More Mule then Rover?

[Tommy_T]

Hello Forum, This is a first post and as it turns out a first personal project for me.

My First Project: General Lawn care Mule.

P - Programmable
A- Autonomous
C - Controlled

M - Motorized
U - Utilitarian
L - Lawn/Garden
E - Equipment


Project budget $2500.00

Because I still have to work I'm giving myself 1 year to complete the project.

Tasks it most perform
1) carry payload of 150lb (at least 2 bags of potting soil)
2) mow grass (both manually(remote control) and autonomously(with supervision))
3) clear snow for drive and walkways manually(remote control)
4) simple to control (even my 75yr old mother can use in her garden)


The main controller is going to be a net-book PC(or my dual core laptop if needed)
remote control operation will be Bluetooth(wireless keyboard) and WiFi.

Servo control is analog(0V to 5V).
Speed controller RobotQ Ax2550 - (Sabertooth 2x25(for testing) and Peripheral Attachments )
Transducers Phidgets 3/3/3, Phidgets 8/8/8, Phidgets high speed encoder cards(at least 2) ,at least 2 encoders.
Analog output Labjack U3-LV

Test bed will be a used power wheelchair.

While disassembling the test bed I got a look at the drive that came with it (Penny&Giles 50/70 Amp VSI speed control).
And I gotta say it is a sweet drive, and if theres a way of using it I could shave $500 off the budget.
The other sweet thing about that drive is it has built in safety features like battery level inductions, differential
analog monitoring ,analog voltage level monitoring and Motor current monitoring.(shorted or stalled motor can't take out a drive..sweet)

using the P&G drive would remove the need for a Microprocessor as a hart beat also saving $100.

But it has a built in acceleration/Deceleration loops that would cause me issues while under autonomous control.

First question: Has anyone ever tried to remove or change the Speed profiles on a Penny&Giles 50/70 Amp VSI speed control ?.

I goggled it and found references to a Speed profile programmer for Dealers, OEMs and Manufactures, but none for end users.

If I can find a way to use the P&G drive I could slip the below item into the budget. (which would be sweet)
http://www.snowblowersdirect.com/Ari...m=shop+portals



Feel free to correct me when you see I'm wrong.

Tommy

[jdolecki]

I'm doing the same thing for a robot base but i have a Jazzy power chair base. ( 100 Dollars craigslist) I have an e-mail into P&G about the drives thay make.

This was the first reply

The parts number you gave are for our VR2 based systems. These have no external input devices except the joystick and an attendant module since these are made primarily for wheelchairs. The R-net system, which is our higher end rehab controller does have modules that handle other input devices.

They R-net is expensive.

So I asked about the communication protocal between the Joystick (Which the also make) and the controler which im waiting for a reply now.

I still need 2 new batteries 12v 35ah $140

Im using a ZOTEC mother board for a brain and running MSRS to control it.

I also was told to just put that controller and joystick on e-bay to offset the cost of a motor controller. Which I will end up doing I think.

So for a 2500 budget you should be able to put together a nice bot.

[Tommy_T]

So I asked about the communication protocal between the Joystick (Which the also make) and the controler which im waiting for a reply now.

jdolecki
I also tried to get the wiring for the joystick to the drive from them, but got no help. But after
opening the joystick it was easy to interface with 2 analog voltages DAC0 for speed DAC1 for
turning. it will only work between 1 and 4V with 2.5 as stop. If you don't want to add analog
you could also control the drive with 2 RC servos.

If I could overcome the Acc/Dec problem I would love to use the P&G drive.

I may be interested in that drive if you are thinking about unloading it, they are very sweet drives.

So for a 2500 budget you should be able to put together a nice bot.

Right now I'm looking at navigation and tracking(not using boundary wire). every idea I come up with
seems to take big bucks from the budget.

Because I come from the manufacturing industries the first direction I'm heading is looking at it as a CNC
machine programed in G-code(it's not working out good for me).


