Dynamic model of a logistic train with different steering systems and tire models

Abstract

Logistic train is one of the recent solutions applied in the intralogistics. It bases on the concept of the "milkrun" delivery method. The main problem in the implementation of intralogistics trains is the possibility to determine whether the train is able to pass the given path without a colliding with surrounding objects. Dynamic model presented in this paper was performed for the three most common steering systems for the trolleys: double Ackermann steering system and two drawbar systems: conventional and virtual clutch. The dynamic model was developed following Lagrange's theorem including the possibility of lateral slip. The system of differential equations was numerically solved. In order to calculate the lateral friction forces we used three different tire models: simplified, sigmoidal and Pacejka Magic formula. The results obtained for different tire models and steering systems are presented in the form of animations presenting train run in various conditions. The analyses have shown that the use of simplified tire models is justified under certain conditions.

Kinematic Model of a Logistic Train with a Double Ackermann Steering System

“…One of the main problems with the application of logistics train that that the transportation routes were usually designed for single vehicles operating and, hence, have limited dimensions, which makes it difficult for trains to pass without collision with the infrastructure [1]. For this reason, research is currently being conducted into the trajectory analysis of steering systems [12,13].…”

“…A logistic train consist of a tractor and a certain number of towed trailers. The tractor towing a set of trailers usually has a classic Ackermann steering system or a rear-wheel differential drive [12][13][14][15]. Ackermann steering system involves one or two steering wheels at the front.…”

“…Trailer steering systems concern two aspects, namely, the way of connecting trailers to adjacent trailers and a tractor, as well as the types of wheels and axles. The conventional steering systems have proved insufficient for trains with a large number of trailers [12,13]. It contains fixed drawbars, two rear fixed wheels and two caster wheels at the front or only two rear fixed wheels [18].…”

“…An illustrative comparison between the two discussed solutions is shown in Fig. 1 [12,13]. Kinematic modelling of a logistic train can be treated as modelling of an articulated n-trailer vehicle [19].…”