Yordan Belev,

Science, Engineering Krasimir Krustev

& Education, 7, (1), 2022, 27-36

Design of a Control System for Self-serve Car Wash

with Industrial Programmable Logic Controllers
with “Internet of Things” (IoT) Capabilities
Yordan Belev*, Krasimir Krustev

University of Chemical Technology and Metallurgy, Sofia, Bulgaria

Received 15 June 2022, Accepted 05 September 2022

ABSTRACT

The report is related to the improvement of the automated self-service car wash system by making
better the monitoring and preventive control systems, as well as the collection and reporting of data from
the operation of the system to achieve more efficient operation and optimization in customer service.
For this purpose, modern industrial programmable logic controllers with “Internet of Things” (IoT)
capabilities are used. The advantages are low operating costs, the long life-cycle of the equipment,
maximum satisfaction of the service customers.
Keywords: industrial programmable logic controller, self-serve car wash, IoT capabilities.

INTRODUCTION latest trends in the spirit of Industry 4.0.

The “Self-Serve” services are evolving at The growing necessity for clean vehicles and
an extraordinary quickness. There is almost no a clean environment also stimulates increased
area that is not affected by the implementation of investment to provide more opportunities for
automation systems for self-service processes. easily accessible, modern, and highly functional
In particular, car washes and the services they self-service facilities with increasingly attractive
offer are increasing and becoming more diverse digital communication systems, payment devices,
due to the rapidly growing number of vehicles and and a variety of services at affordable prices.
the greater need for easy and efficient cleaning. On the other hand, this leads to high
The trends are for even greater development, competition in the market and challenges
both in terms of the size of the sites and in terms entrepreneurs to modernize technologically
of technological development in line with the their machines and equipment in order to gain

*Correspondence to: Yordan Belev, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski blvd.,
1756 Sofia, Bulgaria, E-mail: yordanbelev@uctm.edu

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much more added value, be highly durable, everything in our world under a common
with provided fast and easy maintenance, infrastructure, giving us not only control
with opportunities for technological remote over things around us but also informing us
monitoring, with preventive protection of the about the state of affairs. IoT can improve
equipment, and collection of extensive data from communications in an organization, innovate in
the processes and operations. business, increase customer engagement, and
Due to the rapidly entering industrial help evaluate workflows. IoT is used to automate
programmable logic controllers and Internet of the collection, processing, and analysis of data
Things (IoT) technologies in all spheres of life from various sources [3].
and industry, the attendance of investors in this The challenges for car washes in the spirit of
business will become easier and that will make Industry 4.0 are related to improving the ability
it more sought after and desired. to prevent unforeseen downtime by accidents by
Similar developments already exist in many means of providing early warning of occurred
countries with highly developed industry, while deviations from the normal condition of the
in Bulgaria the technological management of equipment. The neural networks are used to
such sites is based on microcontrollers with more recognize the registration numbers of cars, and
limited capabilities, but there are also those that their subsequently registration in a database for
successfully apply IoT-related technologies [1]. further processing for marketing purposes and
The aim of this development is to implement for various smart applications which made easy
modern industrial programmable controllers customer service.
of the highest class in a modified system for Smart self-service car washes are intelligent
self-service car washes, in order to apply machines because they are equipped with digital
the maximum of the capabilities of IoT for architecture and technologies that allow two-way
monitoring, control, and improved customer dialogue machine/manager, machine/user.
service. Subsequently, based on this model, there Some of the key features of Smart Machines
could be used the application of other means of are:
automation in different technological and price ₋ they use touch-screens,
ranges, depending on market preconditions [2]. ₋ they are integrated with telemetry systems,
The Internet of Things (IoT) is fundamental ₋ they are able to transmit official or advertising
in Industry 4.0. (Fig. 1). IoT aims to unite messages,

Fig. 1. Internet of Things (IoT) and Industry 4.0.

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₋ connected to the internet, Sensitive elements are used for the following
₋ interactive with smartphones and other variables:
technological devices for service delivery [4]. - temperature,
The term SMART MACHINES identifies - pressure,
automated systems that meet the technical - level,
characteristics required by Industry 4.0: - consumptions.
₋ they use digital technologies, A PID controller is used to regulate the hot
₋ controlled by PLC, water temperature through a heat exchanger. The
₋ connected in a network, PID_Temp process object provides continuous
₋ transmit fees electronically, PID control with integrated setup. PID_Temp
₋ use cashless payment systems, is specially designed for temperature control
₋ provide sales information, and is suitable for heating or heating/cooling
₋ report products running out, applications [1]. PID_Temp is cascading and can
₋ generate statistics, be used in manual or automatic mode [6].
₋ they inform about the operating status by Fixed pressure switches are used to regulate
reporting faults, emergencies, diagnostics, the pressure, which, like thermostats, are used to
₋ they exchange information in a bidirectional way, regulate the specific variable at only one operating
₋ the software can be remotely upgraded, point, which is pre-selected by selecting the
₋ they are configurable and remotely monitored, appropriate model of sensitive element. In other
₋ prepared with simple and intuitive man/ words, no setpoint is present in the automatic
machine interfaces, control system [3].
₋ they are safe, To modify the machine in a self-service
₋ provide optimization of logistics (better system will need sensors to be built in to read:
organization for recharging and maintenance - temperature,
of consumables), - fluid flow,
₋ support tools (to help operators be autonomous - level sensors.
in solving the most common problems with
technical support / assistance), DESIGN OF A CONTROL (AND
₋ reliability (on-board real-time diagnostic / MONITORING) SYSTEM FOR AN
monitoring systems) [5]. AUTOMATED CAR-WASH
The basic modified model FCM 918
METHODS MSE-Z of the German manufacturer FRANK
To achieve the goal of the presented project - was chosen to be rebuilt for control with a PLC
to design a control system (and monitoring) of an self-service module (Fig. 2).
automated car wash by means of industrial PLCs, The parameters of the stationary water jet with
a modified stationary water jet FCM918-MSE-Z two guns and three injectors for suction and
is selected to be controlled and diagnosed by a injection of detergents with remote control and
Siemens S7 1200 controller; HMI KP700 and relay-contactor switching of solenoid valves
SCADA S7 WINCC display. TIA Portal V16 device are presented in Table 1.
software was used. Additional equipment includes:
With regard to the control of material ₋ Buffer tank for incoming water 1000 cubic
flows (water and detergent), valves with an meters,
electromagnetic actuator (solenoid valves) are ₋ Particulate filters mesh type 100 µm,
used, which are controlled by a discrete signal. ₋ Softening system type AS-75-760 Logix,
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Fig. 2. Internal and external appearance of the water jet.

