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

12 th International Conference on Urban Drainage, Porto Alegre/Brazil, 11-16 September 2011 

ADESBA - A new general global control system applied to the 

Hildesheim sewage system 

Pabst, M. 1* , Alex, J. 2 , Beier, M. 1 , Niclas, C. 3 , 

Ogurek, M. 2 , Peikert, D. 3 , Schütze, M. 2 

1 ISAH, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany 

2 ifak Magdeburg, Werner-Heisenberg-Str. 1, 39106 Magdeburg, Germany 

3 SEGNO Industrie Automation GmbH, Admiralstrasse 54, 28215 Bremen, Germany 

*Corresponding author, e-mail pabst@isah.uni-hannover.de 

ABSRACT 

The aim of the ADESBA (adaption and development of a pre-configured control box for real 

time control of urban drainage systems) research project was to achieve a simpler, more manageable 

and faster implementation of sewer network control by implementing a preconfigured 

control algorithm in a pre-assembled control box. This paper presents the principles 

and the simulative testing of the ADESBA control box, and the procedure for implementing 

the box in the sewer system of Hildesheim, in order to present a novel way of implementing 

real time control of urban drainage systems in an easier and faster way. 

A simulation of real-life conditions in a sewer network has proven that this algorithm is suitable 

for these purposes. Long-term simulation has shown a clear reduction in stormwater 

overflow discharges (29 percent). The developed control algorithm was implemented in a 

physical control box and a close correlation between the simulation and the real time operation 

was demonstrated both during testing and during operation in the sewer system of the 

city of Hildesheim, Germany. Furthermore, an engineering tool was developed that clearly 

facilitates the implementation and verification management of a control system. 

KEYWORDS 

Combined sewer; real time control; pre configured control box 

INTRODUCTION AND MOTIVES 

Real-time control (RTC) systems provide a commercially interesting alternative to the conventional 

structural extension of sewer networks. It is obvious, and has been demonstrated in 

numerous cases (DWA, 2005), that RTC allows better utilisation of the existing sewer infrastructure 

(which constitutes an asset of high monetary value) and the reduction of pollution 

discharges. Furthermore, it allows the sewer system to be better prepared for future changes in 

flow patterns, including those induced by climate change. Additional benefits are obtained, 

such as increased energy efficiency (prudent operation of sewage pumps). Further environmental 

benefits can be activated by an integrated control of the sewer system and the wastewater 

treatment plant. 

Despite this bundle of benefits provided by real-time control, it still does not seem to be applied 

widely in practice. One reason for this purpose is the fact that, so far, the development 

of control strategies, in particular for complex sewer networks, is a time-consuming and, thus, 

costly task. 

Pabst et al. 1


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). 

2 ADESBA - A new general global control system


SIMULATION STUDY OF THE GENERAL CONTROL ALGORITHM 

AT HILDESHEIM 

The simulation-study of the control algorithm and the testing and pilot implementation of the 

RTC system box were carried out in the city of Hildesheim situated in northern Germany. 

Hildesheim’s sewer system, serving a population of 104000, is partly a combined sewer system, 

partly a separate sewer system. Overall storage volume amounts to 17200 m3, corresponding 

to a specific storage volume of 26 m3/Aimpervious. 

The attached WWTP is designed for a population equivalent of 240,000. The annual average 

rainfall amounts to 580 mm. The combined sewer system consists of 10 hydraulically separate 

sub-catchments with nine stormwater overflow tanks and one stormwater overflow. Compared 

to the total storage volume, Tank 4 (Schützenallee) stands out with its 3,822 m³ capacity and 

its attached impervious catchment area of 140 hectares. Except for the Bergmühlenstrasse 

tank and the Große Venedig storm-water overflow, data on water levels in all tanks (in the 

tank and at the storm-water overflows) and on flow quantities upstream of the throttle are 

available online in a temporal resolution of one minute. Figure 1 illustrates the system layout. 

At present four of the ten storage tanks have been selected for control. Their outflows are controlled 

dynamically to minimise the total overflow volume. 

Figure 1. System schematic of Hildesheim sewer network (based on Pabst et al.., 2010) 

In 2002, the optimum stationary throttle settings with regard to pollutant load reduction were 

calculated, simulating ten years of historic rainfall data using a hydrological sewer network 

model (KOSIM) (Seggelke, 2002). To ensure that the wastewater was properly discharged 

from the catchment by new (higher) throttle settings, a hydrodynamic simulation of the sewer 

network had been performed by using the hydrodynamic software HYSTEM-EXTRAN. 

