XIII Simp osio Brasileiro de Automac a~o Inteligente Porto ... · Keywords| Internet of Things,...

AN MTCONNECT-BASED MONITORING SYSTEM FOR CNC MACHINES

Paulo Estevao Teixeira Martins∗, Marcos Vinıcius Teixeira Martins†, AdrielMagalhaes Souza‡, Eraldo Jannone da Silva§

∗University of Sao Paulo (USP)Department of Electrical and Computer Engineering

Sao Carlos, SP, Brazil

†Federal University of Triangulo Mineiro (UFTM)Department of Electrical Engineering

Uberaba, MG, Brazil

‡University of Sao Paulo (USP)Department of Mechanical Engineering


§University of Sao Paulo (USP)Department of Production Engineering


Emails: [email protected], [email protected], [email protected],

[email protected]

Abstract— With the arrival of the internet as the main means of communication, the interest in monitoringindustrial processes has risen. Supervisory systems based on desktop applications had their spot taken over byWeb applications that can be accessed from anywhere in the world. Although such supervisory systems are alreadyvery present in the industrial environment, there has been great difficulty in applying them to manufacturingsystems, due to the non-uniformity of data collected from machine-tools. The MTConnectTM protocol came tostandardize the data collected from the shop floor and offer them to a Web application in a standard format.This study describes an application of the MTConnectTM system in a real manufacturing system. The wholearchitecture suggested for the case study has been laid out, as well as the Web system proposed for the supervisionof the processes. The implementation of this system has promoted the centralization of the data of interest andhas enabled their use in researching applications, confirming that applications in the Internet of Things (IoT)benefit the 4.0 Industry.

Keywords— Internet of Things, Manufacturing Systems, MTConnectTM, 4.0 Industry

1 Introduction

Production means are based upon the Informa-tion Technology (IT) paradigms, considering thatits expansion implies in the evolution of manufac-turing processes, which tend to follow the rhythmof changes (Sakurai et al., 2016). This scenario isintimately linked to the Internet of Things (IoT),which determines the modus operandi of physicaldevices used to collect and transmit data throughthe web (Santucci, 2010).

In order for the IoT applications to be effi-cient, we need: data exchange through ubiqui-tous wireless technologies, with due safety (Santoset al., 2013); interoperability; monitoring andcontrol; diversification of devices; among others(Sobral et al., 2015).

The IoT enables the control and detection ofdevices in a remote way, through the existing net-work infrastructure. It allows for a direct integra-tion of physical and computing systems, resultingin greater efficiency and accuracy. Monitoring andcontrol are thus benefitted, since that by estab-lishing a direct communication between the com-ponents, human intervention is reduced (Matternand Floerkemeier, 2010).

The aforementioned scenario marks the fourthindustrial revolution, also called 4.0 Industry,which introduces a possibility for machines to be-come more and more autonomous (smart) regard-ing the possibility for interpreting and sendingdata about the manufacturing conditions, even re-porting possible flaws (Pisching et al., 2016).

4.0 Industry focus on the infusion of severaltechnologies that enable the projection of prod-ucts, procedures and smart processes. Such tech-nologies bring more freedom and flexibility inmanufacturing, promote innovation and increasequality and customization of products in orderto cater for the individual demands (Dutra andSilva, 2016). However, even though the modellooks attractive, its application is not simple(da Silva et al., 2015).

The automated production of several types ofparts depends on the data supplied by a diversifiedset of equipments used in the industrial environ-ment. Thus, a uniform and strong communicationis essential in modern production systems. Re-mote Machine Monitoring Systems (RMMS) aresoftwares that have been developed by their com-panies for this reason (Evans, 2011). Several com-panies within this field provide RMMS solutions

XIII Simposio Brasileiro de Automacao Inteligente

Porto Alegre – RS, 1o – 4 de Outubro de 2017

ISSN 2175 8905 2195

for their clients. Such solutions enable the moni-toring of machines by using a client-server struc-ture. However, modern factories operate by usinga great diversity of proprietary protocols, whichmakes it harder to implement standard systems(Mori et al., 2008).

