During the simulation of constrained multibody system,numerical integration is important for solving the Euler-Lagrange equation of multibody system dynamics,which is usually a Differential-Algebraic Equations(DAEs).Using the discrete Hamilton principle,discrete EulerLagrangian equation is obtained first based on Lagrange Interpolation.Then the Romberg,Gauss integral is used to solve the DAEs.At last,numerical results are compared by using Euler method,Runge-Kutta method,Romberg method and Gauss method for a double pendulum system.
