Nicola Mincuzzi
email: nicola.mincuzzi@stiima.cnr.it

Mohammadtaghi Falsafi
email: mohammadtaghi.falsafi@stiima.cnr.it

Gianfranco E Modoni
email: gianfranco.modoni@stiima.cnr.it

Marco Sacco
email: marco.sacco@stiima.cnr.it

Rosanna Fornasiero
email: rosanna.fornasiero@stiima.cnr.it

Managing Logistics in Collaborative Manufacturing: The Integration Services for an Automotive Application

Keywords: Inbound logistics, Interoperability, Data integration, Middleware, Dock re-scheduling, Optimization

The critical success factor of the supply chain management process in a modern manufacturing company consists in the company's capability to exploit the data produced by a growing number of different sources. The latter include a network of collaborative sensors, digital tools, and services, made available to suppliers and other involved supply chain actors by the recent advancements in digitalization. The collected data can be processed and analyzed in near real time to extract significant information useful for the company to take some relevant decisions. However, these data are typically produced under the form of heterogeneous formats, as they arrive from different types of sources. This is the reason why the real challenge is finding valid solutions that support the data integration. In this regard, this paper investigates the potential of a solution for data integration that allows supporting a set of interacting decision-support tools within the inbound logistics of the automotive manufacturing. This solution is based on a message-oriented middleware which enables a collaborative approach where suppliers, trucks, dock managers and production plants can share information about their own status for the optimization of the overall system.

Introduction

In the era of modern manufacturing supply chain management (SCM) is becoming more and more complex [START_REF] Bode | Structural drivers of upstream supply chain complexity and the frequency of supply chain disruptions[END_REF]. Main reasons for this growing complexity are the geographical expansion of the supply chain networks, a huge amount of data (e.g. produced from tracing) which affects the supply chain decisions (e.g. how to manage an anomaly), and the need to increase the speed of decision-making tools due to the advancements of just-in-time delivery practices [START_REF] Hofmann | Industry 4.0 and the current status as well as future prospects on logistics[END_REF]. In addition, some of the traditional challenges in the SCM still persist and are more emphasized due to the mentioned advancements. One of these challenges is the transportation cost which is increased by the geographical complexity and extensive networks as well as sustainability concerns [START_REF] Yu | Product transportation distance based supplier selection in sustainable supply chain network[END_REF]. Another traditional challenge is the scheduling of orders, transport modes, and unloading points in the inbound and outbound supply chains. This challenge is in particular evident in large industries with a lot of inbound and outbound flows where it is difficult to schedule and re-schedule the plans in case of unexpected disruption events. In order to better address the mentioned challenges, the modern factories are transforming their logistics in a collaborative network where suppliers, trucks, dock managers and production plants share information about the status of the inbound resources for the optimization of the overall system [START_REF] Terkaj | The Italian Flagship Project: Factories of the Future[END_REF]. Such a strong collaborative network is crucial for companies willing to respond to the challenges posed by the globalization [5] [6]. In particular, it allows to quickly take decisions along the whole value chain, thus contributing to a more and more highly dynamic supply chain which in turn is a key factor for the I4.0 logistics [START_REF] Camarinha-Matos | Collaborative networks as a core enabler of industry 4.0[END_REF].

This collaborative network can be realized in its full potential only if it is supported by digital tools capable to exchange and share information among each-other [START_REF] Koçoğlu | The effect of supply chain integration on information sharing: Enhancing the supply chain performance[END_REF]. However, the traditional manufacturing tools are typically based on specific data model and the heterogeneity (also called variety) of these models hinders the tools interoperability, i.e. their capability to exchange information, thus also jeopardizing the cooperation of the involved resources within the overall network [START_REF] Modoni | Enhancing factory data integration through the development of an ontology: from the reference models reuse to the semantic conversion of the legacy models[END_REF]. In addition, it is still open so far the debate on which kind of data integration can enhance performance of the supply chain [START_REF] Kumar | The impact of supply chain integration on performance: Evidence from the UK food sector[END_REF]. In order to overcome the issue of data heterogeneity, this paper aims at the development of an experimental platform for integration between traceability systems and management tools and optimization tools within the inbound logistics of automotive assembly plant. The platform leverages the use of a messagesoriented middleware for integration of tracking components with decision-support tools. Thus, thanks to middleware, an optimization tool can exchange significant information with other factory's digital tools (e.g. for production simulation and optimization), thus allowing to re-schedule (e.g. when a disruption event happens) the inbound dock plans and select the best transport modes from the supplier to the docks of the assembly plant.

The remainder of the paper is structured as follows. Section 2 introduces the case study and its problem of interoperability. Section 3 presents the approach and its validation. Section 4 describes the results obtained leveraging the proposed approach. Finally, Section 5 draws the conclusions and summarizes the main outcomes.

The Case Study

The case study is set in an automotive assembly plant and it focuses on the management of inbound logistics whenever a disruption occurs. The latter could happen in the supplier's side, in the transport modes, and in the unloading docks. In case of any of these disruption events, the manager of the supply chain needs to make recovery decisions to reduce the adverse effects of the delay. In addition, the disruptions that happen in the production could have an impact on the decisions in the inbound logistics and therefore, these disruptions should also be considered. The problem that must be faced consists of two main decisions in the inbound logistics of the assembly plant:

1. Dock re-scheduling; 2. Transportation mode selection.

Before a disruption event happens, a dock schedule exists where a set of trucks are assigned to a set of docks for a specific planning horizon. As a result of a disruption event, it is needed to take a decision to re-schedule the assignments, while the second decision considers the possibility of changing the transport mode of the delayed orders with faster modes. The two decisions are interconnected in the way that the arrival time of the orders to the docks changes by influencing the change of the transport modes. The final decision on the dock re-scheduling and transport selection depends on the trade-off between different costs. Transport cost is the cost of using alternative transport modes. Dock setup cost is the cost of employing additional docks. Buffer cost is the cost of using internal transport means for transferring the specific components (part numbers) from the docks to the assembly line. Extra resource cost is the cost of using more resources than the available ones at the docks. Truck waiting cost is the cost of waiting truck in the dockyard when there are no free docks. Finally, the cost of production re-scheduling is the cost when a part number is not available in the assembly line in the planned time, and therefore, a re-scheduling in the production is necessary. The desired solution is a re-scheduled dock plan and transport plan where the sum of all the costs is minimized.

