Virtual Lab Remote Access and Speed Control of DC

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Virtual Lab: Remote Access and Speed Control of DC Motor using Ward-Leonard System Abhishek Choudhary, Shiv Aishwarya Singh, Mohd. Faizan Malik, Anil Kumar, Mukesh Kumar Pathak and Vinod Kumar

Abstract: Limited resources and requirement of regular maintenance of equipment in traditional laboratory supports idea of Web-accessible laboratories which provides facility of online experimentation on real processes. The objective of this project is to demonstrate the real-time web-based laboratory experiment conduction by accessing the laboratory set-up from a remote location and measure the experimental parameters by generating the control commands at a distant client. This architecture is developed to demonstrate the remote learning process using graphical programming tool LabVIEWTM10. The principle behind the implementation of remote laboratory session is to deliver the image of the control panel of the virtual Instruments to the remote client. The experimental hardware is linked to the web-server by Data acquisition (DAQ) interface card. The proof of concept has been demonstrated by controlling the speed of DC motor using Ward-Leonard method and recording the measurements using Virtual Instruments. Keywords: DAQ card, LabVIEWTM 2010, Ward –Leonard system

1. Introduction:

From the early 90s, efforts are being made to run the laboratory experiment via World Wide Web [1]. In 1999, a remote control experiment on oscilloscope was developed in VLAB laboratory of National University of Singapore [2]. The MIT ILAB architecture was also

another milestone in virtualization of instruments. It provides the deployment, management and sharing of online laboratories that interface with hardware device. Concept of such remotely accessing laboratories is very crucial for the developing countries where limited educational facilities are available. The lack of such facilities should not undermine the students studying in these institutes. The virtual Machine and Instrumentation workbench is a novel idea born out of the need for free and straightforward access to better facilities for all the engineering students. The virtual Machine and instrumentation workbench is a grand venture of GOI to enable the students of each and every technical institute of India to get an easy and effective access to the expensive laboratory instruments through virtualisation of the lab equipment.

This venture provides any student to conduct practical experiments through the medium of internet. For a student to try out any experiment, he/she should first get himself/herself registered on the website. After registration, they can choose a time slot offered for the experiment. If it is available, then the user is allowed to conduct the experiments during the allocated slot otherwise he/she can get from the server what user with slot wants it to do. The interface of the experiments has been designed keeping in mind the nature of the experiments to make it as real as possible. A lot of effort has gone into making the application extremely user friendly so that students face little difficulty in carrying out the experiments. After the experiments are conducted, the students are given a multiple choice quiz to refresh their knowledge on the subject. Also, the theory of the experiment conducted is explained briefly yet accurately in the report to get an in-depth understanding of the

experiment. The experimental svisible during the experiment throua camera which is controlled by th

The rest of the paper is organiseSection 2 describes the overalarchitecture including both hasoftware. An application example,control of DC motor using Ward-Lcontrol method is also described Section 3 and 4 discuss the challenges of application respectiSection 5 offers some concludchallenges we are facing and poithoughts for our future work.

2. System Architecture

Electrical Machine AC/DC

Starter Relays

Client without time slot

DAQ Card

D-link Camera

S

Current Sensor Voltage sensor

Fig 1: System architecture of the virtua The paper aims at demonstrating tvirtualization of electrical experiment and it also shows how person to operate and perform thevia internet. Practical knowledgeunderstanding of theoretical knhelps to understand the actuabehaviour of the system (electricThe virtualization is achieved following steps:-

1. Development of hardware 2. Development of server mo3. Development of client mo

setup is also ugh the use of

he user.

ed as follows. l virtual lab ardware and that is, speed

Leonard speed in Section 2. benefits and

ively. Finally, ding remarks, ints out some

e:

RPM Indicator

Client With time slot

Speed Sensor

al machine lab

the process of Machines’

it enables the e experiments

e helps to get nowledge i.e. al (practical) al machines). through the

odule dule

2.1 Hardware uarchitecture

2.2 Server Applicatio

Server application is one oparts of this architecturcontrolling or communicmachine and user. Eleindirectly controlled by serthe help of DAQ card. Server application also doaveraging of various signalperforms the task of signrequest are sent through Server also accesses the cebooking, username and This feature is facilitated server.

