Reasearh On In-arm Hydropneumatic Active Suspension Of Tracked Vehicle

Based on the in-arm hydropneumatic suspension unit(ISU),integrateing with fluidmechanics, theoretical mechanics, thermodynamics, control theory,etc.Using theoreticaland experimental methods, the nonlinear characteristics and active control strategy ofISU are studied.According to the structure of ISU, analyzing to establish stiffness and dampingcharacteristics of ISU, the heat conduction model of ISU liquid chamber and gas chamberwith outside load are built，The temperature rise characteristic of ISU is studied with theformer model.Based on the multibody dynamics theory，virtual prototype model of track vehicle isbuilt，including the multi-dynamics model of running gear in track vehicle, the hydraulicsystem model, road surface model, etc. The virtual prototype model is validated withstatic balancing test，stiffness characteristics test and obstacle-climbing test in high speed.In consideration of uncertainties of road condition and strong nonlinearity of ISU,based on the virtual prototype model of track vehicle, the development environment ofactive hydropneumatic suspension by co-simulation method is set up, thus the controlalgorithm can be developed and verified in this virtual environment. The method ofmodel reference fuzzy PID active suspension control coordinated with optimum dampingratio control is proposed in this paper.The control strategy is focused on the low bandwidth，and the ISU sky-hook singlewheel and half body system serve as the reference model, the fuzzy PID controller isdesigned for the model suspension travel tracking control system. The simulationillustrate that fuzzy PID controllers can track the sky-hook system in the low bandwidthroad inputs with the the variation of parameters.The virtual road test bench experiment of the full vehicle model is designed, basedon the measured data of four kind of road, the riding comfort and power consumption offull vehicle model with active control are also investigated.Hardware and code of electronic control system are designed in the test prototypewith ISU, the stiffness and damping characteristics of ISU is also tested by the benchexperiment. The control effect of ISU active system is tested. The results show that the control system of in-arm hydropneumatic suspension unit obtains good control effects.