Classroom Blackboard Erasing Mechanism

Sounds silly, doesn’t it. The purpose of this mechanism may sound so but the way it works make it interesting. This may not appeal good for a final year mechanical project but the effort required for this project may be far more than many other projects listed in my site. It is always about how to tell the story, if you can keep the examiner interested in its working this will be a good project, but if you weigh more on the practical application I don’t know how it will go.

I mentioned that its practical application doesn’t appeal much, but if you think another way, we been using blackboards and chalks for a long time and we clean them manually breathing chalk dust, don’t we need a change? Most schools in India use them though some rich schools are using white boards and white board markers. We been following the same system for years, so let’s say we are bringing a revolutionary change here.

Now if you make such a claim you need some evidence to support it. For that you can conduct a survey among teachers get their opinion as how frustrating it is to take classes breathing chalk dust. 10-15 teachers would be enough. If you conduct a little bit of research you will find studies that prove prolonged exposure to chalk dust causes respiratory problems. And moreover front bunch students know how irritating it is to sit amid chalk dust (obviously I don’t 🙂 ). Therefore it is necessary to use a mechanism which can replace the manual cleaning of blackboards.

Aim:

The aim of this project is to build an automatic mechanism that can clean chalk marks from the blackboard without any manual labor. This project was done before by a team in Pune University and their detailed project is given at the end of this article. To me the mechanism they built sound complex, there are other easy ways to approach this problem. The duster they are using is a sponge which is the size of a normal blackboard duster. They locate the chalk marks by taking photographs of the whole blackboard and analyzing the location of the marks.

A simpler solution would be to make this a manual mechanism instead of automatic. Use a similar mechanism but make the duster the whole height of the blackboard. So when a button is pushed the duster moves horizontally over the blackboard sweeping the entire board instead of just the area with chalk marks. But definitely such a system doesn’t have the complexity needed for your final year project, I am just saying my opinion here.

The design by the Pune University team is a slider type wipe mechanism which consists of the following:

1. 2 motors
2. 3 guide rails
3. 3 sliders
4. sensors
5. CCD camera and other electronic components for automation

Working:

Credit & reference – Check the full project report here

The rails and sliders are used to move the duster on horizontal and vertical planes. A photo of the clean blackboard is taken and that image is divided into coordinates by a computer program. A CCD camera periodically takes pictures of the blackboard. The computer compares this image with that of the clean blackboard to detect the presence of any chalk marks. If any marks are found the details of its co-ordinates are passed to the moving mechanism. The motors, slider, rail mechanism take the duster to these co-ordinates and remove the marks. Pretty simple, huh?