Table 1. Parameters of a stationary water jet [7].

Type FCM 918 MSE-Z

Maximum pressure 180 [bar]
Flow rate 900 [l/h]
Maximum working temperature of the water 60 [ºC]
Power supply 400/3 [VAC] 50Hz

₋ OSMIX reverse osmosis system, Configuring supervisor control via Siemens

₋ Hydrophore pump, WINCC RT Advanced and OPC UA Server via
₋ High and low-pressure hoses, Siemens PC Station.[8] PROFINET interface
₋ Coin board and control buttons, are illustrated on Fig. 4.
₋ Heat exchanger with Mazzoni diesel burner, Development of a logic scheme for control and
₋ Outdoor temperature sensitive elements; implementation of logic using Lader-diagrams.
pressure and flow. Block diagram of the ongoing processes of the
The Siemens programmable logic controller self-service system with a coin device is illustrated
is selected - model S7 1215C DC/DC/DC and one on Fig. 5.
additional module SIPLUS S7-1200 SM 1223 Fig. 6 presents Ladder Diagram for controller
16DE/16DA. Digital input / output 16DI/16DO, programming [8], input of the coin device and
16 DI 24 V DC, receiver/source, 16 DO, transistor permission of Buttons from 1-5, PAUSE and
0.5A (Fig. 3). STOP at the entrance.
Siemens SIMATIC HMI KTP700 Basic Panel On Fig. 7 is given Automatic temperature
Touch Screen 7 “ and SIMATIC HMI KTP300 control of the heat exchanger with PID controller
Basic 3 “, PROFINET interface are selected. [9], Emergency STOP of the high-pressure pump
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Fig. 3. Controller selection and configuration in Siemens TIA Portal V16.

Fig. 4. Configure supervisory control.

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Fig. 5. Development of a logical control scheme.

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Fig. 6. Ladder Diagram.

Fig. 7. Block diagram for automatic temperature control of the heat exchanger with PID controller [10].
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Fig. 8. HMI operator panel.

Fig. 9. Configuration scheme.

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Table 2. Controller configuration.

Inputs: 12 Outputs: 16
Program buttons from 1-5 – 24V Start-Stop of High pressure pump
Button - Pause – 24V Valves for injectors - 11, 12, 28
Button - Stop – 24V Actuators – 33, 36, 39, 40
Coin acceptor – impulse signal - 5V HMI
Thermostat – 24V OPC UA Server
Temperature sensor 8 - 24V WINCC RT Advanced Scada
Flow sensor 35 - 24V Program display and duration
Pressure switch 36 - 24V

and program interruption. Activation of a signal of Things are presented.

lamp when the permissible temperature of 60 Logic block diagrams and Lader diagrams
degrees is exceeded. for programmable logic controllers have been
HMI operator panel - control and setting developed, as well as the related HMI panel and
the times of each program; high pressure pump WINCC SCADA for control and monitoring
control; control of the hot water heat exchanger of basic system parameters, thus realizing the
is shown on Fig. 8, [11]. main goal of the thesis, namely - improving the
A configuration diagram in the controller management system of self-service car wash with
development environment is shown in Fig. 12, and IoT capabilities.
the description of its configuration is presented The next goal of this development is to create
in Table 2. a web server for remote access to the SCADA
Implementation programs are as follows (Fig. 9): system and to collect statistical information about
- First program – Prewash with high pressure the entire car wash process. Internet applications
and detergent, are used to improve communication and customer
- Second program – Active foam, service, such as cashless payments; promotional
- Third program – Rinse with high pressure, campaigns, including individual promotional
- Forth program – Wax with high pressure, messages.
- Fifth program – Polish with osmotic water,
- Pause – Interrupt the program for 2 min, REFERENCES
- Stop – Cancel the program. 1. Georgieva, V. Gebov, Integrated automation
systems with programmable logic controllers,
CONCLUSIONS SWU, 2008.
The technological processes and the devices 2. M. Hadjiiski, K. Boshnakov, Automation of
of an automated self-service car wash are technological processes, UCTM Sofia, 2015,
described. The tendencies in the development (in Bulgarian).
and application of the modern systems for 3. 2021, https://www.i-SCOOP
management and monitoring of the self-service 4. 2021, https://www.frank-hdr.de
car washes with smart devices and the Internet 5. https://www.handtmann.de/
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6. K. Ishtev, Theory of Automatic Control, 8. 2021, https://mall.industry.siemens.com/

Technical University of Sofia, 2007, (in 9. TD Installations magazine, 2, 2015
Bulgarian). 10. Engineering Review Magazine, 7, 2013.
7. https://www.energybox.com/ 11. Energy Review Magazine, 4, 2014.

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