The solution for this problem proposed within the European research project DISRUPT [START_REF]DISRUPT project[END_REF] is to use an optimization model for the inbound logistics where the objective function is the minimization of all the costs as follows [START_REF] Falsafi | Managing Disruptions in Inbound Logistics of the Automotive Sector[END_REF]: Minimize (Additional costs caused by the disruption events) = Minimize (Transport cost + Dock setup cost + Buffer cost + Extra resource cost)

The input data for the optimization model are the data related to the inbound logistics combined with data resulting of the analysis of other tools. To handle the disruption and its impact on the inbound logistics decisions, three tools collaborate and propose the final solution as follows:

1. Simulation tool; 2. Optimization tool of the inbound logistics; 3. Optimization tool of production scheduling.

The Simulation tool is first applied to quantify the effects of the disruption on the Key Performance Indicators (KPIs). The most important KPI is Job per Hour (JPH). If the impact of disruption on the JPH is negligible, this is considered as the outcome of the analysis. No further analysis is needed in this case. Otherwise, if the effect is not negligible, the optimization tools are required to minimize the negative consequences of the disruption on the JPH. Generally, two scenarios for inbound logistics tool are possible based on the disruption type as follows (Figure 1):

1. The disruption is in the production process (e.g., machine failure). In this case, if the disruption can be managed by the optimization tool of the production schedule, it is not needed to apply the inbound logistics optimizer. The outcome is the updated production schedule. If the disruption is not manageable solely by production scheduling tool, Inbound logistics tool should be used. Apart from the other input data, the re-scheduling cost is obtained by the communication of different alternative dock schedules with the production scheduling tool. 2. The disruption is in the inbound logistics (e.g., the accident of the transport mode). In this case, the disruption should be managed directly by the inbound logistics tool with the communication of data with the production scheduling tool.

Finally, an optimized dock schedule and transport plan are provided to the supply chain manager who is the final decision maker of the inbound logistics. Behind each state of the workflow, there are different modules, performing different functions. The interactions among different digital tools and software applications are essential to the efficient solution of the optimization model.

Fig. 1. Application of inbound logistics tool in different disruption events 3 An Overview of the Platform Architecture

In order to overcome the problem of the interoperability, this section investigates the potential of a solution based on a three layers architecture, where the layers are the following (Figure 2):

• Real Factory; • DISRUPT Platform Cloud;

• Virtual Factory Tools.

The Real Factory comprises the world of the factory, including all aspects inherent the logistic of the fleet of the trucks and the plant production. The DISRUPT Platform Cloud, which is one of the main outcomes of the DISRUPT project [START_REF] Tountopoulos | Towards a cloud-based controller for data-driven service orchestration in smart manufacturing[END_REF], is the middletier of entire system which aims at the integration of all the factory's tools data. In particular, it contains two macro-modules (Event Dispatcher and Digital Twin) that allow to integrate the data generated by the layer of the Real Factory under the form of data streams (Factory Telemetry) [START_REF] Modoni | A telemetry-driven approach to simulate data-intensive manufacturing processes[END_REF]. Specifically, the Digital Twin is a virtual model which represents a faithful mirror of the Real Factory, persisted on two structured databases: Event Disrupt Database (containing the logic to raise the events) and Synchro Factory Database (containing the information related to the supply chain management) [START_REF] Modoni | Synchronizing physical and digital factory: benefits and technical challenges[END_REF]. On the base of the information included in the Digital Twin, the Event Dispatcher raises the events in case of scheduling delays and forward them to upper Layer. The Event Dispatcher leverages a messages-oriented middleware which acts as a glue among the various connected digital tools [START_REF] Modoni | An eventdriven integrative framework enabling information notification among manufacturing resources[END_REF]. Under these conditions, these tools can also run on different platforms and operating systems, as the interoperability is guaranteed by the middleware. Finally, on the top of the architecture, the layer of the Virtual Factory Tools comprises various Factory decision-support tools including an Optimizer for Inbound Logistics and an Optimizer for the production scheduling which leverage the events triggered by Event Dispatcher.

An Example of the Use of the Platform

In order to illustrate, through an example, the use of the above described platform to integrate a specific tool within the collaborative network, this section focuses on the Inbound Logistics Optimizer tool. As described previously, this tool is an optimization model which aims to re-schedule the inbound dock plans and select the best transport modes from the supplier to the docks of the assembly plant when a disruption event happens. The Inbound Logistics Optimizer software architecture is designed foreseeing both a synchronous and asynchronous (or event base) communication with the virtual model of the Real Factory. In addition, it includes a model handler, which represents the core mathematical model of the whole Inbound Logistics Optimizer tool.

In particular, such tool is composed by the following modules (figure 3): (1) Handler Cplex Model, described through the software application Cplex Optimizer1 , which represents the optimization model based on the current status of the factory. By extracting the updated input parameters, this model finds a solution pool with alternative updated dock schedules and transport plans. Afterwards, based on the related decision variables, it calculates the KPIs for each alternative solution. (2) Synchro Factory Database Adapter Library (written in Java), which provides a set of different REST API Web services. In particular, the latter enables the Inbound Logistics Optimizer tool to communicate with the DISRUPT Platform Cloud and to use the CRUD (Create, Read, Update, Delete) operations in order to interact with the databases to create, read, update and delete the static and dynamic data, stored on Cloud platform.

(3) Client Event-Bus (written in Java), which represents the module needed to provide information consistency among the different tools that compose the Virtual Factory Tools layer. The Client Event-Bus2 is based on the Publish/Subscribe messaging pattern, in which a message is delivered from a producer to any number of consumers. Messages are delivered to the queue destination, and then to all active consumers who have subscribed to this queue.

Results

In the proposed approach, through the middleware, a set of input parameters and disruptions are communicated to the Inbound Logistics Optimizer. The optimizer solves the problem by proposing a set of re-scheduled dock plans with the minimum cost as well as the related KPIs. These outcomes are in turn communicated to the middleware, which transmits them to other modules. Exploiting this integration, a set of feasible solutions is provided to the decision-maker in an efficient way. In particular, the results of the inbound logistics optimizer can be divided into three parts as follows:

1.

