The dynamic model of an acceleration driven three-link acrobot is analyzed by using mechanism and data based
methods. The rigid body dynamic and motor driven models are given via mechanism analysis and the pure delay model
is indicated by the acceleration pulse response curve. The three model components are integrated into a complex model
structure for the dynamic model of the whole three-link acrobot. An improved generation algorithm(GA) is used to identify
the parameters of the integrated model. The outputs of the model and robot are compared and the factors causeing the errors
are discussed.