Pabst et al. 3


Since 2007, the Hildesheim urban drainage department implements a step-wise optimisation 

of the throttle settings. In a further step in 2010, with the implementation of the RTC system, 

the dynamic control of the storm-water overflow tanks was further optimised. For this purpose, 

on the basis of the KOSIM model, first of all, a hydrological sewer network model was 

set up in SIMBA, thus allowing to simulate and to analyse the control algorithms in a very 

flexible way. The model was calibrated and verified. Figure 2 presents a comparison between 

the simulated and the measured wastewater treatment plant inflows. 

Figure 2. Results from verification at the inflow of WWTP of Hildesheim 

In this period (23.7.-3.8.2007) 450,681 m³ of wastewater flowed into the WWTP. Due to 

infiltration water flows from the catchments with separate sewer networks, the simulation 

results matches the inflow data roughly by 93%. If the results are compared separately only 

for the part of the combined sewer catchments the difference amounts to only 1%. 

Examples of changes in the disposal of surplus quantities of storm sewage brought about in 

the 23.7.-3.8.2007 period can be taken from Table 1 (cf Figure 2). As at this time operation of 

the throttle discharges involved stationary optimisation at 4 tanks, this variant is also shown. 

Table 1. Simulated CSO discharges during the period 23.7. - 3.8.2007 

CSO (m³) 

Stationary throttle ADESBA-control box 

without opti- with optimization at 4 tanks 9 tanks 

mization 

4 tanks 

Mastbergstr. 208 301 301 0 

Cheruskerring 3.187 2.397 2.397 2.347 

Speicherstr. 801 907 907 318 

Schützenallee 9.196 7.251 6.123 6.731 

Alter Markt 2.124 2.124 2.124 305 

Treibestr. 3.966 3.966 2.347 2.612 

Hohnsen 4.169 4.169 2.413 2.514 

Lönsbruch 537 537 537 156 

Tank WWTP 0 0 0 20 

Total 24.188 21.652 17.149 15.003 

Reduction 10,5 % 29,1 % 38,0 % 

Maximum use of 

Tank WWTP 

34 % 38 % 84 % 100 % 



The results show a considerable reduction in the quantities of CSO due to the use of the RTC 

system. Analysing the maximum utilisation of the stormwater tank capacity in the treatment 

plant, the basic principle of uniform utilisation of storage capacities becomes clear. This increases 

from below 40% in the case of stationary throttle settings to 100% in the case of RTC 

system control of nine tanks. Confirmation of this basic suitability of the control algorithm is 

given in Table 2 in the form of a long-term simulation and the proof of pollutant load reduction. 

Table 2. CSO discharges of long-term simulation (10 years) 

Uniform rainfall 

With virtual non-uniform 

rainfall 

Stationary 

throttle 

ADESBA-control box 

without optimization 

4 tanks 9 tanks 4 tanks 9 tanks 

CSO (m³/a) 171.632 123.888 121.761 120.171 117.444 

Reduction 28 % 29 % 30 % 32 % 

CSO load (kg CSB/a) 19.625 14.233 14.111 13.788 13.569 

Reduction 27 % 28 % 30 % 31 % 

The long-term simulation (10 years) for verifying the load reduction showed a considerable 

reduction in storm water discharges (29 percent) compared to stationary operation. Compared 

to the maximum control potential based on the central basin approach (DWA, 2005), the 

degree of ADESBA control system efficiency, assuming uniform distribution of rainfall, 

amounts to 82% relative to the amount discharged (for RTC of 9 tanks) and to 92% for RTC 

of 4 tanks. Simulation studies with non-uniformly rainfall show that the real control potential 

of ADESBA is even higher. Additional optimisation potential emerges from the possibility of 

prioritising the various tanks, especially with a view to minimising the pollutant load of CSO 

(Lacour and Schütze, 2010). 

DEVELOPMENT AND DEPLOYMENT OF THE ADESBA RTC 

MODULE AT HILDESHEIM 

The ADESBA RTC system box (hardware) was developed by SEGNO company. To enable 

the maximum number of sewage system operators to have equipment compatible with 

existing systems, standard technologies were used when selecting hardware and software 

components. As the PLC family, Panasonic products were envisaged, as the latter provide 

optimum support for the standard version of IEC61131-3 Structured Text. However, in the 

course of the project, customers required the use of Siemens control units with a view to 

permitting the use of existing resources by the municipality of Hildesheim. For this purpose, 

the algorithm created by ifak in the standard IEC61131-3 Structured Text version had to be 

additionally adapted to the Siemens Structured Text version. The rapid and uncomplicated 

adaptation of the control algorithm demonstrates the advantages of the SIMBA simulation 

environment, as described above. Moreover, a test of the RTC module performed in the 

course of the project showed that it can be completely adapted to standard, commerciallyavailable 

programmable logic controllers (Peikert et al., 2010). 

