Driving Stability of Closed Loop Tractor-Semitrailer Vehicle System with Optimal Driver Model

A quasi-linear driver model was developed, and a closed loop tractor-semitrailer vehicle system composed of the driver model and a tractor-semitrailer vehicle model of 3-degrees-of-freedom were proposed. The stability of closed loop vehicle system was studied by simulating the system with different parameter values. A roots-locating numerical method was used to identify critical speed of the system. Some simulation of closed loop vehicle system were made in Matlab and the results shown that driver's inherent time delay, a semitrailer's load and driving speed make important role in stability of closed loop tractor-semi trailer.