Design And Optimization Of Mining Dump Truck Suspension System

As an important component of vehicles to connect the frame with wheels, suspension systems' main role is to pass the force and moment produced by the road's excitation. It also eases vibra-tion due to the impact caused by the road. Then the form of sus-pension structure has a direct influence on the wheel alignment pa-rameters. Elastic and damping elements are directly related to the vehicles' ride comfort and safety. So it is of great significance to optimize the structure of suspension and elastic and damping ele-ments.Firstly this paper introduces the structure and working princi-ple of hydro-pneumatic spring. According to the physical model of single chamber hydro-pneumatic spring, analyze the working prin-ciple through orifice flow equation and gas state equation. Then establish a parametric mathematical equation of hydro-pneumatic spring's nonlinear stiffness and damping characteristic. So use the software AMESim and Matlab/Simulink to simulate the hydro-pneumatic spring stiffness and damping characteristic. Analyze different structural parameters' influences to its stiffness and damping forces. Then provide a theoretical basis to the match be-tween the oil-gas spring and vehicles.Secondly, build the model of mining truck's front double-wishbone hydro-pneumatic suspension in the ADAMS/Car based on Virtual Prototype Technology. Then conduct the kinematic suspen-sion analysis of parallel travel. Through the design of experiment by ADAMS/insight, consider the four wheel alignment parameters as objective functions. Then build the third order response surface approximation model by the dates of experiments. The camber an-gle, toe angle, caster angle and kingpin inclination angle were re-duced to two goal functions by weighting method. The NSGA-? algorithm was used to solve the multi-objective optimization prob-lem. Then obtain the multi-objective functions'Pareto frontier.The optimized results show that the variations of wheel alignment parameters have been decreased partly. So the control stability has been improved obviously.In the end, the eight degrees of freedom vehicle physical mod-el was established in the software Matlab/Simulink based on the parametric mathematic model of hydro-pneumatic spring. The ver-tical acceleration of seats in the cab, Pitching angle and roll angle of vehicle body were analyzed. Then the accuracy was verified by comparing the simulation dates to experimental dates in all work-ing conditions. So the vertical acceleration of seats in the cab pitching angle and roll angle of vehicle body were used as objec-tives functions. Take hydro-pneumatic suspension structure param-eters as design variables. The front and rear suspension dynamic travel and the relative dynamic loads of front and rear tires were used as constrains. The multi-objective optimizations were carried out. The results showed that the seats'vertical acceleration of mining truck have decreased 16.8% and the pitching angle of vehicle body reduced by 8.6% and roll angle of vehicle body diminished by 32% based on the constrains conditions. The ride comfort and control stability of mining truck have been greatly improved.