The development of the AsynchronousJavaScript (AJAX) and eXtensible MarkupLanguage (XML) communication technologieshas revolutionized the world of World WideWeb (Web) applications, after serving as abasis for applying protocols such as CyberOPC(Torrisi, 2011). Initially created with the in-tention of monitoring tools with ComputerNumerical Control (CNC), CyberOPC createdopportunities for the efficient use of monitoringprotocols. MTConnectTM steps into this sceneaiming to establish a more direct communicationbetween the equipments by using XML-structureddata as a pattern in applications for the industry(Sobel, 2009a). In the MTConnectTM datasets are included resources related to the use ofproduction equipments, sensors and several piecesof hardware (Vijayaraghavan et al., 2008).

It is in this current field that this study fitsand aims to develop a system for monitoring theCNC machines available in the Laboratory forAdvanced Process and Sustainability (LAPRAS),a part of Nucleus of Advanced Manufacturing(NUMA) of the Sao Carlos School of Engineer-ing (Escola de Engenharia de Sao Carlos - EESC)of University of Sao Paulo (USP), based upon theMTConnectTM standard.

The paper is structured into 5 subsequentsections, including this one. In Section 2 theMTConnectTM is described in its basic versionfor the shop floor monitoring in general. In Sec-tion 3 we describe the data standard proposedby MTConnectTM Institute with greater detail-ing. In Section 4 we introduce the case studywith the application of the aforementioned stan-dard. Finally, in Section 5, we express the mainconclusions of this work.

2 The MTConnectTM System

The ITs integration into production systems facesthe barriers imposed by the lack of uniformity inthe data generated by the various independentsystems. The purpose of the MTConnectTM stan-dard is to provide a common means of commu-nication between these devices through existingtechnologies (Vijayaraghavan et al., 2008).

The MTConnectTM system architecture isbased on terminologies used in its definition (Fig-ure 1).

Figure 1: The MTConnectTM System Basic Ar-chitecture.

2.1 Device

Device is a set of components that provides dataabout some specific application. Thus, a ma-chine tool can be characterized as a Device (Sobel,2009a).

2.2 Adapter

Adapter is a component that connects the Deviceto Agent, being optional in the MTConnectTM

standard, depending on the Device existing insystem architecture (Sobel, 2009a). With theMTConnectTM standard emergence in the indus-trial environment, some manufacturers alreadyprovide machines capable of making data availabledirectly to an MTConnectTM Agent component.

This Adapter component is a TCP/IP server,which in absence of connected Agents works instand-by. When an Agent component is con-nected, the Adapter starts to collecting data, veri-fying the modified data at each iteration and send-ing the new data to the Agent.

2.3 Agent

Agent is responsible for implementing theMTConnectTM interface, receiving the data fromthe Adapter component and structuring them inthe standard, the XML output (Sobel, 2009a).

The data acquired by the Agent is stored inan adjustable size buffer. When the buffer capac-ity is exceeded, the new data begins to replacethe oldest ones, which are thus lost. One way toavoid this is to use a client application to read thisdata and store it in a database. To perform thiscommunication, the Agent MTConnectTM playsthe role of an HTTP server, processing the clientcomponent HTML requests and providing stan-dardized data.

2.4 Client

The Client, in general terms, is responsible forrequesting the XML output data for some spe-cific function. In other words, it is the compo-nent that will use the data provided by Agent(Sobel, 2009a).

3 The XML-based Model

The MTConnectTM model is basically composedof two main types of XML elements: structuralelements and data elements. Structural elements



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describe the physical and logical parts and sub-parts of a device. Data elements describe thedata that can be collected from a device (Leiet al., 2016). Figure 2 illustrates an example ma-chine represented in the MTConnectTM standardmodel. Its basic components can be classified ac-cording to functional and operational aspects.

3.1 Controller

The Controller interprets information from themonitored system, returning feedbacks that di-rectly influence the device operating conditions.The data items analyzed by the controller consistmainly of tool numbers, controller modes (man-ual, automatic) and execution states (ready, ac-tive, feed-hold).

Figure 2: An MTConnectTM standard schematicmodel.

3.2 Axes

The Axes provide information that coordinatesthe execution of linear and rotational motions.The data items for linear movements consist of po-sition, feed, and acceleration; and the data itemsfor rotational motions determine the speed andmode of rotation.

