Patent ID: 11870371
Assignee: POLIGHT ASA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 2:
3. The method according to claim 2, wherein the hysteresis compensation algorithm comprises:
using dc(V) for increasing, d↑c(V), and decreasing, d↑c(V), voltages determining maximum and minimum voltages, and Vmax and Vmin, of dc(V) as well as providing historical data comprising last upper and lower turning points, Vupper and Vlower;
using a first hysteresis model function dn(V) with V being normalized as, V
    n
  
  =
  
    
      (
      
        
          V
          -
          
            V
            
              l
              ⁢
              o
              ⁢
              w
              ⁢
              e
              ⁢
              r
            
          
        
        
          
            V
            upper
          
          -
          
            V
            
              l
              ⁢
              o
              ⁢
              w
              ⁢
              e
              ⁢
              r
            
          
        
      
      )
    
    ⁢
    
      :
    
  

dn↑=Vn1,1 

dn↓=1−(1−Vn)1,1,

and a second hysteresis model function dr(V) with V being normalized as, V
    r
  
  =
  
    
      (
      
        
          V
          -
          
            V
            min
          
        
        
          
            V
            max
          
          -
          
            V
            min
          
        
      
      )
    
    ⁢
    
      :
    
  

Vr=(V−Vmin/Vmax−Vmin): dr(V)=dn(V)·(dn(Vlower)−dn(Vupper))+dn(Vupper),

determining a hysteresis ratio r:, r
      ⁡
      
        (
        V
        )
      
    
    =
    
      
        
          
            d
            r
          
          ⁡
          
            (
            V
            )
          
        
        -
        
          V
          r
          
            1
            ,
            1
          
        
      
      
        1
        -
        
          
            (
            
              1
              -
              
                V
                r
              
            
            )
          
          
            1
            ,
            1
          
        
        -
        
          V
          r
          
            1
            ,
            1
          
        
      
    
  
  ;

providing a setpoint displacement measure, dsp, for the PEA and determining a corresponding voltage, Vs, from d↑c(V); and
selecting a search range as the interval [Vmin; Vlower], [Vlower; Vupper], or [Vupper; Vmax] in which Vs falls, and performing a binary search algorithm using the function ds(V)=d↑c(V)(d↓c(V)−d↑c(V)) within the selected range and starting at Vs to determine a hysteresis compensated voltage, Vhs, yielding a displacement measure within a preset threshold from dsp.