Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: LEV on March 31, 2014, 09:52:18 AM

Title: Need help - Robot to Detect surrounding Environment
Post by: LEV on March 31, 2014, 09:52:18 AM

Hi All,

I'm starting on a Wall-E type Robot that can travel all terrain and also one that can carry heavy load of up to 200-300kg and can reach speed of up to 25mph.

Apart from the mechanical part I am having problem finding the right powerful and cheap enough Board, modules and which programming language is best to use.

The objective of the Robot is to carry heavy load across all terrain by pre-set destination either by Google Map or designated manual mapping of point A to Point B by initially walk through the path you want the Robot to undertake With the uses of Android tablet or ipad/iphone.

The robot will also need to be able to determine when to cross the traffic light and when to enter the lift.

I was wondering if a visual recognition software comes into play with this kind of setup or would it be better to just program and code it from scratch with the many given variables?
Title: Re: Need help - Robot to Detect surrounding Environment
Post by: jwatte on March 31, 2014, 06:03:14 PM
Just building an all-terrain vechicle that weighs 300 kg and can go at 25 mph is a very tough challenge. Check out some ATVs (four-wheel) or snowmobiles (belt driven) for examples. If you want to get this same performance from electricity/batteries, check into golf carts; maybe you can buy one and mod it.

Second, the safety concerns of "being able to wait for red light" is a real warning signal. Even the best funded companies (Google, CMU, etc) do not run robot vehicles in traffic without people behind the wheel, ready to take over if the robot makes a poor judgment.

Given the requirements I can gather from your list, you're looking at anything from buying a $10,000 existing vehicle and modifying it, to spending > $1,000,000 to design your own. Then, looking at anything from $10,000,000 to $1,000,000,000 to develop robust control software that is safe for the general public.

Maybe I mis-understand your requirements, though, because they are not very clearly laid out.
Title: Re: Need help - Robot to Detect surrounding Environment
Post by: gerard on March 31, 2014, 06:19:08 PM
yeah this is going to cost at least ten thousand dollars just to get a platform that can go that fast and carry that weight
also its not legal to have autonomous robots driving around on streets without a proper vehicle permit

even my simple tracked rc vehicle cost about $1500 in parts, and can carry max about 50kg
it also barely fits through a door

i think you need to reconsider your project, and maybe start with something much simpler
Title: Re: Need help - Robot to Detect surrounding Environment
Post by: LEV on April 01, 2014, 06:15:42 AM
Jwatte:

From the sound of it i may just have to rule out Traffic light detector parts.

Gerard:

I Managed to get the cost for all the parts or shell.

Only problem i'm having at the moment is the what type of board, motor controller and software to go with that enable me to use an Android Tablet to map the path first then set the Robot to take.
Title: Re: Need help - Robot to Detect surrounding Environment
Post by: jwatte on April 01, 2014, 11:18:30 AM
Quote
Only problem i'm having at the moment is the what type of board, motor controller and software

It's unlikely that you'll find off-the-shelf software that knows how to take a GPS waypoint route and the input from a GPS receiver, and turn that into control signals for motor controllers. The closest I can think of is APM:rover; the second closest is ROS Hydro.

To have any idea of what controller and motors you need, we would need to know a lot more about the application.
Is there gearing already?
What is the diameter of your driving sprocket?
What acceleration (in "g" or m/s/s) do you want? Note that this also includes braking for safety.
Do you have batteries? If so, which ones? If not, any particular requirements (specific weight, cost, energy, etc.)
I presume you'll want to do differential steering, which means two motors?
What is the total weight of the vehicle -- load plus vehicle plus batteries?
What is the maximum incline you'll want to be able to climb?

Once you answer those questions, you can select a pair of motors with sufficient running torque (not just stall torque.) You will likely also need to select a gearing solution, unless you happen to find a motor with built-in gearhead to match your needs.
Then look at what those motors need: Are they DC gear motors? DCBL? AC Induction? Which kind will tell you what kind of driver (and possibly inverter) you will need.
Once you have that, you can start selecting among possibly multiple drivers, and then figure out how to send control signals to those drivers.

But it all starts with quantifying the specific numbers.