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Picture of Whiteboard Erasing Robot
My entry for the Microcontroller contest is a whiteboard cleaning robot. The goal of this project was to create a robot which could erase written text on a whiteboard completely autonomously, i.e. no human interface. The processes involved in this project included devising a method for the robot to search a whiteboard for text, designing a way to physically move a robot to the text, and enabling a robot to erase the text.
 
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Step 1: Parts/System Break Down

Picture of Parts/System Break Down
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Parts Included:
Arduino Mega
Arduino Mega Protoshield, with 2 mini breadboards and jumpers
3 VEX motors
BlueSmirf Bluetooth Adapter (located in the yellow VEX case with antenna)
RoboRealm Vision Software
VEX linear sliders
VEX Rack and Pinion gears
VEX 9.6V Battery
4 VEX small wheels
Vex metal, screws, etc.

This project is made up of two main sections. The first section is the actual robot. The robot in theory is somewhat simple. It consists of a base with two wheels which rides on a whiteboard track. The base design allows the robot to cover the entire x-axis of the whiteboard. To move on the y-axis, the robot uses linear sliders to move an arm up and down. Attached to the end of the arm is a dry-eraser that does the actual erasing. 

Building the robot is not hard.  It just consists of 2 motors which each respectively drive 2 small VEX wheels.

Step 2: Computer Vision

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The second section, and more complicated part of the project, is the webcam and computer base control station located opposite the whiteboard. Utilizing an standard webcam and vision software at the computer base station, the robot locates any text anywhere on the whiteboard. It does this by using a series of filters and processing functions within the vision software, RoboRealm. In RoboRealm I used many different filters to find the center-of-gravity of the text on the whiteboard. The center of gravity cannot be found based on just the webcam image. I first used a RGB filter to eliminate everything but the green writing. Then the color is inverted by a Negative filter. The image is then converted from the Negative image ( the pink “hello”) to black and white using a gray-scale filter. This is necessary because the center of gravity can only be found on a black and white image. Then a center-of-gravity module is used to find the center of gravity. RoboRealm is a great software that has many uses and features. To find out more about the software go to www.RoboRealm.com  



*The code that is attached is a basic proof of concept code.  It shows how the eraser would move to the text, no matter where it is on the whiteboard.  Move your mouse to simulate where the text is written.  In order to use the code, you need a copy of RoboRealm.  The standard cost is $89, or you can download a 30-day free trial at http://www.roborealm.com/registration/index.php

Step 3: Microcontroller Control

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Once the program finds the center of gravity of the writing on the whiteboard, it is converted to a point on a coordinate plane. Then using basic math, the program tells the robot to move to this point using motor commands derived from the point on the coordinate plane. All of the math and calculations are performed on the computer and only the motor commands are sent to the robot via Bluetooth. Performing the math on the computer and not on the actual robot makes the system perform significantly faster and smoother.  In this case the microcontroller is only acting as a physical interface.  The only code that gets loaded onto the Arduino Mega is an interface code that allows RoboRealm to communicate with the Mega.

The code attached is the interface code that allows the Mega to communicate over Bluetooth to RoboRealm software.

Step 4: Versatility

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One of the original goals of this project was versatility. This robot is designed to work on any whiteboard at my high school. Every whiteboard in the school has a track at the bottom for holding markers and erasers. By designing the robot to ride on this track, it can work anywhere in the school. 

However riding on this track proved a bigger challenge than I originally anticipated. The track at the bottom of the whiteboard is very narrow. In order to get the robot to stay on this track, I had to build the center of gravity directly over the track; otherwise it would fall off (which happened very frequently in the early design stages). This gave me a very small area to work in and I had to fit all the heavy parts into a tight area, hence the very messy and awkward placement of the battery and microcontroller.

Step 5: Conclusion

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This project is a prototype that was a success and could be expanded greatly. There are many features that could be added to customize the robot in the future, such as
  • Automatic schedule, for example: erase every 10 minutes
  • Work with voice command instead of a webcam
  • A light sensor which would trigger the robot to erase the entire whiteboard when the lights go off i.e. when the teacher leaves the class room for the night
  • Only erasing certain color writing. Since the program uses a RGB filter, the robot could theoretically erase only red, green, blue, yellow, or cyan colored writing

athello1 month ago

This is incredible! It's an amazing project...you should do a full tutorial on it!

Just a thought: If you wanted to make it more efficient, it would be neat if you could attach something like this to the robot instead. It might take less time as opposed to using the smaller eraser :)

kira913 months ago
hi sir your project was amazing can you please send me the circuit diagram? Thank you sir..
rommelbalunsat@gmail.com
AllenKll5 months ago

Nice Project, you should do an Instructable on it. You know, where you actually instruct someone on how to recreate it.

JamesonO7 months ago

could you send me the circuit diagram too...

jameson.p.ocampo@gmail.com

jpeg_nyit1 year ago

Hey what webcam did you use exactly?

tbao1 year ago
Could you send me a diagram of your eraser whiteboard robot?
I would like to build it
Citytech90@gmail.com
Viper05181 year ago
U mad!??!?! This is AWESOME!!!!!!!!!!!!!!!!!!
jacob11123 years ago
How did you use the vex receiver module with the Arduino?
Where's the webcam on this?
zazenergy4 years ago
This is really cool! Next time, please take a video so we can see it in action :)
+1
Mavamaarten4 years ago
That's pretty awesome. Is there by any change a video of this thing in action ?
+1
belmont524 years ago
i would deffinatly like to see a video of this
+1
Try implementing a center of gravity below the track, similar to what you see on steady cam rigs (or tightrope walkers). You do it by placing weight on an arm that hangs under the robot. That will make it much more stable.
TheHawkeye4 years ago
It'd be cool if you could scan and save an image of the board!
vishalapr4 years ago
Very nice! Have a look at my ibles as well, rated 5*
21GeeOff214 years ago
video?
12grahamb (author)  21GeeOff214 years ago
No sorry. Unfortunately I made this in school and my video camera was messed up at the time. I have already taken the robot apart because I needed the parts for another project. I am hoping to build this again and film it after summer break.
-Ben
I really would like to see this in action. A whiteboard erasing robot is a very good improvement for classrooms. Make the world a better place ;-)
nufi4 years ago
hey

cool project! You could even improve if you would save the "scanned" text into a picture and transfer it by bluetooth.