Updated dock schedule 2.

Transport selection 3.

KPIs.

Conclusion

The potential of an approach based on a message-oriented middleware was investigated in this paper to enhance cooperation and collaboration of digital tools supporting logistics within a manufacturing company. The evaluation of the approach in a test environment has demonstrated its validity.

Future works will address the deployment of the proposed solution within the production environment where all the digital tools are deployed and can interact each other. The production environment will give the opportunity to verify the approach under real condition. As the project is still ongoing, the idea is addressing these works in the future months, before the end of the project. Another aspect that must be investigated in the future is the evaluation of the proposed approach within other case studies. It is expected an easy transfer technology from one case study to another thanks to the integration capability of the adopted middleware. authors would like to thank the contributions of the different partners of the DISRUPT project.

Fig. 2 .

 2 Fig. 2. The architecture of the platform

Figure 3 .

 3 Figure 3. Inbound Logistic Optimizer software architecture

Figure 4

 4 Figure 4 represents an overview of the results. Alternative solutions are provided to allow the decision maker to choose among the solution alternatives (sub-optimal solutions) which are not satisfied in the optimum solution, based on different cost types.

Fig. 4 .

 4 Fig. 4. Representation of KPIs for alternative solutions of the inbound logistics optimizer (Optimal: best result with the minimum cost, sub-optimal: alternative results with higher costs)

https://www.ibm.com/it-it/analytics/cplex-optimizer

http://um.terracotta.org/

Acknowledgment

The work on this paper is funded mainly by the European Commission through the DISRUPT project H2020 FOF-11-2016, RIA project n. 723541, 20162018). The


Vasiliki Liagkou
email: liagkou@kic.uoi.gr

Chysostomos Stylios
email: stylios@uoi.gr

VR Training for Security Awareness in Industrial IoT

Keywords: Virtual Reality, VR Training, Industry 4.0, E-learning, Internet of Things, LPWAN

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Nowadays Virtual Reality (VR) is a new pillar for developing training and learning environment for Industry 4.0. VR is able to provide an integrated training environment where users are able to design, test and perform various manufacturing process activities like being on a real workspace. VR has many abilities that make it suitable for a novel manufacturing training environment ( [START_REF] Büttner | The Design Space of Augmented and Virtual Reality Applications for Assistive Environments in Manufacturing: A Visual Approach[END_REF]). Virtual reality applications for training and learning propose have attracted great interest from the research community ([2]- [START_REF] Dw | Virtual reality for education and workforce training[END_REF]). VR have proposed to develop various training scenarios mainly based on 3D role playing games. But, only a few VR scenarios are focused on security issues ([4] - [START_REF] Ryoo | Game based InfoSec education using OpenSim[END_REF]). The majority of simulations and games have been developed in role based use case scenarios and they use two dimensional graphical representations. In this work, we present a 3D training environment on privacy and security issues for an IoT industrial environment.

Collaboration networks ( [START_REF] Camarinha-Matos | Collaborative Networks as a Core Enabler of Industry 4.0[END_REF]) can help Industry 4.0 to support several collaboration environments but this collaborative link between enterprises, customers, employees, and systems is vulnerable to cyber-attacks [START_REF]Overview of Cyber Security in the Industry 4.0 Era[END_REF]. The security challenge is a crucial requirement for industry 4.0 to realize a reliable, trustful and seamless cooperation between enterprises, employees and customers. The new communication technologies include various security mechanisms that can reduce security risks but enterprises and employees hesitate to use them due to their lack of skills and awareness.

To this direction our work tries to investigate the capabilities of Virtual Reality (VR) technology for familiarizing users with the functionalities of a promising Internet of Things communication system suitable for industrial networks... The authors introduce a VR training scheme that help users to investigate the security mechanisms in Low-Power Wide-Area Networks ( [START_REF] Centenaro | Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios[END_REF]). The scope of the proposed VR training scheme is to increase user security awareness by helping users to identify the risks and vulnerabilities that they should have in mind when they use an IoT protocol.

The Internet of Things (IoT) is a basic component of the fourth industrial revolution: Industry 4.0. On the other hand, Low-Power Wide-Area Networks (LPWANs) are becoming one promising IoT communication protocol for the Industrial IoT (IoT) ecosystem since it can provide long-range communication at very low speed to an industrial IoT network. The current implementations could replace 2G/3G/4G/5G cellular networks because LPWAN can also increase the transmission range of devices by trading-off data transmission rate while preserving at the same time power consumption at low levels [START_REF] Centenaro | Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios[END_REF]. The Low-Power Wide Area Networks (LPWANs) exploit the abilities of low frequency signals to transmit over any obstacle or using multipath propagation. They are widely used because of their robustness and reliability [START_REF] Raza | Low power wide area networks: An overview[END_REF]. LPWAN technology has becoming promising and widely adopted for IoT networks because it supports the connection of IoT devices at a distance. LPWANs main characteristics include energy autonomy for the IoT devices along with low cost, great coverage capabilities that are requirements of the Industry 4.0 applications [START_REF] Alexandros | Low Power Wide Area Networks (LPWANs) for Internet of Things (IoT) Applications: Research Challenges and Future Trends[END_REF].

Outline

Our work focus on a new and promising IoT communication protocol, the Low-Power Wide-Area Networks (LPWAN) and it uses a VR training environment for helping users to explore its security mechanisms. The LP-WAN have recently emerged as a hopeful IoT communication system that can satisfy the challenges of industrial networks by enhancing their reliability and efficiency [START_REF] Luvisotto | On the Use of LoRaWAN for Indoor Industrial IoT Applications[END_REF]. The LPWAN can be a solution to the limitations showed by current IoT applied approaches, but their implementations were recently introduced, so it will be necessary users to acquaint their self with the provided security services and increase their awareness. Our envision is that Virtual Reality can help potential users of Industry 4.0 to understand how the security mechanisms that are provided by LPWAN can be integrated through the whole industrial chain.

