Critique my perimeter plan?

[RoboBob]

Greetings All,

I am on a 2.5 acre lot - I purchased a 3550 a little while ago, but just recently have time again to work on deploying it.  Below is my rough perimeter wire plan - Green is Phase 1 for the current 3550 I have.  Orange is Phase 2 if I find the 3550 is sufficient I have someone offering me to sell their 3550.  Red block is the dock placement for phase 1.  Blue Block is dock placement for phase 2.  I was hoping I could run this all off one signal generator with an amplifier (since both robots are already programmed on signal A)




From what I have been told the 2.5 acres is the upper limit for a single 3550.  My current 3550 has high hours (but just installed 2 new batteries - didn't have those before & rebuilt the lawn blade motor - burned out the first 30 minutes of use, sharpened and balanced the blade), so dont really want to push it too hard, that and when summer monsoon season comes around (live in South Florida) - there will only be a short time when the conditions allow the grass to be cut - after heavy rains - 40% of my lawn turns into a pond - it takes a few days to dry out - if lucky there will be 1-2 days after it dries out that the grass can be cut....so was thinking 2 3550s would allow more of the lawn to be cut in that short amount of time - that is if the current 3550 impresses my better half to approve the purchase of the second unit 

[toolbelt]

1.  The wires at the top of each boot should be touching each other for the first 3 inches (a boot is nothing more than a flower bed layout except for the toe part.)

2.  Should the bot hit the back side of the boot that is near the Well, when it’s time to return, it will run into the 12x16 shed as it tries to straddle the wire.   Just move the wire to the right (in your drawing) to go around the shed — again, your dealing with a flower bed called a shed… lol.

3.  The wire next to each sole of the boots, should have bump outs so the bot can’t escape into the other area.  This happens when the bot is running parallel and close to the perimeter wire.  The bump outs cause it to hit the wire keeping it in that area.
Search for 'bump outs' as I'm sure there is an old posting describing them.  If not, let me know and I'll draw up a diagram.

4.  You may get away with using only one signal generator by using electrical relay switches and timers.  Supplying voltage via a timer to a normally open relay would cause it to close making contact, and open when the voltage was removed.  Normally closed relays would work in the reverse.  You could also change the perimeter wire layout using the relays.  Making smaller sized areas using relays would cut down on the signal power required.  Of course you may have to have a PhD to come up with the diagram….lol

5.  The toe of the upper green boot should be close enough to the heel of the other green boot such that there is only a 3 inch gap.  When the bot tries to make the 180 degree turn back at the end of the toe it should detect the other boot wire.

6.  Each 90 degree corner should be a smooth curve….. just a reminder as I’m sure you are aware of that.

7.  Each boot should be at least 12 inches wide so the bot doesn’t escape to the other area.  You may end up with a small strip of uncut grass if it’s too wide so adjust as needed.

Hope that helps..

toolbelt

[RoboBob]

Thanks for your input!

I will try to upload a newer version of the perimeter map today.

Quick questions:
- What should be the distance between the sole of the boot to the opposite perimeter wire?
- What should be the distance between the wire going to phase 2 and coming back out of phase 2?

Thanks!,

Bob

[toolbelt]

When the bot is following the wire it zigs and zags.  I've found that the distant it travels from the wire is about 3 inches or less.  At 3 inches it would be weaving 6 inches so it's most likely even less than 3 inches.  If the wire is 3 inches away from the bottom of the boot you should be okay.  All it would take is a sight adjust to the length of the boot to make a correction.  Of course the sensor will determine how close it can get so it may pay you to run a few tests.

Again 3 inches should be okay for going from phase 2 etc.....however you would have to make a large loop at the end where 'orange' meets 'green' so it can make the 180 degree loop back.

toolbelt

[shep874]

Hi Just some information.  you can run two Lawnbotts  on the same charger and Signal generator.  Just wire the charger to both charge stations and the signal generator to  the parameter wire.  I ran a 3550 and a 3250 for a while and the change to two 3250 so that it did not matter what charge was empty. If empty went in if not went to the other charger. Through programing you can have the is different zone running at the same time.
Hope this info is useful.  Mel

[RoboBob]

Thank you toolbelt and shep874 for your replies!

I finally got the yard ready this past week - lots of filling holes, grinding down stumps, picking up branches & pine cones, etc. and ran the wiring for Phase 1 (almost hit the 2000' limit).  Runs mostly like a champ!  Besides getting stuck on large tree roots, soft fill, debris I missed - all mostly easily remedied.  The only other issue is that it seems to stay in its primarily area - I think this might be because one of the "boots" is about 3 feet behind the charging station - the robot might be getting confused when going counter clockwise and hitting the foot of the boot before hitting the wire that leads it to its charging station...this should also be easily remedied by either shortening the boot or bending the "leg" and having the foot of the booth moved further away from the dock?

