Inhibit engine speed governor

• US 6,371,081 B1
• Filed: 09/29/2000
• Issued: 04/16/2002
• Est. Priority Date: 09/29/2000
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: McDonald, Donald Michael, Hawkins, Jeffery Scott, Avery, Jr., Richard Michael
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): HUYNH, HAI H
• Application Number:
  US09/675,925
• Time in Patent Office: 564 Days
• Field of Search: 123/350, 123/352, 123/396, 123/339.14, 123/339.1, 701/54, 701/84, 701/93, 701/110
• US Class Current: 123/352
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 2250/21 during a transition between engine operation modes or states
• CPC Class Codes: F02D 31/007 controlling fuel supply
• CPC Class Codes: F02D 41/02 Circuit arrangements for generating control signals

Abstract

An engine controller capable of operating in both a torque governing mode and a speed governing mode simultaneously, and a method of operation whereby speed governing may be enabled and disabled while simultaneously providing a valid speed request signal to the controller is disclosed. A speed governor signal having an enabled state and a disabled state is generated external to the controller and monitored by the speed governor. A speed request signal is simultaneously monitored by the speed governor. The speed governor is operative to control the speed of the engine proportional to the speed request signal while the speed governor signal is in the enabled state. The speed governor is disabled by setting the speed governor signal into the disabled state. A torque governor may also be operational within the controller. The torque governor monitors a torque request signal which it uses to control a torque generated by the engine.

Claims

1. An improved controller of an engine to force engine speed to idle even in the presence of a valid speed request, the controller having a torque governor and a speed governor that may be operational simultaneously, the improvement comprising:

a speed governor inhibit signal generated external to the controller and in communication with the speed governor, inhibit signal having an enabled state and a disabled state;

a speed request signal in communication with the speed governor; and

the speed governor being operational to control a speed of the engine proportional to the speed request signal in response to the speed governor inhibit signal being in the enabled state, and the speed governor disabling and forcing engine speed to idle in response to the speed governor inhibit signal being in the disabled state.

2. The controller of claim 1 further comprising:

an initial speed threshold for the speed request signal; and

the speed governor enabling only in response to the speed governor inhibit signal being in the enabled state and the speed request signal being below the initial speed threshold to provide smooth transitioning into speed governing.

3. The controller of claim 1 further comprising:

a low speed threshold for te speed request signal; and

the speed governor disabling and forcing engine speed to idle in response to the speed request signal being below the low speed threshold and the speed governor inhibit signal being in the enabled state to prevent stalling the engine.

4. The controller of claim 1 further comprising:

a high speed threshold for the speed request signal; and

the speed governor disabling and forcing engine speed to idle in response to the speed request signal exceeding the high speed threshold and the speed governor inhibit signal being in the enabled state to prevent an over-speed condition for the engine.

5. The controller of claim 1 further comprising:

a torque request signal in communication with the torque governor and the speed governor; and

the torque governor being operational to control a torque produced by the engine proportional to the torque request signal.

6. The controller of claim 5 further comprising:

a high torque threshold for the torque request signal; and

the speed governor disabling and forcing engine speed to idle in response to the torque request signal exceeding the high torque threshold to provide a requested torque from the engine.

7. The controller of claim 5 further comprising:

an initial torque threshold for the torque request signal; and

the speed governor enabling only in response to the speed governor inhibit signal being in the enabled state and the torque request signal being below the initial torque threshold to provide smooth transitioning into speed governing.

8. The controller of claim 1 further comprising:

a speed request signal in communication with the speed governor;

a torque request signal in communication with the torque governor; and

a conflict resolution scheme to determine how to use the speed request and the torque request signals to control the engine when both the speed governor and the torque governor inhibit signals are in the enabled state.

9. A method of operating a controller for an engine to force engine speed to idle even in the presence of a valid speed request, the controller having a torque governor and a speed governor that may be operated simultaneously, the method comprising:

monitoring a speed governor inhibit signal generate external to the controller, the speed governor inhibit signal having an enabled state and a disabled state;

monitoring a speed request signal;

controlling a speed of the engine proportional to the speed request signal in response to the speed governor signal being in the enabled state; and

disabling the speed governor and forcing engine speed to idle in response to the speed governor inhibit signal being in the disabled state.

10. The method of claim 9 further comprising:

providing an initial speed threshold for the speed request signal; and

enabling the speed governor only in response to the speed governor inhibit signal being in the enabled state and the speed request signal being below the initial speed threshold to provide smooth transitioning into speed governing.

11. The method of claim 9 further comprising:

providing a low speed threshold for the speed request signal; and

disabling the speed governor and forcing engine speed to idle in response to the speed request signal being below the low speed threshold to prevent stalling the engine.

12. The method of claim 9 further comprising:

providing a high speed threshold for the speed request signal; and

disabling the speed governor and forcing engine speed to idle in response to the speed request signal exceeding the high speed threshold to prevent an over-speed condition for the engine.

13. The method of claim 9 further comprising:

monitoring a torque request signal; and

controlling a torque produced by the engine proportional to the torque request signal.

14. The method of claim 13 further comprising:

providing a high torque threshold for the torque request signal, and

disabling the speed governor and forcing engine speed to idle in response to the torque request signal exceeding the high torque threshold to provide a requested torque from the engine.

15. The method of claim 12 further comprising:

providing an initial torque threshold for the torque request signal, and

enabling the speed governor only in response to the speed governor inhibit signal being in the enabled state and the torque request signal being below the initial torque threshold to provide smooth transitioning into speed governing.

16. The method of claim 9 further comprising:

monitoring a torque request signal;

performing a conflict resolution prior to controlling the engine to determine how to use the speed request and the torque request signals to control the engine when both the speed governor and the torque governor inhibit signals are in the enabled state.