A Research On Handling Stability Control For Heavy Vehicles With Semi-Active Air Suspension

Company with the continuous economic development in China, the highway system and road transport has been rapidly developed. As an important part of the road transport, due to the characteristics such as big weight, big cargo volume, high center of mass, tread narrow, heavy vehicles are likely to cause a roll over serious accident at high speeds, resulting in significant casualties and property losses. In order to improve the safety performance of heavy vehicles, variable stiffness of semi-active air suspension and variable work height of air springs was used to improve the capability of the vehicle rollover through appropriate control methods. The content of this paper mainly including the follows:(1) Analysised the basic parameters of air springs and influence of the air inside to stiffness of air spring, according to the knowledge of fluid mechanics, mathematical model of air springs, charge and discharge gas system was developed to provide a theoretical basis for the establishment of air suspension simulation model.(2) According to the theory knowledge of vehicle dynamics, vehicle motion was analysised, the simplified dynamic model based on ECAS was developed to provide a basis for control system design.(3) Basing on semi-active air suspension, a anti-roll control systems including air springs deflated charge control model and vehicle rollover prediction model was designed. According to the characters of variable stiffness and variable working height of semi-active air suspension, using PWM control the gas flow in charging and discharging process to solve the overshoot of vehicle body height reduced, reduced the mass center height of vehicle body; Using Fuzzy controller calculate active control force of the air suspension, an additional roll over torque that can suppress the body roll was formed by the two side air suspension.(4) Basing on the basic parameters of a heavy vehicle that selected, a dynamic model that as an offline simulation platform was built based on semi-active air suspension in MATLAB / Simulink software. the simulation result shows that the anti-rollover controller basing on semi-active air suspension has a stability control action in each condition.