Hi all. I'm working with submerged vehicles; ROVs and AUVs. I need to learn about control and navigation systems for these things, and would like pointers to literature. Anything, from "N&C for dummies" to the latest IEEE Journal articles, is of interest. I appreciate any help. Rune

# Kalman filters: Controlling ROVs and AUVs

Started by ●June 25, 2007

Reply by ●June 25, 20072007-06-25

On Jun 25, 5:27 pm, Rune Allnor <all...@tele.ntnu.no> wrote:> Hi all. > > I'm working with submerged vehicles; ROVs and AUVs. I need to learn > about control and navigation systems for these things, and would like > pointers to literature. > > Anything, from "N&C for dummies" to the latest IEEE Journal articles, > is of interest. > > I appreciate any help. > > RuneYou may want to try a more modern approach - H infinity state estimation and H infinity control. Only slightly different from the mse approaches they minimize the max value of the error. They are more robust to innacurate models and work on deterministic noise sorces even. In fact no knowledge of the noise is needed at all as compared to say the Kalman filter (though weighting must be selected based onSNR). http://academic.csuohio.edu/simond/courses/eec641/hinfinity.pdf (lots of typos on this article but you will get the jist)

Reply by ●June 25, 20072007-06-25

gay.highlander@yahoo.co.uk wrote:> On Jun 25, 5:27 pm, Rune Allnor <all...@tele.ntnu.no> wrote: >> Hi all. >> >> I'm working with submerged vehicles; ROVs and AUVs. I need to learn >> about control and navigation systems for these things, and would like >> pointers to literature. >> >> Anything, from "N&C for dummies" to the latest IEEE Journal articles, >> is of interest. >> >> I appreciate any help. >> >> Rune > > You may want to try a more modern approach - H infinity state > estimation and H infinity control. > Only slightly different from the mse approaches they minimize the max > value of the error. They are more robust to innacurate models and work > on deterministic noise sorces even. In fact no knowledge of the noise > is needed at all as compared to say the Kalman filter (though > weighting must be selected based onSNR). > > http://academic.csuohio.edu/simond/courses/eec641/hinfinity.pdf > (lots of typos on this article but you will get the jist) > >The author of this paper also authored the book "Optimal State Estimation". He starts you on Kalman filtering, takes you through H-infinity filtering, then on to some modern semi-esoteric stuff that requires orders of magnitude more processing power than is available now (but who's to say it still will ten years from now?). I know you're not a total newbie to DSP, but if you don't have much control background you may also be interested in my book (see http://www.wescottdesign.com/actfes/actfes.html). It only covers basic control theory, but it takes you from that basic theory all the way to practical applications using today's technology -- if you haven't closed real loops in real computer hardware I think you'll find it useful. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html

Reply by ●June 26, 20072007-06-26

On 25 Jun, 17:44, Tim Wescott <t...@seemywebsite.com> wrote:> gay.highlan...@yahoo.co.uk wrote: > > On Jun 25, 5:27 pm, Rune Allnor <all...@tele.ntnu.no> wrote: > >> Hi all. > > >> I'm working with submerged vehicles; ROVs and AUVs. I need to learn > >> about control and navigation systems for these things, and would like > >> pointers to literature. > > >> Anything, from "N&C for dummies" to the latest IEEE Journal articles, > >> is of interest. > > >> I appreciate any help. > > >> Rune > > > You may want to try a more modern approach - H infinity state > > estimation and H infinity control. > > Only slightly different from the mse approaches they minimize the max > > value of the error. They are more robust to innacurate models and work > > on deterministic noise sorces even. In fact no knowledge of the noise > > is needed at all as compared to say the Kalman filter (though > > weighting must be selected based onSNR). > > >http://academic.csuohio.edu/simond/courses/eec641/hinfinity.pdf > > (lots of typos on this article but you will get the jist) > > The author of this paper also authored the book "Optimal State > Estimation". He starts you on Kalman filtering, takes you through > H-infinity filtering, then on to some modern semi-esoteric stuff that > requires orders of magnitude more processing power than is available now > (but who's to say it still will ten years from now?). > > I know you're not a total newbie to DSP, but if you don't have much > control background you may also be interested in my book (seehttp://www.wescottdesign.com/actfes/actfes.html). It only covers basic > control theory, but it takes you from that basic theory all the way to > practical applications using today's technology -- if you haven't closed > real loops in real computer hardware I think you'll find it useful.Both books are on order from amazon.com. I've been browsing IEEExplore, but I don't have access to the relevant journals and don't know what to look for. I suppose what I need is similar to aeronautics nav processing, where one fuses data from onboard sensors, sattelites and beacons to produce a position/track estimate. Any suggestions on where to start? Rune

