Method for controlling an automatic transmission
AssigneeZF Friedrichshafen AG
InventorWolfgang Netzer
Life of this patent
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Abstract
A method for control of a transmission of a vehicle, especially of an automatic transmission or an automated manual mechanical transmission with hydraulically actuatable shifting elements is described. A speed signal (n_ab_ist, n_t_ist) of the output train with precalculatable time curve (n_ab_soll, n_t_soll) is determined and for adjustment of a nominal filling of the shifting elements an interference signal (P1, P2, P3, P4, PF1, PF2, PF3, PF4) is applied. In case of a untolerable divergence of the speed signal (n_ab_ist, n_t_ist) of the output train from its precalculated curve, a divergence from the nominal filling of the shifting element is detected, the information being processed for control of the shifting elements.
Claims20
A method for control of a transmission of a motor vehicle with hydraulically actuatable shifting elements wherein a shifting operation of a shifting element includes a rapid filling phase including a rapid filling time and a charge pressure phase wherein a charge pressure is provided to the element, comprising the steps of:
- during a period outside of the shifting operation of the shifting element,
- detecting a divergence of a transmission output train speed signal from a precalculated nominal transmission output speed curve, and
- when the detected divergence is within one of a rapid filling phase tolerance band and a charge pressure tolerance band,
- generating an interference signal according to the divergence, the interference signal being one of a rapid filling time test pulse and a charge pressure test pulse, and
- superimposing the interference signal on a corresponding one of the rapid filling time of the rapid filling phase and the charge pressure of the charge pressure phase to adjust the one of the rapid filling phase and the charge pressure phase to reduce the divergence.
A method for control of a transmission of a motor vehicle with hydraulically actuatable shifting elements wherein a shifting operation of a shifting element includes a rapid filling phase including a rapid filling time and a charge pressure phase wherein a charge pressure is provided to the element, comprising step of:
- during a period outside of the shifting operation of the shifting element,
- detecting a divergence of a transmission output train speed signal from a precalculated nominal transmission output speed curve, and
- when the detected divergence is within one of a rapid filling phase tolerance band and a charge pressure tolerance band,
- generating an interference signal according to the divergence, the interference signal being one of a rapid filling time test pulse and a charge pressure test pulse,
- superimposing the interference signal on a corresponding one of the rapid filling time of the rapid filling phase and the charge pressure of the charge pressure phase to adjust the one of the rapid filling phase and the charge pressure phase to reduce the divergence, and
- determining the precalculated nominal transmission output speed curve as an averaged calculation of a pattern of actual values of the transmission output train speed signal during a time window.
A method for control of a transmission of a motor vehicle with hydraulically actuatable shifting elements wherein a shifting operation of a shifting element includes a rapid filling phase including a rapid filling time and a charge pressure phase wherein a charge pressure is provided to the element, comprising the steps of:
- during a period outside of the shifting operation of the shifting element,
- detecting a divergence of a transmission output train speed signal from a precalculated nominal transmission output speed curve, and
- when the detected divergence is within one of a rapid filling phase tolerance band and a charge pressure tolerance band,
- generating an interference signal according to the divergence, the interference signal being one of a rapid filling time test pulse and a charge pressure test pulse, and
- superimposing the interference signal on a corresponding one of the rapid filling time of the rapid filling phase and the charge pressure of the charge pressure phase to adjust the one of the rapid filling phase and the charge pressure phase to reduce the divergence,
- wherein the precalculated nominal transmission output speed curve is an average of a calculation pattern of actual values of one of an output speed, a turbine speed, or a speed signal equivalent thereto, during a defined time window.
A method for control of a transmission of a motor vehicle with hydraulically actuatable shifting elements wherein a shifting operation of a shifting element includes a rapid filling phase including a rapid filling time and a charge pressure phase wherein a charge pressure is provided to the element, comprising the steps of:
- during a period outside of the shifting operation of the shifting element,
- detecting a divergence of a transmission output train speed signal from a precalculated nominal transmission output speed curve, and
- when the detected divergence is within one of a rapid filling phase tolerance band and a charge pressure tolerance band,
- generating an interference signal according to the divergence, the interference signal being one of a rapid filling time test pulse and a charge pressure test pulse, and
- superimposing the interference signal on a corresponding one of the rapid filling time of the rapid filling phase and the charge pressure of the charge pressure phase to adjust the one of the rapid filling phase and the charge pressure phase to reduce the divergence, thereby
- adapting the corresponding one of the rapid filling time of rapid filling phase and the charge pressure of the charge pressure phase by a corresponding offset value to provide an optimal filing of the shifting element.
The method according to 18, further comprising the steps of:
- after loading the shifting element with a the third charge pressure test pulse,
- detecting the divergence of the transmission output train speed signal from the precalculated nominal transmission output speed curve that is higher than the threshold value, and
- reducing the actual charge pressure by the offset value, and
- during the third charge pressure test pulse, constructively loading the shifting element with the charge pressure pulse to the reduced actual charge pressure,
- detecting the divergence of the transmission output train speed signal from the precalculated nominal transmission output speed curve that is lower than the threshold value, and
- during a fourth charge pressure test pulse, constructively loading the shifting element with a charge pressure pulse to the corrected actual charge pressure during the fourth rapid filling test pulse and over an actual rapid filling pulse time.
Dependencies are inferred from the claim text.