The module is designed to be used as a local control unit in standalone mode as well as for the 

use of RTC system. For this purpose, intercommunication between the various modules has to 

be assured. At Hildesheim, numerous structures are installed in a subterranean fashion so that 

Pabst et al. 5


in this case GPRS cannot be used as the communication medium. This is why, in 

collaboration with the municipality of Hildesheim, SEGNO has used a DSL (broadband 

Internet) network. The result was that, in the case of Hildesheim, network control was 

additionally centralised because the cables to the treatment plant’s central PLC were already 

available (Peikert et al., 2010). 

In addition to having control and communication tasks, the RTC system box can - and should 

- also be responsible for data storage and data management in the sewer network. For the purpose 

of displaying, and inputting or outputting data on the spot, the box has been designed to 

allow the data to be captured via an OPC interface to a visualisation system (InTouch made by 

Wonderware). An additional interface was created for the purpose of configuring the module 

from the visualisation system directly. In this form, even after system commissioning, the 

operator has been provided with a tool that facilitates adjustments to the parameter settings. 

Thus enables the module’s control behaviour to be directly influenced, while operating convenience 

is enhanced (Peikert et al., 2010). 

Moreover, an engineering tool that supports the operation of the ADESBA box with historical 

data, too, has been developed. Thus, it has been successfully verified that the behaviour of the 

physical ADESBA control box is identical to that of the model blocks. This considerably simplifies 

the actual realisation of the control box and verification management of the linked control 

system. Figure 3 shows the function of the engineering tool. 

Figure 3. Engineering tool - test setup with historical data (Peikert et al., 2010) 

Project execution covered not only development but also the testing of the RTC system box - 

i.e. ensuring intercommunication between all the modules involved and their interfaces. 

Another question that is of considerable importance to sewage system operators is how the 

quality of the ADESBA RTC system box can be demonstrated. A fundamental problem when 

testing any RTC system for sewer systems is the non-reproducibility of rainfall events. That 

means control behaviour of control systems cannot be accurately assessed solely on the basis 

of simulation studies - SEGNO has developed an engineering tool that compares data on 

actual events with data on controlled events, thus permitting an assessment of ADESBA’s 



control behaviour. In its “control centre”, the test setup provides for a PC with an interface for 

processing historical data, an (OPC) interface to the various PLCs, a visualisation system and 

an evaluation database. Furthermore, it is possible to match the results produced by the 

ADESBA box with those of the simulation in Simba. Especially when the purpose is 

verification, this ensures a considerable improvement in the presentation of control system 

behaviour. Figure 4 presents this matching operation for the results of simulation with the 

SIMBA-model and the engineering tool in the city of Hildesheim. 

70.000 

60.000 

50.000 

40.000 

30.000 

20.000 

10.000 

throttle flow [m³/d] 

throttle flow tank Schützenallee 

engineering-tool 

simulation model 

0 

28.7.07 0:00 28.7.07 4:48 28.7.07 9:36 28.7.07 14:24 28.7.07 19:12 29.7.07 0:00 

Figure 4. Results of comparison engineering-tool – simulation model 

water level and CSO discharges tank 

Schützenallee 

0% 

0 

28.7.07 0:00 28.7.07 4:48 28.7.07 9:36 28.7.07 14:24 28.7.07 19:12 29.7.07 0:00 

Pabst et al. 7 

120% 

100% 

80% 

60% 

40% 

20% 

water level [-] 

simulation model 

engineering-tool 

Currently, the control system is being implemented in the Hildesheim sewer network. The 

switchover from the test system to actual deployment of the ADESBA control system highlights 

a further advantage of utilising the pre-assembled module. In the validation phase, the 

pre-fabricated interfaces and the high degree of compatibility enabled the control system 

module to be used, first as an engineering tool for the development of a RTC system, and to 

support the verification process, before being integrated into the system. 

With the possibility to set the minimum and maximum throttle discharge the operator can, 

gradually and in a controlled fashion, switch over from a conservative throttle control system 

employing stationary values to the complete dynamical RTC- setup. The gradual implementation 

of a dynamic sewer network RTC system of increasing complexity is thus considerably 

simplified and rendered more practicable. 

CONCLUSIONS 

The conference paper has presented the simulative testing of the ADESBA control box, as the 

procedure for implementing the box in the sewer system of Hildesheim. 

The ADESBA module is a pre-assembled RTC system box designed for controlling 

discharges in sewage systems. It was developed with the aim of considerably simplifying the 

tool of the sewage network RTC system and making it more manageable, thus helping to 

widen its utilisation. The core of this RTC system box consists of a general-purpose control 

algorithm developed at ifak; this permits the use of a pre-assembled RTC control system. The 

development of a special-purpose SIMBA block enables this algorithm both to be tested on a 

simulation basis in the SIMBA model and to be rapidly implemented in programmable 

controllers (Ogurek et al., 2008). 

