BFF Motion Driver v2 - Short User Guide


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9. Roll Cue Settings


The roll cue tuning settings can be made by manually adjusting the parameters in your .bff configuration file (see section 4), or by opening the roll settings window using the R button on the motion driver.

The Roll settings window includes input fields for the detailed parameters and a simple settings wizard which can be used to simplify the process.

For details of each of the  parameters hold the mouse over an input text field and a pop-up help window will appear.

Using the Range and Scaling Wizard

The wizard is on the lower part of the window.

Three inputs are required - 1. the approximate roll motion range of your platform, 2. the aircraft lateral acceleration in G's to be scaled to fit to the roll motion range for the tilt force cue, and 3. the aircraft roll angle to fit to the roll motion range for the angle-following (or roll rate) element of the cue.

If you do not want the platform to tilt to simulate side-ways acceleration and deceleration forces set the acceleration to zero. If you do not want the platform roll angle to follow the aircraft roll movement set the aircraft roll angle to zero.

Click Update_Settings to calculate the detailed range and scaling settings. These are then displayed in the upper part of the window.

The noise and washout filter parameters are NOT set by the wizard - so you will need to adjust these by typing new values in the upper settings area if you wish to change them. There are three filters.

1. The lateral acceleration smoothing/delay filter. This controls the speed with which the platform tilt reacts to changes in aircraft lateral acceleration by filtering out the higher frequency components of the acceleration. Setting larger values (longer time constants) in this low-pass filter removes more of the fast changes and slows the tilt response. Separate time constants are set for in-air and on-ground operations.

2. The lateral acceleration (force tilt cue) washout filter. Increasing the value here slows the washout to mid. However setting the value to zero disables the washout and the acceleration force cue will then be sustained for the full duration of the aircraft acceleration event.

3. The roll angle rate (following) element washout filter. Increasing the value here slows the washout to mid. However setting the value to zero disables the washout and the roll angle cue will then be sustained as long as the angle is held by the aircraft.

Manual Settings

If you know what you are doing it is possible to manually set the parameters. Different scaling/filtering can be applied for in-air and on-ground operations for example to change the cue behaviour when the aircraft is on the runway.

The accelerations seen during ground ops are usually sharper than those experienced by the aircraft when it is in the air and reduced values may be appropriate or softer filtering. The treatment of on-ground sustained cornering forces may also be different to that for in-air shorter term lateral movements.

Use and Save

The changes you make manually to settings or changes made by the wizard will not be made active until the Use button is clicked. They will then be made active in the current driver session, but will not be saved to your .bff file. To save the changes to your file you must use the Save button.

IMPORTANT – Take great care when making changes to the cue settings as they can directly impact on the motion range. It is recommended that the adjusted cue output is viewed in the Virtual Oscilloscope and its stability assessed BEFORE the driver is put back in Drive mode and the platform made active.

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