Security Challenge in Industrial IoT

Industrial IoT systems require an interconnected ecosystem that supports on-line access to interdependent and real-sensing data between enterprises in different geographic places, thus these systems are not designed to be protected against a hostile unsecured internet environment. Security is a critical issue for novel Industrial IoT systems because the transmitted real-time data is confidential and its disclosure could cause huge financial loss for the industry. Nowadays, industrial competitors invest on "Industrial Espionage" in order to gain a completive advance e.g. by finding the design of a new product. Unfortunately, several companies spend a lot of effort to gather competitor's critical knowledge about its manufacturing processes, construction techniques, research plans or pricing/binding deals. If a competitor manages to gather any critical inside information, he could also have access to the enterprise's critical know-how and this fact will cause huge loss of enterprise's intellectual property.

In an IoT industrial system there is a horizontal interaction through the whole value chain from users and partners to customers thus huge amounts of data are being transmitted, audited, aggregated, annotated, stored and processed. If a competitor succeeds to gather a part of these collected data he can use it for creating a competitive advantage and he can also violate company's and customers' privacy ( [12]- [START_REF] Price | Keeping ubiquitous computing to yourself:a practical model for user control of privacy[END_REF]). An IoT system must fulfill the security requirements for preserving data's confidentiality, integrity and privacy. Moreover, it is essential to extend the traditional security requirements in order to guarantee the confidentiality of the aggregated data from smart devices, especially when these devises are distributed in open and uncontrolled environments. Inherently, IoT environment is considered as a vulnerable link in an industrial network since they can be attacked by external devices for compromising their data and disrupting their operation. There are several efficient security solutions for IoT environment in the recent literature and the majority of them try to address resources constraints and scalability issues. The authors in [START_REF] Kouicem | Internet of things security: a top-down survey[END_REF] present an extended review of the most recent proposed security and privacy solutions in IoT systems.

Here we explore a new IoT communication protocol, the Low-Power Wide-Area Networks (LPWAN). Nevertheless the security remains a challenge that must also be considered in LPWAN ( [START_REF] Aras | Exploring the security vulnerabilities of lora[END_REF]- [START_REF] Emekcan | Exploring the security vulnerabilities of lora[END_REF]). The authors in [START_REF] Michorius | Whats mine is not yours: Lora network and privacy of data on publishing devices[END_REF] present a set of security issues of LPWAN server that must be solved. An alternative key management scheme suitable for LPWAN is presented in [START_REF] Naoui | Enhancing the security of the iot lorawan architecture[END_REF]. Here we take a different direction and we try to increase users' security awareness in LPWAN by helping them to exploit the provided security mechanisms.

The VR training Scheme

In this work, we present a Virtual Reality (VR) scheme for training users to the basic security tools of LPWAN. The provided VR scheme help users to exploit the security issues and tools in IoT protocols and to better understand new risks and vulnerabilities that they should consider and address when they use IoT protocol.

Our VR training environment is decomposed in the following four phases that are implemented in VR 3D role based game scenario (see Figure 1). The user must execute specific actions in order to successfully complete each phase and then he can proceed to the next one.

• Introduction section includes VR presentations and 3D visualization of the basic architecture and interactions in LPWAN. • Connection section includes specific visualizations and steps so that the user to be able to understand how he can connect various devices in LPWAN.

The user thought navigation is able to understand how the LPWAN authenticates his device by using a set of keys. Moreover here the user can select two types of IoT devices by following two distinct paths for joining the LPWAN (see Figure 3). • Security Parameters section includes a more detailed description of LPWAN security mechanisms (see Figure 4). During this phase the user has to complete specific tasks in order to visualize how the network server generates and verifies the message integrity code and the corresponding keys.

• Threat section, visualizes how LPWAN tries to prevent replay attack

VR Scheme's Learning Achievements

The presented VR environment improves learning and training processes because it allows capturing attention to IoT users for increasing their awareness of the transmitted data. Our VR training scheme uses a VR character for informing the user about the set of actions that he can make for increase data's confidentiality. Moreover, VR application has included in several points of navigation a VR presenter for familiarizing the user with the available set of actions for protecting his transmitted data. (see Figure 4). The proposed scheme presents the security features and cryptographic information in a logic and direct way. The utilised VR scenario uses several VR spaces that simulate conventional actions. User's avatar could make specific actions like navigation, interaction with objects, communication and objects creation for gaining a dipper understanding of available security tools of LPWAN.

The provided VR environment helps users to think without being influenced by others and it provides a VR experience for a set of connection activities. LPWAN's security tools need specific actions from the IoT user for connecting his device in LPWAN. It is very difficult and unrealistic for users to execute such privacy policies and complex security mechanism. Our VR scenario trains the user how to connect his device in order to follow the right connecting procedures. We have implemented two different VR scenarios where the user's avatar follows specific steps and takes specific actions for connecting two different types of IoT devices, a refrigerator and a mobile phone (see Figure 3). The security factors that must be taken into account by an IoT user for connecting a static or mobile IoT device are different. Our VR scheme help users to understand what factors have to consider for joining in LPWAN network. The main goal of the presented VR platform is that gives the opportunity to the users use some security tools and to visualize a set of vulnerabilities. Most of the security and privacy concerns are invoke by misconfiguration of users. Our VR scenario visualizes in various steps of its navigation the potential risks and vulnerabilities that users should consider and address when they use LPWAN protocol. The presented training environment assess users' knowledge about the provided security level for every action their avatar makes and evaluates if they understand the potential security flaws for its actions (see Figure 4). Finally the user through his VR navigation can control connection procedures of IoT network. The interconnection and communication among the IoT devices and LPWAN server vary according to the user actions or protocols phase. Our VR model visualize transmitted data packages information and servers' interactions in order the user to understand how security policy of LPWAN works and what are the bounds of the provided security level. The user will be able to develop analytic and problem solving abilities. Our proposed VR scheme simulates experiential real life use case scenarios for solving problems in order users to gain a better comprehension of security risks in LPWAN and to help the to understand the functionalities of security mechanisms. User's avatar can throw a dice for generating a random number or it may pic specific boxes for constructing a network package.