For the municipality of Hildesheim’s sewage system in North Germany, this general-purpose 

control algorithm was implemented in a calibrated sewage system model created in SIMBA, 

where it was tested and utilised for verification purposes. Then, in combination with the 

ADESBA RTC system box, it was commissioned and implemented in the real sewer network 

for routine operations. 

CSO discharges [m³/d] 

180.000 

160.000 

140.000 

120.000 

100.000 

80.000 

60.000 

40.000 

20.000


The experience and results obtained during the implementation of the RTC system box at 

Hildesheim, together with the module’s evident versatility and adaptability, all point to its 

being widely usable in all kinds of dendritic sewage systems - the target envisaged when the 

project was launched. This is accomplished above all by a simple but adequately accurate 

configuration, which, like the stored control patterns, is, on the one hand, largely pre-set with 

a view to minimising the optimisation and adaptation effort required while, on the other hand, 

remaining adequately open so as to be versatile and adaptable to the system-specific 

requirements of drainage control systems. Here, the pursuit of standardisation, e.g. in respect 

of sewer system-specific requirements, can lead to further simplification and hence even 

greater versatility. 

The results of the simulation study for the city of Hildesheim showed a considerable reduction 

in storm water discharges (29 percent) compared to stationary operation. The results of the 

comparison between the engineering-tool and the simulation model showed a good correlation. 

The technical implementation of the ADESBA RTC system box was fast and without 

any complications. 

In May 2010 the ADESBA+-projekt funded by the German Federal Ministry of Education 

and Research (BMBF) has commenced. The project’s aim is to enlarge the developed general 

RTC system to a pollution-based RTC system for an optimised and energy-efficient operation 

of the wastewater system. There will be a challenge, to bring the different goals of reduction 

of storm water discharges and uniform influent to the WWTP in line. Another aim is to develop 

and implement an optimal pump set control system for energy optimisation. 

ACKNOWLEDGEMENTS 

Funding of this project by BMWi (Federal German Ministry of Economics and Technology) is 

gratefully acknowledged. 

REFERENCES 

Alex, J., Schütze, M., Ogurek, M., Jumar, U. (2008). Systematic Design of Distributed Controllers for Sewer 

Networks, IFAC World Congress, 2008, Proc. on CD 

DWA (2005). Framework for Planning of Real Time Control of Sewer Networks. Advisory Leaflet DWA- 

M180E, German Association for Water, Wastewater and Waste, DWA, December 2005 

ifak (2009). SIMBA6 – Simulation of Wastewater systems, Reference and Tutorial, ifak – Institut für Automation 

und Kommunikation e. V. Magdeburg, Germany 

Lacour, C., Schütze, M. (2010). Real time control of sewer systems using turbidity measurements, Novatech, 

Lyon 2010 

Ogurek, M., Alex, J., Schütze, M. (2008). Simulation als Basis für Entwicklung, Test und fehlerarme Inbetriebnahme 

von Automatisierungssystemen komplexer Prozesse, EKA 2008 Magdeburg 

Pabst, M., Beier, M., Rosenwinkel, K.-H., Schütze, M., Alex, J., Peikert, D., Niclas, C. (2010). Adaption und 

Entwicklung einer vorkonfektionierten Steuerungsbox zur Abflusssteuerung von Kanalnetzen; Korrespondenz 

Abwasser, 57, 6, 551 – 557 

Peikert, D., Pabst, M., Ogurek, M. Schütze, M. (2010). ADESBA Steuerungsbox – Ein Hilfsmittel für ein flexibles 

und anpassungsfähiges Entwässerungskonzept; 22.Norddeutsche Tagung für Abwasserwirtschaft und 

Gewässerentwicklung, Lübeck 2010 

Schütze, M., Alex, J., Ogurek, M. (2005). A general algorithm for the development of control algorithms for 

RTC of sewer systems. 10th International Conference on Urban Drainage (ICUD). Copenhagen. 21 – 26 

August 2005 

Schütze, M. (2008). SIMBA – Ein Simulator für Kanalnetzsteuerung. DWA-Seminar „Abflusssteuerung in Kanalnetzen 

– Kostengünstige Reduzierung der Entlastungen aus Mischsystemen“; Heidelberg, 27.10.2008 

Schütze, M., Haas, U. (2010). Real time control of a drainage system, applying the new German RTC guidelines, 

Novatech, Lyon 2010 

Seggelke, K. (2002). Integrierte Bewirtschaftung von Kanalnetz und Kläranlage zur Reduzierung der Gewässerbelastung, 

ISAH Hannover Diss. 2002

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