Method for automatically adjusting reference models in vehicle stability enhancement (VSE) systems

Abstract

A method for automatically adjusting a vehicle stability enhancement (VSE) system is disclosed. The VSE system is used in conjunction with a steering system having a plurality of driver-selectable steering modes associated therewith. In an exemplary embodiment, the method includes configuring a reference model within the VSE system to generate desired vehicle handling aspects, the desired vehicle handling aspects being a function of one or more driver inputs to the steering system. Then, a determination is made as to which of the plurality of driver-selectable steering modes is activated, wherein each of the desired vehicle handling aspects generated is made further dependent upon a specific steering mode selected.

1 . A method for automatically adjusting a vehicle stability enhancement (VSE) system, the method comprising: 
 configuring a reference model within the VSE system to generate desired vehicle handling aspects, said desired vehicle handling aspects being a function of one or more driver inputs to a steering system and including at least one of a desired steady state yaw rate, a desired steady state sideslip, a desired damping ratio, and a desired natural frequency;    configuring a set of lookup tables for generating each of said desired vehicle handling aspects, wherein each lookup table within said set of lookup tables is individually tuned so as to correspond to said specific steering mode selected; and    determining which of a plurality of driver selectable steering modes associated with the steering system is activated;    wherein each of said desired vehicle handling aspects generated is further dependent upon a specific steering mode selected.    
   
   
       2 . (canceled)  
   
   
       3 . The method of  claim 1 , wherein said one or more driver inputs further comprise: 
 a handwheel angle (HWA); and    a vehicle speed.    
   
   
       4 . (canceled)  
   
   
       5 . The method of  claim 1 , wherein: 
 said set of lookup tables corresponding to said desired steady state yaw rate have said HWA as a first input thereto, and said vehicle speed as a second input thereto;    said set of lookup tables corresponding to said desired steady state sideslip have said HWA as a first input thereto, and said vehicle speed as a second input thereto;    said set of lookup tables corresponding to said desired damping ratio have said vehicle speed as a first input thereto; and    said set of lookup tables corresponding to said desired natural frequency have said vehicle speed as a first input thereto.    
   
   
       6 . The method of  claim 5 , further comprising: 
 configuring a switching mechanism, said switching mechanism having a plurality of outputs therefrom corresponding to said desired vehicle handling aspects; and    said switching mechanism further having said set of lookup tables as inputs thereto;    wherein, responsive to said specific steering mode selected, said switching mechanism selectively couples said inputs thereto to said outputs therefrom.    
   
   
       7 . The method of  claim 3 , wherein said desired steady state yaw rate for a given selected steering mode is generated by: 
 configuring a base lookup table to accept said HWA as a first input thereto and said vehicle speed as a second input thereto;    configuring a rear angle lookup table to accept a commanded, open-loop rear wheel angle (RWA) as a first input thereto and said vehicle speed as a second input thereto; and    summing a resulting output from said base lookup table with a resulting output from said rear angle lookup table.    
   
   
       8 . A vehicle stability enhancement (VSE) system, comprising: 
 a reference model configured to generate desired vehicle handling aspects, said desired vehicle handling aspects being a function of one or more driver inputs to a steering system and including at least one of a desired steady state yaw rate, a desired steady state sideslip, a desired damping ratio, and a desired natural frequency, said steering system having a plurality of driver selectable steering modes associated therewith;    a vehicle state estimator, said vehicle state estimator accepting vehicle inputs thereto and generating vehicle parameter estimations therefrom;    a set of lookup tables configured for generating each of said desired vehicle handling aspects, wherein each lookup table within said set of lookup tables is individually tuned so as to correspond to said specific steering mode selected; and    a vehicle control block, said vehicle control block receiving said desired vehicle handling aspects and said vehicle parameter estimations as inputs thereto, and said vehicle control block further generating vehicle control outputs to be applied to said steering system;    wherein each of said desired vehicle handling aspects generated is further dependent upon a specific driver selectable steering mode selected.    
   
   
       9 . (canceled)  
   
   
       10 . The VSE system of  claim 8 , wherein said one or more driver inputs further comprise: 
 a handwheel angle (HWA); and    a vehicle speed.    
   
   
       11 . (canceled)  
   
   
       12 . The VSE system of  claim 8 , wherein: 
 said set of lookup tables corresponding to said desired steady state yaw rate have said HWA as a first input thereto, and said vehicle speed as a second input thereto;    said set of lookup tables corresponding to said desired steady state sideslip have said HWA as a first input thereto, and said vehicle speed as a second input thereto;    said set of lookup tables corresponding to said desired damping ratio have said vehicle speed as a first input thereto; and    said set of lookup tables corresponding to said desired natural frequency have said vehicle speed as a first input thereto.    
   
   
       13 . The VSE system of  claim 12 , further comprising: 
 a switching mechanism configured to have a plurality of outputs therefrom corresponding to said desired vehicle handling aspects; and    said switching mechanism further having said set of lookup tables as inputs thereto;    wherein, responsive to said specific steering mode selected, said switching mechanism selectively couples said inputs thereto to said outputs therefrom.    
   
   
       14 . The VSE system of  claim 10 , wherein said desired steady state yaw rate for a given selected steering mode is generated by: 
 a base lookup table configured to accept said HWA as a first input thereto and said vehicle speed as a second input thereto;    a rear angle lookup table configured to accept a commanded, open-loop rear wheel angle (RWA) as a first input thereto and said vehicle speed as a second input thereto; and a resulting output from said base lookup table being summed with a resulting output from said rear angle lookup table.