|
|
Heather's Honors Engineering Project
SFA Rover
|
For an honors project in Engineering 112 at SFASU, I created a robot out of a plastic pencil box. The details of the project can be found at Dr. Dan Bruton's SFA Rover Project page. Chris helped me a lot throughout this project. His beginner's robot page can be viewed at www.robots101.com.
|
|
Robot
|
|
|
|
The robot has a bumper from a remote controlled racecar attached to the front with two push buttons. When the robot hits something on the right side of the bumper, the right push button is depressed. This makes the robot stop, back up, turn to the left, and continue moving forward. If the robot collides with an object on the left side of the bumper, the left push button is hit. The robot stops, backs up, turns to the right, and continues going forward. Because of the bumper, the robot can maneuver around obstacles and keep moving without any human interference.
|
|
|
Click on the picture to the left to view a video of the robot bouncing off the walls in a hallway of the Miller Science Building at SFA. It is a 9MB file so it will take awhile to load. Right click on the image to the left and click on Save Target As... to download the video. You need QuickTime to view this video clip.
|
|
Vehicle
|
|
I used a plastic pencil box from Target as the chassis. It is a rear-wheel drive vehicle, and the wheels and motors came from pololu.com. The front wheel is a simple castor. To keep the wheels from being visible from the outside, I cut slits in the bottom of the pencil box for the rear wheels. I mounted the front castor onto a small project box and cut sections out of the project box so the castor wheel had free rotation. Then I mounted the project box onto the pencil box. On the lid of pencil box, I attached the project board with zip ties through holes I had drilled into the lid. I drilled a hole for the switch in the lid as well. Pictures of the robot in various stages of construction are to the right. Mouse over an image to see a description and click on an image to enlarge it.
|
|
|
Circuitry
|
|
|
The robot utilized an H-bridge to control the direction of the motors. The diagram to the right illustrates how the circuitry was put together on the H-bridge.
The brain of the robot was a PIC 16F84A from www.microchip.com. The configuration of the circuitry on the PIC chip is shown in the diagram below.
|
|
|
Click on the images to the right to view the finished circuitry of the robot. The green LEDs are used to connect pins 7 and 9 of the PIC chip (the forward motor controls) to the ground. The red wires leading from pins 6 and 8 of the PIC chip (the reverse motor controls) are connected to the red LEDs that are stuck into holes drilled in the back of the pencil box. They act as brake/reverse lights when the robot collides with an object. The red LEDs are also grounded.
|
|
Resources
|
|
|
- Dr. Dan Bruton's SFA Rover Project page holds all the parameters for the project. The page describes the different components (from motors to PIC chips) in great detail and gives information on where they can be obtained.
|
- A book called the Robot Builder's Bonanza was very helpful in figuring out the circuitry. This book is very easy to understand and is a valuable resource to beginners. Click on the image to the right to go to the book on Barnes and Noble's website.
|
|
|
|