[RoboBob]

In the event someone in the future gets the idea that you can run two transmitters of the same channel on your yard - you need atleast 300 feet between the two closest points of the two perimeter wires.

So back to the original idea of using a signal booster to use one transmitter for the entire property (but will really be pushing the limits of the booster - Max 4000 feet of wire - I used nearly 2000 feet for the smaller phase 1 project).  Would the following idea work?:

Treat phase 2 like a flower bed - run a short run 12" from phase 1 (green) to phase 2 (orange) with the wires touching for this run then opening up to the entire phase 2 perimeter wiring - the closest the two runs will meet is the border between the two south of the screened deck/pool at 12" apart.  The 12" of touching wire should nullify the signal between the two phases and make the robots in each phase think they are on their own transmitter/perimeter?  The lawnbott in phase 1 (green line w/ red box) would ignore phase two (orange line with blue box) and run the phase 1 without issue.  Same for lawnbott is phase 2 - would disregard phase 1 wiring.

Image of the idea:


Would this work?

Thanks again!

[toolbelt]

Look up an old posting (Aug 16, 2011) concerning Two Signal Generators.  I posted a diagram that breaks a lawn up into 6 parts.  A switch is used to switch the signal from one set of 3 areas to the other set.  A 24 hour timer controls the power to the switch….power On, power Off.  Simple as that.
Here is a link to it:  http://forum.paradiserobotics.com/index.php?topic=349.0

Note the perimeter wire has, what I call ‘bump outs’, to make sure the bot doesn’t escape from one area to the other.  The only way it can escape without them is to be running parallel with the wire.  The bump outs are close enough to the top/bottom of the boot such that they are hit stopping the bot from going into the next area.

You might want to see if something like this will work for your layout.  You could increase the amount of wire by 2x since you will be only using half at one time.

Just a quick glance at your diagram.  Doesn't the rules for flower bed require the bot to go counter clock wise around them?
toolbelt

[RoboBob]

Hello Toolbelt,

Oh yes - sorry I didn't really update the drawing as I was doing this as quickly as possible (at work :-p) - I have incorporated bump outs, rounded corners, etc that you highlighted in previous posts - so far Phase 1 has been a great success - minus the vertical "aerial" roots that need to be cut flush with the ground.

Not quite sure if two signal generators with a switch would be a good fit for me.  I've noticed the current lawnbott doesn't really adhere strictly to the schedule.  For example: I've seen one occurrence where the lawnbott went back to its dock early then exit it 45 minutes before the end of its shift and went to do a secondary area for 2 hours or so (1:15 mins after it should have gone back to its dock)

For the idea I had about the "Treat phase 2 like a flower bed" - probably wasn't the best term - I would cross the wires at the end so the clockwise and counter-clockwise wires would be properly set for phase 2 - somewhat better illustration below, but not to scale ;-) - the 12" run + bump outs should be enough to keep the two lawnbotts in their own zones/phases?  that corner for phase 2 at the junction between phase 1 and 2 would be curved :-)

[toolbelt]

How about the above?  You will need to remove the green and orange wires that are close together.  Make sure the bot can turn around between wire A and the red charger when it's mowing that area.
Run a wire from the charger terminals to the other charger terminals making sure you connect the left hand side to the left hand side and right hand side to right hand side.... ie. + to +, - to -. 
Set the time for start-up at different times remembering that once turned off it starts over in the main area.

The switch timer is set to sync with the bots mow time.

You only need to connect the wire coming from one signal generator to one of the bots charger but you still need the wire for the plates as stated above.

If possible could you relocate the Red charger next to the Blue one, leaving at least 6 feet between them  If so you would still need wire B going from the switch to the green wire but Wire A (orange)  could go straight up to connect at the junction of green and orange.  Thereby eliminating the tight areas.

Not worded the best but we can always hash it out..... lol

toolbelt

[toolbelt]

Even better if you could place both chargers at the bottom of the screened deck/pool area.  That would allow the wire coming off the switch to go directly to the green wire thereby eliminating the other tight area.  Maybe build little 'dog houses' to sit over the chargers so they don't look too bad being there....

toolbelt

[RobotLady]

I didn't study your layout but the wires can never cross.  The robot will have signal issues and give an "out of border" message.  Hope this helps...

RobotLady

[toolbelt]

In my drawing I show the wires crossing BUT the switch isolates the wires so the signal is present on one set of wires at a time.  RobotLady did not say which drawing she was referring to.

toolbelt

[RoboBob]

Thank you both for your inputs!

My better half has put a halt on proceeding with Phase 2 - until I can get the new issue of the robot flipping itself upside down resolved first.  -- http://forum.paradiserobotics.com/index.php?topic=431.0