oh boy this is deffently dagerous waters that you are venturing into. this endevor is not impossable, but is defenetly a chalange. more so then a FIRST compition.
okay first of all, can you install any pasive/active guidence aids in the room. how bout infared beacons below each picture set to a diffrent frequency. or RFID tags on the ground at the foot of each painting. you could theoreticy navagate using sonar as long range and optical sensors as short range but that gets pretty prosseser intensive. wire in the floor with a hall-effect sensor would be effective to some degree, at least in stoping the robot from bariling into the walls.
there are many ways a robot can recognize people. i am not sure which one you are looking to persu. if there are many moving objects in a room and you need to distinguish people from them, you need a much higher level of complexity then if you assume all moving objects are people and you start talking to a dog or whatever. also, do you have to track the people? do the people follow the robot or does the robot follow the people. what if the people are un intrested; does the robot continue its pre-definded shpell till its done or does it stop when the people leave. the former is a lot less complcated then the latter, as the later requires full invirmental awarness, which tho not inpossable, is awfly hard to program.
anyway for detecting people you can use (1) sound (2) light.
(1)there are many ways of doing both. the most simple is to have a single microphone hooked up to a comparitor, and fix a bell or something on the door. when someone enters, it starts the robot going thrugh its paces. more advance use of sound would be to have a passive sonar unit detect change in echo, indecating a change in enviroment and thus have the robot start.
and greet it (with an audio recording). Next, it is supposed to go around the room, stop at each picture, and explain a little about it (again, pre-recorded audio tracks). After going around the room, it is then supposed to come back to its original position. Oh, and by the way, I am planning to use the EDU robot controller for this.
(2)light is the most common means of detecting changes in inviroment, everything from a small pasive IR sensor (like you would have for a walkway light) to a camera with a full image prossesing cpu. im not even gonna start to get into the algorithoms required for full color image prossesing (BAD idea for a scince fair project - - i know from expearence), but ill tell you that there is a software package that includes a USB webcam that you plug into a laptop and that offers a GUI for customizing image driven robot navigation. it was on the back of Nuts And Volts a few months back ill see if i can dig it up.
this is gonna be the easent part of the whole thing. once a person is detected, and durring or after the go-to-person routine (if you have one) you play a message. there are HUNDRADS of audio recording chips avaliable, with a large arangemnet of diffrent features. some can be loaded with MP3 or WAV files and some you have to record with a microphone on the board. Parallex (
http://www.parallax.com/html_pages/p...dio_visual.asp ) sells a basic microprossesr friendly one if your just a begener. if you wana go deeper, check out digikey (
www.digikey.com ) for a large selection of recordign chips and associated parafanalia.
also a tip: even if you have your audio recorded, your gonna need an amp and speakrs to play it. just remember that.
as i said before, there are many ways of doing this. if you had >3 beacons of IR, UV, RF, etc, placed at known postions around the room, you could triangulate your postition using basic trig. if the room was big enught, you might want to look into GPS, global posting system, recever, which can output serial data which is pretty easy for a microcomputer to read. if you had a rough idea of where you are going, you might wana try ultrasonic obsical avoidence. your gonna need it anyway so that you dont run anyone over. besides ultrasonic, theres also IR and bumper switch, but i would sugest ultrasonic because of the scale involved. unless of course you wanted to use passive radar.... anyway there are 2 elements to this problem. first you have to find your way around the room, stoping at each picture.. then you have to not hit anyone.
the first is simple enugh, you could use a track, reflectors on the floor, a painted line, reflectors on the walls, or a IFM acccleromitor with one hellof a algrotiom. i would not sugest dead recogning because of the problem that was pointed out eariler:
also dead recoging is just plain not fun.
to avoid not hitting anyone, i would deffently suggest ultrasonics. if you can not find anything, the best pic-friendly ultrasonic board is from Devantech (
http://www.parallax.com/detail.asp?product_id=28015 ) and it 30 bucks. you would need 8 for reasonable accurcy, mabybe 16.
as for staying away from the wall, you can also use the ultra sonics for this. you basicly write the algorithom so that it doenst run into anything, be it person, wall, expensive statue, dog, etc. there are many papers books, etc on writing ultrasonics algorithoms.
now this is a BAD idea. first of all, the innovation first edu robot controler is an underpowerd over modulerized P.O.S (no offence to all of you at first, i understand that it is hard work keeping this compititon fair). when you are not restrected to using standerized parts, EXPAND. buy a pic programer and burn a 16f84 for goodness sakes. or a BS2 from parallax agein. or ANYTHING else. but you dont wana use the edu controloer. theres 8 outputs and 6 inturpts. the smallest pic you can buy for an equilivent price has 42 outputs, and 16 intrutpts. if you are scard to move away from FIRST techonlogy you should not be attempting this project. because FIRST parts are not the answer to life.
the last point i wana make is that batterys dont last forever. if you dont want to have a 40 foot extention cord trailing the robot, your going to need some sort of automatic charging station. this could be a small box in the corner of the room under one beacon. but it is a nessesety unless you feel like changing the battery 8 or 9 times a day. if a 20AH 12 v battery lasted thrugh 2 tours, id be impressed.
EDIT: the best of luck to you on your endevor. i hope you can find my advice usefull