Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering
Transport Technology

R. van der Wekken Automatische positionering van hijswerktuigen voor zware lasten.
Literature survey, Report 95.3.TT.4552, Transport Engineering and Logistics.

The main subject of this report is the automatic positioning control of hoisting equipment for heavy loads. De control of a logistic proces is mainly decentrally organized, with a hierarchical structure of the different levels. The lowest level in this chain is occupied by the Automatic Positioning System (APS). This system receives a transportation job from the higher level: transport load A from position 1 to position 2. The subsystems of a standard APS are the Sensor system, the Drive system and the Control system (on a hierarchically higher level). The Sensor system gathers all information (except the information presented by the higher level) that the Control system needs to regulate the Drive system. This report deals mainly with the interaction between the Control- and Sensor system, because a lot of the problems are caused by them. In the driving branch there is a progressive transition to the use of AC-drive, that has al lot of advantages.

This report contains a survey of hoisting equipment for heavy loads which are controlled by cartesian coordinates (x-, y- and z-axis). These are the Stacker Crane (Material Handling in warehouses), the Overhead Travelling Crane (storage at fabrication facilities) en Handling Equipment in the container handling (RMG, RTG en Ship-to-Shore Crane). Within the limits of automatic positioning, hoisting equipment has a lot of influence parameters. One of these characteristics is the sway of the load resulting in several parameters.
To be able to fully automate hoisting equipment, reduction of sway is very important, resulting in a fast development of Anti-sway systems.
The most important features when chosing an APS are: performance, environmental influences, static- and dynamic forces, costs and performance requirements of the operator (desired accuracy and reliability).

The Stacker Crane as well as the Overhead Travelling Crane can be automated very well. Especially the absence of the environment influence on the sensors resulted that there are practically no problems on this field anymore. Another advantage is the fact that the work done by these cranes consists mainly out of steady movements.

The opposite holds for hoisting equipment in the containerhandling. There are two main influence parameters that obstruct the use of APS:
  1. weather influence during outside operations (wind, rain and snow);
  2. relative large forces and accelerations which are characteristic for container handling;
New developments to handle these problems are the use of absolute positioning techniques like transponders based on radiosignals. Besides that the use of electronics and control systems is growing rapidly.

In general during fine-positioning the use of direct-positioning techniques is increasing more and more, within this technique the distance between the hoisting element and the load is measured directly without the intervention of the hoisting equipment.

The second part of this report deals with the ACTIV transhipment concept (container handling). The ACTIV-equipment can be automated very well based on existing sensorsystems.

Reports on Transport Engineering and Logistics (in Dutch)
Modified: 2008.01.18; , TU Delft / 3mE / TT / LT.