Method for engine control

• US 6,330,873 B1
• Filed: 12/30/1997
• Issued: 12/18/2001
• 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:
  US09/000,502
• Time in Patent Office: 1,449 Days
• Field of Search: 123/320, 123/321, 123/322, 701/102, 701/103, 701/29, 180/169, 180/170, 180/178, 180/179, 307/10.1
• US Class Current: 123/322
• 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 the 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, at least one sensor for sensing a vehicle operating parameter from which current vehicle speed can be derived, and means for indicating an overspeed condition, comprising:

providing a plurality engine braking levels operable to a effect a plurality of engine braking loads when activated;

receiving a first commanded engine braking level from the vehicle operator;

sensing the current vehicle speed;

determining a second commanded engine braking level by comparing a current vehicle speed with at least one predetermined speed limit;

selecting the one of the first or second commanded engine braking levels corresponding to the lesser engine braking load; and

activating the engine brake at the selected engine braking level.

2. The method of claim 1, wherein the means for engine braking comprises modifying the exhaust stroke pressure of at least one of the cylinders.

3. The method of claim 1, wherein receiving a first commanded engine braking level includes sensing a state of each of a plurality of vehicle cabin switches corresponding to respective ones of the plurality of engine braking levels.

4. A method of controlling the road speed of a vehicle including a multi-cylinder internal combustion engine having means for increasing the engine load, an electronic control unit with memory for controlling the engine, at least one sensor for sensing a vehicle operating parameter from which current vehicle speed can be derived, comprising:

determining a desired vehicle road speed;

sensing at least one vehicle operating parameter to obtain the current vehicle speed;

comparing the desired road speed to the current vehicle speed to determine whether an overspeed condition exists; and

when an overspeed condition exists, increasing the engine load so as to reduce the road speed of the vehicle.

5. The method of claim 4, wherein increasing the engine load includes modifying the exhaust stroke pressure of at least one of the cylinders.

6. The method of claim 4, wherein the vehicle includes at least one accessory powered by the engine and wherein increasing the engine load includes activating the at least one accessory.

7. The method of claim 4, wherein the engine includes at least one cooling fan and wherein increasing the engine load includes activating the at least one cooling fan.

8. The method of claim 4, wherein the vehicle includes at least one air conditioner and wherein increasing the engine load includes activating the at least one air conditioner.

9. The method of claim 4, wherein the vehicle includes at least one air compressor and wherein increasing the engine load includes activating the at least one air compressor.

10. The method of claim 4, wherein the engine includes at least one accessory powered by the engine, and wherein increasing the engine load includes at least one of modifying exhaust stroke pressure of at least one of the cylinders and controlling the at least one accessory powered by the engine based on the comparison.

11. The method of claim 4, wherein the engine includes at least one cooling fan, and wherein increasing the engine load 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.