To enhance the quality for vehicle tracking

a robust

H

∞

filter algorithm under road situation is proposed in this paper.It notices that the running vehicles are constrained by the road network.Using the road network as filtering constraint condition

a dynamical system model with road constraint is built and the corresponding robust

H

∞

filtering equation is derived.The simulation results show that

the proposed algorithm has more tracking accuracy and better filtering performance than unconstrained

H

∞

filter and Kalman filter algorithm.