3.3 Asset

For a complete model description, it is necessaryto define an asset. It can be characterized as an el-ement that despite being associated with the man-ufacturing process is not a component of the de-vice, which allows its removal without impairingthe operation. In the example of Figure 2 the En-ergy Meter sensor is an asset component of thepresented Device.

4 Case Study: MTConnectTM StandardApplication

A supervisory system was developed, based onthe MTConnectTM standard, for monitoring the

following machines existing in LAPRAS: a ZemaNumerika G-800HS external cylindrical grindingmachine, a Romi D-800 machining center and aRomi GL-240M turning center, which have GE-FANUC CNCs. The MTConnectTM system archi-tecture (Adapters, Agent e Client) implemented inLAPRAS is shown in Figure 3.

Figure 3: MTConnectTM monitoring system ar-chitecture implemented in LAPRAS.

4.1 Adapters

Four Adapter components were implemented, asshown in Figure 3. As these programs start,they wait for an Agent component connection,and when it is established, they begin to read thedevice data and send it to the Agent componentthrough (TCP/IP) sockets.

4.1.1 CNC Adapters

CNC adapters were coded using C++ language.These are executed by the server, where eachone is responsible for making the connectionwith one of the three machines mentioned above,through the FANUC proprietary protocol, Fo-cas 2 (Fanuc OpenFactory CNC API Specifica-tion 2). Adapters communicate directly with ma-chine CNCs and send collected data to AgentMTConnectTM (Figure 3).

4.1.2 Zema Instruments Adapter

The Zema Instruments Adapter was specially de-veloped to standardize the data acquired from in-struments installed externally to Zema grinding.These instruments correspond to an electric multi-variate power meter (solid state transducer) UPD600, from Ciber Brasil; a turbine type compressedair flow meter, VTG-019A020211RAA20 model,Incontrol trade mark; a Contech Turbine CuttingFluid Flowmeter model SVTL 1”, with a Con-tech microprocessed indicator model CTH 2265;and a sound noise meter (decibelimeter), modelDEC-460, trade mark Instrutherm. This Adapter



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Figure 4: Zema Numerika G-800HS grinding machine MTConnect model.

was encoded using the Labview 8.5 version. Itcaptures the information at 5 samples per second(5 Hz), running outside the server computer, butconnected to the same internal LAPRAS network.

4.2 Agent MTConnect

For the Agent component implementation the1.4.0.2 cppagent version was used, which is anopen source program coded in C++ (Sobel,2009b). In the system architecture implementedin LAPRAS a single Agent component was used(instead of one Agent for each Adapter), in orderto centralize the data flow and facilitate futuremachines incorporation into the monitoring sys-tem. To do this, a simple change in the XML In-put scope has to be done. For example, to add theZema machine it is necessary simply create a newdevice named “Zema G-800-HS” inside the De-vices structure. It is not necessary to implementa new Agent, nor even change the current compo-nent code. Figure 4 presents the Zema G-800-HSdevice XML model, representing all the compo-nents of the existing machine tool in LAPRAS.

In order to keep up the system with the cp-pagent updates it was decided to use the MT-Connect Institute cppagent without modification.This choice facilitates the incorporation of newfeatures and benefits into the system, once thereis no need to adapt the cppagent every time a newversion is released. As the data are already for-mated in the MTConnect standard by cppagent itis unnecessary to do this in the adapters, which itwould be an option since all adapters where codedby the authors. If we choose to do this we will losethe facility of update the Agent component, sincewe will have to modify the cppagent at every newrelease and adapt it to our system architecture.

Besides this modification would have to be donein all adapters, which will become a redundantwork and if new devices were incorporated intothe system it would be necessary to add this codefor their adapters too.

4.3 Client

The stage of collected data visualization couldhave been made in the Agent itself, by joining theClient and Agent components. This is possiblebecause the Agent already implements an HTTPserver, where the data is already available in theMTConnectTM standard. Therefore, it would besufficient to stylize the data, and the user couldview them through a browser. In fact, the 1.4.0.2cppagent version already comes with stylesheetsthat format the data in tables, which is much bet-ter than viewing them in the XML Output itself.However, using this approach would deprive theproject of other tools used in Web projects, whichwould imply dynamic pages, with more elaborategraphical components to analyze and handle thedata, and would allow the connection to somedatabase.

