Abstract
The concept of controllability coming from linear system theory is applied to the motion of a tractor-semitrailer vehicle during straight-line braking. Some states of braking with locked up wheels at different axles are considered. The question whether the system is always controllable must be answered in the negative for locked up wheels at the tractors front axle. In other cases controllability in its mathematical meaning which, however, does not always appear to be fully adequate for practical problems, is possible.