function [Fx,Fy]=FDM_circular(X,Y,X_dot,Y_dot) Fx=0; Fy=0; epsilon=0.6%偏心率=0.6 L=0.03; d=0.06%轴颈直径d lambda=L/d; m=40; n=30; phi1=0; phi2=2*pi; delta_phi=(phi2-phi1)/m; delta_lambda=2/n; k=1; P0=zeros(