Low cost HUD (or HUD-like) display?

Discussion in 'Instruments / Avionics / Electrical System' started by cluttonfred, Aug 26, 2014.

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  1. Aug 26, 2014 #1

    cluttonfred

    cluttonfred

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    On a tangent to the https://www.homebuiltairplanes.com/...l-system/16252-cheap-efis-finally-coming.html thread, I have often wondered why no one is making a very cheap, simple HUD to replace basic flight and engine instruments for experimental and ultralights. And I mean simple, perhaps just a monochrome display of digital readouts and analog bar graphs for key instrument functions.

    The challenge is always keeping it simple without all the bells and whistles, but done right it could actually be cheaper than the equivalent analog gauges. I can easily imagine a light plane with little if any instrument panel, just a small console or side panels for radios and switches, and all the basic instrument functions on the little HUD.

    A properly collimated (focus off in the distance) display would be nice, but even a simple reflective display, the equivalent of one of those iPhone apps for displaying GPS info reflected in the windshield, would still help simplify and unclutter the panel.

    So, why is no one doing this?
     
  2. Aug 26, 2014 #2

    Hephaestus

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    Can be done relatively easily - even as simple as a tablet on the dash... Little better some 7segment displays run by arduino - on the dash a pair of lenses to get true infinite focus.

    I dunno about you guys, but I'm looking forward to the Google glass type scenario - HUD is useful looking ahead - following where I look seems more useful than a HUD.
     
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  3. Aug 26, 2014 #3

    cluttonfred

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    I don't think it's quite as easy as all that if you want readability in full sunlight, for example, but still, it shouldn't be that hard either. Google Glass is no for me, I already wear glasses. ;-)
     
  4. Aug 26, 2014 #4

    Hot Wings

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    Forget the HUD and Google glasses. Just inject all pilots with high levels of Midi-chlorians and change the pilot training syllabus to take proper advantage of the little critters. :gig:



    Seriously - something like the Google glasses would be my personal choice.
     
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  5. Aug 26, 2014 #5

    bmcj

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    We so often neglect the other senses too. Soaring pilots make good and effective use of audio variometers.
     
  6. Aug 26, 2014 #6

    Vigilant1

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    "HUD display", is that like "ATM Machine" and "hot water heater" ?:)

    I understand the attraction of the idea, but I don't think it would be useful or desirable for most people operating in a VFR environment. People seem to have enough trouble seeing me and my little plane without things being projected/cluttering up their field of view right in the spot where our closing rate will be the highest. It's different for a fighter plane: visual lookout is still very important, but the info on the HUD >augments< this scan ("Look inside the circle, the radar says the bogey is there") and provides info needed to keep the pilot alive and maximize the chances of mission success. For airliners which spend a very small portion of their time in the VFR "world," it's probably good to have the info on a HUD for the critical phases of flight, especially since most of these guys are in controlled airspace (and presumably at minimal risk of hitting a VFR airplane that isn't under ATC direction) anytime the wheels are off the ground.

    For most of us "fun flyers", I think it best to keep the windscreen real estate free of clutter and to keep our eyes outside the cockpit the vast majority of the time. For those who see the need, a good (and cheap) approach that facilitates this would be a master caution light at the top of the panel that alerts the pilot to out-of-spec parameters (oil temp, oil press, CHT, voltage, even fuel level, etc) or other lights that can provide time critical info without need to refocus (e.g. LRI/AoA warnings to let us know we are getting into treacherous territory and provide a useful backup to ASI during landing).

    Just my opinion.
     
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  7. Aug 26, 2014 #7

    Pops

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    One time as a winter project, I made a warning panel for all out of spec parameters with flashing LED's and voice warnings to the audio panel for installation at the top of the radio stack. Never did install it. After I had a vacuum failure about 15 miles from the airport in hard IFR almost down to minimums with a strong cross wind. I caught the failure as it happen. Dan
     
  8. Aug 26, 2014 #8

    cluttonfred

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    Understood, Vigilant1, though I disagree. Having a simple HUD in your field of view while you are looking outside seem much better for situational awareness to me than having to look down in the cockpit to read conventional gauges. Depending on the design, reducing the size of the panel may also offer opportunities to increase visibility. I am not thinking about adding a lot of bells and whistles, rather I am thinking of a simple, self-contained unit that could replace all the needle gauges and save weight and money at the same time. I'd still want all the old-fashioned gauges in a biplane or a Cub, but this could serve well for an ultralight or a new design.
     
