Abstract. When autonomous vehicles pass through uneven roads, especially the consecutive speed control humps (SCHs) on expressways, the
speed of them will have a significant influence on the safety and comfort of
driving. How to automatically select the most appropriate speed has become a
practical research subject. This paper studies the nonlinear vibration
process of the suspension system when the autonomous vehicle passes through
the SCHs on a highway. Firstly, the paper establishes a
four-degree-of-freedom (4-DOF) nonlinear half-vehicle model and a
stimulation function of trapezoidal SCHs and then uses the Runge–Kutta method to numerically solve the differential equations of motion of the suspension system. In the next part, the paper chooses the genetic algorithm to build a
multi-objective optimization problem model, which selects the vertical
displacement of the vehicle body, the suspension's dynamic deflection and the dynamic load of the tire as optimization objectives and combines the method
of the unified objective function to find the optimal passing speed. Finally, the paper designs and carries out the solution process of the
multi-objective optimization problem for the vehicle under three scenarios, conventional passive suspension, semi-active suspension, active suspension,
and compares the optimized state with the pre-optimized state to prove the
effectiveness of the optimization model.