Data Socket is a light weiguser application programmfor connecting to data sources – local files, fileservers, and data items on OSocket in LabVIEWTM simexchange between applicaclient. It is better than TCinto an unstructured streaserver application and it chinto its original format in c

2

used in system

on

of the most important e as it acts as a

cating link between ectrical machine is rver application with

oes filtering and time ls of sensor. So it also nal conditioner. User

data socket server. entral database for slot password validation. by Microsoft ODBC

ght, standalone, end-ming interface (API) from a number of es on FTP or Web ODBC Servers. Data

mplifies real time data ations on server and CP/IP in which data am of bytes in the hange the bytes back lient application. So,

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there are lots of chances in losing data packets. However, Data socket was designed purposely for sharing and publishing live data in measurement and automation applications.

Server module is divided into three tabs:

• Home tab • Admin tab • Experiment tab

Fig 2: Tab flow diagram in server module

Fig 3: Figure shows the server window. The administrator user id and password are required for login. At this point

of time application is in anonymous state.

Fig 4: This is the home tab in server module. Here, booked slots are indicated with green led.

Whenever administrator starts the server application, he encounters home Tab. Administrator enjoys various facilities such as modifying user account.

2.2.1 HOME TAB

As soon as, administrator login is done with correct username and password, tab changes to home as shown in Figure 4.

In this tab, administrator can see slots booked on that particular day and name of the user who have current slot.

2.2.2 ADMIN TAB

This tab helps administrator to employ his admin rights. This tab is divided into three parts:

• Admin: This part of admin tab has a very important control which employ administrator to allow user to connect to machine or not. This facility is useful when admin is performing some assessment work and he does not want user to interfere.

• Edit user: Here, administrator can modify the user account information.

• Contact user: This part enables administrator to contact user. This feature is highly useful when administrator want to inform user about the change in schedule.

Fig 5: Figure shows the contact user par

2.2.3 EXPERIMENT TAB

This is the main tab as it containconcerned to start and control These controls can be altered bysoon as user changes any contapplication these changes are refserver application through data soc

Fig 6: Various sensor readings are beingfigure. Graph is showing the generated

respect to time

The server responds to user acthelp of DAQ card. Server applicahelp DAQ card sends the controacquires the values of sensed data.

rt of admin tab.

ns all control of Machine.

y the user. As trol in client flected to the cket server.

g shown in this d voltage with

tion with the ation with the ol signal and

2.3 Client Module

Similar to the server applicalso works in different statthe whole experiment into f

• Home • Perform experimen• Observation plot an• Evaluation • Report generation

The client module connecserver module via sharedshared over internet by usServer toolkit of the Lapplication is designed iexercise limited control ovserver application.

2.3.1 Home tab

This tab works in the similmodule home tab accept twe have not allowed thconnect to the central dinstead, it connect via the s

Fig 7: Client tab structure is s

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cation, client module tes. We have divided five basic steps as:

nt nd calculation

cts or contact to the d variables that are sing the Data Socket LabVIEW™. Client in such that it can ver machine through

lar way as the server that in client module he user to directly database of the lab erver application.

shown in flow diagram

This state avails the user to see ththe lab as well as allow to login toexperiment so that he can book thmodify his booked slot. User waccess the experiment.

Fig 8: On this window user can book slot the slot. He can see the already boo

2.3.2 Perform Experimen

The user with slot can perform thon this tab. After starting the maccan vary the generated voltagegenerator terminal as per desired or decreasing the value of the separated filed of DC generator.

Fig 9: DC Generator field resistance setuusing solid state relays where relay sig

controlled

he updates of o perform the he slot or can with slot can

and can modify

oked slots.

nt tab

he experiment hine, the user e across the by increasing resistance of

up is developed gnals are user

Generated voltage and spesaved in table format by cbutton. This window showslaboratory to the user, so tchanges that are happeninHence, it provides a real lab

2.3.3 Observation calculation ta

This state of client mobservation in the grapperforms the required calcend to find the other pdisplay the final observatio

Fig 10: This figure presents thwindow of client

Fig. 11: Figure shows the grapharmature voltage of the gener

experimen

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eed readings can be licking on the ‘save’ s the live view of the that he can sense the

ng with the machine. boratory scenario.

plotting and ab

module presents the phical format and culation at the back parameters and will on to the user.

he perform experiment t module.

h between the speed and ator as recorded in the nt.

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2.3.4 Evaluation tab

Here, the user is provided with number of multiple choice questions related to the experiment, he had performed. The data base of prerecorded questions is available at the server end, these question are published over the internet. The purpose of this tab is to evaluate the user’s understanding of the experiment.

Fig 12: Figure displays the evaluation state of the client

module

2.3.5 Report generation tab

Here, user enters into the last step of experiment. In this tab, Client module piles up all the observations like graphs, recorded readings, number of questions attempted, and number of questions corrected etc. With the help of report generation toolkit in LabVIEW™ an html page based report is displayed in a web browser active X control object.

