- مبلغ: ۸۶,۰۰۰ تومان
- مبلغ: ۹۱,۰۰۰ تومان
The most dangerous motions of combination vehicles can be classified into three groups. The first type is called jack-knifing, which is mainly caused by the uncontrolled large relative angular motion of the tractor and the trailer, which results in the lateral slip of the rear axles of the tractor. The jack-knifing phenomenon is one of the most common causes of serious traffic accidents in which tractor/semi-trailers are involved. The main problem with this type of stability loss is that if the articulation angle exceeds a certain critical limit, the driver becomes unable to control the motion of the vehicle by steering the tractor. Even before reaching this critical angle, the problem may become worse if the driver steers the tractor in an inappropriate direction. In solo vehicles, this accident type corresponds to the so called spin-out. The second typical class of dangerous motions of articulated vehicles is the lateral oscillation of the trailer, which may be caused by some disturbances (e.g., side wind gust, abrupt steering effort by the driver) acting on the vehicle. When the design and/or operating parameters of the system are close to the critical values, the vehicle becomes self-excited. This means that after some disturbance, the vehicle loses its stability and the system’s trajectory will tend to some other limit set, which normally results in an accident. Typical and the most dangerous commercial vehicle accident is the roll-over. Interesting statistical analysis was found, in which the roll-over accidents were categorised as follows (see in [1, 2]): · preventable, which means that the driver would have been able to avoid the accident if a warning device had been installed on the vehicle. Only 3.3% of a total accidents were judged to be preventable; · potentially preventable, which means rollover might have been prevented depending on the skill of the driver and performance of the warning device (38.4%); · non-preventable, into which class the 49.7% of the total accidents were categorised; and · preventable unknown, which involves only 8.6% of the total number of accidents.