function dy=acrobot3_eq0(t,y,c,m,a,l,I,g); 

%---2005.12.10----
%%%  nonlinear System
%ƒŠƒ“ƒN‚Q‚ð–³Ž‹
%---definition---
%--------------------------------------------------------------------------
%
%Link1Šp“x�@�@Link1Šp‘¬“x    Link1Šp‰Á‘¬“x�@
%---y(1,1)   y(2,1)          y(3,1)      
%
%            dy(1,1)        dy(2,1)           
%--------------------------------------------------------------------------
%       Ž©—R�U“®ƒVƒ~ƒ…ƒŒ�[ƒ^
%       (ma^2+I)q''+cq' + ma sin(q)=0  
%                      c                          mag
%     q'' +        --------   q' +          ----------  sin(q)=0
%                  (ma^2+I)                   (ma^2+I)
%--------------------------------------------------------------------------

global ni
dy=zeros(2,1);

dy(1,1)=y(2,1);
dy(2,1)= -c/(m*a^2+I) * y(2,1) - m*a*g/(m*a^2+I) * sin( y(1,1) );