VR Exploitation's Security Requirements

In this work, we investigate how VR technology is able to create and evaluate experiential learning simulations that address IoT users' needs for privacy and security awareness. It has presented a 3D role playing game, which was tested by a group of students who evaluated handling the security features of a LPWAN. The majority of IoT Industrial use cases must take a very careful consideration of security requirements and the implemented VR training platform investigate users' awareness to the following privacy and security concerns in IoT networks:

Confidentiality/Non Leakage of Sensitive Information

Leakage of critical information to unauthorized users or competitors is unacceptable for any industry. Usually, an industrial plan deploys a lot of smart devices that are used for collecting manufacturing processes data. If these devices are hacked by an attacker, then he can monitor all industrial activities and access critical information. To avoid this attack, LPWAN uses symmetric data encryption between gateway and devices. VR users through their navigation to the learning world are able to understand how the encryption of the payload is by default enabled in every transmission in LPWAN. Moreover, VR user understands what information is transmitted by an IoT device thus the VR environment visualizes the contents of every transmitted package by including the information of identifiers and payload data. Complementary LPWAN do not use a specific gateway, thus our scheme visualizes how the data frames do not include any gateway identifier. In this way, user must be aware that it is possible for anyone to receive the encrypted data packets. LPWAN tries to authenticate the IoT device for detecting the unauthorized access.

VR training schemes includes two different VR scenarios in order to visualize how the LPWAN network authenticates an IoT device by two different joining methods.

The application data should remain confidential against theft and tampering since application data of IoT could be industrial or enterprise. The VR training scheme shows at different scenes of the navigation that a 128-bit Application Session Key is used to encrypt the data frame between the IoT device and the application server (see Figure 4).

Integrity

Preserving the data integrity is one critical requirement, so LPWAN have to include a method for preventing any unauthorized on stored and transferred Data integrity in LPWAN can be realized by the computation message authentication code (MAC) functions. The VR training scheme includes a 3D game for visualizing how the message authentication code is produced using the Network Key, which is confirmed by the Network server. It shows at different scenes of the navigation how an IoT device can be authenticated by using the network key. Finally LPWAN also encrypts the transmitted data file.

Robustness

An industrial IoT network should be shielded against various attacks and threats caused by human factors or natural disasters. LPWAN uses a frame counter for upstream and downstream messages which will block a transmission from being sent more than once. The VR scenario visualizes how this generated number prevents the replay attack.

Implementation Details

Here, we have designed, developed and presented a training scenario by using the Unity 3D environment. The Virtual reality application is built in WebGL Unity Project. The WebGL build option allows Unity to publish content as JavaScript programs that use HTML5 technologies and the WebGL rendering. Just a few web browsers support WebGL, and most of the mobile devices are not supported by Unity WebGL. Actually, Mozilla Firefox browser supports all the utilities of WebGL. We

Conclusion and Discussion

This work presents developing and usage a Virtual Reality (VR) training environment that can help potential users of LPWAN to familiarize with the provided security mechanisms by LPWAN and to increase their security awareness. We used a small group of master students in Computer Security theme for training purposes. Most students found the proposed VR scheme useful for exploiting new technologies. In addition, we explored how useful students found the VR technology as a training tool. Whereas 95% of them believe that VR is the easiest and most convenient way to explore IoT system's functionalities. All students strongly agreed that protecting their data in an IoT environment is important to them. Overall, 85% of the students declared that they would prefer the utilized VR scheme to include more entertaining and game role characteristics. We are planning to further update VR model and to redesign the VR use case scenarios in order to provide a more entertaining game-role based experience.

  have created the 3D objects for the VR training environment via importing collada files, into the Project's asset. The VR training environment is accessed by iframe and when users navigate on a VR training game through the browser. The developed scripts in VR Training environment are created in Unity Project by writing scripts in C# Language.

Fig. 1 .••Fig. 2 .

 12 Fig. 1. VR Training Phases.

Fig. 3 .

 3 Fig. 3. VR for connecting two different IoT devices.

Fig. 4 .

 4 Fig. 4. Transmitted package from Network server and Packet Construction

Acknowledgements

This work has been partially supported by the "TIPHYS 4.0-Social Network based doctoral Education on Industry 4.0" project No 2017-1-SE01-KA203-03452 funded by ERASMUS+ of the European Commission.


Magdalena Muszyńska

Dariusz Szybicki
email: dszybicki@prz.edu.pl

Piotr Gierlak
email: pgierlak@prz.edu.pl

Krzysztof Kurc
email: kkurc@prz.edu.pl

Andrzej Burghardt
email: andrzejb@prz.edu.pl

Marek Uliasz
email: marek.uliasz@pwrze.utc.com

Application of Virtual Reality in the Training of Operators and Servicing of Robotic Stations

