Method for Operating a Vehicle Drive and Device for Carrying Out Said Method

Abstract

The invention relates to a method for operating a vehicle drive comprising at least one internal combustion engine and at least one electric machine that is mechanically coupled to the internal combustion engine, in addition to an energy accumulator that is actively coupled to the electric machine and/or the internal combustion engine. According to the invention, the internal combustion engine and the electric machine or machines generate a required drive target torque at approximately the same time, a required optimum target torque of the internal combustion engine being limited to an optimized minimum torque lying above a minimum torque of an internal combustion engine or being limited to an optimized maximum torque lying below a maximum torque of an internal combustion engine and/or a modification speed of the optimum target torque of the internal combustion engine.

1 . A method of operating a vehicle drive with at least one combustion engine, at least one electric machine mechanically coupled with the at least one combustion engine, and an energy accumulator actively coupled with the electric machine and/or the combustion engine, the method comprising: 
 generating a requested drive target torque by the combustion engine and the electric machine, essentially together;    limiting a requested optimum target torque of the combustion engine to an optimized minimum torque above an optimized minimum torque of the combustion engine and/or an optimized maximum torque of the combusion engine; and    limiting a modification speed of the optimum target torque of the combustion engine.    
   
   
       2 . A method according to  claim 1 , further comprising triggering at least one electric machine according to a difference of an unlimited target torque and an actual torque of the combustion engine.  
   
   
       3 . A method according to  claim 1 , wherein the electric machine is used to operate the combustion engine in a consumption favorable and/or emission favorable torque between the optimized minimum torque and the optimized maximum torque.  
   
   
       4 . A method according to  claim 1 , wherein the optimized minimum torque, the optimized maximum torque, or the modification speed of the optimum target torque is set up subject to the working conditions of the combustion engine.  
   
   
       5 . A method according to  claim 1 , wherein the optimized minimum torque, the optimized maximum torque, or the modification speed of the optimum target torque is set up subject to the working conditions of the electric machine.  
   
   
       6 . A method according to  claim 1 , wherein the optimized minimum torque, the optimized maximum torque, or the modification speed of the optimum target torque is set up subject to the working conditions of the energy accumulator.  
   
   
       7 . A method according to  claim 1 , wherein the optimized minimum torque, the optimized maximum torque, or the modification speed of the optimum target torque is set up subject to a process of target torques.  
   
   
       8 . A method according to  claim 1 , wherein the target torque is derived from a position of an accelerator pedal or a position of a brake pedal; or the modification speed of the optimum target torque is derived from a modification speed of the position of the accelerator pedal or the position of the brake pedal.  
   
   
       9 . A method according to  claim 1 , wherein the target torque is determined depending on an idle motion regulator, an active vibration damping, or gear control.  
   
   
       10 . A method according to  claim 1 , further comprising considering a charge target torque to ensure supply of an on-board supply and/or the energy accumulator.  
   
   
       11 . A method according to  claim 1 , further comprising increasing a torque range or torque dynamics of the combustion engine in case of inadmissible working conditions or inadmissible performance of the energy accumulator or the electric machine.  
   
   
       12 . A method according to  claim 1 , wherein in cases of temporary dynamic processes, an intervention in the limits of the torque range or the torque dynamics does not occur.  
   
   
       13 . A device that carries out a method to control torque in a drive with at least one combustion engine, at least one electric machine, mechanically coupled with the at least one combustion engine and an energy accumulator, actively coupled with the electric machine or the combustion engine, the device comprising a limiter unit designed to limit a requested optimum target torque of the combustion engine to an optimized minimum torque above a combustion engine-minimum torque or an optimized maximum torque below a combustion engine-maximum torque, or to limit a modification speed of the optimum target torque of the combustion engine.  
   
   
       14 . A device according to  claim 13 , wherein the limit unit is designed to stop an intervention in case of inadmissible working conditions or inadmissible performance of the energy accumulator or the electric machine in the limits of a torque range and/or torque dynamics of the combustion engine.