Initial Project Update 3

Last I had told you, I had written a little application that let me control the servos via jstick instead of command line or remote desktop stuff. Some of you have used to software to move the camera around etc. At this point I figured it was time to get serious and move on from my brothers to building my own chassis etc.

I started doing lots of research and looking for parts etc.
www.northerntools.com
www.wmberg.com
www.robotcombat.com/store.html
www.lynxmotion.com
were some of the great places I found for parts etc.

I decided to buy my own motors and not try and steal the ones from my brothers robot. I went to ebay and got a sweet deal on a pair of used wheelchair motors. After shipping it cost me $75 bucks or so.

They are pretty sweet. They have built in gears and seem pretty strong but I havent really been able to test them as I dont have anything to fit on the shaft.
Here's a pic.


Now that I had my own motors, I started some serious design on the chassis. The earlier rendering was just a concept type thing. Now I know what I was dealing with and could start some serious design work.

The speed controller that I had drove things like a tank. Basically both wheels on one side are powered in tandem. To turn one side goes forward, the other backwards. I figured since I had 2 motors and not 4 I would use a chain drive to move both wheels with one motor. Here is my first design.


As you can see, a single motor drives the two wheels on a chain, the sprocket above the motor is a tension/idler sprocket that would be ajustable to make sure the chain is tight.



I modeled the motors more accuratly to the real thing using drawings from the manufacturers website. The wheels are 12.5 inches if you need to get a sense of scale. The body is 10x30x36in I think. It would about 4.5 inches of ground clearance.


My second design was to have the two motors directly connected to the wheels. This made the things a little simpler but the downside is that I wont be able to gear up/down the drive system by changing my sprockets out. This is the design im favoring at the moment.


Here is a closeup of how I would have to use two bearings (green things) to keep weight pressure off the motor shaft. I'd have to use some kind of coupling as well. (red thing)


Top View


Heres a little animation I made.
http://www.cp-tel.net/pasqualy/land...comotion001.mov


So this is where I stand.
Once I decide on the final design of the chassis I have to find the money to buy the parts and material. Then I have to find the time to head down to the farm and get one of my brothers to help me weld it. I don't weld well enough to do it myself.
Money is a big issue here. Any way I look at it, its going to cost me at least $200 bucks in parts including wheels, bearings, chian, sprockets, etc. Then I have to buy the aluminium for the frame. Then I have to buy batteries. Probably another $200 there. Though I have a few 6V's that I can rig up that I got from various broken UPS's.
I'm also looking at a mini itx board from via. They have one that has a built in 12V power supply hookup that will work perfect for me. Another $150 bucks or so. I have a notebook harddrive for it and adapter already lined up as well as a pci 802.11b card and antenna.

I'm also looking at incorporating something like this from lynxmotion.
http://www.lynxmotion.com/Category.aspx?CategoryID=25

I may build my own however and make it a little more robust.

Anyway, I'll post further updates as they come. As you can see above I just ordered a little electric BB shooter and I plan to mount that on the current battle bot for fun.
Let me know what you think about my chassis designs. Im very open to ideas right now. Personally I think the damn thing is too wide.

Initial Project Update 2

After getting the prototype robot to work and prove that my idea was sound, I had to work on refining the method. Specifically I needed something other than the crappy bandwith hogging processor melting remote desktop method. I figured I'd have to learn to program well enough to write my own little client server application that would take joystick and other inputs from one PC and then send it over TCP/IP to the robot's computer and then dumpded down onto the SV203 board. Also the robot PC would have to take inputs such as sound, video, etc and send them back to the controlling PC so that I could see what I'm shooting at, where I'm going, etc etc.

We tried a neat little program that forwarded incoming telnet data to a com port. It worked pretty neet but you had to type all the commands in by hand. Very slow.
We played around a bit more with the virtual desktop method. Here is my friend Ogrenutz looking around my office. We just stuck a web cam on top of two servos.



It was pretty freeking neat having someone control something in my office like that, kinda creepy. For fun we attached a pen to a servo and I let him knock coke cans off the desk.


Unfortunatly I taped over the video of this. The best I have is me doing some servo tests. Fun with lasers and cigarette smoke!
http://www.cp-tel.net/pasqualy/land...s/servotest.wmv ~2megs

My friend roXet and his wife came over to play with it so we wired it up and had a go. I had gotten my own laptop working so we were able to be a little more brave with it, including putting the smackdown on a stool in the office. Here is a video of us rigging it up and driving it around. We did find out that the range of 802.11b is pretty pathetic. (duh) so one of the big obsticals will be getting that range increased.
http://www.cp-tel.net/pasqualy/land...t_tech_test.wmv ~6megs


Playing around with the thing via remote desktop worked but it sucked pretty hard. So I started playing around with Visual Basic and cooked something up.
Most of my programming consisted of tearing bits of useful code from other progams and stuffing them into mine so that I had this frankenstine beast that was a monster but it worked.


