Fire Fighting Robot

 

 

 

Team Members

 

Viet Do

Ryan Norder

Ryan Spraetz

 

Objective

 

Our robot is to enter a “home” and seek out a spot where there is extreme heat possibly due to a fire.  This home has two rooms and can be seen in the video section.  The doors of the rooms are fluorescent green or orange so that the color camera can determine the location of the door and enter the room to see if there are flames.  The locations of the doors are initially unknown to the robot. Upon entering the room, the robot will once again use the color camera to pinpoint a spot where there is a large concentration of light.  Once the robot has driven up to the light source, the heat sensor is activated to check and see if there is a large amount of heat being generated.  If there is an excessive amount of heat generated, the fan is turned on and rotated quickly with a servo motor to put out the flame. If the flame is not put out the fan will turn on again and continue to blow on the flame. Once the flame is extinguished, the robot leaves the home.  If the heat sensor does not find excessive heat (in the case of just a light being present) it will leave the room and enter the second room.  Once the robot has entered the second room it will search out the fire and extinguish it using the fan.  Finally, after the fire has been extinguished the robot will leave the home. 

 

Color Camera

 

As mentioned previously, the color camera was used to find the doors and the light sources.  The camera is programmed to find a color based on a range of hue and saturation.  When the amount of pixels of that color exceeded a certain number, we were confident that the camera had found what we were looking for and then the robot was programmed to drive to it.  This code was called anytime we needed to search out a door or a light source.  We are only looking for the biggest object of that color. 

 

Heat Sensor

 

The heat sensor was used to distinguish a light from a flame.  This was done by determining the largest value in the 8x32 array.  The heat sensor is on a servo motor and it records values at 32 positions throughout the 180rotation.  The heat seeking code will traverse the array to find only the temperature that is above a certain threshold.  If the temperature is below this threshold it gets set back to 0, and if it is above the threshold it gets set to 100.  These values are set so that it is easier to debug using the VB code. Once this largest value was determined, the program decided whether or not the max temperature was high enough to be a flame.  The temperature for the flame is around 215.  If this temperature exceeded the decided temperature, the fan was activated and the flame was extinguished.  If not, the fan was not activated and the robot continued to search for the flame.  The data sheet for the heat sensor can be found at http://www.robot-electronics.co.uk/htm/tpa81tech.htm.

 

Search Algorithm

 

The robot will start at the entrance and look straight ahead for a door.  If one exists, the robot will go to it. If not, the robot will go inside the maze and turn right toward the corner of the maze.  The robot will once again look for a door.  It will head to the door and when the color camera sees more than 5000 pixels of the door it will move an extra 5 tiles straight ahead.  This will make sure that the robot gets through the door. Now the robot will look for the candle.  The camera color is changed to look for the light.  The robot will determine if the light is a flame or a decoy.  Now the robot will turn 180 degrees and go out the same way it came in.  The robot will head back to the corner of the room.  If the light was a candle, the robot can leave the maze.  If not, the robot will look for the next room.  The robot will look around for the room and then go toward it.  The robot will then go through it and put out the flame and leave the room.  See the video section to get a visual of this process.

 

IR Sensors

 

The IR sensors are used to avoid obstacles and to wall follow throughout the search process.

 

Fan

 

The fan used is a 24V PC cooling fan.  It is mounted on a servo motor because the oscillating fan extinguishes the flame better than a stationary fan does.

 

Pictures

 

The following pictures show the front of the robot, which contains all of the equipment that was used.

Click on pictures for a bigger image.

 

F:\scratch\mechlabspr06\Fire\100_0471.JPG

 

F:\scratch\mechlabspr06\Fire\100_0472.JPG

 

 

Videos

 

F:\scratch\mechlabspr06\Fire\Fire1.MOV

F:\scratch\mechlabspr06\Fire\Fire2.avi

 

Code

 

F:\scratch\mechlabspr06\Fire\ Fire Extinguisher.zip