Experimental studies of the car-trailer system when passing by a suddenly appearing obstacle in the aspect of active safety of autonomous vehicles

Abstract

Experiment studies focus on increasing active safety (steerability and stability) of the combination of vehicles (car with a trailer). The aim of the conducted studies is increasing active safety in the motion of autonomous vehicles with trailer via creating algorithm of functioning of a system which facilitates forecasting of the possibility of dangerous behaviour occurrence for the vehicles combination during complex road manoeuvres at a high velocity. Within this scope the system will ensure collecting data from the environment, data selection (detecting the situation which requires reaction), as well as joining the information which require decision making about the further steps of the current manoeuver. As a result, corresponding control signals will be sent to the controllers.

The starting point in this work are synchronous measurements of physical quantities for the car and trailer. They enabled the analysis of trends in changes of relative position between the car and the centre-axle trailer during avoiding a suddenly appearing obstacle. The analysis results of these measurements enable pointing out the symptoms which will signal the possibility of danger in the movement of the combination (e.g. dropping a trailer). A special feature of the study is that the mass of a pulling car is comparable to the trailer’s mass (1800 kg and 1840 kg).

The values of indexes which characterize the changes of quantities describing the movement of the combination of vehicles during avoiding a suddenly appearing obstacle have been measured. The subject of analysis was a difference in time of occurrence of characteristic indexes’ values among the physical quantities describing the motion of the car and the vehicle. The results of the study confirmed that in the course of measured quantities such characteristic values can be detected, whose occurrence for the trailer is delayed by 0,2 to 0,5 s with respect to the car driving at a velocity of 60 km/h. This time span is sufficient for a corrective measure done by the controller of the autonomous car.