Keywords: virtual reality, robotic stations, operator training, robot service

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The article presents the concept of training operators and service technicians in the support, maintenance and servicing of robotic stations. The training system is implemented as part of a collaborative network consisting of a university and companies forming part of the Aviation Valley Association (Fig. 1). This network consists of autonomous components that vary with respect to the operational environment, social capital and culture [START_REF] Camarinha-Mato | Collaborative networks: a new scientific discipline[END_REF], [START_REF] Shuman | Collaborative networks are the organization: an innovation in organization design and management[END_REF]. The aim of the university is to conduct scientific research, educate students and influence the technological development of the region. The goals of companies are widely known to be the satisfaction of the needs of other entities of social life through the production of products and services. In the Podkarpackie region of Poland, the Aviation Valley Association was established to strengthen the role of south-eastern Poland as one of the leading regions in the aviation industry in Europe. • The creation of favorable conditions in order to enhance the development of aerospace industry enterprises in this region. • The protection of enterprise and businesses in the aerospace industry. Aviation Valley connects over 160 companies from the aviation industry. Cooperation with higher education institutions, especially with the Rzeszow University of Technology, is very important for this association. Joint research projects are carried out as part of this cooperation. An example of cooperation with the companies of Aviation Valley presented in this work focuses on designing advanced robotic stations and robotization of various types of processes. One such jointly developed process is the robotic quality control of jet engine components presented in the works [START_REF] Burghardt | Robot-operated inspection of aircraft engine turbine rotor guide vane segment geometry[END_REF], [START_REF] Burghardt | Software for the robotoperated inspection station for engine guide vanes taking into consideration the geometric variability of parts[END_REF], [START_REF] Burghardt | Robot-operated quality control station based on the UTT method[END_REF]. Robotic machining processes in the aviation industry and diagnostics of the components of robotic stations are the subject of publications [START_REF] Teti | Advanced monitoring of machining operations[END_REF], [START_REF] Gierlak | Hybrid position/force control in robotised machining[END_REF], [START_REF] Burghardt | Monitoring the parameters of the robot-operated quality control process[END_REF], [START_REF] Burghardt | Experimental Study of Inconel 718 Surface Treatment by Edge Robotic Deburring with Force Control[END_REF], [START_REF] Barnfather | A performance evaluation methodology for robotic machine tools used in large volume manufacturing[END_REF], [START_REF] Kurc | Non-contact Robotic Measurement of Jet Engine Components with 3D Optical Scanner and UTT Method[END_REF], [START_REF] Hui-Ping | Communication of multi-robot system on the TCP/IP In: mechatronic science, electric engineering and computer (MEC)[END_REF], [START_REF] Szybicki | Robot-Assisted Quality Inspection of Turbojet Engine Blades[END_REF], [START_REF] Szybicki | Calibration and verification of an original module measuring turbojet engine blades geometric parameters[END_REF]. The existence of this collaborative network allows companies to implement advanced robot-related solutions, and academic staff can co-create and publish interesting works. A very important component of the university's cooperation with companies is the education of students within the so-called dual courses conducted simultaneously at the university and in companies, as well as commissioned work related to training. An example of such work is the training of robotic operators and servicers. The idea of organizing training in the field of robot service and servicing appeared during meetings of the University employees with representatives of associated companies in the Valley. The university has staff specializing in robot programming, designing robotic stations and station servicing. In addition to the staff at the Faculty of Mechanical Engineering and Aeronautics, 10 different types of robots, grouped into dedicated stations, are available (Fig. 2).

Virtual Reality

Virtual reality (VR) is an interactive computer simulation that detects and simulates the presence and actions of the user in a virtual environment and sends sensory feedback to one or more senses in such a way that the user has the feeling of immersion in the simulation [START_REF] Burdea | Virtual reality technology[END_REF]. The virtual environment is represented by the description of computer-generated objects in the simulation as well as the principles and relations of managing them. These objects have such physical characteristics as size, shape, colour, mass and behaviour. The features of virtual environment objects depend on the degree of interactivity of a given component and the complexity of the physical model of the virtual environment. For the virtual reality to be realistic, it must react to the user's actions, i.e. be interactive. The user's ability to influence the environments generated by the computer is one of the forms of interaction. Another option is to change the location and orientation from which the user sees the environment. If multiple users can exist in one virtual environment, the virtual reality system should allow interaction between them. Flight training simulators are one of the best examples of the practical application of virtual reality [START_REF] Shao | Development of a 1: 1 Scale True Perception Virtual Reality System for design review in automotive industry[END_REF]. Pilots can practice flying in different conditions. Flight exercises in difficult weather conditions are particularly beneficial for the training process, and the occurrence of airplane system failures can be simulated. Pilots can thus experience how the machine behaves in certain situations and their errors will not cause a plane crash. Driving simulators have been developed for a similar purpose -they enable safe driving lessons in various conditions (rain, ice, congestion) or tests of new cars [START_REF] Gallagher | Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training[END_REF]. In a virtual environment, you can change any of the car's functions (both aesthetic and functional) and then observe how real drivers react to the changes. The simulation allows to test cars designed before building a prototype.

Thanks to widespread access to VR equipment, new applications using virtual reality are constantly emerging. Scientific institutions also contribute to the development of virtual reality applications. The Fraunhofer Institute for Factory Operation and Automation IFF develops high-level interactive VR environments that can be specifically used in a wide range of industrial training programs [START_REF] Koźlak | Virtual reality technology for military and industry training programs[END_REF]. The work [START_REF] Koźlak | Virtual reality technology for military and industry training programs[END_REF] presents a methodology for creating an example of a virtual educational platform for operators. Realistic models of components used by the company for which the platform was built were used to build the virtual environment. On the other hand, in [START_REF] Matsas | Design of a virtual reality training system for human-robot collaboration in manufacturing tasks[END_REF], a virtual reality system was proposed for training employees of industrial plants on sites where they cooperate with robots. The motivation to build the station was to improve security. Thanks to this, an inexperienced employee will be able to learn the principles of safe cooperation with machines. The work [START_REF] Ortiz | Virtual training for industrial automation processes through pneumatic controls[END_REF] presents the use of VR technology and computer graphics by industry in order to reduce production costs, minimize learning curves and eliminate hazardous situations. In addition, examples of procedural training and VR simulators are shown, as well as their use for military training and support for soldiers. The authors of work [START_REF] De Pace | An Augmented Interface to Display Industrial Robot Faults[END_REF] built a virtual reality application to teach the management of industrial processes, with particular emphasis on pneumatic systems. The virtual application includes the environment of a virtual laboratory and a virtual industrial plant. The proposed solution allows the participation of multiple users in one virtual environment and interaction between them.

Designing of a Training Program and Virtual Robotic Stations

For the construction of a training program together with industrial partners, it was decided to use currently available tools for designing and programming robots offline. The computer tools offered on the market allow for the three-dimensional design of robotic stations and the creation of simulation models through which the way a new station will look and function can be seen in detail before its launch. Due to the previously accepted assumption that the training is to concern ABB robots, the company's tool, RobotStudio, was used to build virtual stations (Fig. 3). The RobotStudio software from ABB is a robot programming environment. It can be used to build robotic stations and program robots both off-line and on-line. Virtual controller technology is implemented in the environment, allowing for a precise reflection of the actual work of the controller, and hence, among others, accurate determination of the actual work cycles of the device. The latest versions of the software work with VR glasses, allow to program robots in the virtual world and interact with their components (Fig. 4). High-performance PCs with RobotStudio software and Oculus Rift glasses were used to build training stations. Oculus Rift is a set of virtual reality goggles. After they are placed on the user's head, they display the image of a computer-generated world or a film recorded in 360 degrees. The user can look around them in a natural way, moving their head or body. The image displayed in front of the eyes is then transformed to create the illusion of being in the virtual world or in the centre of the action taking place in the film. The Oculus Rift version used was equipped with a screen displaying to each eye independent images with a resolution of 1080 × 1200 pixels. Connection with the computer is made by means of HDMI and USB interfaces. The movements of the user's head are tracked by two sets of sensors that are responsible for tracking the rotation and position of the head in space. The idea is that the device should properly interpret both shaking the head from side to side and, for example, leaning it forward.