Therefore, we chose to deploy a Web server asa single block in the system architecture (Figure3), keeping the Agent component as just a dataserver. This Web system was encoded in PHP(Hypertext Preprocessor) and JavaScript, usingMySQL (MY SQL - Structured Query Language)as database.

Symfony was used in this Web server devel-opment, which is a widely used PHP frameworkin the Web developer community. Symfony is dis-tributed under Open Source MIT license and ismaintained by SensioLabs and a huge fan com-munity and framework investors (What is Sym-



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Figure 5: Overview of the Web System developed for LAPRAS.

fony, 2017). Furthermore, Symfony is designed tobe fast, secure, flexible and easy to update. Thus,using this tool ensures a Web application withlong term support, facilitating eventual changesover new features embedded to the platform.

For the design, the Bootstrap framework wasused, which allows the creation of responsivepages, that adapt to any screen size.

The overview of the developed Web system isshown in Figure 5. This system enables the ma-chine tools monitoring in real time, showing thecomplete information of each machine. Produc-tion order, current part, and total number of partsdata are available in this system home screen.Production details, process data and machine toolspecific data, can be accessed at the bottom ofeach machine or at the side navigation bar. Be-sides the real-time data monitoring possibility, thesystem allows them to be saved in standard for-mats, such as: .csv, .pdf, .txt, among others.

The supervisory system enables the data vi-sualization separately, according to the machinestructure itself, based on each one XML model.This data arrangement facilitates the supervisor’sanalysis and decision-making process. Moreover,the Web system provides the option of viewing thedata in tables or graphs, and the latter can pro-vide a more detailed analysis of specific data. Forexample, one Zema grinding interest parameteris the electrical power consumed by the machineduring the manufacturing process, because of itsclose link to the grinding forces and consequentlyto the specific energy in grinding.

According to Figure 6, at the beginning oc-cur one short increment on active power, beingnecessary to activate the primary machine’s sub-unit. Followed by the turn on the machine’s sub-units hydraulic, cooling and pumping of cuttingfluid system, causing increase in the required ac-

tive power. Later there are two peaks causedby inrush currents of three-phase induction mo-tors, existing in exhaustion subunit and grindingwheel, respectively. Finishing with subunit shut-down and restart operation.

Besides the active power graphic, we may gen-erate graphics for each electric current phase, pathposition, path feedrate, air flow, fluid flow andsound spectrum. Those graphics are generated onreal time, being an important indicator for moni-toring the actual stage of grinding operation.

Time (s)0 50 100 150 200 250

Act

ive P

ow

er

(kW

)

0

5

10

15

20

25

30

Figure 6: Total active power consumed by ZemaG-800HS grinding during a manufacturing pro-cess.

5 Conclusions

This paper has presented a supervisory system,based on the MTConnectTM standard, applied inthe industrial environment of LAPRAS, accord-ing to worldwide tendencies in IoT for the devel-opment of 4.0 Industry. A Web application wasdeveloped to allow monitoring in real time andexport data in a remote way, allowing it to be ac-cessed from anywhere with an internet connection,through a browser.



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The use of Symfony for implementing the Websystem has brought several advantages for the de-veloped application, such as: extensive support;fast browsing; and flexibility, making it easier foroccasional future changes. Besides, methods forprocessing HTML requisitions in a safe and re-liable way are offered, which is one of the mainconcerns about development of Web applications,especially in manufacturing environments. Theimplementation of the supervisory system basedon this platform consists of an edge regarding tothe easiness of keeping the Web system up-to-date with safety requirements that shall be im-plemented by the Symfony community. The pos-sibility of creating graphs or tables is also an ad-vantage, because it provides a graphical analysisof the project in real time, helping the analysis ofthe manufacturing processes. It is important tohighlight that Symfony platform was developedwith the aim of being a freeware framework whichprovides interoperability between several applica-tions, thus harmonizing with the MTConnectTM

Institute ideology itself.Finally, it can be evidenced that IoT appli-

cations benefit the 4.0 Industry, especially in thehigh-performance measures, due to the high ag-gregate value.

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