Research On Integrate Control Of Breaking And Handling Stability Of Tractor-semitrailer

With the development of our national economy and the increased requirements of peoplefor goods, Highway Transportation of China is growing up rapidly. Many advantages oftractor-semitrailer have made it become one of the most important delivery vehicles and playa very important role in road transport. Tractor-semitrailer is different from ordinary vehicles,because it has two parts: tractor and semitrailer. They are linked by some mechanicalconnectors like fifth wheel and coupling pins, which make tractor-semitrailer has a morecomplex dynamic system than other vehicles. If tractor and semitrailer can not match well, itwould make some unstable situations such as collapsing drift and sideslip in breaking. Theseunstable situations can lead to accident easily. Therefore, research on running safety ofTractor-semitrailer has a very important significance in guaranteeing road traffic safety.Breaking stability and Handling stability of tractor-semitrailer, two important reasonsaffecting the running safety of Tractor-semitrailer are analyzed with independent and integratemethods. First of all, the Handling stability model of Tractor-semitrailer is established andsimulations on side velocity of tractor, yawing angular velocity of tractor, pull angle of tractorand pull angular velocity of tractor are made by the software Matlab/Simulink. Based onwhich made above, the PID controller is used to control the angle of steering wheel. Theovershoot of side velocity of tractor, yawing angular velocity of tractor, angle of pull oftractor and pull angular velocity of tractor are decreased by PID controller.Secondly, the breaking model of Tractor-semitrailer is built up and simulations on speedof Tractor-semitrailer, speed of every wheel, slip rate of every wheel and braking distance aremade by the software Matlab/Simulink. The slip rate of every wheel is controlled by PIDcontroller for about0.2and the breaking distance is decreased about25.6%.Lastly, the Breaking stability and handling stability integrated model are built up andsimulations on some major parameters such as yawing angular velocity of tractor, pull angleof tractor, pull angular velocity of tractor and the breaking distance are made. The result ofintegrated model is different from that of the single model, some value of parameter haschanged. The slip rate of every wheel resulted in the breaking distance is decreased by26.4%and the yaw velocity of tractor is reduced by68.4%.