Propelled and steered converter dolly for improved shunting of semitrailers at goods terminals
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Distribution of semi-trailers from goods distribution terminals to customer loading
docks are carried out by human drivers. Goods are transported to these distribution
centers longer and heavier vehicles (LHV). These truck-trailer combinations need to
be reconfigured in order to reroute traffic to customer end points. This requires a lot
of driver skill and hence increases time and cost. These inland distribution centers or
dry ports present an opportunity to improve shunting operation efficiencies through
automation of a self-steered and self-propelled intelligent dolly (i-Dolly). This thesis
explores the dominant methods of localization, path planning and path following
used in autonomous systems. MATLAB Simulations for certain reversing maneuver
of a single iDolly unit were performed using differential equations that described
the reversing motion. The simulations were used to correlate results found during
the practical tests on the scaled down model. For the physical tests, an over-head
camera was used to implement a local positioning system with the use of ArUco
markers. A scaled-down truck, used as surrogate for an i-dolly, was augmented with
a cubic spline path planning algorithm and a path following stanley controller. The
resulting system showed to have a maximum cross track error of 0.3 cm from the
planned course when the coupling maneuver was successful. It was observed that
the system was at times unsuccessful in the coupling maneuver, during which the
cross track errors reached values of 1.5 cm. The recommended expansion on the
work done would be to investigate higher precision hardware for localization and
tracking at a small scale as well as setting up tests on more maneuvers. These could
be further applied to full-scale model.
Beskrivning
Ämne/nyckelord
i-Dolly, autonomous systems, ArUco markers, cubic spline, Stanley controller, longer and heavier vehicles (LHV), semi-trailers, transportation