Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology / Logistic Engineering
M.J. Terstegge Besturing en botsingsdetectie in multi-AGV-systemen.
Masters thesis, Report 99.3.LT.5191, Transport Technology, Logistic Engineering.
Every year containerized transport shows a large growth worldwide. As a response to the growing demand for transportation and in order to reduce labor costs, Europe Combined Terminals (ECT) in Rotterdam was the first to introduce a high degree of automation on its terminals. For the operation of the Automated Guided Vehicles (AGVs) that operate on these terminals, ECT uses the operating system Process Control System (PCS).
The Centrum Transport Technologie has started research on the design of a new generation of container terminals. These have to be equipped for handling the soon to be expected Jumbo Container Vessels with a capacity of 8000 TEU (Twenty-feet Equivalent Units). This resulted in the AGV operating system TRACES (TRAffic Control Engineering System), that is developed by Delft University of Technology.
In this report, the working of PCS and TRACES is described and a qualitative comparison is made between these two AGV operating systems. Dynamic routing is a feature, which is possible with TRACES, but not with PCS. However, these possibilities in TRACES have not yet been deeply studied. Therefore it remains uncertain what TRACES is capable of.
TRACES is still in development and cannot yet offer the safety that PCS offers in collision prevention. In addition to this, there are still some practical problems occurring on container terminals, for which TRACES does not yet have a solution, such as complete deadlock prevention and topology changes. Therefore, TRACES is not yet completely suited for application in an operational environment.
Because of its flexibility and because TRACES, contrary to PCS, is not designed on one specific principle of AGV routing, TRACES is particularly useful for the quick setup of new terminal designs in a simulation environment.
A number of FAMAS-simulations have been realized using TRACES. A reference case has been established that models the DSL terminal of ECT and two simulations are made of possible future terminal layouts. These simulations contain a number of simplifications, such as the lack of realistic turning and acceleration behavior, which results in the fact that it is uncertain whether the AGVs in the simulation can drive collision free.
To increase the reliability of the TRACES-simulations, the software module TRAVIS (TRACES Visualization) has been developed. In this report, the implementation and working of TRAVIS is described. This module can be linked with the existing simulations and is capable of detecting collisions between AGVs. With this module, a number of errors in the TRACES DSL simulation could be discovered that previously were 'invisible'.
Besides collision detection and distance monitoring, TRAVIS offers a new visualization for TRACES. In this visualization, realistic turning behavior and acceleration behavior have been added to the square tracks followed by the AGVs in the simulation, which results in AGV movements that look more natural.
Reports on Logistic Engineering (in Dutch)
