Zf Batavia L.l.c.

Zf Friedrichshafen Ag

Bernd L&ouml;ffler

Hans-Dieter Hengstler

Joachim Cichy

Peter Janssen

A method is described for control of a CVT automatic transmission ( ) in which a sensed main pressure (p_hd_act) and a sensed contact pressure (p_s _act) of a secondary pulley ( ) are entered as signals in an electronic transmission control ( ). For diagnosis of an error in the sensing of the main pressure (p_hd_act) and/or of the contact pressure (p_s _act) of the secondary pulley ( ) their actual values or comparison variable (&verbar;p_hd_act-p_hd_nom&verbar;, &verbar;p_s _act-p_s _nom&verbar;) formed therefrom are compared with applicable threshold values (p_hd_min, pd_phd_regdiff, p_s _min, pd_ps _regdiff) associated with a range of plausible pressure values.

Method of controlling a CVT automatic transmission

Engine torque control system based on the dynamic behavior of a driven automatic transmission consists in that the engine dynamics is limited as function of a sporting mode.

Engine torque control system based on the dynamic behavior of a driven automatic transmission

Within the scope of the process for variator slip treatment in continuously variable automatic transmissions of a motor vehicle, upon detection of variator slip, a characteristic field ( ) of slip meter is locally incremented according to ratio value (iv) and to engine torque (M_mot) and simultaneously an evaluated slip meter ( ) of an evaluation module ( ), likewise according to ratio value (iv) and to engine torque (M_mot), is increased, wherein via the evaluation module ( ), the variator slip is assessed according to duration and intensity. Besides, a characteristic field ( ) of slip status meter connected with the evaluated slip meter ( ) is incremented together with the evaluated slip meter ( ), a signal being passed on to an error memory ( ) so that, with the entry of the error, slip, evaluated slip and slip status meter are entered in the error memory ( ) as environmental conditions. Thereafter the contact pressure security is locally varied according to the characteristic field ( ) of the slip status meter.

Growing community of inventors

Ravensburg, Germany

Bernd Löffler

Growing community of inventors

Ravensburg, Germany

Bernd L&ouml;ffler

Bernd Löffler