Reply by ●June 26, 20072007-06-26

Rune Allnor <allnor@tele.ntnu.no> writes:> I've been browsing IEEExplore, but I don't have access to the > relevant > journals and don't know what to look for. I suppose what I need is > similar to aeronautics nav processing, where one fuses data from > onboard sensors, sattelites and beacons to produce a position/track > estimate. > > Any suggestions on where to start?Rune, I'm not sure it's directly relevant, but there is an article from the airborne laser scanning (ALS) community by Baltsavias: Baltsavias, E.P., 1999. Airborne laser scanning: basic relations and formulas. PRS, Vol. 54, No.2-3, pp. 199-214. ftp://igpho.ethz.ch/pub/manos/papers/formals_prs.pdf that ties together some things there. ALS fuses GPS, navigation systems, the laser scan angle and time-of-flight measurements to get 3D data. It's a different problem, but I suspect there's details in the literature that will help you out. Ciao, Peter K. -- "And he sees the vision splendid of the sunlit plains extended And at night the wondrous glory of the everlasting stars."

Reply by ●June 26, 20072007-06-26

Rune Allnor wrote:> On 25 Jun, 17:44, Tim Wescott <t...@seemywebsite.com> wrote: >> gay.highlan...@yahoo.co.uk wrote: >>> On Jun 25, 5:27 pm, Rune Allnor <all...@tele.ntnu.no> wrote: >>>> Hi all. >>>> I'm working with submerged vehicles; ROVs and AUVs. I need to learn >>>> about control and navigation systems for these things, and would like >>>> pointers to literature. >>>> Anything, from "N&C for dummies" to the latest IEEE Journal articles, >>>> is of interest. >>>> I appreciate any help. >>>> Rune >>> You may want to try a more modern approach - H infinity state >>> estimation and H infinity control. >>> Only slightly different from the mse approaches they minimize the max >>> value of the error. They are more robust to innacurate models and work >>> on deterministic noise sorces even. In fact no knowledge of the noise >>> is needed at all as compared to say the Kalman filter (though >>> weighting must be selected based onSNR). >>> http://academic.csuohio.edu/simond/courses/eec641/hinfinity.pdf >>> (lots of typos on this article but you will get the jist) >> The author of this paper also authored the book "Optimal State >> Estimation". He starts you on Kalman filtering, takes you through >> H-infinity filtering, then on to some modern semi-esoteric stuff that >> requires orders of magnitude more processing power than is available now >> (but who's to say it still will ten years from now?). >> >> I know you're not a total newbie to DSP, but if you don't have much >> control background you may also be interested in my book (seehttp://www.wescottdesign.com/actfes/actfes.html). It only covers basic >> control theory, but it takes you from that basic theory all the way to >> practical applications using today's technology -- if you haven't closed >> real loops in real computer hardware I think you'll find it useful. > > Both books are on order from amazon.com. > > I've been browsing IEEExplore, but I don't have access to the > relevant > journals and don't know what to look for. I suppose what I need is > similar to aeronautics nav processing, where one fuses data from > onboard sensors, sattelites and beacons to produce a position/track > estimate. > > Any suggestions on where to start? > > Rune >I think you were on target (in general, at least) in asking about Kalman filtering for this part. The definition of Kalman filter has taken on the meaning of "a multivariable signal processing algorithm that takes data from a big wad of inputs and coughs up the best output(s)" -- in this wide sense you were asking for just the right thing, at least inasmuch as H-infinity, extended Kalman and particle filters all fit the definition as well as a plain old Kalman filter. Dan Simon's book should prove very helpful for you here. I know enough about Kalman filters to construct one to the narrow definition, so when I have a problem that's narrowly defined enough I can be useful (and if you're conservative in your choice of weightings you can make it generally useful, although not necessarily optimal). The next time I have occasion to do a multivariable estimation problem I'll be leaning on the Simon book, and I expect to be able to do a pretty good job of it. When (or if) you get to the point where you're actually controlling the motion of the vehicle you'll find my book useful, although I imagine you'll have to concern yourself with all sorts of nonlinearities and axis cross-coupling that one can normally avoid in simpler control problems. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html

