Method and device for controlling a multicylinder internal combustion engine

• US 20030159677A1
• Filed: 03/10/2003
• Published: 08/28/2003
• Est. Priority Date: 02/25/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Uhl, Stephan
• Granted Patent: US 6,941,930 B2
• Time in Patent Office: Days
• US Class Current: 123/436
• CPC Class Codes: F02D 2041/1409 using at least a proportional, integral or derivative controller
• CPC Class Codes: F02D 2041/1422 Variable gain or coefficients
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• 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: Y02T 10/40 Engine management systems

Abstract

In a method for controlling a multicylinder internal combustion engine, where a cylinder-equalization control is performed to adjust cylinder-specific torque contributions to the overall torque of the internal combustion engine, it is provided for a functioning monitoring to be carried out for the cylinder-equalization control, and, in response to disturbances in the area of the cylinder-equalization control, for at least one error signal to be generated, indicating the existence of a disturbance.

Claims

1. A method for controlling a multicylinder internal combustion engine, a cylinder equalization control being carried out for adjusting cylinder-specific torque contributions to the overall torque of the internal combustion engine,

wherein the functioning of the cylinder-equalization control is monitored, and, in response to disturbances in the area of the cylinder-equalization control, at least one error signal is generated, indicating the existence of a disturbance.

2. The method as recited in claim 1,

wherein in the context of the cylinder-equalization control, for each cylinder of the internal combustion engine, within a defined operating range, at least one combustion-influencing performance quantity is controlled on an individual basis, and an error signal is generated when at least one cylinder-specific control reaches a limit of the defined operating range.

3. The method as recited in claim 1 or 2,

wherein in response to an error signal, a defined change in the control characteristic of the control follows, in particular by a canceling of the closed-loop gain.

4. The method as recited in claim 3,

wherein subsequent to a first change in the control characteristic, as a response to a new error signal, the controller characteristic is changed at least one additional time, in particular through a subsequent cancellation of the control loop gain.

5. The method as recited in one of the preceding claims,

wherein as a response to an error signal, preferably following an at least one-time change in the control characteristic, the control is switched off by the functioning monitoring, the control characteristic being reset, in particular, to the originally defined operating characteristics, or, as a response to an error signal, preferably following an at least one-time change in the control characteristic, the control is stopped by the functioning monitoring, the active controller characteristics being retained.

6. The method as recited in one of the preceding claims,

wherein as a response to an error signal, preferably following an at least one-time change in the control characteristic, an external warning signal is emitted, in particular for activating a preferably optical warning display that is directly perceivable by the operator and/or for generating an entry into a memory of a diagnostic system capable of being externally queried.

7. A device for controlling a multicylinder internal combustion engine, comprising a cylinder equalization control for adjusting cylinder-specific torque contributions to the overall torque of the internal combustion engine,

characterized by a device for monitoring the functioning of the cylinder-equalization control, which is designed such that, in response to disturbances in the area of the cylinder-equalization control, at least one error signal is generated, indicating the existence of a disturbance.