PetToyBot

This is a pet toy robot, not a pet robot like Aibo

But children like it more than pets do 

this is second prototype of my Pettoybot. First one was on $10 toy RC car platform. but it runs too wild, so I made this gentle two wheel one caster version.

 Mission of this robot is play with pet. So I give him a sensor to detect pets movement and tell him to follow the movement of pets.

 Pet detecting sensor is  just the same one in the portal lamp in ordinary house. the lamp automatically lights on when human step below it. It uses PIR (Pyroelectric Infra Red) sensor, that detect change of infra red right not the infra red light itself. Just continuous light up infrared light to the sensor dosen't make any signal. 

Human and mammal  pets radiate infrared lights so their movement make change of infrared light that can detectd by PIR sensor. And there are a lot of infrared light already in our environment so any thing that move can be detected by PIR sensor

But when robot with PIR sensor moves the PIR sensor makes signal crazily. so there was no robot using the sensor yet.

(Rodney Brooks already made robot Genghis with this PIR sensor in 1988.)

I made the solution :)  When sensing, stop the robot.  go and stop to sensing go and stop..  repeat this~ 

 And I gave him a Sharp range sensor that detects 2~80 cm. I installed the sensor slantly to the down front so it can detect cliff and obstacle.  When the range is too far it means there is cliff and the range is too short it means there is obstcle.

the brain of Pettoybot is Arduino. mmm Ah, it ha slaser pointer to play with cats 

The case is made of fiberglass composite and paintng and long time of sand paper work.

It takes about two month to make this robot

 and I will add auto self recharging function and  recharging station  with IRbeacon

major parts 

MCU: Armega128 * 1 , Atmel

PIR sensor:  LHI-878 * 4, Perkin Elmer

range sensor:  GP2Y0A21YK * 1, Sharp

motor drive chip: L293 * 1

PIR sensor signal amplifying OPAMP: LM324N  quad opamp 

two Tamiya truck wheel and a caster

double gear box by Tamiya