Using Visual Basic, I first got a little telnet type prog working that let me send commands via a text box or a button to the servo. Then I got it to take commands from a joystick and send it to the servo.
Then I figured out how to make a simple client/server chat program.
Then I used that to take data from a jstick, send it over tcp/ip to another computer, and have that computer send it to the SV203 board. It worked really crappy at first because the board was getting flooded with commands because of the way the code was written, but man oh man when my pal in Kentucky moved his jstick and I saw the little webcame jerking around I was really excited.
About a month later or so, I finally got around to fixing things and got rid of the flooding problem. What I really need to do now is get video from the robot PC over to the controller PC. If any of you coders out there want to help me with this I would really appreciate it. I'm not much of a coder at all.

Anyway, another update soon. I'm almost caught up to where I stand currently. Just have to tell you about the motors and chassis design etc.

Initial Project Update 1

Here is an early mockup I made in 3ds Max.



The idea is to have a PC mounted on a mobile platform that controls the platform's systems like motion, sensors, and gun turret, etc. That PC can then be controlled via wireless ethernet or cell phone dialup or whatever from another PC. Sort of like a mars rover.
In my back yard.
With guns...

The weapon system will be based around this thing from www.gatlingguns.com


I'll have to check with the ATF before I actually mount the thing I guess. Appently as long if it only fires one bullet per keypress I'm ok, otherwise its a machine gun

Right now I'm using my brother's battle bot as a prototype platform. He actually competed but got whupped in his first fight. So I borrowed the bot, got it working and then started chaning things to my liking.

I'm using a SV203 servo controller to interface between computer and the speed controller etc. http://www.pontech.com/products/sv200/

As you can see, it basically takes data (in the form of ascii commands) over a good ole serial port and controls servos, reads voltage, or acts like an on off switch.
The "controls servos' part is the important one. If you imagine any ole R/C car or whatever its basically got a device that takes input from a radio control and moves servos and speed controllers. Instead of doing it with a radio handset, this thing does it from a serial cable.
This allows me TONS of flexability. I can plug in the SV203 and control it with commands over hypertermal, or I can write my own software and do it with a joystick, or a gui of buttons and sliders. I can also set up client/server software so that I can send commands over tcp/ip from a remote pc to the pc that actually is connected to the SV203.
Then if I want to I can just replace the SV203 with any stander R/C reciever and use a radio control to dive it around.

Here it is connected to my laptop and a pair of servos. You can see the software that comes with the board on my screen.





Now that I've given you guys a brief intro to the project, here is a chronicle of what has gone on so far.

The first task was to get my brothers battle bot in working order. Its basically a box with 4 14.4 volt Drill motors in it and some kinda chainsaw thingy. It was the first robot he built but it turned out pretty nice. You can stand on the thing and drive yourself around and when the batteries are at full charge you cant stop it as long as it has traction. It was in pretty bad shape when I got it though. It has been impaled on the spike strips and some of the stuff inside was gutted when he was helping another team out with their robot.

I had to first figure out how it was supposed to work and then get it all wired up agian and make it work.
Here I am with the speed controller. Its a $300 dollar unit so I was really nervous playing with it.


I finally got it to work. Here you can see his pimping R/C controller. The reciever is that little black box above the speed controller (the blue metal box).



Once I actually got it working again (and crashing it around the office and destroying a few cardboard boxes)it was a simple matter of replacing the R/C controller with my SV203. At that point I could control the wheels with little sliders on the screen. However this was pretty lame because I was thethered to the darn thing with a serial cable.

So as a test we set up a quick wireless lan. Then I just remote desktoped onto the laptop so that I could control the robot from my desktop pc. Now this was a terribly terribly ineffecient way to do things. But it was just a test and we didn't have time to do anything different.

Here's how it looked, please don't laugh too hard



We were doing this with my roomates way expensive laptop so we had to make sure it was in a nice protective box with packing peanuts and everything. Here is a video of how it all worked out. Crude but it showed the idea was sound.
http://www.cp-tel.net/pasqualy/land...controltest.wmv (17megs)