Method and device for checking the performance reliability of a timer

• US 6,768,939 B2
• Filed: 08/29/2001
• Issued: 07/27/2004
• Est. Priority Date: 09/01/2000
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Weiss, Ruediger, Grass, Gerd
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Hoang, Johnny H.
• Application Number:
  US09/942,414
• Publication Number:
  US 20020029766A1
• Time in Patent Office: 1,063 Days
• Field of Search: 701/114, 701/115, 701/34, 701/66, 700/79
• US Class Current: 701/114
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue

Abstract

A method and a control unit are proposed for checking the performance reliability of a timer that is arranged outside of the control unit, used in particular for controlling an internal combustion engine, and that supplies time information to the control unit, further time information being generated internally in the control unit and being compared to corresponding time information supplied by the external timer. Because an internal time meter is started in the control unit and the comparison of the time information supplied by the external timer and by the internal time meter is carried out at arbitrarily specifiable points of time, a malfunction of the external timer can be determined during the entire operating time, and furthermore, a deviation can be calculated with higher accuracy.

Claims

1. A method for checking a performance reliability of an external timer that is arranged outside of a control unit and that supplies the control unit with time information, comprising the steps of:

generating time information internally in the control unit;

comparing the generated time information to corresponding time information supplied by the external timer;

starting an internal time meter in the control unit; and

comparing time information supplied by the internal time meter to the time information supplied by the external timer at arbitrarily specifiable points of time.

2. The method according to claim 1, wherein:

the control unit controls an internal combustion engine.

3. The method according to claim 1, wherein:

the step of comparing the time information supplied by the internal time meter to the time information supplied by the external timer is performed over an entire operating time of the internal time meter.

4. The method according to claim 1, wherein:

a start of the internal time meter occurs with a switch-on of an ignition of an internal combustion engine.

5. The method according to claim 1, further comprising the step of:

directly after a start of the internal time meter, checking a signal supplied by the external timer for a presence of time information.

6. The method according to claim 1, further comprising the steps of:

comparing time segments supplied by the external timer to time segments supplied by the internal time meter; and

in response to one of a deviation over a predetermined threshold value and upon exceeding a predetermined interval, recognizing the external timer as faulty and entering a corresponding fault code into a fault storage of the control unit.

7. A control unit for checking a performance reliability of an external timer that is arranged outside of the control unit and that is operatively connected to the control unit in order to transmit time information, comprising:

a computer unit for comparing the time information transmitted by the external timer to time information generated internally in the control unit; and

an internal time meter operatively connected to the computer unit such that the time information generated by the internal time meter can be compared to the time information transmitted by the external timer at arbitrarily specifiable points of time.

8. The control unit according to claim 7, wherein:

the control unit controls an internal combustion engine.

9. The control unit according to claim 7, further comprising:

a storage unit connected to the computer unit, wherein;

in response to a deviation of the time information generated by the internal time meter and the time information transmitted by the external timer that is one of above a predetermined threshold value and outside of a predefined interval, a fault code can be entered into the storage unit.

10. A device, comprising:

an external timer; and

a control unit connected to the external timer, the control unit including;

a computer unit for comparing time information transmitted by the external timer to time information generated internally in the control unit, and

an internal time meter operatively connected to the computer unit such that the time information generated by the internal time meter can be compared to the time information transmitted by the external timer at arbitrarily specifiable points of time.