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13. Important Flight Events

Setting the configuration parameters for the motion driver can take a fair bit of trial and error. You will get there quicker if you have good knowledge of the actual flight accelerations associated with the main motion events of a flight.

With knowledge of the actual acceleration magnitudes you can consider where you wish to set cap levels and how to fit force cue angles to the actual working range of your platform. See sections 8, 9 & 10 for details of the configuration settings.

To assist in your set up activities there is a short list of the flight events you may wish to consider. Some of these produce relatively small acceleration changes and the set up task may be one of finding a good balance between having sufficient sensitivity in the force cueing to be able to feel the events in the platform and having enough scaling not to loose lots of the higher magnitude acceleration changes.

The more moment range your platform has the easier this balancing act is.

My suggested list of key motion events is:
 

Events affecting pitch motion of the platform:

1. Throttle-up on take-off.

2. On-runway braking – when landing or general manoeuvring.

3. Significant throttle adjustments in flight – eg reducing speed on approach.

4. Flaps operations – decelerations when flaps are extended and accelerations when they are withdrawn (air braking and spoiler operations may be included here).

5. Pitch attitude changes at take-off rotation.

6. Pitch attitude changes on touchdown.

7. Pitch attitude changes during normal air manoeuvres.

Items 1 to 4 affect the fore/aft force cue sensitivity and items 5 to 7 affect the pitch angle following sensitivity.

Events affecting the roll motion of the platform:

1. On-ground cornering – taxiing.

2. Lateral force impulses during flight turbulence.

3. Lateral force impulses during in-flight rudder adjustments.

4. Bank attitude changes on touchdown.

5. Bank attitude changes during normal air manoeuvres.

Items 1 to 3 relate to lateral force cue sensitivity and items 4 & 5 to bank angle following sensitivity.

And events affecting the heave motion of the platform:

1. Lift-off accelerations.

2. Touch-down bumps.

3. Short term in-flight pitch adjustments.

4. Turbulence.

5. Off-runway excursions!

6. Runway roughness (difficult unless you have good high frequency response).

Note that I do not suggest trying to simulate sustained g-forces with the heave DOF - the ability of any motion platform to generate sustained linear accelerations is very limited and the heave might be best used for short frequency heave motions.

For Pitch and Roll DOF's consider the acceleration/force cue events separately from the angle “following” events as they have separate set up parameters in the configuration file.

The motion driver includes a Virtual Oscilloscope facility which allows the cue output from the driver to be traced in real-time. It also has in-program settings adjustment. These two facilities allow you to make changes to the cue settings whilst the driver is active and to visually inspect the effects of those changes in the motion cues. This sould be done WITHOUT the motion platform being active and allows a good deal of experimentation with the settings before proceeding to test them on the live platform.

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