RobotStudio makes available, for example, three-dimensional models of robots offered or their controllers. Unfortunately, they are not detailed models, there are no components inside; they only show the dimensions and external appearance. For the purpose of the training program, precise, interactive models of components of robotic stations were built. 3D CAD software was used to build the models. Next, the models prepared were exported to the RobotStudio software using the SAT standard (Fig. 5). Due to the adopted training program, the focus was on support and servicing of 6-axis robots and the latest IRC5 controller. ABB's technical and service documentation was used for the building of detailed models of station components (Fig. 6). Based on photographs and available units, detailed models of the most important components of the IRC5 controller were built, such as, for example, an axis computer, a main computer and drive controllers. Models of IRC5 components are equipped with interactive components (e.g. LEDs) informing about status, operating mode and failures. The built-in components are connected programmatically with a virtual controller that allows the execution of robot programs. In addition, the models built were equipped with a mechanism that randomly generate failures, display error messages and prompt methods for solving problems. The picture of the upper computer, its model and information displayed using the VR technique is shown in Fig. 7.

The method of informing and possible causes of failure

Photo of a main computer

The presentation of status information Fig. 7. The idea of building interactive components of a robot controller.

Similarly to the IRC5 controller model, models of the most common robots were built. They are equipped with gears, brakes and components related to the calibration and replacement of oils in the gears (Fig. 8).

Examples of activities performed by the operator A fragment of the virtual environment Fig. 8. A section of the virtual environment developed.

As part of the work, scenarios of failures, repairs and servicing of robotic stations were prepared using VR. The person being trained, equipped with glasses and hand controllers, deals with support and servicing of the station. Their tasks include identification of the type of controller failure based on the symptoms, operation of the robot consisting in the calibration, checking of shock absorbers and the replacement of oil in the gears. The structure of functioning and the components developed allow the training program to be developed in the future.

Conclusion

The article presents a developed system of training of operators and service technicians in the field of operation, maintenance and servicing of robotic stations. This system uses virtual reality, thanks to which the training is interactive and allows advanced operations without the risk of damage to expensive equipment. As part of subsequent works, a training program with the use of virtual reality will be expanded. There will be added next activities performed on the robots and the expanded base of possible system failures. The number of stations whose service can be simulated will be increased. The students will be more involved in the project and a database of virtual-interactive objects subject to servicing and service will be built. In subsequent works, we plan to use the augmented reality as an element complementing the training system. The concept and the training program were created thanks to the existence of a collaborative network based on the Aviation Valley Association. At present, no company, university or government has the time or resources for continuous innovation. The global market places higher and higher demands, and there is a tendency towards specialization and continuous development. In the case of the collaborative network discussed, the cooperation of the university, bringing tools and specialist knowledge, with companies, which have experience and high technology, can bring mutual benefits and create new value. The presented cooperation stems from a common belief that together network members can achieve goals that would not be possible to achieve separately or would require more time and resources.

Fig. 1 .

 1 Fig. 1. Diagram of the functioning of the discussed collaborative network. The detailed goals of Aviation Valley are: • The cooperation with universities of technology, which would promote new ideas and scientific research within the aerospace industry. • The further development of aerospace research, aptitudes and skills. • The organization and development of a low cost supply chain.• The creation of favorable conditions in order to enhance the development of aerospace industry enterprises in this region. • The protection of enterprise and businesses in the aerospace industry. Aviation Valley connects over 160 companies from the aviation industry. Cooperation with higher education institutions, especially with the Rzeszow University of Technology, is very important for this association. Joint research projects are carried out as part of this cooperation. An example of cooperation with the companies of Aviation Valley presented in this work focuses on designing advanced robotic stations and robotization of various types of processes. One such jointly developed process is the robotic quality control of jet engine components presented in the works[START_REF] Burghardt | Robot-operated inspection of aircraft engine turbine rotor guide vane segment geometry[END_REF],[START_REF] Burghardt | Software for the robotoperated inspection station for engine guide vanes taking into consideration the geometric variability of parts[END_REF],[START_REF] Burghardt | Robot-operated quality control station based on the UTT method[END_REF]. Robotic machining processes in the aviation industry and diagnostics of the components of robotic stations are the subject of publications[START_REF] Teti | Advanced monitoring of machining operations[END_REF],[START_REF] Gierlak | Hybrid position/force control in robotised machining[END_REF],[START_REF] Burghardt | Monitoring the parameters of the robot-operated quality control process[END_REF],[START_REF] Burghardt | Experimental Study of Inconel 718 Surface Treatment by Edge Robotic Deburring with Force Control[END_REF],[START_REF] Barnfather | A performance evaluation methodology for robotic machine tools used in large volume manufacturing[END_REF],[START_REF] Kurc | Non-contact Robotic Measurement of Jet Engine Components with 3D Optical Scanner and UTT Method[END_REF],[START_REF] Hui-Ping | Communication of multi-robot system on the TCP/IP In: mechatronic science, electric engineering and computer (MEC)[END_REF],[START_REF] Szybicki | Robot-Assisted Quality Inspection of Turbojet Engine Blades[END_REF],[START_REF] Szybicki | Calibration and verification of an original module measuring turbojet engine blades geometric parameters[END_REF]. The existence of this collaborative network allows companies to implement advanced robot-related solutions, and academic staff can co-create and publish interesting works. A very important component of the university's cooperation with companies is the education of students within the so-called dual courses

Fig. 2 .

