Design method for transition curve path section

Abstract

The invention discloses a design method for easing a curved road section, which comprises the following steps: (1) a circular curved turning radius R and the designed vehicle speed V are determined; (2) a value of roll angular jerk J0, when the length l from a point of tangent to a calculation point of a transition curve is zero, is selected, and then an initial value of the length S of the transition curve is calculated; (3) whether values of roll angular jerk j, roll angular acceleration a, and roll angular velocity omega meet the requirement of indicators of the human engineering is checked according to the initial value of the length S of the transition curve; (4) a curvature radius r of each point on the transition curve is calculated; (5) a curve rotating angle alpha of each point on the transition curve is calculated; and (6) a plane coordinate of each point on the transition curve is calculated. The design method for easing the curved road section can ensure that an eased curved road section is more smoothly connected with linear road sections and circular curved road sections at both ends, and avoids the roll angular velocity and the roll angular acceleration of a vehiclefrom producing a sudden change at both ends of the eased curved road section, thereby increasing the comfort of people inside the vehicle.

Description

technical field [0001] The invention relates to a design method for a transitional curve section, in particular to a design method for a non-circular high-speed ring road transitional section used in an automobile test field. Background technique [0002] When the car is changing from driving on a straight line to driving on a circular curve, its motion state will change as follows: [0003] 1. The inclination angle of the vehicle relative to the vertical axis is changed from the original drainage slope angle (that is, the inclination angle of the road itself) to the inclination angle θ on the driving line of the circular curve section (the angle between the tangent line at the driving line of the cross-section curve section and the horizontal axis). [0004] 2. The turning radius changes from infinity to R, and the centrifugal acceleration changes from zero to V 2 / R, the yaw rate (the angular rate around the vertical axis) changes from zero to V / R. [0005] If these chan...

AI Technical Summary

Problems solved by technology

The disadvantage is that this design will impact the driving vehicle due to the sudden change of the roll angle acceleration at the straight point of the gentle curve section, which will make the occupants of the vehicle feel uncomfortable, and long-term driving will affect driving safety.

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