E. Bahlmann
Automation in Warehouses
Literature survey,
Report 2005.TL.7004, Transport Engineering and Logistics.
In this report the automation of processes especially in a warehouse is
discussed. Due to changes in the market, warehouses were forced to change
their way of working. To follow the questions of the market, it is
necessary to increase the productivity (throughput) of a warehouse. To
increase the production in an economical way, automation of processes will
be a good option.
This report will give an overview of the topics that are enclosed in the
mechanisation and automation of processes in a warehouse. First the
mission and tasks / processes of a warehouse will be worked out. A
description will be given of the different areas in a warehouse and the
different types of equipment that can be used. The used equipment can vary
from simple hand driven equipment to fully automated systems. Direct
relation can be seen between the amount of personnel in a warehouse and
the degree of automation. Automation brings high costs in the starting
phase but during time, automated systems become more economic because the
price per product that is handled will be lower. Finally when it is chosen
to automate a certain process the question will rise: What is needed to
design and install such an automated system? For this case one process,
the stacking and receiving of pallets, will be worked out into detail. The
advantages of an Automatic Stacking and Receiving system (AS/R system)
will be shown. Furthermore a detailed description of the sub processes
and the necessary sensor and actuator systems in the AS/R system will be
worked out.
Abstract
Warehousing is a very old but also very important activity. Warehousing forms
the link between the producer and the retailer. Specialism of a warehouse is
to gather the goods from producers, store them for some time and then to send
them further in the logistic chain.
Warehousing has changed from typical handwork in the past till highly automated
systems which are nowadays in use. Developments in this field are still going
on. Reason for the change from handwork to automated systems is the question of
the market. With automated systems, a warehouse will be able to cope with this
question. Customers are asking for shorter delivery times and more, even
different types of goods. For a warehouse it will be necessary to work in an
economic way. So storage density per square meter must be high, throughput time
low and the inventory must even be low. Automated systems have the possibility
to give an answer to these conditions. They have a lot of advantages when they
are compared with other types of human driven equipment. This literature study
gives an introduction to automation in warehouses. Main question is: What
are the facts that need to be taken into account when you want to automate
a certain part of a warehouse?
In this study, the basic elements, advantages and fields of automation in
a warehouse will be worked out. To design a reliable automated system
which is able to answer the questions of the market, a lot of study of the
working principles of the system is needed. All facts that are related to
the system that has to be designed must be considered. Two examples are:
the products that have to be handled and the interaction between other
types of handling equipment. Very important part of study is the control
system of the automated machine itself. How will the system receive the
necessary information from the environment and how and with help of which
devices can it react and interact with the environment?
To get a better overview of the own control system of an automated machine
a practical example is worked out into more detail. The example is the
Automated Storage and Retrieval System, a system that nowadays can be
found in the more automated warehouse. This system is able to store loads
in and retrieve loads from a certain location. For this system are the
processes looked up into detail. The different sub- processes are analysed
and if possible sub-processes are grouped. For each sub-process it is
looked up what type of sensor and actuator system can possibly be
installed to control that group of sub-processes. It is difficult to find
a sensor / actuator system that exactly answers the design questions. So
practical experience and a good consideration of the pro's and contra's of
each sensor / actuator system must help to make the final decision
for a certain control system. When all different sub-processes have their own
control system it will also be important that the different control
systems can work together. All different sub-processes have to complete
the total process of the equipment. When all sub-processes work in the
right way, exclusively and together, a reliable solution is found for the
total process.
Reports on Transport Engineering and Logistics (in Dutch)
Modified: 2006.03.06;
logistics@3mE.tudelft.nl
, TU Delft
/ 3mE
/ TT
/ LT.