A Identification Algorithm of Freeway Steady-state Speed-Density Balance Relational Expression Based on the Power Series Expansion and the Least Squares Method

This paper proposes a novel identification algorithm to the freeway steady-state speed-density balance relational expression of the Markos Papageorgiou’s freeway traffic flow model. Two stages are involved. First, use the power series principle to transform this relational expression from nonlinear model into linear model. Second,use the least squares method to identify the linear model and further get all unknown parameters of the nonlinear model. So,the identification to the freeway steady-state speed-density balance relational expression can be achieved. Both theory analysis and simulation research show that ,comparing with conventional nonlinear identification algorithm,this algorithm highly improves operating speed of model identification and can achieve arbitrary identification accuracy. This algorithm successfully solves the problem of identifying the relational expression in engineering and has great promotion value.