Automatic clutch calibration
AssigneeVolvo Truck Corporation
InventorsLars KARLSSON, Johan BJERNETUN
Life of this patent
Estimating the term…
Abstract
A method for automatic detection of need for clutch calibration includes registering and storing in a data memory, before or in connection with engine shut down, a value of a clutch operating parameter, registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up, and determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.
Claims24
Method for automatic detection of need for clutch calibration, the method comprising:
- registering and storing in a data memory, before or in connection with engine (102) shut down, a value of a clutch operating parameter;
- registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up;
- and
- determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.
Method according to any of the preceding claims, wherein the value of the clutch operating parameter is derived from a clutch actuating position (p11, p12, p13, p21, p22, p23) along the clutch characteristic curve (310, 320).
Method according to any of the preceding claims, wherein the clutch operating parameter is the clutch actuating position (p11, p12, p13, p21, p22, p23) along the clutch characteristic curve (310, 320).
Method according to any of the preceding claims, wherein the stored value of the clutch operating parameter is derived from any of the clutch engaged position (p23), the clutch engagement position (p21), or the clutch disengagement position.
Method according to any of the preceding claims, comprising performing an automatic clutch calibration if a need for clutch calibration has been determined.
Method according to any of the preceding claims, comprising performing at least one additional disengagement-engagement sequence if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter is within a predetermined range, and subsequently registering a new corresponding value of the clutch operating parameter.
Method according to any of the preceding claims, comprising registering and storing the value of the clutch operating parameter at each clutch engagement and/or disengagement occurrence.
Method according to any of the preceding claims, comprising regularly updating the stored the value of the clutch operating parameter based on an average value calculated using a set of recently registered values of the clutch operating parameter.
Method according to any of the preceding claims, wherein the predetermined threshold value is larger than 1 millimetre, preferably larger than 2 millimetres, more preferably larger than 3 millimetres, and even more preferably larger than 4 millimetres.
Clutch system comprising a friction clutch (101) having and an electronic control unit (107), characterized in that the control unit (107) is programmed to automatically detect need for clutch calibration by performing the steps of:
- registering and storing in a data memory, before or in connection with engine (102) shut down, a value of a clutch operating parameter;
- registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up;
- and
- determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.
A computer system (700) for implementing a method for automatic detection of need for clutch calibration, the method comprising
- registering and storing in a data memory, before or in connection with engine (102) shut down, a value of a clutch operating parameter;
- registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up;
- and
- determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.
Dependencies are inferred from the claim text.