Candle Approach and Extinguishing with New Robot

This video showcases some of the issues currently being worked on. The robot can navigate the hallways properly but has some difficulty properly aligning with the candle and keep moving straight towards the candle. Another major issue is from the video you can see that the fan had to be manually started because of an issue with not enough current being diverted from the board to the fan motor, preventing the DC motor from self-starting like its supposed to. To try and fix this issue, a battery with a higher amp output is currently being tested with the robot.

Reconstruction

A few things were added to the robot to allow for more room for sensors and the extinguishing apparatus. Most notably a third plate was added to the robot to give it more of a cylinder shape. The fan was moved to the front of the robot and an LCD screen was added to allow for easier display of data used to debug the programming.

The base from the original robot was kept, the third plate was added using the hexagonal standoffs. This physical change has not effected the flow of the algorithm too drastically so no major changes have been made other than some continuing debugging of certain areas where the robot's actions are unpredictable. 

Things that were removed from the robot:

    -Compass sensor because of its inaccuracies
    -Fan mounting arm to reduce weight and also proved to be unnecessary with 3rd plate added
    -Left ultrasonic sensor was not being used in any of the code so it was also removed

This video showcases the robot's ability to navigate the maze utilizing the wall following algorithm outlined in the algorithm subsection of the Overview page. The robot currently can handle outside corners only but work is being done to integrate the front ultrasonic sensor and wheel encoders to handle the inside corners while wall following.

CO2 Characterization (using 16g tank)

Distance (in)  (0 Degrees)            Result

5                                                     instant extinguish
15                                                   instant extinguish
25                                                   instant extinguish
(canister low on CO2) 30                   no extinguish
(canister low on CO2) 35                   no  extinguish
30                                                   instant extinguish
35                                                   instant extinguish
40                                                   instant extinguish

12'' angle test

Degrees from flame                      Result

0                                                    instant extinguish
5                                                    instant extinguish
10                                                  instant extinguish
15                                                  2 pulses to extinguish (still nearly instant)
20                                                  3 pulses and no extinguish


From this data, it can be observed that while the CO2 provides a quick extinguish, if the canister is not full or accidentally discharges some of its load in the wrong direction, after only 3 short pulses the CO2 canister did not have enough gas to blow out the candle.

The sensors have arrived!

The compass sensor as well as the ambient light sensor have been delivered and are being integrated into the robot's design and algorithm. The compass will allow the robot to make more reliable 90 and 180 degree turns no matter the surface its turning on.

The following is a picture of how the compass sensor is placed on the robot. The placement is purposefully far from the rest of the electronics of the robot to minimize interference with the compass's reading, coming largely from the magnetic field generated by the DC drive motors while turning.

Sensor characterization for all of the sensors used on the robot is underway and will be included soon.

Robot Initial Setup

Our robot is currently in its development stage as some of the sensors are still in the process of being delivered. Here is a photo of our current progress along with a parts list!

Parts List:

• DFRobot Romeo microcontroller (Arduino ATMega328P processor)
• DFRobot 2WD Mobile Platform
• 3 Ping ))) distance sensors
• DFRobot flame sensor
• HiTec HS-311 hobby servo
• 9.6V Ni-Cd rechargeable battery (main power source)
• 9V Duracell battery (servo power source)
• Various Erector Set parts for additional construction

Future Components:

• Sound sensor
• Light sensor
• LSM303 Tilt Compensated Compass
• DC motor (running the prop that extinguishes the flame)

All components and parts purchased from the following vendors:

         RadioShack

         DFRobot