Study On The Minimum Safe Distance Between Trucks On The Curved Slope Of Mountain Highway

The road characteristics of curved slope section of mountain highway are more complex than ordinary roads,so it is difficult to guarantee the safety of heavy trucks,and rear-end accidents often occur,leading to traffic breakdown.In order to reduce the probability of rearend collision,the most fundamental and effective method is to keep a safe distance between the front and rear trucks.On the premise of considering truck safety and road capacity of mountain highway,this thesis studies the minimum safe distance of trucks under the conditions of different driving speeds,different longitudinal slopes and circular curves in curved slope combination sections.By establishing the mathmatical model of minimum safe distance between trucks,the minimum distance under different combinations of curved slopes is obtained.Finally,the Truck Sim simulation software is used to verify the determined minimum safe distance between trucks.The research contents and main achievements of this thesis are as follows:(1)According to the relevant road regulations,the mountain road grade is selected,and the range of the mountain road section with curved slope is defined by analyzing the road parameters of the mountain road section.Secondly,combined with the characteristics of mountain road driving,this thesis selects the representative truck.The calculation formula of brake acceleration of the truck is determined by analyzing the force of the truck when driving in the combined section of curved slope.(2)The influencing factors of the distance between trucks in the curved slope section are analyzed in detail,and the mathmatical model of the minimum safe distance is built based on three braking conditions,and the minimum distance on the uphill and downhill are calculated respectively.Under each combination of curved slope,the minimum safe distance between front and rear trucks is directly related to the truck speed,and the variation range of distance between front and rear trucks increases greatly with the increase of the speed.In addition to radius and longitudinal slope of road circle curve,the minimum safe distance has an important relationship with the speed deviation between front and rear trucks.The distance increases with the increase of the speed deviation.In the process of uphill driving,the increase of the longitudinal slope value is beneficial to the truck braking to some extent.When driving downhill,the driving speed of the following truck will affect the minimum safe distance to a great extent.(3)The Truck Sim simulation software is used to establish the simulation model of twotruck following,build the truck model,road model,driver model and braking control system,and verify the minimum safety distance calculated under three working conditions.The simulation results show that the calculated minimum safe running distance can meet the safe running requirements of trucks under real working conditions.