Research On Bionic Suspension For Heavy-duty Engineering Vehicles

Heavy-duty engineering vehicles usually travel on mountain roads with poor or bumpy conditions.The road conditions vary greatly with uncertainties and harshness.Therefore,there are often very large requirements for the driving stability,smoothness and passability of engineering vehicles.Based on this premise,designing a bionic suspension that can adaptively adjust the damping characteristics and stiffness characteristics according to the road conditions in real time to ensure the engineering vehicles is in the optimal vibration-damping state,which is of great significance for heavy-duty engineering vehicles.Based on theoretical basis of functional bionics,the structure of the leg is divided into two parts--damping adjustment and stiffness adjustment by analyzing the changes and adaptabilities of the leg structure of running horse.The mechanical characteristics and vibration reduction function of the suspension are analyzed,which provides a reasonable basis for the follow-up hydraulic simulation part.At the same time,add the speed control valve and accumulator to the bionic suspension system as the corresponding damping adjustment and stiffness adjustment components in the hydraulic system.As the main principle of the active adjustment of the suspension system,hydraulic components such as hydraulic cylinders,relief valves and check valves are added,combined with the principle of functional bionics,to form the design scheme of the bionic suspension system of this paper.And Establish a 1/4 suspension model in the AMESim hydraulic software.After verification of the rationality of the scheme,the suspension scheme was improved and debugged in a targeted manner.Through the simulation test of AMESim hydraulic software,the damping characteristics and stiffness characteristics curves of the suspension system were obtained.Meanwhile,determine that the characteristic curve and the vibration reduction curve are in line with the vibration reduction performance of vehicle suspension.Study the two main parameter variables of throttle valve hole diameter and accumulator pre-inflation pressure,and the influence of other parameters of some bionic suspension system components on damping and stiffness characteristics.Establish a functional model for vehicle height adjustment to ensure that the height of the car body can be adjusted by the bionic suspension system under different driving conditions.Due to the poor driving conditions of engineering vehicles,D-class and E-class random road surface spectrum excitations are established by Matlab/Simulink,and the canopy damping control is proposed for damping adjustment and the corresponding control method is established.Taking the longitudinal acceleration of the vehicle body and the root mean square value of longitudinal acceleration as the evaluation indexes of vibration damping performance,compare the vibration reduction performance and power stability between the active bionic suspension system after adding control and the suspension system without control.Based on the Kriging model,the approximate response surface is established.The Latin hypercube sampling method is used to select 30 sets of sample points.The particle swarm optimization method is used to obtain the minimum longitudinal acceleration root mean square value response.Through the optimization program of Matlab,the optimum solution in the range of values is obtained,and the optimum values of different parameters under different road conditions and velocities are obtained and the main parameters of the suspension system are optimized.Through the analysis and comparison of the bionic theory and the verification of the simulation test,the damping,stiffness and vibration reduction characteristics of the scheme can be obtained,and the optimal solution can be obtained,which provides the theoretical basis and support for the in-depth study of this topic.The design of this paper proposes a new scheme and idea for the suspension system of heavy-duty engineering vehicles.After perfecting,it can be applied to practical engineering vehicles,reduce the space of suspension system layout and improve real-time vibration reduction performance.