1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Question: Hover assist gauge formula

Discussion in 'Gauges' started by Davst, 27/4/12.

  1. Davst

    Davst

    Joined:
    24/4/12
    Messages:
    25
    Hi. I'm doing a project where I'm developing a hover assist gauge. I do know that there are 1 or 2 of these floating around, but I'm doing this for my own sake of learning.

    Since I am new to FSX development I'm fussing over an issue I have.

    I want to show current drift (implemented) and also Yoke position (implemented) but I also want to show a suggested counteraction to bring you to a steady hover. (Chase the ball type representation)

    The issue I'm having is that a centered yoke position will not mean that you stay in a static hover, if i just give a division of the inverted current drift, in the big picture that'd bring you closer to a hover, but at a close to hover it wouldn't give the correct info to "stay on the ball" if you know what i mean

    Eg.. at a still hover it'd say keep the yoke dead centered since there is no drift. Whereas in alot of helicopters I've tried in FSX a centered yoke will cause the helicopter to start flying forward and to stay in one position you actually have to angle the yoke back slightly.


    What I'm wondering is are there any FSX variables that could help me predict this and take it into account in my display or is that something that I'd have to model for each helicopter.

    Since there are some autopilot gauges out there I'm figuring that it can be solved.. I'm just curious if anyone can point me in the direction as to how.

    Ty in advance =)

    Ofc the results will be freeware and accessible to anyone who wants them when they are done.
  2. delivery guy

    delivery guy

    Joined:
    31/1/10
    Messages:
    712
    Country:
    unitedstates
    i looked into this many years ago and there are freeware ones you can add.
    I found that they too had many issues to deal with. So after finding out what it takes to create one, i realized it's much tougher than i thought. I mostly write XML and i think you need to write this in C++.

    So my only tip is too let you know that it's not easy but that does not mean you can't pull it off. So i figure i would just give you my 2 cents.

    Good luck!:D
  3. Roy Holmes

    Roy Holmes Resource contributor

    Joined:
    20/2/11
    Messages:
    794
    Country:
    us-virginia
    I have found the best variable to use for fore-aft hover assist is (A:Velocity body z, knots) and for lateral control (A:velocity body x, knots). It is also useful to have a vertical speed indication. The presentation is of a horizontal bar for fore-aft which is read relative to a vertical scale. If you are moving forwards the bar is above center, so you ease back on the cyclic to center it.

    Depending on the dynamics of the particular helo, a centered yoke will probably have you flying forwards. The actual yoke position will vary as you enter a hover, initially being back to kill speed, then moved as necessary to zero forward speed, which takes some anticipation.

    So my advice would be to forget about an indication of yoke position and just interpret a gauge to work out what to do with the yoke.

    In the attached picture, the hover assist gauge is the middle one on the right side of the HH-3E panel, needles are centered, static hover. The gauge is 3D.

    Roy

    Attached Files:

  4. mike november

    mike november

    Joined:
    29/12/10
    Messages:
    70
    Country:
    germany
    Your hover indicator looks great Roy. :) Any chance I might use it for my Seaking project?
  5. Roy Holmes

    Roy Holmes Resource contributor

    Joined:
    20/2/11
    Messages:
    794
    Country:
    us-virginia
    That one is 3D, so it is part of the interior model with animated indicators. I still have code and bitmaps for a 2D version.

    If you send me a PM with a picture of what the one in your Seaking looks like, I'll see if the bitmaps are suitable or I'll make new ones and send you the package

    Roy
  6. mike november

    mike november

    Joined:
    29/12/10
    Messages:
    70
    Country:
    germany
    Thx for the offer Roy,

    you have PM. :)
  7. Roy Holmes

    Roy Holmes Resource contributor

    Joined:
    20/2/11
    Messages:
    794
    Country:
    us-virginia
    Lars
    Here is the 2D gauge code. The bitmaps are not as pretty as your picture, PM me your email and I'll send them to you.
    Code:
    <?xml version="1.0" encoding="UTF-8"?>
    
    <Gauge Name="Seaking_Hover">
    <Image Name="Hover.bmp" Bright="Yes"/>
    
    <!-- ======================= Hover Gauge===================== -->
    	<!--Groundspeed Needle-->
    	<Element>
    		<Position X="95" Y="117"/>
    		<Visible>(A:Velocity body z, knots) 20 &lt;</Visible>
    		<Image Name="Horizontal.bmp" Luminous="Yes">
    			<Axis X="27" Y="1"/>
    		</Image>
    		<Shift>
    			<Value Maximum="20" Minimum="-20">(A:Velocity body z, knots)</Value>
    			<Nonlinearity>
    				<Item Value="20" X="95" Y="160"/>
    				<Item Value="0" X="95" Y="117"/>
    				<Item Value="-20" X="95" Y="75"/>
    			</Nonlinearity>
    		</Shift>
    	</Element>
    	<!--Vertical speed Bug-->
    	<Element>
    		<Position X="38" Y="117"/>
    		<Image Name="Hover VSI.bmp" Luminous="Yes">
    			<Axis X="0" Y="3"/>
    		</Image>
    		<Shift>
    			<Value Maximum="1000" Minimum="-1000">(A:vertical speed, feet/minute)</Value>
    			<Nonlinearity>
    				<Item Value="1000" X="38" Y="77"/>
    				<Item Value="0" X="38" Y="117"/>
    				<Item Value="-1000" X="38" Y="161"/>
    			</Nonlinearity>
    		</Shift>
    	</Element>
    	<!--Lateral speed Needle-->
    	<Element>
    		<Position X="95" Y="117"/>
    		<Image Name="Lateral.bmp" Luminous="Yes">
    			<Axis X="1" Y="27"/>
    		</Image>
    		<Shift>
    			<Value Maximum="20" Minimum="-20">(A:velocity body x, knots)</Value>
    			<Nonlinearity>
    				<Item Value="20" X="54" Y="117"/>
    				<Item Value="0" X="95" Y="117"/>
    				<Item Value="-20" X="138" Y="117"/>
    			</Nonlinearity>
    		</Shift>
    	</Element>
    	</Gauge>
    Roy
  8. jeroen79

    jeroen79

    Joined:
    4/7/11
    Messages:
    66
    Country:
    netherlands
    @Davst:

    You could setup a PID loop to drive the 'suggested counteraction' needles of your gauge.

Share This Page