Transmission control system

A control device for controlling a gearshift from a first gear to a second gear in a transmission which has an input shaft and an output shaft;

• first and second step-down devices for providing various step-down ratios;
• a first clutch being associated with the first step-down device and a second clutch being associated with the second step-down device in order to connect the respective step-down devices in a torque-transmitting manner between the input shaft and the output shaft;
• and the first gear being obtainable by actuating the first clutch and the second gear by activating the second clutch, the control device comprising:
• an interface for detecting operating condition parameters of the transmission, the operating condition parameters comprising at least one of a rotational speed and a transmitted toque of at least one of the input shaft, the output shaft, the first clutch, the second clutch, an intermediate shaft, and input sides and output sides of the first and the second step-down devices;
• a processing device for determining optimized degrees of actuation of the first and the second clutches by a search method related to a transmission model, which determines the degrees of actuation of the first and the second clutches on a basis of the operating condition parameters in relation to a predetermined optimization criterion, and the degree of actuation being defined as a percentage of clutch engagement on a scale from a fully disengaged condition to a fully engaged condition;
• the transmission model is based on slip;
• and
• a control device for adjusting the first and the second clutches to the determined degrees of actuation.

A method of controlling a gearshift from a first gear to a second gear in a transmission having an input shaft, an output shaft, and first and second step-down devices for providing various step-down ratios, the first step-down device having a first clutch for connecting the first step-down device in a torque-transmitting manner between the input shaft and the output shaft, and the second step-down device having a second clutch for connecting the second step-down device in a torque-transmitting manner between the input shaft and the output shaft, the first gear being obtained by actuating the first clutch and the second gear being obtained by activating the second clutch, the method comprising:

• determining operating condition parameters of the transmission the operating condition parameters comprising at least one of a rotational speed and a transmitted toque of at least one of the input shaft, the output shaft, the first clutch, the second clutch, an intermediate shaft, and input sides and output sides of the first and the second step-down devices;
• determining optimized degrees of actuation of the first and the second clutches by a search method relating to a transmission model, which determines the degrees of actuation on a basis of the operating condition parameters in relation to a predetermined optimization criterion, and the degrees of actuation being defined as percentages of clutch engagement on a scale from a fully disengaged condition to a fully engaged condition;
• basing the transmission model on clutch slip;
• and
• adjusting engagement of the first clutch to a determined degree of actuation of the first clutch and adjusting engagement of the second clutch to a determined degree of actuation opt the second clutch.