Kraftmouse

Introduction

Our mouse, Kraftmouse, needs to find a new home and the only way that Kraftmouse can distinguish between homes is via differences in light intensity. Kraftmouse's ultimate mission of finding a new home can be divided into two tasks.

Task 1
Kraftmouse starts its trek at the end of a long corridor at which a rectangular room is situated. In order for Kraftmouse to start its new home finding process, it has to first make its way out of the rectangular room and enter and travel down a corridor. Towards the end of the corridor, there is a sharp right turn in which Kraftmouse must maneuver through to ultimately make its way out of the corridor.

***Picture of Maze/Track***

Task 2
	Just upon exiting the corridor, Kraftmouse activates a transmitting RCX unit by crossing a gate. By crossing the gate, Kraftmouse officially leaves the corridor system and enters the outside surrounding environment in search of a new home.  Kraftmouse then receives a random signal from the transmitting RCX unit and the signal is received by the RCX unit onboard Kraftmouse via infrared signals. The transmitting unit sends one of two possible commands:
* Command 1: go to the new home that displays a bright light.
* Command 2: go to the new home that displays a dim, not so bright, light.

*** Picture of Gate Mechanism and Transmitting RCX Unit***
***Picture of the Two Different Homes-Bright and Dim***

	Aside, while Kraftmouse is attempting to make its way out of the corridor system, when a bright pulse of light is shined on its body, it is to arrest all motion and essentially stop dead in its tracks.

Hardware

	Throughout the entire development, our team experimented with many different designs for Kraftmouse. The three main design prototypes, in the order in which they were developed, included: a two light sensor design, a two touch sensor design and a one light sensor design in conjunction with infrared transmission/receiving system.

Two Light Sensor Design
	Initially in the design process, a two light sensor design seemed the most obvious solution for our problem of navigating Kraftmouse out of the corridor system. By using two light sensors positioned at the front of Kraftmouse at 45 and 135 degrees, we postulated a plan to exit the corridor by simply reading light intensity levels off the surrounding walls, which were initially white in color. The theory behind this was that as Kraftmouse got closer to a wall, the light being transmitted by the light sensor would be reflected off the white walls thus producing a light intensity level corresponding to a bright light level. The motor on that particular side at which the bright light level was being observed would speed up therefore turning Kraftmouse away from the obstruction, the wall, and towards open space and ultimately to a new home.
	Unfortunately, as the lab progressed, so did the environment of the corridor. More specifically the wall color. From a once white, fully reflective shade, the walls of the corridor were changed to an extremely absorbing dark black shade in which our light reflection system would not work. It seemed that with the black walls, an insufficient amount of light was being reflected back to the light sensor ultimately resulting in a malfunctioning two light sensor system.

Two Touch Sensor System
	Our second design prototype was a design comprising of a two touch sensor system in order to get out of the corridor. Initially in the design process we focused simply on getting out of the corridor and once we got Kraftmouse out of the corridor environment, we would then focus on task two; new home detection using varying light intensities. This system seemed to work well in accomplishing task one. In solving the problem of Task 2, the actual searching for a new home depending on the signal received from the transmitting RCX unit, we ended up in revamping the two-touch sensor to a new design; an infrared system.

Barrier Detection System
	This system evolved through solving Task 2, finding the appropriate brightness of house. Through solving Task 2, our development team decided that the two touch sensor design used to exit the corridor system was not necessary. Through using an infrared system, called the Barrier Detection System (BDS), we developed an infrared system in which we can detect walls in the corridor via "infrared ping." Aside, note that our hardware allows the operating software, Not Quite C, to take repeated ping measurements at an extremely fast rate so that Kraftmouse can detect infrared pulses reflecting off walls.
**A Picture of our Final Kraftmouse**

Free Wheel Design to a Skid Plate
	Another hardware design modification done to Kraftmouse was that the initial design for the propulsion mechanism consisted of two motors and a pivoting two wheel support on front, essentially a tricycle design with the power to the two rear wheels. Through many trials, it was concluded that the free rotating wheel supporting the front of Kraftmouse was insufficient in transporting Kraftmouse. The free wheel caused Kraftmouse to behave extremely unpredictably and also resulted in many situations where Kraftmouse would get stuck against a wall, especially a corner.
	Thus we improved this supporting, free-pivoting wheel system by using a stabilizing peg on the front end with a skid-plate at the bottom of the skid plate, a design adapted from Pathfinder I.