Fig 13: Client module in report generation tab

3. Benefits of the application

The application serves various purposes. It uses a single hardware and provides remote access for multiple users. The live video streaming is another feature that eliminates the need of being physically present in the lab. We have also provided an HTTP based chatting service on our website that can directly allow the user to contact to the administrator of the lab for assistance.

4. Challenges

The future work will be directed to deal with some issues to increase the reliability. As the number of users increase, the bandwidth limitation will prevent the live streaming of the experiment. The number of lost data packet also decreases the reliability of the laboratory architecture.

5. Conclusion

The complete experimental setup, which is remotely controlled by the user, has been developed. The details of the hardware and software system have been discussed. Efforts are being put to make the experiment user friendly. The concept can be extended to develop new experiments. This will pave the way for the better quality of education in India.

6. Acknowledgement:

Authors are thankful to MHRD and IIT Roorkee for providing financial assistance and laboratory facility and infrastructure to develop the virtual laboratory.

7. References:-

1. A. Bhandari, M.H. Shor, Access to an instructional control laboratory experiment through the World Wide Web, in Proceeding of the 1998 American Control Conference, Philadelphia, 1998, pp. 1319–1325.

2. C.C. Ko, B.M. Chen, S.H. Chen, V. Ramakrishnan, R. Chen, S.Y. Hu, Y. Zhuang, A large scale web-based virtual

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oscilloscope laboratory experiment, IEE Engineering Science and Education Journal 9 (2) (2000) 69–76.

3. http://www.ni.com/datasocket/

Abhishek Choudhary is pursuing Bachelor’s degree in electrical Engineering from Indian Institute of technology (IIT) Roorkee. He has been working as student research assistant in Virtual Electrical Machine Lab (VEML), IIT Roorkee (India). His research interest includes Wireless Communication and Sensor Networks, Signal & Image Processing, Computer Vision, Vision Guided Robotics, Bio-Medical Instrumentation. He has also completed project on implementation and design of 'smart' Wireless Sensor Networks in Integrated Sensors, Intelligent Systems (ISIS) Laboratory at the University of Calgary, Canada. Shiv Aishwarya Singh is pursuing Integrated dual degree in electrical Engineering from Indian Institute of technology (IIT) Roorkee. He has been working as student research assistant in Virtual Electrical Machine Lab (VEML), IIT Roorkee (India). His research interest includes power electronics, power system and control engineering. Mohd. Faizan Malik is pursuing Integrated dual degree in electrical Engineering from Indian Institute of technology (IIT) Roorkee. He has been working as student research assistant in Virtual Electrical Machine Lab (VEML), IIT Roorkee (India). His research interest includes power electronics, digital image processing and control engineering. Anil Kumar completed his Bachelor’s degree in Electrical Engineering from Indian Institute of Technology (IIT) Roorkee and is working as Junior Research Fellow at Biomedical Signal Processing Lab, IIT Roorkee, India. His research interest includes Machine Learning, Biomedical Signal and Image Processing, Autonomous Robotics, Computer Vision, Computer Aided Instrumentation and Software Application Development. He has successfully completed major projects sponsored by IRDE Defense Research and Development Organization (DRDO India), Rajasthan Electronics and Instruments Ltd. (India) and Ministry of Human Resource and

Development (MHRD) India. Mukesh Kumar Pathak did his graduation in Electrical Engineering from L.D. Engineering College, Ahmedabad (Gujarat), India, in 1986. He joined Electrical Engineering Department of NIT, Kurukshetra (Haryana), India, as a Lecturer in 1987. In 1989, he joined Electrical Engineering Department of NIT, Hamirpur (HP), India, where he served till 2007. Presently, he is working as an Assistant Professor in Electrical Engineering Department of IIT Roorkee, India, where he joine din 2007.He obtained both his M.Tech and Ph.D. degree from IIT Delhi, India. He has co-authored a book on Electric Machines. He is a member of IEEE, life fellow of Institution of Engineering (India), life member of Indian Society of Technical Education (ISTE) and Systems Society of India (SSI). Vinod Kumar is Professor and head of Electrical Engineering Department, Indian Institute of Technology Roorkee, India. He is also head of Continuing Education Centre and Quality Improvement Program Centre of IIT Roorkee. He received his both Masters and PhD degree from IIT Roorkee (erstwhile University of Roorkee). He has many academic awards, distinctions and scholarships and more than 150 research papers to his credit. He has 34 years of rich experience of teaching & research. He is a life fellow of IETE and is a senior member of IEEE. His areas of interest are Biomedical Signal and Image Processing, Pattern Recognition, Medical Instrumentation.