Patent ID: 11908319
Assignee: XIDIAN UNIVERSITY
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. The speed measurement method according to claim 1, wherein, in step 10), estimating the speed of the vehicle using the minimum variance method based on the alignment results comprises calculating the speed by means of the following equation:, Σ
        
         i
         =
         0
        
        m
       
       (
       
        
         L
         i
        
        -
        
         x
         
          k
          ⁢
          0
         
        
       
       )
      
      2
     
     
      v
      k
     
    
    -
    
     
      ∑
      
       i
       =
       0
      
      m
     
     
      
       (
       
        
         L
         i
        
        -
        
         x
         
          k
          ⁢
          0
         
        
       
       )
      
      ⁢
      
       
        t
        ^
       
       
        i
        ,
        k
       
      
     
    
   
   =
   0
  
  ,
 

where vk is a speed of a k-th vehicle, and xk0 is a position of the k-th vehicle at moment 0; and
setting the position of the first geomagnetic sensor in each group of geomagnetic sensors as the origin;
where {circumflex over (t)}i, k is a measurement time when an i-th vehicle corresponding to a k-th geomagnetic sensor in each group of geomagnetic sensors passes, and Li is a distance from the i-th geomagnetic sensor to the origin.