I've been lurking around these forums for a couple months now and thought I'd finally jump in. I have learned so much from these forums and I'm amazed at all the very talented people here. Your input and ideas would be very welcome for a new project that I plan to undertake
(<-- one of the things I learned: smilies are big).
I'll start with a little intro: I'm 24 and tinkering and robotics have always been a hobby of mine. I've done RC rovers, autonomous robots and designed and built a couple multi rotor RC aircrafts. I've got a BS in mechanical engineering and also a BS in physics; I couldn't stop at learning the way things worked, I had to know how to apply it too
. I'm a machine designer by profession but focused on controls/mechatronics in college.
Now to describe a bit what I'd like to build.
Stand.jpg [ 137.61 KiB | Viewed 10442 times ]
So, obviously it's a quad. But, it also has driven tracks on each tibia(?). My inspiration for the design came from limitations. Walking and rolling both have their advantages and shortcomings so I figured "why not combine them?"(not a new idea, I know).
Another picture in tracked mode.
Roll.jpg [ 161.47 KiB | Viewed 10442 times ]
Another showing a rolling turn.
turn.png [ 298 KiB | Viewed 10442 times ]
It is not meant to be overly powerful while it is in "tracked" mode, speed was more of the objective here. However, I chose tracks to still handle rough terrain. I figured that if there was a difficult obstacle in its way then walking might be a better option. At the moment, I do not plan to experiment with TA, which will most likely be necessary down the road. First, I just want to develop a stable platform that can walk and roll.
I'll describe where I'm at with this project and hopefully you guys can give me some pointers.
I am in the process of designing a board for my specific purpose using the propeller. It will have:
12 servo outputs
2 motor direction outputs (to control forward, backward, left and right)
4 motor speed outputs
4 encoder inputs (to precisely control motor speeds in turns)
6 radio inputs (all I can afford at the moment until the propeller 2 comes out. It will suffice right now: I currently only plan 4 operational modes)
Also, 2 outputs independent of the micro controller to control the rotation of the top turret and the the pitch of the camera mount.
I chose the propeller because parallel processing should help operation in many ways, especially when I start tinkering with TA. I plan to program this quad from scratch. I've seen that people have used the phoenix code for quads but I would like to optimize it to the propeller and would like to be intimately familiar with its controls. I've already worked out the math for all the inverse kinematics and am currently mulling around with a rule based sequencing engine based on COG, contact patch and direction. Mind you that all my work with this is "pseudo code", I'm a decent programmer and I'm learning SPIN so all my work is still on paper.
There are quite a few parts on here that I want to source from lynxmotion (SES parts, bearings, servos) and others from various places. There are also quite a few custom parts that I have designed and plan to build myself. I have a small CNC mill that is perfectly capable (check out zentoolworks.com , great stuff).
What I hope to hear from you guys are any loose bits of advice that you might have. Are there things I'm overlooking? Things I need to check before proceeding? Are there any adherent problems you see with my mechanical design?
I do not plan on buying any parts for at least a month. I will probably start by buying a prop dip to test with and all the parts for one leg so that I can measure myself and be sure that what I'm going to machine will work.
Thanks for anything guys,
P.S. I tried to integrate pictures into the thread. Sorry if its messed up, I'm new.