Where to start? An advanced project for the inexperienced.

[Bob65536]

My goal is to basically build a small (~200lb) robotic front-end loader capable of doing automated or semi-automated yard work. A micro turbine will power a hydraulic pump that will power the loader. Another person is designing most of the mechanical side. Its my job to design most of the electronic side.

I have 8 years of experience in C++ and I have dabbled in many other languages like assembly, PHP, BASIC, etc. So I feel very comfortable with the programming side of it. What I have no experience with is electronics. I have no illusion that I'm going to be able to put it together overnight or that anyone will design it for me. I have a few questions though and I would appreciate any answers.

1. I'm going to have to learn about electronics and digital electronics. What are some good learning resources for especially as it applies to robotics?

2. Its complex enough that the brains will probably have to be an old laptop. I saw some boards that can be used to interface a laptop to IO devices via USB. So far I count 4 inputs and 7 outputs. I know I will need at least a couple more inputs, because I don't know how I'm going to get the navigation to work exactly. The only problem I see is most of the chips I found don't have that many pins. Any critiques or suggestions on what I have there?

3. The loader will run exclusively in a five acre area. I was thinking the best system for navigation would be if you could have beacons placed in the area that the robot could use to calculate its position. At times it may have to get within 6 inches of certain objects and GPS by itself would probably not be accurate enough. I will probably need sonic rangefinders so that it can avoid dynamic objects that can't be mapped out like animals and vehicles. Is there anything available commercially for beacons or would GPS and sonic detectors be the best route to go?

Thanks for any input.

 

[duffy]

Tell me more about this micro-turbine.

A GPS can get resolution to less than an inch if you are willing to mount a stationary one close by. The robot communicates with it, compares readings and subtracts the error.

I'm not sure an "old laptop" is going to be up to snuff if a camera is one of the devices you are considering plugging into those USB ports. We use dual-core Pentiums at work for image recognition, and they are barely fast enough.

Any large bookstore will have a section on robotics with details about ultrasonic and IR and other sensors for that kind of obstacle avoidance.

 

[Video Warrior]

You might find these Thinkbotics helpful. I found some good tips on ranging with both ultrasonic TD and IR in the amphibionics book.

 

[Leftyretro]

For you topic #2, have a look at the Arduino USB connected microcontroller board. It has 6 analog inputs and 14 digital pins (programmable to be inputs or outputs).

It's programmed in C and both the hardware and the free to download PC based IDE software is open sourced and will run on Windows/Linux/Mac.

SparkFun Electronics - Arduino USB Board

I'm having a blast with mine.

Lefty

 

[Pommie]

A GPS can get resolution to less than an inch if you are willing to mount a stationary one close by. The robot communicates with it, compares readings and subtracts the error.

Hi duffy,

This is something I have been trying to find an answer to for some time. I even started a thread. Do you have any references or experience of this system and it's accuracy. Any reply would be better on the other thread so as not to take this one off at a tangent.

Thanks,

Mike.