 2 Fig. 2. A photograph of one of the robotic stations. Companies in Aviation Valley are currently investing in robotization, more and more advanced stations are being created, and more processes are becoming robotized and automated. Due to ongoing robotization, training and raising of awareness among staff regarding robots are necessary. After analysing the needs of companies, it was decided to prepare a common training program for robot operators and service technicians. The program has been prepared so that it can also be used in an engineering study program. Market research was carried out and due to the advantage of robotic stations with ABB robots, training related to the company's solutions was prepared. The first training was carried out for Pratt & Whitney Rzeszow S.A. (P&W). After consultation with the company's representatives, analysis of the most frequent support and servicing procedures and review of the types of stations, it was decided to use virtual reality to prepare interactive training. The use of virtual reality made it possible to adapt the training program to specific robots that exist in P & W without interrupting production. It was possible to develop alternative scenarios for support, repairs and maintenance. In addition, in the safe simulation environment operators could perform advanced maintenance activities.

Fig. 3 .

 3 Fig. 3. View of a station designed in the RobotStudio software.

Fig. 4 .

 4 Fig. 4. The concept of cooperation of RobotStudio software with VR tools.

Fig. 5 .

 5 Fig. 5. Diagram of the export of detailed models.

Fig. 6 .

 6 Fig. 6. Construction of the IRC5 controller.


Ethics. An International Journal of Moral, Political, and Legal Philosophy, 125 (2), 2015, p. 543-545. On Norman Wilde's "The Meaning of Rights" 1

Charles Girard

In "The Meaning of Rights," Norman Wilde offers an original account of rights, still of interest.

Rights, he contends, are possessed by an individual by virtue of the social function she fulfills. It is because individuals belong to a common social order, in which each has her part to play, that they are "entitled to the conditions necessary for playing it" [288]. This approach allows for a nuanced view, according to which rights are neither absolutely inherent to the individual nor entirely dependent on social conventions. But is such a function-based justification of rights plausible?

A right is a claim to exemption from interference (or to aid) in the exercise of a power to do. As such, it presupposes the existence of a social order giving significance to the claim: the exemption (or the aid) must be demanded of someone. Rights only have meaning, therefore, "within the sphere of social relations" [288]. Human beings form associations to pursue shared purposes, and their organization gradually creates permanent social structures, such as schools, churches, or unions. These institutions operate as programs of work, assigning a function to each of their members and defining what they can do. To belong to an institution is "to have committed one's self to a scheme of life involving specific duties and specific rights" [285].

What makes a right not only meaningful, but justified, then, is that the exemption (or the aid)

Ethics. An International Journal of Moral, Political, and Legal Philosophy, 125 (2), 2015, p. 543-545. being demanded is a necessary condition for the performance of one's duty within such a social order.

Wilde's account stands out as original when contrasted with standard justifications of rights. It is neither a status-based nor a contractual account: it does not rest on the recognition of certain attributes of the individual human being that would make it fitting to ascribe her certain or on the determination of principles that would be chosen by properly situated and motivated individuals agreeing on the basic terms of their association. It rather is an instrumental account: rights are possessed by the individual to the extent that they are needed for her to "fulfill [her] function" [292]. Nonetheless, Wilde does not define rights simply as means for achieving a desired distribution of interests. They are rather preconditions that make it possible for individuals to act as members of a social whole, thus contributing to the pursuit of a common good. They are not determined directly on the basis of social goals, but on the basis of the functions assigned by institutions to their members. While individuals may or may not use their rights to pursue the institution's purpose, their possession of them is, however, a "negative condition" [290] for its achievement. This account might be accused of making rights entirely dependent upon contingent social arrangements. Wilde, however, rejects such a conclusion, since he denies that they "are created by the grant of society" [293]. Although their existence is conditioned by the existence of social institutions, rights are not created, but only recognized and enforced by social conventions and laws. The individual fighting for her emancipation, for instance, does not ask society to bestow upon her a new right to freedom, but to acknowledge that she already has one by virtue of her place in the social order. In a slaveholding society, the slave's right to be free pre-exists its recognition by the slave-owner. Admittedly, individuals need to see themselves as members of

Ethics. An International Journal of Moral, Political, and Legal Philosophy, 125 (2), 2015, p. 543-545. the same social order for rights to be recognized, since it is only when they can invoke a "common program" that they can successfully claim the protections necessary to its realization.

But it is enough that individuals belong to the same social order, even unwittingly, for rights to exist. The reason appears to be that the common purpose embodied in an institution can only be "real" and "common" [296], if it is possible for its members to endorse it freely. Accordingly, they must have extended freedoms. To adequately perform one's function, one needs to be able to adopt freely the common purpose from which it derives.

A mirror-objection could now be advanced: rights grounded on social functions might appear to be as indifferent to social circumstances as "absolute" rights, since their existence does not depend on their social recognition. However, Wilde also rejects this view, since rights are not "possessions of the individual irrespective of conditions" [295]. While certain freedoms are necessary conditions of the intelligent interest of the individuals in the institution's purpose, the extent of rights also varies with circumstances. It depends on what is consistent with, or conducive to, this purpose in concrete situations. We should thus distinguish between the ideal rights individuals would have if society were constituted "as it should be," with each member dedicated to the common good, and the concrete rights that "can be safely acted upon at a given stage of society" [296]. This function-based account of rights ultimately rests on a functionalist view of institutions. Two premises allow Wilde to claim that rights are neither absolute individual attributes, indifferent to circumstances, nor social conventions, entirely dependent on them. Firstly, institutions must be functionally organized towards the realization of a shared purpose. Society itself, as a network of institutions, must in fact be seen as functionally organized around common purposes. Secondly, the functionality of an institution must rest on the possibility for its members to endorse its

Ethics. An International Journal of Moral, Political, and Legal Philosophy, 125 (2), 2015, p. 543-545. purpose freely. Only under this assumption can membership alone create extended freedoms. If institutions could adequately accomplish their purposes even when their members were not free to endorse them, a view assigning differentiated functions to individuals could invoke a functionbased account to justify allocating deeply unequal rights, for instance, to slaves and slave owners.

Unfortunately, neither "The Meaning of rights" nor Wilde's 1924 book, The Ethical Basis of the State 2 , fully substantiate these premises, which would make plausible a view in which "my rights belong, not to myself in my private capacity, but to the part I have to play in the human drama"

  essay on Norman Wilde, "The Meaning of Rights," Ethics 34 (1924): 283-297. 2 Norman Wilde, The Ethical Basis of the State (Princeton: Princeton University Press, 1924).