Patent ID: 11961648
Assignee: BEIJING UNIVERSITY OF TECHNOLOGY
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 2:
3. The rapid demagnetization method of claim 2, wherein an input of the demagnetization parameter optimizing module is the characteristic information {ρrecord, ηmaterial, ζforce, . . . }, a type of the magnetic recording mode; a type of a hard disk material and a multiple of an intensity of an external magnetic field with respect to the coercive force of the magnetic medium to be demagnetized; an output of the demagnetization parameter optimizing module is an optimized set value {Hopersp, αopersp, . . . } of the demagnetization parameters comprising the intensity of the demagnetizing magnetic field and demagnetization angle; and an intermediate processing process of the demagnetization parameter optimizing module involves a magnetic medium characteristic matching sub-module and an optimized set value acquisition sub-module, expressed as equation (6):

{Hopersp,αopersp, . . . }=fparaset({ρrecord,ηmaterial,ζforce, . . . })  (6);

wherein {Hopersp, αopersp, . . . } represents the optimized set values of the demagnetization parameters consisting of the intensity of the demagnetizing magnetic field and demagnetization angle; and fparaset(·) represents a mapping model configured to obtain the optimized set value of the demagnetization parameters;
based on the characteristic information of the magnetic medium to be demagnetized, the type of the magnetic recording mode and the multiple of intensity of an external magnetic field with respect to the coercive force of the magnetic medium to be demagnetized, the demagnetization parameter optimizing module executes the following steps:
matching the characteristic information of the magnetic medium to be demagnetized with characteristics in the magnetic medium characteristic database to obtain a matching rate ξnewdiskfeature, expressed by equation (7):, {
       
        
         ρ
         record
        
        ,
        
         η
         material
        
        ,
        
         ζ
         force
        
        ,
        …
       
          
       }
      
      
       →
       
        
         f
         match
         object
        
        (
        ·
        )
       
      
      
       ξ
       newdisk
       feature
      
     
     ;
    
   
   
    
     (
     7
     )
    
   
  
 

wherein fmatchopiset(·) is a matching model based on a template matching algorithm;
comparing ηnewdiskfeature with a set threshold value θthresholdfeature provided by a technician performing a demagnetization operation;
if feature ηnewdiskfeature≤θthresholdfeature, which indicates that a similarity between a hard disk to be demagnetized and a demagnetized hard disk in the database is considered by the technician to be within an allowable set threshold value, making a prediction based on the characteristic information of the magnetic medium to be demagnetized using a constructed demagnetization parameter optimizing and setting model foptiset(·) to obtain the optimized set value {Hopersp, αopersp, . . . } of the demagnetization parameters, expressed by equation (8):, {
     
      
       
        
         
          
           {
           
            
             H
             oper
             pre
            
            ,
            
             α
             oper
             pre
            
            ,
            …
           
              
           }
          
          =
          
           
            f
            optiset
           
           (
           
            {
            
             
              ρ
              record
             
             ,
             
              η
              material
             
             ,
             
              ζ
              force
             
             ,
             …
            
               
            }
           
           )
          
         
        
       
       
        
         
          
           {
           
            
             H
             oper
             sp
            
            ,
            
             α
             oper
             sp
            
            ,
            …
           
              
           }
          
          =
          
           {
           
            
             H
             oper
             pre
            
            ,
            
             α
             oper
             pre
            
            ,
            …
           
              
           }
          
         
        
       
      
      ;
     
    
   
   
    
     (
     8
     )
    
   
  
 

wherein {Hoperpre, αoperpre, . . . } is a prediction value obtained based on foptiset(·) using the {ρrecord, ηmaterial, ηforce, . . . } as input; and foptiset(·) is constructed using a neural network algorithm; and
if ξnetworkfeature>θthresholdfeature, which indicates that the similarity between a hard disk to be demagnetized and a demagnetized hard disk in the database is considered by the technician to be not within the allowable set threshold value, taking a default set value of the demagnetization parameters as a current optimized set value of the demagnetization parameters of the magnetic medium to be demagnetized, expressed by equation (9):

{Hopersp,αopersp, . . . }={Hoperdefault,αoperdefault, . . . }  (9).