State-of-the-Art Remote Laboratories for Industrial Electronics Applications

• Mohamed Tawfik• Elio Sancristobal• Sergio Martin• Gabriel Díaz• Manuel Castro

• Rosario Gil

Electrical & Computer Engineering DepartmentSpanish University for Distance Education (UNED)

The implementation of practical sessions in engineering education:

• Paves the way for students to be familiar with the instruments and thus, with the industrial real-world.

• Augment the learning outcomes by strengthening the understanding of scientific concepts and theories.

Unfortunately, there exist a wide gap between the engineering educational curricula and the industrial real-world owing to:

• The lack of experimentation availability. • The high cost of equipment and administration burdens.

• Remote laboratories addresses these needs providing on-line ubiquitous workbenches unconstrained by neither temporal nor geographical considerations.

• Recently, hundreds of remote laboratories for industrial electronics applications have been developed at many universities.

• Despite this, the design of remote laboratories has not received too much attention; most of the published literature focus only on the objectives of a certain application, within a conducted course or on their functional and operational aspects.

• To fill this gap, in this contribution we present a generic study on state-of-art remote laboratories for industrial electronics applications and their development addressing all the design process stages and cutting edge technologies adopted.

Remote laboratories are those laboratories that can be controlled and administrated online. They differ from the virtual simulated laboratories as they are interacting with physical instruments.

e.g. Virtual Instrument Systems in Reality (VISIR)

VISIR is a remote laboratory for wiring and measurement of electronic circuits remotely.

The common generic architecture design of today’s remote laboratory for industrial electronics applications.

There exist two major challenges in building remote laboratories:• Selecting the lab server software.• Selecting the client-server communication technology.

The common outstanding technologies applied for remote laboratories lab server software development are LabVIEW and MATLAB.

VS

Both possess rich and powerful features:

• Data exchange with other GUI applications such as COM, ActiveX, CGI, Java and .Net applications, and web services.

• Support for standard Application Programming Interfaces (APIs) such as IVI, VISA, PXI, GPIB, VXI, USB, LXI, and others.

• Connection with ODBC or OLEDB compliance database; compilation as DLL files to be called from the Lab server software as a driver to execute the experiments on the hardware.

• Support for OPC Servers to enable HMI and SCADA.

VS

• LabVIEW is the most popular remote laboratory environment and it is the most outstanding representative of graphical programming language visualization and parameter tuning for remote operation.

• MATLAB is the most powerful computing language for control algorithm development and simulation

• Full using of their advantages can achieve high efficiency programming. In numerous remote laboratories applications, a hybrid method was adopted; the signal acquisition and the GUI were developed with LabVIEW, while numerical calculation and signal processing were developed with MATLAB.

LabVIEW can support several ways of hybrid programming with MATLAB by means of:• ActiveX automation technology• DLL technology• COM technology• MathScript RT Module

Mathscript module allows embedding .m file scripts in LabVIEW applications by connecting the text-based I/O variables with the inputs and outputs of LabVIEW.

The client-server layer is responsible for the communication between user interface and the lab server

• The client-server layer is responsible for the communication between user interface and the lab server

Lab Server SoftwareUser Interface

There exist a wide variety of technologies for the communication between client-server:

Desktop Sharing security problems• Virtual Network Computing (VNC)very slow• Remote Desktop Protocol (RDP) limited to a single connection

Common Gateway Interface (CGI) performance problems ActiveX and Java Applets plugins required

Rich Internet Applications (RIAs) plugins required LabVIEW Web server only with LabVIEW applications

Asynchronous JavaScript and XML (AJAX) the actual trend

Each of these solutions have its relative advantages and disadvantages, which are well discussed in the paper. However, the trend is more shifted towards web standards such as AJAX and Web services. On the mean time for LabVIEW applications LabVIEW web interface is the common choice.

For more information about remote laboratories, we invite you to access to the web page of the Electrical & Computer Engineering department of the UNED.

http://ohm.ieec.uned.es/

Research on Technologies for Engineering Education

Thanks for your Attention!

Rosario Gil

Electrical & Computer Engineering Department (DIEEC)Spanish University for Distance Education (UNED)