Patent ID: 11938923
Assignee: TONGJI UNIVERSITY
Field: Transport (Mechanical engineering)
Classification: CPC B  Y | IPC B

Claim 1:
2. The longitudinal and lateral vehicle motion cooperative control method according to claim 1, wherein the desired yaw rate of the vehicle is calculated using a second-order reference model, and a transfer function from a front wheel rotation angle δf to the desired yaw rate γref of the vehicle is expressed as follows:, γ
    ref
   
   
    δ
    f
   
  
  =
  
   
    K
    γ
   
   ⁢
   
    
     1
     +
     
      
       τ
       γ
      
      ⁢
      s
     
    
    
     
      
       1
       
        w
        n
        2
       
      
      ⁢
      
       s
       2
      
     
     +
     
      
       
        2
        ⁢
        ζ
       
       
        w
        n
       
      
      ⁢
      s
     
     +
     1
    
   
  
 

wherein a stability factor of the vehicle is defined as, K
   =
   
    -
    
     
      m
      ⁡
      (
      
       
        
         C
         f
        
        ⁢
        
         L
         f
        
       
       -
       
        
         C
         r
        
        ⁢
        
         L
         r
        
       
      
      )
     
     
      2
      ⁢
      
       C
       f
      
      ⁢
      
       C
       T
      
      ⁢
      L
     
    
   
  
  ,, and a distance between front and rear axles is defined as L=Lf+Lr; a natural oscillation frequency of a second-order reference model system is defined as, w
    n
   
   =
   
    
     2
     
      V
      x
     
    
    ⁢
    
     
      
       
        C
        f
       
       ⁢
       
        
         C
         r
        
        (
        
         L
         -
         
          K
          ⁢
          
           V
           x
           2
          
         
        
        )
       
      
      
       mI
       z
      
     
    
   
  
  ,, a damping coefficient of the second-order reference model system is, ζ
   =
   
    
     
      m
      ⁡
      (
      
       
        
         C
         f
        
        ⁢
        
         L
         f
         2
        
       
       +
       
        
         C
         r
        
        ⁢
        
         L
         r
         2
        
       
      
      )
     
     +
     
      
       (
       
        
         C
         f
        
        +
        
         C
         r
        
       
       )
      
      ⁢
      
       I
       z
      
     
    
    
     2
     ⁢
     
      
       
        LmI
        z
       
       ⁢
       
        C
        f
       
       ⁢
       
        
         C
         r
        
        (
        
         L
         -
         
          K
          ⁢
          
           V
           x
           2
          
         
        
        )
       
      
     
    
   
  
  ,, a yaw-rate steady-state gain is, K
    γ
   
   =
   
    
     V
     x
    
    
     L
     +
     
      K
      ⁢
      
       V
       x
       2
      
     
    
   
  
  ,, a yaw-rate differential coefficient is defined as, τ
    γ
   
   =
   
    
     m
     ⁢
     V
     ⁢
     
      L
      f
     
    
    
     2
     ⁢
     
      C
      r
     
     ⁢
     L
    
   
  
  ,, m is a mass of the vehicle, Iz is a rotational inertia of the vehicle about a center of mass, Vx is a longitudinal speed of the vehicle, Lf and Lr represent lengths of front and rear half axles, respectively, and Cf and Cr represent stiffnesses of front-rear axle tires, respectively.