PURPOSE: To provide a calibration method and its system for an articulated vehicle automation system including an articulation angle sensor to speedily recover after controlling a brake of the articulated vehicle automation system, preventing a state known as brake induction type trailer deflection and/or jackknife, restraining it or restraining it to the minimum.

CONSTITUTION: An ABS type valve 174 arranged on the upstream side of a glad-hand articulation part of a tractor 12, sensors 170, 172 to detect/transmit a signal to enable computation of a tractor-trailer articulation angle(AA), a rate of change of the articulation angle (dAA/dt) and a secondary derivative of the articulation angle (d2AA/dt2) and a control device 70 furnished with a timer to control the ABS type valve of a trailer brake by receiving an input signal, processing it in accordance with a specified logical rule and transmitting a command output signal are arranged on the tractor.