Lightweight Robot

Problem
Why does anyone want to make a robot? The answer is to do things for them. We decided to build a lightweight robot that may be able to address some of the needs of the everyday person who at any given time and for any given reason is just not able to get up. You may be too busy or you may just be too lazy; and our robot will be able to get what you need or get who you need.

Conceive
The most important detail about our robot was that it must be lightweight. We did not want a hulking noisy beast that would disrupt the regular flow of whichever setting it was used it. Also if the robot was too large or too heavy it could possibly damage the terrain it moved on and where it could go would be limited as well. Also, the smaller the robot the cheaper, and the easier to operate; in terms of coding and in terms of power supply. Keeping the robot lightweight, small and compact was the best option fiscally and logically. Next we wanted the robot's chassis to be as simple as possible, to allow for more efficient further growth. We also wanted the robot to be able to carry certain things on its back; such as the arduino/motor shield and other things such as notes or other small items. A flat top would be most conducive to this purpose. We wanted the robot to have the smallest amount of wheels as possible in order to keep coding and directionality less complex. However with only two wheels in the back balance could become an issue, so we thought maybe a non-motor controlled "nose" wheel in the front would be beneficial. Another of our goals was simplicity, so the least complex and most user friendly motor types would be the best. Servo motors fit this bill. In order for our robot to effectively be able to navigate its place of use, we had to give it certain technological upgrades. We would need the robot to be able to avoid obstacles, because it is not as if everything in a house or an office etc. always stays in one place. An obstacle may show up in a certain place one day where it wasnt before. For our robot to effectively avoid these obstacles, it would need an ultrasonic sensor to be able to locate the obstacles and the distance between them, then act accordingly. The robot would also need some way to direct itself, or follow directions that the user wouldnt have to get up to give. In this case, a reflectance sensor would be most useful. We could tape down white colored lines that would lead to various rooms.

Design
Chassis

The chassis was built with a light but sturdy and easy-to-cut wood acquired at home depot. We started with a 10.5 inch long, 8 inch wide plank of the wood. The wood was also approximately 1.5 inches deep. To make the two slots in the back for the wheels we cut 3.5 by 2 inch slots in the left and ride sides of the board; 2 inches from the extreme back of the board. Also a 2 inch wide nose was cut out at the front of the chassis. The board was narrowed down into the nose by cutting at a 30 degree angle from the sides approximately 3 inches down the length of the board. With our design there was space left at the top and bottom of the chassis for the motors and the arduino/motor shield. Also in the center of the board 6 inches from the back, there is a hole where all of our needed wires can come up through or go down through.

A code that successfully incorporates the ultrasonic sensor with the motor movements is still in progress.

Next Steps
The next step in our project is the completion of the object avoidance code utilizing both the ultrasonic sensor and the servo motors. Once this code is complete our robot will be able to avoid objects which is imperative for its purpose. After that we will begin incorporating the reflectance sensor array so that the robot will be able to follow preset directions in the form of white tape. Once its navigation upgrades have been made, the next steps we would take would be optimizing its ability to carry things; which may mean some changes for the chassis. We will also work on how we could operate it and maybe turn it on or off wirelessly.