Study On The Time-Varying Suspension System Control For Heavy-Duty Vehicles Based On Vehicle Road Interaction

With the vigorous development of commercial freight transportation,the demand for heavy-duty vehicles in the transportation industry has rapidly increased,causing increasingly significant damage to roads.Early road damage,in turn,exacerbates car vibrations,seriously affecting the comfort and stability of vehicle operation,and increasing the dynamic load on vehicles,leading to more serious road damage.Therefore,this paper regards the car and road as an interactive and coupled system,fully studies the dynamic response and parameter optimization of the system,and designs an active suspension control algorithm for heavy-duty vehicles based on this research.The main research content and results are as follows:By improving the roller tire model,coupling the 1/4 vehicle dynamic model with the Euler-Bernoulli beam on a Kelvin foundation,a two-dimensional vehicle-road coupling dynamic model is constructed.On this basis,a three-dimensional vehicle-road coupling model is developed by using a 7-DOF full-vehicle model and an elastic plate model to extend the two-dimensional dynamic model.The vehicle-road-interaction model is a linear time-varying system.After decoupling the system coupling equation using the modal superposition method,a Time-Frozen algorithm is proposed to solve the system response.Compared with the traditional Newmark-β algorithm,the algorithm has more accurate results,less computation time,and greatly improved efficiency.Comparing the vehicle-road coupling system with the traditional model that does not consider the coupling effect,the results show that relying solely on reducing the wheel load to improve road friendliness when designing suspensions is insufficient,and the road vibration response must also be considered.Parameter analysis is carried out on the vehicle-road-interaction system to determine the modal number and effective vibration length of the road,ensuring the accuracy and efficiency of subsequent control research.The influence of 11vehicle-road system parameters,such as vehicle speed,vehicle load,road roughness,road layer thickness,elastic modulus,suspension stiffness,and damping,on road vertical vibration response is studied.The results can provide theoretical guidance for the design of road-friendly suspensions for heavy-duty vehicles,thereby reducing road fatigue damage and improving the service life of roads.Based on the vehicle-road-interaction dynamic model and using LQR control theory,a road-friendly active suspension control strategy that is robust and stable is designed with vehicle acceleration,dynamic tire-road deformation,and suspension relative displacement as multi-objective functions.At the same time,in response to the problem of the long time and difficulty in determining the optimal parameter combination of the weighted matrix parameters of the algorithm,a particle swarm algorithm is proposed to optimize its weight parameters,and then simulation calculations are performed to verify the effectiveness of the proposed algorithm.Finally,a series of parameter studies were carried out using MATLAB to verify the effectiveness of the proposed control algorithm at different speeds,truck loads,and random road levels.Numerical results show that heavy-duty vehicles using the time-varying LQR control algorithm can effectively reduce road damage,improve ride comfort,but slightly increase suspension deflection.Compared with passive suspensions in traditional vehicles,vehicle-road coupling force can be reduced by 61%,effectively reducing road vibration amplitude and improving vehicle friendliness to the road.This study will have significant engineering application value in optimizing the design of overloaded vehicles,reducing damage to road surface deformation,enhancing the lifespan of highways,and lowering road maintenance costs.