• CPC Class Codes: F16H 2061/0015 Transmission control for optimising fuel consumptions
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 59/52 dependent on the weight of the machine, e.g. change in weight resulting from passengers boarding a bus
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration

Abstract

A system for controlling operation of an internal combustion engine includes a control computer responsive to a number of engine/vehicle operating conditions to control engine operation to thereby control engine speed and engine or vehicle acceleration. In one embodiment, the control computer is configured to determine an engine or vehicle acceleration limit value based on current engine or vehicle speed, and an engine speed limit value based on current engine load, and to control engine fueling and/or speed to thereby limit engine speed to the engine speed limit value and/or engine/vehicle acceleration to the engine/vehicle acceleration limit value. In another embodiment, the control computer is configured to determine a pseudo-load value, which is preferably a vehicle mass value and/or road grade value estimated from current vehicle acceleration and engine fueling conditions, determine an engine speed limit value based on the pseudo-load value and current vehicle speed, and control engine speed and/or fueling to thereby limit engine speed to the pseudo-load-based engine speed limit value. In either case, the concepts of the present invention provide for increased fuel economy by limiting engine speed and/or acceleration during shifting, while providing for additional engine speed, and correspondingly higher engine power, when there exists a legitimate need therefore.

Claims

1. A system for controlling an internal combustion engine, comprising:

means for sensing speed of an internal combustion engine and producing a corresponding engine speed signal;

means for sensing road speed of a vehicle carrying said engine and producing a corresponding vehicle speed signal;

a fuel system responsive to a fueling signal to supply fuel to said engine; and

a control computer producing said fueling signal, said control computer responsive to said vehicle speed signal and said fueling signal to determine an estimated vehicle mass value and to at least said vehicle mass value to determine an estimated engine load value, said control computer determining an engine speed limit based on said estimated engine load value and said vehicle speed value and controlling said fueling signal to thereby maintain said engine speed value below said engine speed limit.

2. The system of claim 1 further including an engine speed governor responsive to a reference engine speed and said engine speed signal to produce said fueling signal;

and wherein said control computer is operable to limit said reference engine speed to said engine speed limit to thereby control said fueling signal and maintain said engine speed value below said engine speed limit.

3. The system of claim 1 wherein said control computer is further responsive to said vehicle speed value and said fueling signal to determine a road grade value, said control computer determining said estimated engine load value based on said estimated vehicle mass value and said road grade value.

4. The system of claim 1 wherein further including means for determining a currently engaged gear ratio of a transmission coupled to said engine;

and wherein said control computer is operable to delay production of said engine speed limit for a time period defined by said vehicle speed signal.

5. The system of claim 4 wherein said control computer is operable to increase said time period as said vehicle speed signal decreases.

6. The system of claim 4 wherein said control computer is operable to provide no delay in production of said engine speed limit if said vehicle road speed is above a predefined vehicle speed value.

7. A method for controlling an internal combustion engine carried by a vehicle, comprising the steps of:

sensing engine speed of an internal combustion engine;

sensing vehicle speed of a vehicle carrying said engine and determining a corresponding vehicle acceleration value;

determining an engine fueling value;

estimating a vehicle mass value based on said vehicle acceleration value and said engine fueling value;

estimating an engine load value based on at least said estimated vehicle mass value;

determining an engine speed limit based on said estimated engine load value and said vehicle speed; and

controlling engine speed of said engine to thereby maintain said engine speed below said engine speed limit.

8. The method of claim 7 further including the step of estimating a road grade value based on said at least said engine fueling value and said vehicle acceleration value;

and wherein said step of estimating an engine load value includes estimating said engine load value based on said estimated vehicle mass value and said estimated road grade value.

9. The method of claim 7 further including the steps of:

determining a currently engaged gear ratio of a transmission coupled to said engine; and

delaying said step of controlling said engine speed for a time period defined by said vehicle speed signal if no gear ratio is currently engaged with said engine and if said vehicle speed is below a vehicle speed threshold value.