Let's Make Robots!

SplatBot MkIII - Fire fighting Wild Thumper!!

Locates fires and puts them out.

SplatBot MKIII is my first attempt at a fire fighting robot. The "Wild Thumper" 6WD chassis is the production version of my original 6WD chassis and the new flame tracking sensor is a new version of my IR compound eye. My first attempt at an IR compound eye was tested (and failed) on my original SplatBot.

My first challenge is to see if the new eye actually works. The outputs tested ok with a multimeter but getting it to work with the Wild Thumper robot controller to opperate a pan / tilt assembly and track an object is another problem.

The design is very similar to SplatBot MkII except much larger and the bottles are mounted higher so the suspension can flex without hitting the bottles.

 

12-10-2010
Update:

After a few problems with electrical noise and a faulty IC socket on the flame tracker I finally got the robot to track movement of my soldering iron. The sensors are much slower to respond than the phototransistors on the IR compound eye so the eye can loose track of an object that moves too quick but for locating a fire this is not a big issue.

I am definitely going to have to add other sensors for navigation as this chassis has the high speed 34:1 ratio gearboxes. I will also have to add a remote kill switch. My biggest worry is that it will run into the fire, catch fire itself and then run around berserk possibly creating other fires. This might defeat the purpose although it might make a good Anti-mov entry.

13-10-2010

I have attached a video of the flame sensor tracking the motion of a 60W soldering iron.

 

16-10-2010

I have attached a video of the robots second attempt at putting out the fire (the first attempt ended with the robot sitting on the fire). Overall it's working but it needs a lot of fine tuning. Right now I am using RC to guide the robot to the fire and then the autonomous system detects the fire, aims the cannon and runs the pump.

Next step is to adjust the suspension to handle the full 4Kg load of water better and improve the cannon. The software needs to improve it's aim and to check the fire after it's out for hot spots. In the second attempt there was still some flame that the robot missed.

 

18-10-2010

I have added more videos including the first failed attempt to fight a fire. This was due to the fact I was using a TV remote to control the robot and the flames interferred with the signal.

The Wild Thumper is a tough little bunny and despite sitting in the flames the only damage was one motor housing got singed. The aluminium chassis absorbed enough of the heat to protect all the wiring and electronics.

In the third attempt I have fixed a problem with the tracking system and added a scanning function. You can see about 1/3rd of the way through the video of the third attempt that a small flame is initially missed until a scan is done. The flame is then detected and extinguished.

At the moment I have not had time to adjust the suspension and all the waters weight is on the back wheels. This will be corrected in the next video.

 

 

 

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The sensor detects radiated heat so while it might detect a bar heater at 5 meters it won't detect a waste basket full of paper on fire at 5 meters. That's because a lot of the fire's heat is dispersed by convection whereas the bar heater has almost all of it's heat radiated outward.

This sensor is only intended for short range 1-2 meters to guide the water cannon to the hottest part of the fire. A better system for detecting fire at a distance would be to use an IR camera. There have been a few examples using a Wii remote camera on this site.

Hey oddbot

Just want to know that how does it find fire ? i mean it looks for the fire continously moving its head(sensor) like in an obstacle avoiding robot or it finds the fire like say by "Heat seeking" method or something else ?

 

As I mentioned earlier, the robot is guided to the fire by remote. Once in range (LEDs change from blue to red) of the thermopile sensors the software takes over and aims at the hottest spot while activating the pump. When no heat is detected then the cannon starts scanning again.

Small fires like candles and burning newspaper do not radiate a lot of "black body" infrared which is what the thermopiles detect. To really detect a fire you need several sensors working together.

Thanks for the above info

can you recommend one or maybe more than one fire sensors that can be used in autonomous fire fighter ?

pls oddbot will u be my teacher?

 

At LMR, everyone is a teacher and a student at the same time.

I'm sorry but I do not have time to teach anyone and my expertise is limited to electronics. Robotics needs programming skills (mine are limited) and mechanical aptitude.

You would do far better reading books on electronics and programming. That is how I taught myself. Study the robots on LMR and don't be afraid to ask questions.

I used to work in fire restoration.

The damage fire can do is unbelievable. I've seen solid metal structures melted by small house fires. Not to mention the amount of deaths caused by fire.

Every house should be fitted with a SplatBot MkIII.

Great work OddBot.

I don't think the robot is any where near ready to go into anyones home including mine. It would be a bull in a china shop.

I do think that fire fighting is a worthy area of research for robots.

nice work on mk3 odd. what type of nozzle are you using? i was thinking if you used a flat spray nozzle you could get better area coverage and faster extinguishing. also citric acid and a bicarbonate solution will have a similar effect to gareths suggestion

At the moment no nozzle is used, the hose is just fish tank tubing. This gives more volume of water but less range. When I get time to refine the project I will consider a nozzle to extend the range. I am not concerned about width of the spray as the robot automatically aims for the hottest part of the fire, as the water cools that section the robot automatically moves the cannon to the next hottest spot.

The scan pattern helps the robot catch any spots it may have missed or that have re-kindled.