Reply by ●June 27, 20072007-06-27

Rune Allnor <allnor@tele.ntnu.no> wrote in news:1182749246.005438.80620 @w5g2000hsg.googlegroups.com:> Hi all. > > I'm working with submerged vehicles; ROVs and AUVs. I need to learn > about control and navigation systems for these things, and would like > pointers to literature. > > Anything, from "N&C for dummies" to the latest IEEE Journal articles, > is of interest. > > I appreciate any help. > > Rune >Hi Rune, No satellite navigation (GPS) when submerged! Sam

Reply by ●June 27, 20072007-06-27

On Wed, 27 Jun 2007 15:47:03 +0200, SamSvL wrote:> Rune Allnor <allnor@tele.ntnu.no> wrote in news:1182749246.005438.80620 > @w5g2000hsg.googlegroups.com: > >> Hi all. >> >> I'm working with submerged vehicles; ROVs and AUVs. I need to learn >> about control and navigation systems for these things, and would like >> pointers to literature. >> >> Anything, from "N&C for dummies" to the latest IEEE Journal articles, >> is of interest. >> >> I appreciate any help. >> >> Rune >> > > Hi Rune, > > No satellite navigation (GPS) when submerged! > > SamNo, but if you can surface & stick an antenna up you can get a fix, and use it to calibrate your inertial sensors. You'd be able to get LORAN down a few meters at least -- I'm not sure how far it'd penetrate the water, but if they can use 30kHz to communicate with subs 100kHz should get down some. Given a compass, inclinometer and a water-speed gauge you could use dead reckoning, particularly if you could surface every once in a while to upgrade your knowledge of drifts. Rune -- I think you need to post this to yet another newsgroup. Find the one that covers choosing the right sensor technologies for AUV's and you'll be fine... -- Tim Wescott Control systems and communications consulting http://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

Reply by ●June 27, 20072007-06-27

"Tim Wescott" <tim@seemywebsite.com> wrote in message news:d7SdnQtp4pLsGR_bnZ2dnUVZ_tXinZ2d@web-ster.com...> On Wed, 27 Jun 2007 15:47:03 +0200, SamSvL wrote: > >> Rune Allnor <allnor@tele.ntnu.no> wrote in news:1182749246.005438.80620 >> @w5g2000hsg.googlegroups.com: >> >>> Hi all. >>> >>> I'm working with submerged vehicles; ROVs and AUVs. I need to learn >>> about control and navigation systems for these things, and would like >>> pointers to literature. >>> >>> Anything, from "N&C for dummies" to the latest IEEE Journal articles, >>> is of interest. >>> >>> I appreciate any help. >>> >>> Rune >>> >> >> Hi Rune, >> >> No satellite navigation (GPS) when submerged! >> >> Sam > > No, but if you can surface & stick an antenna up you can get a fix, and > use it to calibrate your inertial sensors. > > You'd be able to get LORAN down a few meters at least -- I'm not sure how > far it'd penetrate the water, but if they can use 30kHz to communicate > with subs 100kHz should get down some.subs use a floating antenna for LORAN

Reply by ●June 27, 20072007-06-27

On Wed, 27 Jun 2007 10:42:09 -0500, BobF wrote:> "Tim Wescott" <tim@seemywebsite.com> wrote in message > news:d7SdnQtp4pLsGR_bnZ2dnUVZ_tXinZ2d@web-ster.com... >> On Wed, 27 Jun 2007 15:47:03 +0200, SamSvL wrote: >> >>> Rune Allnor <allnor@tele.ntnu.no> wrote in news:1182749246.005438.80620 >>> @w5g2000hsg.googlegroups.com: >>> >>>> Hi all. >>>> >>>> I'm working with submerged vehicles; ROVs and AUVs. I need to learn >>>> about control and navigation systems for these things, and would like >>>> pointers to literature. >>>> >>>> Anything, from "N&C for dummies" to the latest IEEE Journal articles, >>>> is of interest. >>>> >>>> I appreciate any help. >>>> >>>> Rune >>>> >>> >>> Hi Rune, >>> >>> No satellite navigation (GPS) when submerged! >>> >>> Sam >> >> No, but if you can surface & stick an antenna up you can get a fix, and >> use it to calibrate your inertial sensors. >> >> You'd be able to get LORAN down a few meters at least -- I'm not sure how >> far it'd penetrate the water, but if they can use 30kHz to communicate >> with subs 100kHz should get down some. > > subs use a floating antenna for LORANWell, there's nothing like practical knowledge to blow theory all to hell. Come to think of it, a GPS receiver on a tether may work, also, if you are working that close to the surface. It adds some interesting twists to your "Kalman" filter, to be sure, but it may work. -- Tim Wescott Control systems and communications consulting http://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html