Progress Blog #4: The End is Near

Over the period of Mar. 26 – Apr. 16, team 36 started conducting the validation tests. Before the validation tests, final adjustments to the Arduino code for the servo motors and the IR flame sensors were made. The team calibrated all four flame sensors and tested them numerous times with fires placed at different positions in front of the device. The team also used an aluminum epoxy bond to seal the gaps in the aluminum outer shell. Team 36 then conducted the validation tests. After the validation tests, the team spray-painted the outer aluminum shell and the device black for its final look. The following figure is the final stage of the Autonomous Firefighting Device and Team 36:

For the device evaluation, the team sought to ensure that the device met the problem statement needs of identifying the presence of a stove fire, alerting of the fire’s presence, and extinguishing the fire source. To do these two validation tests were conducted. The first validation test examined the device’s accuracy and range in identifying the fire location, calibrating motor movements to move the nozzle in the fire's direction, and extinguishment. Fires were set at each stove to test the 1ft and 3ft detection range of the device. Percent error and Arduino input data were then collected with each trial run to determine the accuracy of the device’s detection equipment. The following is a video of the first validation test: 

The following figures demonstrate sample data from the top and bottom left stoves: 

The percent and accuracy data calculations for all trials are determined in the next figure:  

 

The team’s device achieved its intended goal as it delivered a percent error of less than 10% for each stove distance and an overall accuracy of over 90%. The device was also able to get the intended IR flame reading of over 730nm for each fire that was conducted, calibrate its nozzle position to the direction of the fire, and extinguish each trial fire. 

The second validation test observed the device’s ability to handle a high heat environment. It consisted of the device being near a boiling pot of water for 2 hours to mimic a regular cooking session. With every 30-minute increments, the device was then tested by lighting a fire and having it effectively extinguish it. The following is a video of the second validation test: 

 

The team’s device achieved its intended goal by withstanding a 212°F and humid environment for 2 hours by remaining in its on and initial position for each 30-minute increments and extinguished each trial fire. 

A major shortcoming that the team had to overcome was the testing environment. Initially, the team had intended to use an actual kitchen for the evaluation of the device. However, due to the lack of kitchen testing availability because of COVID restrictions, it was decided that the team would recreate the measurements of a stove-top and back wall within a team member’s garage to execute the testing. Each stove was placed symmetrically on the ground as it would be on a stovetop and the device was placed 1ft off the ground as it would be 1ft above the stovetop. 

If given the chance to rebuild the device, there are a few changes that should be implemented. The device’s visual systems would benefit greatly with the addition of a heat camera to replace the IR sensors. Although the device can meet the goals within the given parameters, it had a few sensory bugs that can be easily bypassed with a more advanced detection component. The device’s flame retardant compound, Purple K, should also be reevaluated due to the unique clumping factor that sometimes clogged itself. Purple K was used due to its high efficacy in putting out kitchen fires, but if a liquid or a less clumpy compound is found, Team 36 recommends switching to that for the rebuild. Lastly, it is recommended that when testing, one should use a real stove with a real flame. Team 36 was unable to do so because of a lack of funding, but it would greatly reduce the time it takes to test the device and make its product ready.