Academic Company Events NI Developer Zone Support Solutions Products & Services Contact NI MyNI

Remote-Access Web-Based Physics Labs for Equipotential Field Line Mapping

  Print

Enlarge

Equipotential Lines

Author(s):
Alex See - Monash University Malaysia
Ang Jin Leong - Monash University Malaysia

Industry:
Education

Products:
PXI/CompactPCI, LabVIEW

The Challenge:
Developing a remote-access, Web-based Internet-controlled system for performing a first-year engineering undergraduate physics lab experiment to map equipotential and electric field lines.

The Solution:
Using a National Instruments LabVIEW-coded program to perform motion control over an XY motion mechanism, which holds the probe and takes voltage reading across various water tray positions.

"By using industry-standard software such as LabVIEW, we provided the opportunity to fully integrate hardware and a computer directly in the labs environment. "

Remotely Controlled Labs Experiment

Remote-access, or Web-based labs, are becoming popular with many university professors due to the ubiquity of the Internet as a communication medium.At Monash University Malaysia, undergraduates perform experiments in labs. They often encounter insufficient lab instruments and equipment and are limited by lab hours. This especially happens when the experiment involves expensive instruments and many undergraduates in one session. In fact, such occurrences are very common in many universities and higher-learning institutions around the world.

A remotely controlled lab experiment, based on National Instruments remote panel technologies provides a way for students to carry out the lab experiment without physically being present in the labs and being restricted by labs hours. Students also could repeat the experiment using this user-friendly, computer-controlled instrumentation. With the system we developed, the experiment was operational around the clock, 24 hours per day, seven days a week.

One of the applications involved a remotely controlled system to perform a popular physics experiment, equipotential and electric field line mapping. In this experiment, a student uses NI LabVIEW to search for an equipotential line voltage. LabVIEW searches by moving probes across a water tray. A search algorithm ensures that the program searches in an efficient manner, from one edge to another, rather than searching randomly. The algorithm considers the water tray boundaries so that the search only happens within the water tray.

The system includes a delete function so that the student can delete the last mapping entry, if unsatisfied with the shape of the equipotential line traced and displayed on the front-panel graphical user interface (GUI).

Program Search Sequence

We developed and programmed the search sequence program using the LabVIEW graphical development environment.The equipotential line search includes a series of repeated actions. XY mechanism motion control elements are integrated to move the probe to the desired position, using the NI PCI-7344 high-performance motion controller. Following are the general search sequence steps:

  1. Move the probe to the edge
  2. Find the XY position whereby the required potential lies
  3. Move the probe for a small fixed interval in X direction
  4. Find the Y position whereby the required potential lies
  5. Repeat steps 3 and 4 until the probe reaches the other edge, which stops the search sequence (this would find the following XY points, which have the same potential difference)
  6. Display the recorded equipotential line XY points in a graph

Conclusion

When all the power supplies are connected properly and the XY stepper motor mechanism is configured properly, the system traces the equipotential line one by one, as requested by the student. The system obtains an acceptable result and displayes the equipotential lines patterns in a graph.

A login screen requires students to provide a user name and password to remotely access the experiment. The user profile database is in Microsoft Excel format. Students can generate a completed report via the LabVIEW Report Generation Toolkit for Microsoft Office and submit electronically via e-mail to the instructor for assessment.

With LabVIEW, we rapidly developed a remote-access Web-based physics labs experiment for first-year engineering undergraduates at Monash University Malaysia. This remote, Web-based pilot experimentation augments the traditional labs experience. By using industry-standard software such as LabVIEW, we provided the opportunity to fully integrate hardware and a computer directly in the labs environment.

For more information, contact:

Dr. Alex See

Monash University Malaysia

School of Engineering, NO 2, Jalan Kolej, Bandar Sunway

Singapore

E-mail: alex.see@eng.monash.edu.my

 

Browse All Case Studies »

  Print