Transmission control system and method for compensating roadway changes in a transmission control system of an automatic vehicle transmission

Abstract

A method for compensating roadway changes in a transmission control system of an automatic vehicle transmission, according to which each change in the roadway is recognized and compensated. Also disclosed is a transmission control system of an automatic vehicle transmission, particularly for carrying out the inventive method, comprising at least one device for detecting and compensating changes in the roadway.

1 . In a transmission closed-loop control system of an automatic vehicle transmission, a method for the compensation of closed-loop control changes comprising the steps of: 
 detecting each said closed-loop control change; and,    compensating each said closed-loop control change.    
   
   
       2 . The method as described in  claim 1 , wherein at least one of said detected closed-loop control change is compensated in relation to a reference model within the closed-loop control system of the transmission control system without an adaptation of controller parameters being carried out.  
   
   
       3 . The method as described in  claim 1 , wherein there is differentiation at least between temporarily occurring temperature-related closed-loop control changes and changes of closed-loop response characteristic having a long-term effect that are a function of the operation and hardware.  
   
   
       4 . The method as described in  claim 1 , wherein the compensation is adapted to a changed loop-control response characteristic.  
   
   
       5 . The method as described in  claim 1 , wherein the compensation of the closed-loop control changes is limited.  
   
   
       6 . The method as described in  claim 1 , wherein the closed-loop control changes having a long-term effect are stored in memory.  
   
   
       7 . The method as described in  claim 1 , wherein at least one parametric model of the transmission control system is used.  
   
   
       8 . The method as described in  claim 7 , wherein the parameters of the model are identified during a gear change while taking into consideration predetermined boundary conditions.  
   
   
       9 . The method as described in  claim 8 , wherein a parameter estimating procedure is implemented in the transmission control system.  
   
   
       10 . The method as described in  claim 8 , wherein a voltage (U k ) that is compensated and limited to maximum battery voltage and/or at least one measured transmission motor speed (n) are used for the identification of the model parameters.  
   
   
       11 . The method as described in claims  8 , wherein variations between the identified model parameters and parameters of the reference model are used for the dynamic compensation.  
   
   
       12 . The method as described in  claim 1 , wherein the compensation is carried out in several steps.  
   
   
       13 . The method as described in  claim 12 , wherein, after an identification of the model parameters has been carried out, a new loop gain (k) is calculated in a first step with the identified model parameters.  
   
   
       14 . The method as described in  claim 12 , wherein in a second step loop gain (k) is compensated with an executed temperature compensation.  
   
   
       15 . The method as described in  claim 14 , wherein the temperature compensation is carried out before the limitation of position controller voltages (U R ).  
   
   
       16 . The method as described in  claim 15 , wherein maximum battery voltage and conversion to PWM variables are used to limit position controller voltages (U R ) as manipulated variables.  
   
   
       17 . The method as described in  claim 12 , wherein a filtering of loop gain (K 1 ) is carried out in a third step.  
   
   
       18 . The method as described in  claim 17 , wherein a first-order discrete filter having a constant filter constant is used.  
   
   
       19 . The method as described in  claim 12 , wherein a filtered gain value (K 2 ) is limited to a defined value range in a fourth step.  
   
   
       20 . The method as described in  claim 19 , wherein compensation gain (K c ) resulting from an executed limitation is carried out on a one-time basis with a loop gain (K r ) of a reference model after startup.  
   
   
       21 . The method as described in  claim 12 , wherein compensation gain (K c ), which changes during operation, is stored in an EEProm during an “ignition off” state in a fifth step.  
   
   
       22 . The method as described in  claim 21 , wherein the stored value of said compensation gain (K,) is used as a starting value in a next “ignition on” state.  
   
   
       23 . The method as described in  claim 22 , wherein temperature-related closed-loop control changes that occur are compensated by a temperature compensation between the “ignition off” and “ignition on” states.  
   
   
       24 . The method as described in  claim 12 , wherein a static compensation of the position controller voltage (U R ) is carried out in a sixth step.  
   
   
       25 . The method as described in  claim 3 , wherein during shift and select operations signals of input voltage and/or speed of transmission motors are used to identify the closed-loop response characteristic of the motors in an online state.  
   
   
       26 . The method as described in  claim 25 , wherein a discrete motor model is used for a transmission actuating mechanism.  
   
   
       27 . The method as described in  claim 26 , wherein at least one PT1-element and one I-element (integrator) are used in the motor model.  
   
   
       28 . The method as described in  claim 27 , wherein the input voltage (u k-1 ) and the motor speed (N k-1 ) of a position controller interrupt, which are used as input variables of the PT1-element, are acquired beforehand.  
   
   
       29 . The method as described in  claim 27 , wherein currently modeled motor speed (n k ) is converted from the I-element (integrator) into corresponding motor increments (x k ).  
   
   
       30 . The method as described in  claim 27 , wherein the following equation is used for the PT1-element:  
         n   k   =A·n   k-1     30  B·u   k-1 .  
   
   
       31 . The method as described in  claim 27  wherein the following equation is used for the I-element:  
         x   k   =x   k-1   +K·T   A   ·n   k .  
   
   
       32 . The method as described in  claim 25  wherein various states are defined for the online identification.  
   
   
       33 . The method as described in  claim 32 , wherein transitional conditions are selected for the various states.  
   
   
       34 . The method as described in  claim 33 , wherein at least one control-side observer is used to estimate an applied current strength for a transmission motor of the transmission actuating mechanism.  
   
   
       35 . The method as described in  claim 34 , wherein current strength of each transmission motor is estimated by the observer and a control-side current strength limitation is provided by the observer.  
   
   
       36 . The method as described in  claim 35 , wherein the loop-response characteristic of each transmission motor is identified by the observer and the required current strength is estimated via the determined closed-loop control parameters.  
   
   
       37 . The method as described in  claim 36 , wherein at least the applied voltage and/or the measured motor speed are estimated as closed-loop control parameters.  
   
   
       38 . The method as described in  claim 36 , wherein the loop-response characteristic of each transmission motor is represented with at least one PT,-model having variable parameters.  
   
   
       39 . The method as described in  claim 34 , wherein the following equation is used as a movement equation for the transmission motor:  
     
       

       {dot over (n)}=a·n+b·u.  

     
   
   
       40 . The method as described in  claim 39 , wherein parameters a and b are identified during a gear change in the position-controlled state.  
   
   
       41 . The method as described in claims  34 , wherein the motor voltage (U), the motor speed (n) and the current strength (I) are estimated via the following equation:  
     
       
         
           
             I 
             = 
             
               
                 
                   U 
                   - 
                   
                     
                       
                         k 
                         Φ 
                       
                       · 
                       
                         
                           2 
                           ⁢ 
                           π 
                         
                         60 
                       
                     
                     ⁢ 
                     n 
                   
                 
                 R 
               
               . 
             
           
         
       
     
   
   
       42 . A transmission closed-loop control system of an automatic vehicle transmission, comprising: 
 means for detecting each said closed-loop control change; and,    means for compensating each said closed-loop control change.