Method and system for identifying the degree of a slip of a belt part of a belt transmission
AssigneeRobert Bosch GmbH
InventorsKlaus Ries-Mueller, Joachim Luh
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for detecting a slip (s) of a belt part of a belt transmission, especially of a CVT transmission, having a transmission rpm ratio (ji). According to the invention, a slip of the belt part is detected by evaluating the change of the transmission rpm ratio (ji).
Claims39
Method for detecting a slip (s) of a belt part (34) of a belt transmission (10) having a transmission rpm ratio (ji), including a CVT transmission (10), characterized in that a slip of the belt part (34) is detected via the evaluation of the change of the transmission rpm ratio (ji).
Method of one of the above claims, characterized in that countermeasures are initiated with the detection of a slip (s).
Method of one of the above claims, characterized in that the belt part (34) runs about two conical wheel pairs (30, 32) with an adjustable contact pressure;
- and, that the countermeasures include increasing the contact pressure.
Method of one of the above claims, characterized in that a conclusion is drawn as to the state of wear of the belt part from the detected slip (s).
Method of one of the above claims, characterized in that the belt part (34) runs over the two conical wheel pairs (30, 32) with an adjustable contact pressure;
- and, that the contact pressure is adjusted in dependence upon the state of wear of the belt part (34).
Method of one of the above claims, characterized in that the slip (s) is defined as follows:
- s=1 −(ig/ji),
- wherein:
- s is the slip;
- ig is a geometric transmission ratio;
- and, ji is the transmission rpm ratio.
Method of one of the above claims, characterized in that the geometric transmission ratio is assumed as a constant value (c).
Method of one of the above claims, characterized in that the geometric transmission ratio (ji) is set to the maximum value of the geometric transmission ratio (jimax) when the state “maximum transmission ratio” is detected.
Method of one of the above claims, characterized in that the geometric transmission ratio (ji) is set to the minimum value of the geometric transmission ratio (jimin) when the state “minimum transmission ratio” is detected.
Method of one of the above claims, characterized in that the slip detection takes place only in the state “maximum transmission ratio”.
Method of one of the above claims, characterized in that the slip detection essentially takes place only in the state “minimum transmission ratio”.
Method of one of the above claims, characterized in that a slip change (ds) is determined as follows:
- ds(n)=([ji(n+1)−ji(n)]−K/N,
- wherein:
- ds is the slip change, n is an index or a computing raster;
- ji is the transmission rpm ratio;
- K is a compensation term;
- and, N is a normalization term.
Method of one of the above claims, characterized in that the compensation term (K) is provided for compensating relatively slow changes of the transmission rpm ratio (ji).
Method of one of the above claims, characterized in that the compensation term (K) is determined via a median value formation.
Method of one of the above claims, characterized in that the compensation term (K) is determined via a mean value formation.
Method of one of the above claims, characterized in that the compensation term (K) is determined as follows:
- K=[ji(n+4)−ji(n−4)]/8,
- wherein:
- K is the compensation term;
- ji is the transmission rpm ratio;
- and, n is an index or a computing raster.
Method of one of the above claims, characterized in that the normalization term (N) is provided for adapting the slip change (ds) to different rpm ranges.
Method of one of the above claims, characterized in that the normalization term (N) is determined as follows:
- N=[ji(n)]3,
- wherein:
- N is the normalization term;
- ji is the transmission rpm ratio;
- and, n is an index or a computing raster.
Arrangement for executing the method of one of the above claims.
System for detecting a slip (s) of a belt part (34) of a belt transmission (10) having a transmission rpm ratio (ji), especially of a CVT transmission (10), characterized in that the system detects a slip of the belt part (34) via the evaluation of the change of the transmission rpm ratio (ji).
Dependencies are inferred from the claim text.