Dale, Of course you're quite correct. Even using a gyroscope and magnetic compass as aircraft do, short term straightness is anything but easy. As you say, the front of the mower can go off long before you know it.
I think most of us would wind up with snake ditches. tom On Mon, Aug 17, 2009 at 04:48:44PM -0400, Dale Leavens wrote: > It is a lot more complicated than that. > > I have a self propelled lawn mower. I have some very clearly defined boarders > and have practiced many times trying to guide it along in a straight line > parallel to where I am walking. There are several techniques I have used. A > really thick rope stretched tightly along the ground can be followed by the > feet, a very straight line but the front wheels of the mower are at least > five feet in front of the operator's feet. The machine can be several inches > off of line before the operator can detect it. > > It doesn't get a whole lot better walking along beside the handle of the > mower, close enough to be able to operate the clutch handle and retain the > safety shut-off but still at least two feet closer to the wheels, it is still > very difficult to calculate and adjust to keep the machine running straight > and parallel to the rope I am walking along. > > As a dedicated mobility device though, there are already many. Aircraft have > very accurate directional devices, it would be possible to calibrate already > available technology for the purpose but again, without the ability to > recalibrate according to small changes like maybe walking around a tree, just > following a straight line has quite limited value. Robots can go in a very > straight line if necessary but mostly it isn't a very useful ability. > > > > ----- Original Message ----- > From: Tom Fowle > To: blindhandyman@yahoogroups.com > Sent: Monday, August 17, 2009 9:59 AM > Subject: Re: [BlindHandyMan] Re: following straight lines: > > > Max, > We just bought some from U.S. digital that resolve to ten thousand divisions > per revolution they're about $95.00 each without the counting electronics. > Somebody who remembers trig would have to decide how far you could travel > before getting signifficantly off course with that kind of resolution > available <GRIN> > > I think a 64 step per rev unit might doo pretty well, or maybe a 256. I > think they'd cost in the neighborhood of forty bucks. > > Maybe the tape and winder or some simpler windup string might be cheaper! > <GRIN> > > Tom > > On Sun, Aug 16, 2009 at 09:20:53PM -0500, Max Robinson wrote: > > I was thinking more along the lines of a shaft encoder but they can get a > > bit pricy. > > > > Regards. > > > > Max. K 4 O D S. > > > > Email: m...@maxsmusicplace.com > > > > Transistor site http://www.funwithtransistors.net > > Vacuum tube site: http://www.funwithtubes.net > > Music site: http://www.maxsmusicplace.com > > > > To subscribe to the fun with tubes group send an email to, > > funwithtubes-subscr...@yahoogroups.com > > > > ----- Original Message ----- > > From: "Tom Fowle" <fo...@ski.org> > > To: <blindhandyman@yahoogroups.com> > > Sent: Sunday, August 16, 2009 8:34 AM > > Subject: Re: [BlindHandyMan] Re: following straight lines: > > > > > > > Max, > > > I suspect you'd have some trouble with the tape join to the presumed > pot > > > on > > > the helmet, and with the resolution of the pot. I actually think you'd > > > get > > > better resolution of the angle with my second idea, having a pointer on > > > the > > > digger, in front of you, to check against the tape. > > > > > > At work, we've actually talked a bit about studying techniques for > > > following > > > straight lines. Might put this in the hopper. Paper in a few years or so > > > <GRIN> > > > > > > Tom > > > > > > On Fri, Aug 14, 2009 at 09:51:53PM -0500, Max Robinson wrote: > > >> Interesting. An extension of this would be to use an angle sensor that > > >> will > > >> control a tone generator like the auditory gimmick. When the tape is > > >> straight ahead or behind the tone would be at it's lowest. If you got > > >> off > > >> line the tone would increase. You could easily tell which way to turn > by > > >> experimentally turning your head to see which way you are off. > > >> > > >> Regards. > > >> > > >> Max. K 4 O D S. > > >> > > >> Email: m...@maxsmusicplace.com > > >> > > >> Transistor site http://www.funwithtransistors.net > > >> Vacuum tube site: http://www.funwithtubes.net > > >> Music site: http://www.maxsmusicplace.com > > >> > > >> To subscribe to the fun with tubes group send an email to, > > >> funwithtubes-subscr...@yahoogroups.com > > >> > > >> ----- Original Message ----- > > >> From: "Tom Fowle" <fo...@ski.org> > > >> To: <blindhandyman@yahoogroups.com> > > >> Sent: Friday, August 14, 2009 8:56 AM > > >> Subject: [BlindHandyMan] Re: following straight lines: > > >> > > >> > > >> > Actually I wonder if a self winding tape could be put on a hefty > stake > > >> > beyond the eventual end of the proposed ditch. Then fasten the free > > >> > end > > >> > of > > >> > the tape to your helmet, everybody working with heavy equipment > wears a > > >> > helmet of course, and just reach up once in a while to see that the > > >> > tape > > >> > remains straight ahead of you. It winds up as you follow it along. > > >> > > > >> > For even more accuracy, fasten a stick to the digger so it points at > > >> > the > > >> > tape where you can reach it to check. > > >> > > > >> > Tom Fowle > > >> > > > >> > > > >> > ------------------------------------ > > >> > > > >> > Send any questions regarding list management to: > > >> > blindhandyman-ow...@yahoogroups.com > > >> > To listen to the show archives go to link > > >> > > http://www.acbradio.org/pweb/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=33&MMN_position=47:29 > > >> > Or > > >> > ftp://ftp.acbradio.org/acbradio-archives/handyman/ > > >> > > > >> > The Pod Cast address for the Blind Handy Man Show is. > > >> > http://www.acbradio.org/news/xml/podcast.php?pgm=saturday > > >> > > > >> > Visit The Blind Handy Man Files Page To Review Contributions From > > >> > Various > > >> > List Members At The Following address: > > >> > http://www.jaws-users.com/JAWS/handyman/ > > >> > > > >> > Visit the archives page at the following address > > >> > http://www.mail-archive.com/blindhandyman@yahoogroups.com/ > > >> > > > >> > If you would like to join the JAWS Users List, then visit the > following > > >> > address for more information: > > >> > http://www.jaws-users.com/ > > >> > For a complete list of email commands pertaining to the Blind Handy > Man > > >> > list just send a blank message to: > > >> > blindhandyman-h...@yahoogroups.comyahoo! Groups Links > > >> > > > >> > > > >> > > > >> > > > >> > > > > > > > > > ------------------------------------ > > > > > > Send any questions regarding list management to: > > > blindhandyman-ow...@yahoogroups.com > > > To listen to the show archives go to link > > > > http://www.acbradio.org/pweb/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=33&MMN_position=47:29 > > > Or > > > ftp://ftp.acbradio.org/acbradio-archives/handyman/ > > > > > > The Pod Cast address for the Blind Handy Man Show is. > > > http://www.acbradio.org/news/xml/podcast.php?pgm=saturday > > > > > > Visit The Blind Handy Man Files Page To Review Contributions From > Various > > > List Members At The Following address: > > > http://www.jaws-users.com/JAWS/handyman/ > > > > > > Visit the archives page at the following address > > > http://www.mail-archive.com/blindhandyman@yahoogroups.com/ > > > > > > If you would like to join the JAWS Users List, then visit the following > > > address for more information: > > > http://www.jaws-users.com/ > > > For a complete list of email commands pertaining to the Blind Handy Man > > > list just send a blank message to: > > > blindhandyman-h...@yahoogroups.comyahoo! Groups Links > > > > > > > > > > > > > > > > > > > [Non-text portions of this message have been removed] >
