ADESBA - A new general global control system applied to the ...

12 th International Conference on Urban Drainage, Porto Alegre/Brazil, 11-16 September 2011
The vast majority of RTC control algorithms applied in practice are individual solutions
which cannot be transferred to other sewer systems. The PASST program (RTC planning aid)
of the DWA (German Association for Water, Wastewater and Waste) (DWA, 2005) helps
network operators to carry out a simple assessment and evaluation of the potential for RTC in
their drainage systems. But so far no tool for the simplified creation, realisation and implementation
of an RTC system has been available on the market.
This is where the ADESBA project came in. The objective of this project, which is funded by
the German Federal Ministry of Economics and Technology, was to facilitate the implementation
of a pre-assembled control algorithm within a physically pre-assembled control box in
order to simplify the implementation of RTC systems, making it faster and more easily manageable.
The general control algorithm has been developed at ifak Magdeburg, a non-profit institute
for applied research. The algorithm has been implemented in standard process controllers and
the hardware subsequently tested by SEGNO automation company in Bremen. The Institute
of Sanitary Engineering of Leibniz University of Hannover (ISAH) has confirmed the validity
of the algorithm by additional simulation studies and has implemented this type of real-time
control system into practice in the city of Hildesheim in cooperation with Segno (see Pabst et
al., 2010).
CONTROL SYSTEM DESIGN AND CONTROL ALGORITHM
The general-purpose control algorithm developed at ifak is the essential, key step in the
development of the ADESBA RTC system box and is described in greater detail by Alex et
al., 2008 and Schütze et al., 2005. The development and implementation of this generalpurpose
control system algorithm makes possible a pre-assembled, configurable control
system based on a small number of securely pre-defined input parameters.
The basic idea behind the ADESBA control system is the coordination of combined
wastewater flows in the various branches of the system in order to ensure uniform utilisation
of storage capacities of the whole sewer system. The control system elements are the throttle
valves of the storage facilities and of the other overflow structures of the sewer system. The
overall objective is the reduction of CSO discharges.
The SIMBA simulation system (ifak, 2009) was used to develop, test and refine the
underlying control algorithm. This software is based on the MATLAB/Simulink system,
which offers specific resources for the simulation of control systems. SIMBA has specific
features, allowing it to be used as a versatile simulator for the development and assessment of
sewer system real time control (Schütze, 2008).
The interface between the mapping of features in the simulation model and their actual
implementation in the PLC was considerably facilitated by a SIMBA block permitting the
description of automation functions in the Structured Text language (IEC 61131-3 Standard).
This enables control algorithms developed and tested on the basis of simulation to be
implemented in PLCs rapidly and with a minimum of error (Ogurek et al., 2008).
Furthermore, the concept of a general control algorithm enables the possibility of a modular
design principle. That means that the key elements of the sewer system are considered in a
modular fashion, implying that identical control boxes can be installed.
Simulation studies also for other sewer networks have proven the successful performance of
this general control algorithm (see, for example, Schütze and Haas, 2010).
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