Method for operating a driving device for a working machine

Abstract

A method is provided for operating a drive device for a working machine, where the drive device has an engine and a power-split gearbox with a variator for continuously variable adjustment of the transmission ratio of the gearbox. The method includes outputting a target output speed of the drive device based on a target speed request from an operator of the working machine. The method further includes recording an actual capacity utilization of the drive device and comparing the recorded actual capacity utilization with a target capacity unitization of the drive device. The method further includes outputting a target engine speed of the engine based on the comparison of the actual and target capacity utilization of the drive device.

1 . A method for operating a drive device ( 1 ) for a working machine ( 100 ), wherein the drive device ( 1 ) has an engine ( 2 ) and a power-split gearbox ( 3 ) with a variator ( 5 ) for continuously variable adjustment of a transmission ratio of the gearbox ( 3 ), the method comprising:
 outputting (VIII) a target output speed of the drive device ( 1 ) based on a target speed request (v) from an operator of the working machine ( 100 ), recording (V 2 ) an actual capacity utilization of the drive device ( 1 );   comparing (V 3 ) the recorded actual capacity utilization with a target capacity utilization of the drive device ( 1 ), and   outputting (VIII) a target engine speed of the engine ( 2 ) based on the comparison of the actual and target capacity utilization of the drive device ( 1 ).   
     
     
         2 . The method according to  claim 1 , wherein:
 recording the actual capacity utilization of the drive device ( 1 ) includes recording (V 2 ) of an actual capacity utilization of the power-split gearbox ( 3 ); and   outputting (VIII) of the target engine speed of the engine ( 2 ) comprises increasing (V 4 . 1 ) the target engine speed of the engine ( 2 ) when the actual capacity utilization of the power-split gearbox ( 3 ) is higher than the target capacity utilization of the power-split gearbox ( 3 ), and reducing (V 4 . 2 ) the target engine speed of the engine ( 2 ) when the actual capacity utilization of the power-split gearbox ( 3 ) is lower than the target capacity utilization of the power-split gearbox ( 3 ).   
     
     
         3 . The method according to  claim 2 , wherein recording (V 2 ) the actual capacity utilization of the power-split gearbox ( 3 ) comprises recording a state variable of the variator ( 5 ) of the power-split gearbox ( 3 ). 
     
     
         4 . The method according to  claim 1 , comprising:
 receiving (I) a cruise control activation request and the target speed request (v);   activating (III) the cruise control when an activation condition is met; and   determining (IV) a cruise control target output speed of the drive device ( 1 ) based on the received target speed request (v) and a cruise control logic circuit (L 2 ).   
     
     
         5 . The method according to  claim 4 , wherein activating (III) the cruise control when the activation condition is met comprises checking (II) that an accelerator pedal ( 13 ) of the working machine is actuated beyond a threshold value and that the output speed of the drive device ( 1 ) is greater than a threshold value. 
     
     
         6 . The method according to  claim 4 , comprising
 ascertaining (V 1 ) a minimum engine speed (c) for providing the target speed request (v) based on the target speed request (v) and a maximum transmission ratio (i) of the gearbox ( 3 ).   
     
     
         7 . The method according to  claim 4 , wherein the method, when cruise control is activated, comprises:
 receiving (VI) an accelerator pedal position and ascertaining (VII) a conventional target output speed of the drive device ( 1 ) based on the received accelerator pedal position and a conventional operating logic circuit (L 1 ) of the drive device ( 1 ); and   outputting (VII) of the target output speed comprises outputting the greater of the ascertained cruise control target output speed and the conventional target output speed.   
     
     
         8 . A control device ( 8 ) configured to carry out the method according to  claim 1 . 
     
     
         9 . A power-split transmission ( 3 ) having a variator ( 5 ) for continuously variable adjustment of a transmission ratio of the gearbox ( 3 ) and a control device ( 8 ) configured to carry out the method according to  claim 1 . 
     
     
         10 . A working machine ( 100 ) with a drive device ( 1 ) comprising:
 an engine ( 2 ),   a power-split gearbox ( 3 ) having a variator ( 5 ) for continuously variable adjustment of a transmission ratio of the gearbox ( 3 ); and   a control device ( 8 ) configured to carry out the method according to  claim 1 .