The robotic fish model selected in this paper which consider an idealized bcf propulsive fish model that consists of only three links : the rigid body in the foreside ; the high aspect ratio caudal fin ; the caudal peduncle which connects the caudal fin and the body 机器鱼的模型建立是把理想的bcf推进式鱼类分为三个部分，分别是：前部刚性的身体，大展弦比的尾鳍和一个连接以上两部分的尾颈。
