The graph above is the system I want to solve , and I've attached my program.

The system is complicated, there is more than six general coordinates in this system. And the equations of motion are extremely complicated.

When I tried to solve those equations with NDSolve , the error occured and pop up a message:

NDSolve::ntdv: Cannot solve to find an explicit formula for the derivatives. Consider using the option Method->{"EquationSimplification"->"Residual"}. 

I followed the hint, and it works. But the result is not what I've expected.

I have two questions. First, is there any way I can solve my complicated equations directly?

Second, will the simplification change the characteristics of those equations? How can I check those equations after simplified?

Attachments: