Research On Forward Safety Control Strategy Of Truck Based On Road Adhesive Coefficient Estimation

With the increasing of vehicle population,the probability of traffic accident is increasing.Due to the characteristics of large mass,high center of gravity and long braking distance,trucks are more prone to rear-end collision,braking instability and other accident.In order to reduce the rear-end collision and improve the forward safety of trucks,it is of great theoretical significance and application value to research the coordinated control of Advanced Emergency Braking(AEB)system and Anti-lock Braking System(ABS).This dissertation researchs the method of road adhesion coefficient estimation and the forward safety control strategy of truck.Firstly,a three-degree-of-freedom dynamic model of truck and the Dugoff tire model is established and verified by test data.Based on Unscented Kalman Filter(UKF)and strong tracking UKF,the effectiveness of the estimation method is verified by simulation.Then,the traditional AEB control strategy based on safety distance and collision time is established for the truck,and the AEB control strategy based on road adhesion coefficient estimation is proposed.The AEB control effect is verified through simulation and comparative analysis.Two fuzzy sliding mode ABS controllers with and without road adhesion coefficient estimation are established.By comparation with the traditional ABS logic threshold control method,the ABS control effect is verified with simulation.Finally,AEB/ABS coordinated control strategy with road adhesion coefficient estimation is proposed,and the hardware-in-loop test is carried out to verify the control effect.The research results of this dissertation can provide new ideas and references for road adhesion coefficient estimation and forward safety control strategy research of truck.It has been found that(1)the road adhesion coefficient estimation methods based on UKF and strong tracking UKF can both estimate different road adhesion coefficients.Compared with the UKF method,the strong tracking UKF method has faster convergence speed and higher accuracy.(2)AEB control based on road adhesion coefficient estimation can avoid rear-end collision of truck under different adhesion coefficient road surface.Compared with traditional AEB control,early warning and emergency braking advance time can reach 0.8s and 2.8s.(3)Under the condition of medium and low adhesion coefficient road surface,the control effect of the fuzzy sliding mode ABS control with of road adhesion coefficient estimation is better than that of the fuzzy sliding mode ABS control and ABS logic threshold control.(4)Compared with single AEB and ABS control,AEB/ABS coordinated control strategy with estimation of road adhesion coefficient can effectively improve the longitudinal safety of the truck with 8.4% improvement in braking distance and 5.9% improvement in braking time.