Method and device for error detection and diagnosis in a knock sensor
First Claim
1. A method for one of (i) fault detection and (ii) fault diagnosis in a knock sensor which is assigned to the cylinders of a multi-cylinder internal combustion engine in a predefinable manner and which supplies an output signal dependent upon the noise recorded, comprising the steps of:
- one of (i) detecting a fault and (ii) diagnosing a fault on the basis of one of (i) at least one cylinder having a highest noise generation and (ii) at least one cylinder that supplies a loudest noise at the knock sensor; and
detecting a fault if a noise-dependent instantaneous value one of (i) exceeds at least one predefinable upper threshold level and (ii) falls below a predefinable lower threshold value.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and a device for fault detection or diagnosis may be used on a multi-cylinder internal combustion engine with a knock sensor. For diagnostic purposes an instantaneous reference value formed from the sensor signal may be compared with predefinable upper or lower reference threshold levels. If the instantaneous reference value exceeds or falls below the thresholds to a predefinable extent, a malfunction is detected. The reference levels correspond, for example, to the background noise present in knock-free operation. The fault detection or diagnosis may be performed only for the cylinder which emits the loudest noise or from which the loudest noise is recorded.
-
Citations
20 Claims
-
1. A method for one of (i) fault detection and (ii) fault diagnosis in a knock sensor which is assigned to the cylinders of a multi-cylinder internal combustion engine in a predefinable manner and which supplies an output signal dependent upon the noise recorded, comprising the steps of:
-
one of (i) detecting a fault and (ii) diagnosing a fault on the basis of one of (i) at least one cylinder having a highest noise generation and (ii) at least one cylinder that supplies a loudest noise at the knock sensor; and
detecting a fault if a noise-dependent instantaneous value one of (i) exceeds at least one predefinable upper threshold level and (ii) falls below a predefinable lower threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A device for one of (i) fault detection and (ii) fault diagnosis in a knock sensor assigned to cylinders of a multi-cylinder internal combustion engine in a predefinable manner and supplies an output signal dependent upon the noise recorded, comprising:
an arrangement configured to detect maximum values and to transmit for fault detection purposes only one of (i) signals which come from the cylinders having a highest noise generation and (ii) signals from a cylinder that supplies a loudest noise at the knock sensor.
-
11. A device for one of (i) fault detection and (ii) fault diagnosis in a knock sensor assigned to cylinders of a multi-cylinder internal combustion engine in a predefinable manner, the device configured to perform a method that includes the steps of:
-
one of (i) detecting a fault and (ii) diagnosing a fault on the basis of one of (i) at least one cylinder having a highest noise generation and (ii) at least one cylinder that supplies a loudest noise at the knock sensor; and
detecting fault if a noise-dependent instantaneous value one of (i) exceeds at least one predefinable upper threshold level and (ii) falls below a predefinable lower threshold value. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A method of fault detection in a knock sensor used to detect knocking in the plurality of cylinders, which is assigned to a plurality of cylinders of a multi-cylinder internal combustion engine in a predefinable manner and which supplies an output signal dependent upon the noise recorded, comprising:
-
identifying at least one of the plurality of cylinders as having the highest noise generation during normal operation of the combustion engine;
detecting a fault only on the basis of at least one of the plurality of cylinders having the highest noise generation during normal operation of the combustion engine; and
detecting a fault if a noise-dependent instantaneous value one of (i) exceeds at least one predefinable upper threshold level and (ii) falls below a predefinable lower threshold value.
-
Specification