  9. Aug 26, 2014 #9

    Topaz

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    Ayup. I have a neat little audio vario that clips to my hat, right near my ear. It's not as precise as the regular instrument, but it's "good enough" for in-between panel scans.

    I agree with Vigilant1 on this topic. The problem with a true HUD is that it's not going to be "simple and inexpensive". For it to genuinely allow you to "look through the HUD" to continue see-and-be-seen scanning, the HUD needs to be focused at infinity, so you're not having to refocus between the HUD and the distant traffic. Otherwise, all you're doing is cluttering up the field of view, just as Vigilant1 says. This is why fighter and commercial HUDs have the fancy optical stacks between the display and the HUD plate. Getting the optics right is a heck of a lot more involved than simply angling a glass plate over some kind of sunlight-readable display.

    Also, I personally think the utility is limited. Do you really need to look at the instruments that much? Keep that one little windshield scratch on the horizon, glance at the instruments now and again during your see-and-avoid scan, and that should do it. Unless you're an airliner needing to follow a tight airway, or flying IFR, you really should have your eyes outside much more than looking at the instruments. Your eyes, ears, and the seat of your pants will tell you more, faster, if not quite as precisely. I suppose if one really could do a HUD cheaply and easily, then sure. Why not? But "cheap and easy" is probably little more than a fantasy here. It's not going to be either, if done in a way that actually makes it useful.

    I think the idea of a master caution-and-warning light is a very good one.
     
  10. Aug 26, 2014 #10

    Direct C51

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    I am with Topaz on this one. I have over 2000 hours in an aircraft that uses a small HUD over the right eye. This HUD shows all flight instruments, velocity vector, flight path vector, waypoints, and even other aircraft. For normal VFR flight, I took it off a year ago and never looked back. We have a tendency to get focused on it and stop looking outside. I flew the HUD and not the aircraft. I got consumed with the instruments in my eye, and stopped looking outside for reference. This made me a very very precise pilot. I would routinely fly within 2 knots and 20 feet of my intended airspeed and altitude, but I lost my outside scan. I would say my situational awareness of other aircraft was less than 50%, and I stopped enjoying the scenery. I took off the HUD and it took some adjustment to fly again, only glancing at the instruments every few seconds, and looking outside the majority of the time. I see a lot more aircraft now, and enjoy the flying a lot more. For VFR flight, I would never want a HUD, even if it was free and weightless. When you leave normal VFR flight, and get in to this aircraft's main role, the HUD is an absolute requirement.
     
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  11. Aug 26, 2014 #11

    gtae07

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    A few uses I could see, especially with a head-mounted (Google Glass?) display...

    VFR:
    Traffic alerts--I don't know if you'd want it showing all the time (concerns over distraction, complacency, etc) but if your Flarm/ADS-B unit pings it could flash an arrow pointing to the target. It would be faster at least than having to look down at a panel and then trying to look up and match it with what was displayed. Flick a stick switch to acknowledge.

    Airspace--a moving map works well most of the time, but might be nice in really crowded spaces.

    Racing league/Red Bull for the Rest of Us--Design a course, load it in your HMD and smart avionics unit, and fly it at 5000ft instead of 50ft.

    Instruments for backseaters or aircraft that just don't have room for any (P103, hang gliders, etc.)


    IFR: If this can be made to be suitably reliable (and one day, it will be), wouldn't it be nice to fly an approach in IMC with almost the same visual cues you'd get on a CAVU day, rather than the highly abstracted references of a relatively tiny six-pack or EFIS display and some needles?




    I expect that the first units like this to be sold on the market will be in the neighborhood of Google Glass price + $1-2k, tie into the EFIS serial stream, and come with a "not for navigation" disclaimer. I also expect that there's a lot more potential in such a head-mounted system than we would expect; making use of some of that might mean having to think outside the bounds of the way things have always been done before.
     
  12. Aug 26, 2014 #12

    Topaz

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    I think the idea of a little head-mounted display is nice, for all the reasons you state. But why do something dedicated? Why not just use Google Glass as-is? The functions we want are just software, and you Bluetooth the thing to your input sensors and their processor, which stays in the airplane.

