Method for engine control

• US 5,483,927 A
• Filed: 03/17/1995
• Issued: 01/16/1996
• Est. Priority Date: 08/27/1993
• Status: Expired due to Term

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: Babcock, Douglas J., Letang, Dennis M., Weisman, S. Miller II
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US08/406,114
• Time in Patent Office: 305 Days
• Field of Search: 180/170, 180/178, 180/179, 123/41.12, 123/41.49, 123/321, 123/322
• US Class Current: 123/41.12
• CPC Class Codes: B60K 2031/0091 Speed limiters or speed cutters
• CPC Class Codes: B60K 31/045 in a memory, e.g. a capacitor
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2050/0042 Transfer function lag; delays
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: F01P 2023/00 Signal processing; Details thereof
• CPC Class Codes: F01P 2023/08 Microprocessor; Microcomputer
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F01P 2025/40 Oil temperature
• CPC Class Codes: F01P 2025/46 Engine parts temperature
• CPC Class Codes: F01P 2031/00 Fail safe
• CPC Class Codes: F01P 7/04 by varying pump speed, e.g. by changing pump-drive gear ratio
• CPC Class Codes: F01P 7/048 using electrical drives
• CPC Class Codes: F01P 7/08 by cutting in or out of pumps
• CPC Class Codes: F02B 3/06 : with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 2041/1432 : the system including a filter, e.g. a low pass or high pass filter
• CPC Class Codes: F02D 2200/1015 : Engines misfires
• CPC Class Codes: F02D 2200/501 : Vehicle speed
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02D 2250/38 : Control for minimising smoke emissions, e.g. by applying smoke limitations on the fuel injection amount
• CPC Class Codes: F02D 31/007 : controlling fuel supply
• CPC Class Codes: F02D 31/009 : for maximum speed control
• CPC Class Codes: F02D 41/008 : Controlling each cylinder individually
• CPC Class Codes: F02D 41/0085 : Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio
• CPC Class Codes: F02D 41/12 : for deceleration F02D41/0005, F02D41/107 take precedence
• CPC Class Codes: F02D 41/1498 : measuring engine roughness
• CPC Class Codes: F02D 41/40 : with means for controlling injection timing or duration
• CPC Class Codes: F02D 41/402 : Multiple injections
• CPC Class Codes: F02D 41/403 : with pilot injections
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

A method for comprehensive integrated control of a compression-ignition internal combustion engine having integral fuel pump-injectors utilizing an electronic control unit is disclosed. The control strategy integrates various functions of engine control including fuel delivery, cooling fan control, engine speed governing and overspeed protection, engine braking, torque control, and vehicle speed diagnostics and control. Cooling fan control is integrated with vehicle speed diagnostics and control as well as fuel delivery to provide an integrated cruise .control function which incorporates engine braking. The method also includes improved control over the various engine speed governors while improving idle quality by balancing the power delivered by each of the engine cylinders when at idle. The integrated torque control employs functions to reduce NOx emissions and noise utilizing adaptive fuel delivery timing and a split injection strategy.

Claims

1. A method of controlling road speed of a vehicle including a multi-cylinder internal combustion engine having at least one cooling fan and an electronic control unit with memory for controlling the engine, the method comprising:

determining a desired vehicle road speed to obtain a desired road speed signal;

sensing at least one vehicle operating parameter to obtain an actual road speed signal;

comparing the desired road speed signal with the actual road speed signal; and

controlling the at least one cooling fan based on the comparison.

3. A method for governing the operation of a vehicle having a multi-cylinder internal combustion engine and an electronic control unit with memory for controlling the engine so as to improve the response time of a vehicle control system thereby improving control of the road speed of the vehicle, the method comprising:

sensing at least one engine operating parameter to obtain an engine operating signal;

sensing at least one vehicle operating parameter to obtain an actual road speed signal;

determining a desired vehicle road speed to obtain a desired road speed signal;

processing the engine operating signal to obtain a plurality of engine signal components;

applying a first filter to at least one of the plurality of engine signal components so as to determine a moving average value of the at least one engine operating parameter over a predetermined interval;

applying a second filter to at least one of the plurality of engine signal components not subjected to the first filter so as to determine an instantaneous value of the at least one engine operating parameter;

combining the moving average value and the instantaneous value so as to obtain a controlling value;

determining a system gain factor based on the at least one engine operating parameter;

comparing the desired road speed signal with the actual road speed signal;

controlling the vehicle based on the system gain factor, the controlling value, and the comparison so as to reduce the response time of the control system.

4. The method of claim 3 wherein controlling the vehicle includes at least one of modifying fuel delivery to the engine and modifying exhaust pressure of the engine.

5. The method of claim 3 wherein controlling the vehicle includes modifying the engine braking based on the comparison.

6. The method of claim 5 wherein the engine includes at least one cooling fan, and wherein modifying the engine braking includes at least one of modifying the exhaust stroke pressure of at least one of the cylinders and controlling the at least one cooling fan based on the comparison.

7. A method of controlling road speed of a vehicle including a multi-cylinder internal combustion engine having means for engine braking, an electronic control unit with memory for controlling the engine, a plurality of sensors for sensing vehicle operating parameters, and means for indicating an overspeed condidion, the method comprising:

determining a desired vehicle road speed to obtain a desired road speed signal;

sensing at least one vehicle operating parameter to obtain an actual road speed signal;

sensing the requested fueling level of the engine to obtain a requested fueling level signal;

evaluating a first comparison of the desired road speed signal to the actual road speed signal;

comparing the actual road speed signal to a first parameter stored in the memory associated with a nonzero fueling level request and a second parameter stored in the memory associated with a zero fueling level request;

initiating a variable time interval based upon at least one of the comparisons;

indicating an overspeed condition and storing at least one of the vehicle parameters in the memory when the variable time interval expires; and

modifying the engine braking based on the first comparison so as to control the road speed of the vehicle.

2. The method of claim 7 wherein the engine includes an engine brake, the method further comprising controlling the engine brake based on the comparison.

8. The method of claim 7 wherein initiating a variable time interval comprises:

incrementing a variable when the road speed of the vehicle exceeds a parameter associated with the fueling level request and the variable value is less than a predetermined limiting value; and

decrementing the variable when the road speed of the vehicle is less than the parameter associated with the fueling level request but greater than zero.

9. The method of claim 8 wherein the engine includes at least one cooling fan, and wherein modifying the engine braking includes at least one of modifying exhaust stroke pressure of at least one of the cylinders and controlling the at least one cooling fan based on the comparison.