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Page 260                         Sun et al. Intell Robot 2023;3(3):257-73  I http://dx.doi.org/10.20517/ir.2023.17

                                           Table 1. Physical meanings in path following control
                                       Parameter  Physical meaning
                                                the mass of vehicle
                                                the lateral forces of the front tire
                                               
                                                the lateral forces of the rear tire
                                              
                                                the tire slip angle of the front tire
                                             
                                                the tire slip angle of the rear tire
                                             
                                                the vehicle sideslip angle
                                                the yaw inertia of the vehicle
                                            
                                                the center of gravity of the vehicle to the front wheel axis
                                            
                                                the center of gravity of the vehicle to the rear wheel axis
                                            
                                                the front tire cornering stiffness
                                            
                                                the rear tire cornering stiffness
                                            
                                                the lateral offset from the vehicle center of gravity to the
                                                closest    on the desired path
                                                the error between the actual heading angle    ℎ and the
                                                desired heading angle      
                                                the yaw rare of the vehicle with ¤    ℎ =   
                                                the longitudinal velocity of the vehicle
                                            
                                                the lateral velocity of the vehicle
                                            
                                                the front-wheel steering angle
                                             
                                                the curvilinear coordinate of point    along the path from
                                                an initial position predefined
                                                the curvature of the desired path at the point   .
                                         (  )
                                                          &$1 %86
                                       3DWK SODQQLQJ                    6WDWH VHQVLWLYH
                                              (&8                       (YHQW WULJJHU
                                                   7RUTXH
                                                   VHQVRU
                                                            6WHHULQJ
                                                             VKDIW
                                                            5HGXFHU
                                              &XUUHQW      6WHHULQJ JHDU
                                               0RWRU  &OXWK
                                        Figure 1. Path following control diagram with SS-ETC scheme.


               TheframeworkofthenetworkedpathfollowingcontrolisshowninFigure1. Then,themathematicalmodeling
               of path following control of AVs is given as follows

                                                
                                                 ¤   =          +          +    1
                                                
                                                
                                                
                                                   
                                                 ¤ =    −   (  )     
                                                                                                        (1)
                                                 ¤
                                                    =    11    +    12    +    1       +    2
                                                
                                                
                                                
                                                  ¤    =    21    +    22    +    2       +    3 .
                                                
               with
                      (      +      )  (            −            )
                  11 = −    ,    12 = −(1 +    ),
                                            2
                                                 
                                      2   2
                                        
                     (            −            )  (         +            )
                  21 =       ,    22 = −(    ),
                                                   
                                       
                  1 =  ,    2 =  .
                                  
               Further, define the state vector   (  ) = [  ,   ,   ,   ] , the control input   (  ) =       , the state-space form of the
                                                           
               path following model [32]  of AVs can be given as follows
                                                 ¤   (  ) =     (  ) +     (  ) +   (  )                (2)
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