h=r+A s -r-As According to the definition of the constraint B ,×可，=0 toeitheativeoation (Rv)v,=(RAv:)A=(A Rv:)Av =VRTATAV F D》=-yRAy=-vB,y=0 According to the definition of the constraint 0to restrict P be parallel to the axis D》=(RA,）'h=0 AA=A= cos(p,-9,)-sin(p,-9,) sin(,-)cos(o;-) 。--a =0 RA=AR RA=BAccording to the definition of the constraint 0    vi v j  0   vi  h      i j i i j j Rv v  RAv A v T T   0 T RAivi  h  i ij j  v RA v T   i i j j  A Rv A v T              sin( ) cos( ) cos( ) sin( ) T j i j i j i j i i j ij         A A A    0                   i ij j i i t i j t i j t i j v B v RAv h T T ( , ) 2 ( , ) ( , ) 1    to restrict the relative rotation P i i i Q j j j h  r  A s  r  A s  ( , ) 2 t i j Φ  ( , ) 1 t i j Φ Bj y  x  O j x y j   Cj j r  Q Q j r Q j s P i s i x  i y  Ci Bi ir  P P ir h  i v  j v  0 T  vi  Bijv j  RAi  AiR j i j i  v R A A v T T T RAij  Bij According to the definition of the constraint to restrict PQ be parallel to the axis