Research On Ride Comfort Control Of Heavy-duty Vehicle Based On Grounding Pressure

Natural disasters in our country,the rescue traffic complex and often poor,therefore it puts forward higher requirements on special rescue vehicles.The passive suspension is generally used to rescue vehicles,vehicle riding comfort under the bad road conditions is difficult to meet this demand,so the research has the rescue vehicle active suspension in order to improve the ride comfort,vehicle to improve rescue ability has important theoretical significance and practical application value.Based on the research and development of the national key program project "high mobile emergency rescue vehicles(including fire trucks)special chassis and suspension is the key technology research"(item number 2016 YFC0802902),This paper studies how to control the active suspension to distribute the contact force between each tire and the ground reasonably in the process of vehicle driving.The active suspension control method based on the ground pressure,and how to improve the ride comfort of the three-axis emergency rescue vehicle.At first,this paper proposes a new ground pressure measurement method based on differential pressure method,in view of the ground pressure measurement methods of oil cylinder friction problem,the Stribeck friction nonlinear model is established,and by using the genetic algorithm for identification of friction parameters to get a precise grounding pressure data;Secondly according to the valve controlled asymmetrical hydraulic cylinder of the suspension system,through the establishment of hydraulic spring stiffness model and valve control cylinder model,using state feedback for fourth order nonlinear valve controlling cylinder system linearization,the linearized model of sliding mode variable structure control,using the simulation tools study of sliding mode control based on feedback linearization force tracking control effect;And random road,convex hull surface motivation model is established and nine degrees of freedom model of passive suspension,according to the suspension control objectives and riding comfort evaluation index,put forward the control target of earth pressure constant,based on ground pressure control method,the simulation results show that this method is compared with the passive suspension,effectively improve the vehicle riding comfort;Finally,based on feedback linearization of the sliding mode variable structure tracking control and valve control cylinder force based on vehicle riding comfort control of ground pressure test,the test results show that the vehicle riding comfort evaluation index vehicle centroid acceleration root-mean-square fell by 45.3%,effectively improve the vehicle riding comfort,greatly improve the emergency rescue vehicles through sex and rescue capabilities.