Model 1:4 body system 2 少2 1=2,12=4 B B2 Revolute joint H2:B~B2 C R P=Hj=2,s9=(9y0 QH,i=1,s=(”yP） 天 Hi B Bi i kind j i T 叫 C 1 (r) 1 -10 4 00 2 (r) 2 -20 1 10 T 2, Qj Qj Qj P=H2 j  s  x y B1 B2 B3 C1 1 x 1 y C2 2 x2 y O x y Revolute joint H2：B1  B2 l1  2, l2  4 Hi Bj Bi i kind j i c 1 (r) 1 -1 0 4 0 0 2 (r) 2 -2 0 1 1 0 QT j s PT i s Tj v Ti v H2  T 1, Pi Pi Pi Q=H i  s  x y 2Model 1: 4 body system