PUB thread

[brakar]

Loosen up and talk about what you feel like. No limits, no harassing.

[airmcn_3]

Loosen up and talk about what you feel like. No limits, no harassing.



Cool, Lets talk about rudder control........

How you use it in flight including through turns and strong cross wind conditions...


Anybody care to comment?

Chris

[stikmunkeyrc]

Cool, Lets talk about rudder control........

How you use it in flight including through turns and strong cross wind conditions...


Anybody care to comment?

Chris

My guess is you want to know this in relation to autopilot so here:

1. I use it to coordinate my turn in manual pilot mode and program it in auto mode as well.

2. I use it in crosswind landing and take off with opposite aileron input to maintain aircraft direction

3. Yaw stabilisation and gain is very important in adjusting the autopilot for initial flight testing and just has hard to do as it is for pitch

4. In most case you wouldn't want to fly autonomously with bank angle beyond 30 degrees so having rudder to help coordinate the turn is the best way...just like real airplane

5. You'll also need rudder to maintain track - i.e. the autopilot can use rudder/aileron to maintain the commanded track in crosswind situation.

....

[airmcn_3]

My guess is you want to know this in relation to autopilot so here:

1. I use it to coordinate my turn in manual pilot mode and program it in auto mode as well.

2. I use it in crosswind landing and take off with opposite aileron input to maintain aircraft direction

3. Yaw stabilisation and gain is very important in adjusting the autopilot for initial flight testing and just has hard to do as it is for pitch

4. In most case you wouldn't want to fly autonomously with bank angle beyond 30 degrees so having rudder to help coordinate the turn is the best way...just like real airplane

5. You'll also need rudder to maintain track - i.e. the autopilot can use rudder/aileron to maintain the commanded track in crosswind situation.

....


Very good! Your spot on!

You seem to have a good clamp on what it is going to take to tune your autopilot.

Dean and I were sitting here talking about this last night; you seem to have somehow listened in on our conversation.... ;)

Just kidding, I guess when you get down to it there is truly only one way to fly coordinated turns.....

Chris

[stikmunkeyrc]

Hi Chris,

It's an important feature of an AP to be able to maintained commanded track especially through turn. By that I mean the AP has to be able to do preturn so that the turn radius is inside the commanded flight box - ie sharp corner. It's nice to have an "flyable" AP it's really no good if it doesn't start making a turn until it reach the corner then what will happen is the plane will over shoot the corner and have to make a "tear drop" coming back in to meet the other leg, etc...

[small_rcer]

Using the rudder for coordinated turns may be a result of insufficient differential in the ailerons. The rudder usually helps prevent adverse yaw. The most common cause is the down going aileron creates more drag than the up going aileron. So instead of banking and pointing in the desired direction the plane banks but points somewhat in the opposite direction of the intended path. As Atto is (was?) configured it uses a single output for ailerons. Then to correct this adverse yaw you need rudder.

If you use mechanical differential in the aileron setup you should get a coordinated turn or can adjust the differential until you get a coordinated turn up to a given degree of bank. This way you can reduce or eliminate the need for rudder in turns.

Another way of affecting this is the size of the fin and rudder. If you using a plane that is close to neutral in flying characteristics, once the plane is in a bank it tends to stay there. If the rudder/fin area is small, the plane will tend to have positive spiral stability and slowly level out. Visualize a plane in bank and with less lateral area aft, the tail will drop into the bank rolling the plane level. The opposite may happen if the rudder/fin area or tail lateral area is too large. The nose will drop more than the tail and enter a spin. This is negative spin stability. Using this characteristic you can change the tail size to affect the yaw and spin stability. This is the same yaw you get in an uncoordinated turn.

Often a plane with negative spin stability can be more responsive in certain flight attitudes. Also the more effective dihedral you have the larger the tail surface can be to offset the spin stability of the higher effective dihedral.

Jim

[brakar]

Anyone currently using atto 1.8 for aerial photographying who are going to switch to the new atto IMU - or are you happy with the old one? brakar

[Jack Crossfire]

This must be the support group for people who are too hopelessly addicted to aerospace to focus on their day jobs, UAV's anonymous. Well OK. The boss said "we need to sell twinkie phones, people!" but then the LCROSS flight director's blog started looking really tempting & I couldn't stop. Fell off the horse once again.

[patrickegan]

Good topic Jack!

[spitfiremk9]

Anyone currently using atto 1.8 for aerial photographying who are going to switch to the new atto IMU - or are you happy with the old one? brakar

Hi Brakar
I'm going to give it a shot, I havent bought 1.8 as I have too many " middle of the road APs, but I don't think I will be able to resist Atto IMU! IT sounds as though Dean has put tremendous effort into it and I get the impression that he knows what He's talking about, so it will be interesting to have a play with it
Equaly interesting will be the price I think

[brakar]

From the corner of the pub and a bit premature, I have been thinking about making a few small atto programs, at least one formaking/editing the setup-file and one to edit/verify the waypoint-file. I am no big programmer, mostly used to vb and .net. Anybody who would like to participate in such a project? brakar

[brakar]

The other night, after an evening at the pub, I found myself wondering about a few pieces of software I had stumbled across; the ossimplanet/imagelinker, and the GRASS (open-gis) packages. Seemed pretty nice and usefull to me, at least from an aerial photographers point of view. However, almost whitout any references from RCGroups. Implying what? Only me who had stumbled across these beauties, or...

brakar

[dmgoedde]

...Atto IMU...IT sounds as though Dean has put tremendous effort into it and I get the impression that he knows what He's talking about, so it will be interesting to have a play with it
Equaly interesting will be the price I thinkYeah - the price. I've learned the hard way that to be profitable things aren't nearly as rosy as I used to think or hope. Overhead is a killer. IMU Atto takes a LOT more effort to develop and produce than the v1.8 unit. I realize I am not answering directly on the price question. Let's just say that now I don't judge other autopilot companies nearly as harshly as I used to. On the plus side, I do have MUCH lower staffing, so I will be able to charge less and hopefully still turn a profit after expenses. Let's also say here that I am really paranoid about having everything engineered fully and really minimize quirks, so you can bet it will be of high quality.

[brakar]

Why does is seemes that everybody has left this forum? has it become too serious?

[Gary Mortimer]

I have a whiskey in my hand and am not feeling serious!!

But I do have a cold.

So its medicinal

honest

no really

[brakar]

I am just finished with my round of pig-flu. That was serious, (not really). But I seriously hope the whiskey does more good to you then the tamiflu did to me.

Prosit!