Wednesday, 11th June 2014

Had my exam today in the morning. I could do reasonably well……lets hope for good result.

After coming back from college at 5.00PM , started working on my project…..I am really enjoying time with GSoC. Thought of using some different method to determine acceleration due to gravity.

Used the same set up of linear track in inclined position at about 45 degrees. Allowed vehicle to glide downwards and plotted position-time graph. Got straight line with positive slope as expected. Then used photo-gate with expeyes kit and could make time measurements.

Got this pick-up ready ……pickup for acceleration

 

This can generate a square wave as it passes through photogate. Acceleration can be determined  using the signal generated. Excited to see its working.

But now I have a problem ….how to measure the acceleration from the wave pulse generated. I think I should find time between rising and falling edge  the wave-pulse. Will work on this tomorrow ……..Feeling Sleepy now…. 🙂

This is the photo-gate I have used ….(photo from www.expeyes.in)

light-barrier Need to modify this as it is difficult to mount above linear track. will be going for design similar to photogate which I used with old version of ” Phoenix” box……..

 

 

Its here…

old photogate

………………………..

 

Any idea for easy measurement of acceleration using the pickup shown above?

Some proprietary closed source devices use this method……….( of course they come at a very high cost price)

Please share any modification in the pickup oar any idea for accurate measurement of acceleration using photo-gates….

This will result in a very low cost setup………thanks to FOSS…… 🙂

I love being a FOSSASIAN….. 🙂 🙂 🙂

 

Monday, 9th June 2014

Today the attempt to use two sensors at a time got little success. Used two srf05 modules to plot graphs. Both the graphs were out of phase as expected.

I will take a break of one day to prepare for my B.Ed. Exam which is on 11th June.

Will be back on 11th June evening with detailed experiment update.

 

GSoC Weekly Report 3

Third week of coding was very much productive.

We could plot position -time and velocity-time graphs using  the time and position data obtained from SRF 05 Sensor. I just moved  a notebook in-front of the sensor, up and down  and could plot position against time . But the plots were little noisy and giving unusable estimates of  the acceleration.

Therefore  I had to spend time to understand some filtering techniques. Google Search led me to the Kalman filter which is is a mathematical method that uses noisy measurements observed over time to produce values that tend to be closer to the true values of the measurements and their associated calculated values. With the inputs from my colleagues at FOSSASIA I could gather some good information about filtering techniques.

Experiment with Spring oscillations is also set up and could generate plots. GUI needs to be created for this experiment.

For experiments with Sound related phenomena we used two microHope boards to convert square wave into a sine wave. Wrote programs for two sound experiments. For reference, Used programs written by Dr. Ajith Kumar, the inventor of ExpEYES.

Tried the experiments with square waves SQR1 and SQR2 from ExpEyes kit. We are also working on preparing a stand alone board which can give variable frequency sine waves. This will be useful in  experiments like interference of sound, phenomena of beats and Lissajous figures.Uploaded these programs to Git repo.

This weeks work in points

  • Written python Codes for following mechanics experiments
  1. Study of One dimensional motion by plotting Position Time Graph
  2. Study of phase relation in graphs using two sensors.
  3. Plotting velocity-time and acceleration-time graph.
  • Code to use Two sensors simultaneously is ready to be tested tested. Used SQR1 and IN1 channels for accessing the second sensor.
  • Experimental set up to determine Spring Constant by method of oscillations is ready. Tested the code.
  • Set up for producing sine waves from square waves is ready. Using two MicroHope kits. We are working on a stand alone kit which can produce two variable sine waves.
  • Tried some filtering techniques for plotting smooth acceleration graphs.

To Do Next Week

  • Set up experiments involving collisions
  • Set-up experiment to determine acceleration due to gravity by motion on incline.
  • Write code for using photo-gates for determination of speed and acceleration.
  • Write code for plotting multiple graphs on a screen.
  • Main Focus Next week will be on completing documents on experimental procedures and uploading them on Gtt.

https://github.com/wavicles/Plugins-for-ExpEYES

Saturday, 7th June 2014

Today In the morning  wrote programs for two sound experiments.For reference, Used programs written by Dr. Ajith Kumar, the inventor of ExpEYES.

Tried the experiments with square waves SQR1 and SQR2 from ExpEyes kit. We are also working on preparing a stand alone board which can give variable frequency sine waves. This will be useful in  experiments like interference of sound, phenomena of beats and Lissajous figures.Uploaded these programs to Git repo.

 

 

Thrusday, 5th June 2014

Yesterday night I tried to plot graphs using  the time and position data obtained from SRF 05 sensor. I just moved  a notebook in-front of the sensor, up and down  and could plot position against time . But the plots were little noisy and giving unusable estimates of  the acceleration.

Today spent time to understand some filtering techniques.

Google Search led me to the Kalman filter which is is a mathematical method that uses noisy measurements observed over time to produce values that tend to be closer to the true values of the measurements and their associated calculated values.

I have downloaded some docs on filtering techniques and now I am studying them. I think I should take help from my mentors and fellow coders from FOSSASIA………

Before I go to sleep will try to finish   the setup to generate sine waves for sound experiments……..Its almost ready …..:)

generating sine wave for sound expt

Used two microHope boards to convert square wave into a sine wave. And this is the ultrasonic sensor set up ……….. appears complicated   🙂

setup srf srf

 

Any suggestion to plot smooth graphs in python  from noisy measurements????