Patent ID: 11859686
Assignee: HARBIN ENGINEERING UNIVERSITY
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 3:
4. The method according to claim 3, wherein the step 4 comprises: step 4.1: determining an electromagnetic force-displacement expression of the negative stiffness electromagnetic actuator, and making the electromagnetic force-displacement expression of the negative stiffness electromagnetic actuator about the structural parameters and the control current equal to an electromagnetic force-displacement expression about ideal negative stiffness:, F
       mag
      
      =
      
       
        2
        ⁢
        
         N
         1
         2
        
        ⁢
        
         I
         
          c
          ⁢
          1
         
         2
        
        ⁢
        
         μ
         0
        
        ⁢
        
         S
         
          i
          ⁢
          n
         
        
        ⁢
        
         S
         out
        
        ⁢
        
         
          (
          
           
            S
            
             i
             ⁢
             n
            
           
           +
           
            S
            out
           
          
          )
         
         [
         
          
           1
           
            
             (
             
              
               a
               ⁢
               x
              
              +
              b
             
             )
            
            2
           
          
          -
          
           1
           
            
             (
             
              
               a
               ⁢
               x
              
              -
              b
             
             )
            
            2
           
          
         
         ]
        
       
       =
       
        
         k
         m
        
        ⁢
        x
       
      
     
     ,
    
   
  
  
   
    
     
      
       F
       mag
      
      =
      
       
        k
        m
       
       ⁢
       x
      
     
     ,
    
   
  
 

wherein km represents a magnitude of the ideal constant value negative stiffness; and
step 4.2: analyzing the electromagnetic force-displacement expression, and determining the expression of currents passing through the first coil and the second coil with respect to the displacement, the magnitude of the ideal constant value negative stiffness and the structural parameters when the negative stiffness electromagnetic actuator takes the current as the input control variable:, I
       
        c
        ⁢
        1
       
      
      =
      
       
        1
        
         2
         ⁢
         a
         ⁢
         
          N
          1
         
        
       
       ⁢
       
        
         
          -
          
           k
           m
          
         
         
          
           μ
           0
          
          ⁢
          b
          ⁢
          
           S
           
            i
            ⁢
            n
           
          
          ⁢
          
           S
           
            o
            ⁢
            u
            ⁢
            t
           
          
         
        
       
       ⁢
       
        
         
          
           (
           
            
             a
             ⁢
             x
            
            +
            b
           
           )
          
          2
         
         ⁢
         
          
           (
           
            
             a
             ⁢
             x
            
            -
            b
           
           )
          
          2
         
        
       
      
     
     ,
    
   
  
  
   
    
     
      
       ax
       +
       b
      
      =
      
       
        
         
          (
          
           
            
             l
             8
            
            
             μ
             r
            
           
           +
           
            
             2
             ⁢
             
              l
              b
             
            
            
             μ
             r
            
           
           +
           
            2
            ⁢
            g
           
           +
           
            2
            ⁢
            x
           
          
          )
         
         ⁢
         
          (
          
           
            S
            
             i
             ⁢
             n
            
           
           +
           
            S
            out
           
          
          )
         
        
        +
        
         
          
           2
           ⁢
           
            l
            a
           
          
          
           μ
           r
          
         
         ⁢
         
          S
          
           i
           ⁢
           n
          
         
         ⁢
         
          S
          out
         
         ⁢
         
          (
          
           
            1
            
             S
             1
            
           
           +
           
            1
            
             S
             2
            
           
          
          )
         
        
       
       >
       0
      
     
     ,
    
   
  
  
   
    
     
      
       b
       -
       ax
      
      =
      
       
        
         
          (
          
           
            
             l
             8
            
            
             μ
             r
            
           
           +
           
            
             2
             ⁢
             
              l
              b
             
            
            
             μ
             r
            
           
           +
           
            2
            ⁢
            
             (
             
              g
              -
              x
             
             )
            
           
          
          )
         
         ⁢
         
          (
          
           
            S
            
             i
             ⁢
             n
            
           
           +
           
            S
            out
           
          
          )
         
        
        +
        
         
          
           2
           ⁢
           
            l
            a
           
          
          
           μ
           r
          
         
         ⁢
         
          S
          
           i
           ⁢
           n
          
         
         ⁢
         
          S
          out
         
         ⁢
         
          (
          
           
            1
            
             S
             1
            
           
           +
           
            1
            
             S
             2
            
           
          
          )
         
        
       
       >
       0
      
     
     ,
    
   
  
  
   
    
     
      
       ax
       -
       b
      
      <
      0
     
     ,
    
   
  
  
   
    
     
      
       
        I
       
       
        c
        ⁢
        1
       
      
      =
      
       
        
         
          1
          
           2
           ⁢
           a
           ⁢
           
            N
            1
           
          
         
         ⁢
         
          
           
            -
            
             k
             m
            
           
           
            
             μ
             0
            
            ⁢
            b
            ⁢
            
             S
             
              i
              ⁢
              n
             
            
            ⁢
            
             S
             
              o
              ⁢
              u
              ⁢
              t
             
            
           
          
         
         ⁢
         
          b
          2
         
        
        -
        
         
          a
          
           2
           ⁢
           
            N
            1
           
          
         
         ⁢
         
          
           
            -
            
             k
             m
            
           
           
            
             μ
             0
            
            ⁢
            b
            ⁢
            
             S
             
              i
              ⁢
              n
             
            
            ⁢
            
             S
             
              o
              ⁢
              u
              ⁢
              t
             
            
           
          
         
         ⁢
         
          x
          2
         
        
       
       =
       
        
         I
         1
        
        -
        
         I
         2
         2
        
       
      
     
     ,
    
   
  
  
   
    
     
      
       
        I
       
       1
      
      =
      
       
        1
        
         2
         ⁢
         a
         ⁢
         
          N
          1
         
        
       
       ⁢
       
        
         
          -
          
           k
           m
          
         
         
          
           μ
           0
          
          ⁢
          b
          ⁢
          
           S
           
            i
            ⁢
            n
           
          
          ⁢
          
           S
           
            o
            ⁢
            u
            ⁢
            t
           
          
         
        
       
       ⁢
       
        b
        2
       
      
     
     ,
     
      
       I
       2
      
      =
      
       
        
         a
         
          2
          ⁢
          
           N
           1
          
         
        
        ⁢
        
         
          
           -
           
            k
            m
           
          
          
           
            μ
            0
           
           ⁢
           b
           ⁢
           
            S
            
             i
             ⁢
             n
            
           
           ⁢
           
            S
            
             o
             ⁢
             u
             ⁢
             t
            
           
          
         
        
        ⁢
        x
       
      
     
     ,
    
   
  
 

wherein Ic1 represents a current passing through the first coil, and a current Ic2 passing through the second coil is equal to the current Ic1; and μr represents a magnitude of a relative magnetic conductivity of materials of the first iron core, the second iron core, the first armature and the second armature.