Tommy

[zoomkat]

Not sure why people try to build lawn mowing devices from scratch, but probably not such a good idea (poor cutting and possibly dangerous). A better deal would be to convert an existing riding mower for autonomous/remote control. Mowers like below can haul 200+lb on top (aka fat people), have onboard electric start/generator, and with larger gas tanks can run for many hours/miles. Once the project is done, one still has a riding mower that can be used as origional or sold to recover some of the cost. On the local Craigs list old working riding mowers can be had for $150 and up.


http://www.walmart.com/ip/Weed-Eater...Mower/13346325

[Tommy_T]

Not sure why people try to build lawn mowing devices from scratch

zoomkat
I bet that type question comes up often when ever some teen age girl wants to sail around the world
solo, or that 75 year old grandpa wants to climb mount everest. I can't even figure a motive for either
of the above examples, but for myself I gravitate towards projects that have not been completed
yet. I understand that thousands of people have taken on the lawn mowing project(some can even fly),
but no one has cracked Autonomous lawn mower nut yet. I also understand that for far less
money I can buy a cute little toy that could mow my mother's lawn almost(they are very
limited currently in size of lawn ,slops, dog crap and attractive cutting paths).

build lawn mowing devices from scratch

At this point I'm thinking it would be cheaper to design and build from scratch, then mod. a wheelchair frame
to the task.(I'm on my second one as a test bed, trying six wheels on the ground, not four).

and with larger gas tanks can run for many hours/miles.

Part of the project is to think GREEN, while not in the current budget at some time solar cells will
be added to charge the batteries.

Tommy

[lnxfergy]

zoomkat
I bet that type question comes up often when ever some teen age girl wants to sail around the world
solo, or that 75 year old grandpa wants to climb mount everest. I can't even figure a motive for either of the above examples, but for myself I gravitate towards projects that have not been completed yet.

+Rep.

-Fergs

[DresnerRobotics]

Not sure why people try to build lawn mowing devices from scratch, but probably not such a good idea (poor cutting and possibly dangerous). A better deal would be to convert an existing riding mower for autonomous/remote control. Mowers like below can haul 200+lb on top (aka fat people), have onboard electric start/generator, and with larger gas tanks can run for many hours/miles. Once the project is done, one still has a riding mower that can be used as origional or sold to recover some of the cost. On the local Craigs list old working riding mowers can be had for $150 and up.


http://www.walmart.com/ip/Weed-Eater...Mower/13346325

Some people like actually building things instead of just talking about it.

[zoomkat]

Some people like actually building things instead of just talking about it.

Well, so far all of this has just been talk, so I'm not sure as to the point of your statement. That being said, I think this project as currently described will probably fade away as a collection of half built parts. The difficult part of "Autonomous" operation does not appear to have been addressed. I've seen various lawn mowing bot pix on the web and have my opinions as to their good/bad points. If the most difficult parts of a project isn't resolved early on, then generally a lot of time and $$$ is waisted. Having ~1 acre of grass to cut every so often, I'm familiar with real world grass cutting issues. Just giving some practical opinions to the project person before he finds himself "in the weeds" with his project.

[DresnerRobotics]

Well, so far all of this has just been talk, so I'm not sure as to the point of your statement. That being said, I think this project as currently described will probably fade away as a collection of half built parts. The difficult part of "Autonomous" operation does not appear to have been addressed. I've seen various lawn mowing bot pix on the web and have my opinions as to their good/bad points. If the most difficult parts of a project isn't resolved early on, then generally a lot of time and $$$ is waisted. Having ~1 acre of grass to cut every so often, I'm familiar with real world grass cutting issues. Just giving some practical opinions to the project person before he finds himself "in the weeds" with his project.

I was mostly referring to your posting style in general, not this thread in particular. That is, that you tend to lean on the negative side of things in most of your posts, yet have failed to show any real work of your own that would validate your largely negative and opinionated stance.

[Tommy_T]

I think this project as currently described will probably fade away as a collection of half built parts

zoomkat
While my chances of cracking the Autonomous nut may only be 10% within the one year time frame,
I still have a useful tool for my mom.

I would love to post a few pictures, but with the frame covering being 10lb of duct tape, 4 yd of cardboard,
plastic tarp I even think theres some bailing twine in there someplace. I'v run it in the rain with no problems
so the duct tapes is working, it just looks like hell.

cosmetics never made it to the budget.

Tommy