# Free Range Robots (and hallways)

Uff-da... So I have pulled the training wheels off of Walter and am letting him rove around sans fences. I have actually had great luck with pre-solving a lot of problems (table legs and driving under things) but still I am running into a few problems.

I ask this as an open question.

What is a hallway to a robot? --We all know the right-left-right-left-right-left problem with corners and now, I am finding the same with hallways but instead, with my outward shooting side (keep away from the wall) sensors. Not to mention, if it is a dead end, it is continuing to follow standard code, turning away from the obsticle when it gets to the end thus leading to a 1/4 turn away, finding it just turned into a wall and backing only to find its ass hitting the other wall. --Here are some senerios --tell me what you think.

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Ok I've not read all of that but the idea of getting your robot to make their way about the house I would solve with the A* algorithm. Especially if what the little guy needs to learn is purely static. Let the robot create the weighted network based on physical measurements of purely non colidable area. Landmarks can be placed on the graph too such as recharge stations. Now the robot can run A* to get exactly where he wants in the shortest route while avoiding static scenary completely. Table legs and such items could be checked with a UV sensor and then map node movement around it. Lots of good algorithms for working out graphs in rooms if you want to be more complex. You are having a pathfinding problem and computer games have had this problem solved and efficiently too.

If memory and processing can handle this, it is great for organising the static area. Dynamic objects can be detected at runtime predicting collision based on object velocity it sensors. A* can be made more efficient depending on the situations such as if you expect lots of dynamic collisions you could use D* and so many other variations can speed up processing. Take advantage of this highly efficient algorithm research and robots spacial awareness can look very realistic and clever.

Idea 1: I once tried to teach my robot tricks that i reinforced - something like teaching a dog that only knows 6 movements. Once in a while a dog would try another trick or incorporate another trick to get a treat and the most effective trick that results a treat would be remembered more. Combination of movement would be the trick that i want to reinfoce. I tried once to program lexi to have only six actions and repeat the 3 most reinforced actions. Reinforcement comes from a remote control that I press whenever I want to reinfoce an action. After a exhasting coding and testing I run out of time to fix the code not to mention my non-expertise about programming.

Point:I have the same idea with rik about possitive reinforcement and learning to map out a room.

Idea 2: I always want a robot that has beacon around it like a fence and a safety net which indicates the safety zone and unknown zone which is on the outside. Getting a beer on the fridge is too complicated. I think just roughly mapping an area in the middle of the room that has no obstacle is a success to me.

Goal:Put down the robot in any place on the room and map its safe zone. Safe zone means an areas without any obstacle.

Plan:I think putting beacons before hand is not giving the robot independence. I been having this idea from my first RC car, after driving out of range of the remote I taught what if the car can drop a recieve to the farthes the remote can reach and transmit the signal to have a farther range. ON THE MAPPING BUSSINESS: what if a robot can bring like 6 IR beacons and drop it around him(or maybe another one to act as the point where the robot is place to start with). The robot would navigate to one beacon to another and constantly pushing it away the center. The area inside the IR beacon fence is the safe zone and outside is the unknown zone. Or maybe navigate from center to an IR beacon, push the ir beacon away the center, go back to the center, navigate to another beacon AND REPEAT. If it works like what I envision it(like in perfect world), you can drop a robot in any place and it could map an increasingly larger safe zone that (maybe) another robot that has another mission can use.

Point:Maybe we could teach a robot skills to "live" like a simple organism(simple goals) and better teach a robot skills to learn (simple things).

Your video's inspired me to improve mine and now! Super arty backdrops for dull diagrams. Is there a nobel prize for artistic diagrams?  :p

I hope this schematic says it all, because I need to go to bed now.

See ya tomorrow night.

yes we are. I jotted down some random notes here.

Whoa... Back two steps, folks... We are getting into mapping and object recognition etc... You guys are talking like you are programmers with your anurisms and the like! I.e. Painting "room names" on the ceiling isn't really cheating.

This is not even close to "cheating" --there is no cheating!! First off, remember guys I am an artie using picaxe(es) and BASIC, second, the goal is simple navigation between "tasks", "bases" and for "personality" reasons. "Mapping" is great, but in reality the necessity for "mapping" would be (really) to be sure he comes back with my beer! Not to mention, I think I am the unofficial king of "fuck solving the problem, I'll work around it"! So back to the point, the painted ceiling idea is rock-solid gold! There has got to be a bunch of "marks" one could come up with that a robot could see on a ceiling. Not to mention, if that mark included a direction marker, a compas would not even be needed, simply making all 90 degree turns off of wheel encoders alone.

I do like rik's ideas... If it were 8 or 10 years ago, the "smoke signals" would have been so strong, the robot would know it was near me simply by noting when it's sharp sensors stopped working!

Chris, you must have plenty of little, agile bots running around your house by now. They could do the scouting. Maybe have one in every room. Guide Walter through the rooms an halls by signals (sound, light, RF, IR).

Now that is a "free range idea" for ya!

Hows this one?

I started with the go get a beer, come back as step one of the whole navigation thing. My first thought is the beacon theory -I have played with an IR beacon system that works very, very well. Simply an IR led constantly spitting out an IR signal. On top of walter is a IR sensor at the back of a long tube thus only seeing the IR beam from straight ahead. When scanning this sensor with a servo, I can easily find a bearing of the beacon and drive in that direction. Using this system, and some simple "first beacon, turn right...second beacon turn left" I am confident I can get from A to B. This is, of course, saying I am willing to pre-set beacons before the run.

I do like the ideas mentioned above, measuring rooms, using doors as start-points etc. Speaking in terms of what is in my head right now, lets look at this problem backward... With the beacon system I was stuck on the idea of how to get back from B to A. The theory I came up with is a basic grid system. I think this theory is hand-in-hand with any kind of "start-point" or junction idea. As a way of mapping, if the robot stays on a X/Y grid system making only 90 degree turns, EEPROM recording of turns and distance traveled should be a piece of cake. Of course, a return path would be as easy as playing back from the EEPROM in reverse order. I even took a look at I2C compases for the job. If a good, simple start-point/ junction system could be established, household navigation should be a breeze and you could do away with any beacon crap.

You know, it's funny... my original post was really about basic ideas on the subject of sensor reading and movement reactions but now that I think about it, I think this was really the conversation I wanted to have.... and I do think a blind wal-around of my house is a good idea -both for the learing and comedic value.

--Juctions... I wonder if there is any reason I couldn't just put a big color-coded dot in the center of each room... Find the center, align yourself with north, all is good from there.

problem i can see with a compass is interference fro mthe structure of the building and possibly power lines. Im not sure how much of an impact this would have but i was always tought to read a compass away fro structures.

That's not a free range bot.

And I admit, I would not easily program a robot to map the house by itself. So there has to be a solution in between those two extremes.

How about guessing every once in a while. Maybe a recognising method that would indicate direction only. Like "North" or "Kitchen". And let Walter figure everything else out by itself. All it needs to "understand" is whether it is getting closer to a target or not.

Positive reinforcement is a motha!