Let's Make Robots!

My New Robot Ideas

     Hi all, I have been mostly a silent observer (http://letsmakerobots.com/node/3817 is the exception). Anyways, a few days ago after talking to a CIA tech genius about robotics and the field of electronics I was inspired to build something again. I dont want it to be a small little bot that once the novelty wares off is imediatly sent to a shelf. I want it to be something slightly usefull, fun, and constantly runing. I have two cats and it would be excellent if this robot was like another pet.

     As I was searching this site a while ago I happened upon a contest to build a piggy bank robot seen here http://letsmakerobots.com/node/2850.  Sure the timeframe for this contest is over but after talking to the afore mentioned CIA techy, I thought of this contest (not sure why) and so my goal is to build a robot that achieves the following

   1. Is an effective piggy bank (holds coins which can be removed at a later time)
   2. Is able to measure the amount of coins it holds (not necessarily the value possibly just weight)
   3. Moves around with the added weight of many coins
   4. Fully autonomous
   5. Has the ability to follow moving objects such as people and cats like a "pet"
   6. Has a personality

     I have had several ideas for each of these requirements. For number one I will most likely create a chassis with a large box on top. I would like to build the chassis myself as I have never done so and I have several pains of acrylic from a project several years ago. It would also be important to have all of the electronics self contained so that the coins do not interfere with electronics and vice versa.

     To the second requirement I though of using a FSR or force sensing resister under a pane of acrylic. Though it might not be able to detect  one or two coins it would be able to detect larger numbers of coins.

      To the third requirement after doing research on torque and RPM and the requirements of these needed to move a robot of a given weight I think i might use two Banebots planetary gear motors rated at 640 RPM and 143 ounce inches of torque. This would prevent me from having to create a gearing system.

      The autonomy is the easy part as i have created a fully autonomous bot before (not posted here because I did not feel like documenting it (very lazy I know!). I would probably use sonar as the main obstacle avoidance mechanism.

      This next part sounds hard. First there is the issue of tracking objects for which I will probably use a system similar to  OddBot's http://letsmakerobots.com/node/4428. The tricky part is making this follow a pair of walking legs. if it is following a solid object, I do not believe it would be that hard to create a polar coordinate system for the bot to find the angle and distance to the object, but again....the issue comes when the object is a pair of legs. I might need to wear REALY big boots...

     This last one is a bit tricky as well. I think i might do it with a robot "head" and backlit LED eyes.

    Well that was a lot for one day, I need to get some sleep. If anyone thinks they have an Idea of how to do something for this project just post it below! advice is VERY welcome!