    I see something like this as far more useful than a fixed HUD, especially for the ability to point out traffic. Again, I will say that I think this is severe overkill for a Day-VFR "fun" airplane for all the reasons Direct C51 states, but the ability to add in the ability to point out traffic and cues to find it, coupled with the small size and "footprint" of the display means it would be a lot more useful on the average day-VFR flight, at least for me. But then, I fly in the LA/OC Basin, which is generally a lot more congested airspace than most people have to deal with.

    To the extent that such things promote "looking at the instruments all the time", however, they concern me. I don't know how many pilots could resist the temptation to start "flying the instruments instead of the airplane", as was stated so well above.
     
  13. Aug 26, 2014 #13

    Vigilant1

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    I don't want to share the skies with somebody doing this--living a virtual-reality Walter Mitty world when they should be concentrating on traffic. Isn't VFR aviation good enough without tarting it up? What next: Add in virtual adversaries for virtual air combat? ("Red Flag for the rest of us" -- in the same airspace where people are trying to actually fly using the world-as-it-is. We have MOAs for a reason). On top of everything else, it sounds like a good way to assure the FAA eventually requires ADS-B In and Out for everybody.
     
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  14. Aug 26, 2014 #14

    bmcj

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    I can foresee the day when computer imaging and interpretation will lead to a computer camera system that can detect and point out other traffic in realtime on a solely visual level. This will be independent of radar or equipment carried on the other aircraft.

    Granted, it will be some time before such a system is refined, and you have to wonder if there will still be VFR flights allowed by then.
     
  15. Aug 26, 2014 #15

    gtae07

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    Oh, no objection to it at all. And in the experimental market, that's what I bet it'll be--a fancy dongle that plugs into your EFIS, or a standalote ADAHRS unit (iLevil?) for steam/non-EFIS aircraft, plus Google Glass. There may also need to be some kind of reference/calibration process for the head tracking.

    Anything going into a certified airplane, even for VFR use only, will probably take a dedicted unit.

    Agree. I will state that, having transitioned from VFR-minimum steam and a 195 to a Skyview in the same airplane, I don't find myself looking in the cockpit any more than before. On local hops (most of my flying), I might twiddle the zoom knob on the map; other than that, I don't touch it.
     
  16. Aug 26, 2014 #16

    gtae07

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    I guess you don't want to be sharing the skies with anyone doing aerobatics at all, even with a designated "box".

    Why not take a cue from the racing world (we've had a lot of this discussed lately) and hold "track days" for this kind of thing? Block out a space around a given airport just like you would already do for aerobatic competitions, air racing, or practicing for same, and have at it?

    Ok, Mr. Ford. We'll take our black cars (err, airplanes) and like them. And we'll watch what little significance and attraction sport and personal flying still has wither away as our older generations die out and the purists insist that if 1930s flying isn't your thing, you don't deserve to be doing it.
     
  17. Aug 26, 2014 #17

    Hephaestus

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    Well - you could do this today - pair of 720° ip cameras and a netbook - scan track and ID targets is kids play (download the code tweak and compile)
     
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  18. Aug 26, 2014 #18

    Vigilant1

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    Why would you "guess" that? I've got no problem at all with people flying acro, assuming they are being responsible. Which means clearing turns and keeping >both< eyes open for others without deliberately introducing visual inputs that block their view of the real world (where real things are--solid things that crunch and burn if smacked together). If they want to play Ricky Racer with their virtual friends and not respect the rules we've established to keep each other safe, I would prefer that they get an X-Box.

    Super. Just NOTAM off a section of sky and have at it.
     
    Last edited: Aug 27, 2014
  19. Aug 27, 2014 #19

    mwflyer

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    The whole purpose of a HUD is to get the head up and out of the cockpit. Otherwise those big polycarbonate domes on those very expensive fighters would be a bit of a waste. Likewise HOTAS (Hands On Throttle And Stick) keeps the pilot from having to to look into the cockpit to find a control.

    A visual traffic spotter/tracker/announcer would make VFR more of a reality than the current system of good luck in a big sky.
     
  20. Aug 27, 2014 #20

    cluttonfred

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    OK, folks, we have gotten completely off topic. The idea was simply a low-cost HUD to in lieu of basic VFR gauges: ASI, ALT, VSI (optional, perhaps just a scaled arrow), RPM, other engine parameters (optional), GPS track or compass heading, slip/skid (optional), turn rate (optional). Traffic avoidance and the rest are far beyond the scope of what I am suggesting. Here is a quick and dirty sketch to illustrate what I mean. Cheers, Matthew

    hud.jpg
     

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