Flight Simulator Tuning

1 Introduction

Depending on the flight characteristics (passenger flight vs aerobatics vs dogfight), your cockpit configuration (open cabin vs closed cabin vs vr) and personal preferences (seeing the motion vs feeling the motion), you might need to use different set of quick-tune. By default motion profiles come tuned for aerobatics/dogfight "feeling" experience, but it can be easily changed to "seeing" experience, you might even call it "arcade" style.

2 Names of the forces

Before you continue, familiarize yourself with names of the forces (accelerations) and angular velocities that affect the airplane and in the result motion platform's operation.

3 Roll and Pitch

Usually linear accelerations reproduction is pretty straightforward and easy to understand and tune. Roll and pitch provide much more flexibility and if tuned incorrectly might cause undesired and odd motion platform operation. Therefore in this article we will focus only on roll and pitch to keep the document short.

4 Roll

Summary roll of the motion platform is a combined result of the following components

• Body Roll Sustained
• Body Roll Intermittent
• Lateral G-Force Sustained

Body Roll Sustained is a relative constant angle relative to horizon (bank). Usually it is easy to interpret as the motion platform matches plane position on the screen. It works correctly for passenger flight but quickly become troublesome in inverted flights, aerobatics and dogfights due to limited motion platform work envelope, since most of the motion platforms cannot perform 360 degree rotation.

Body Roll Intermittent, as defined by the Classical Washout principles, simulates changes in roll rate (changes in angular velocity). It shows only the beginning and ending of the maneuver (changes in angular velocity) and returns the motion platform to neutral position during the maneuver (when angular velocity is constant or zero). It is very good for dynamics flights like aerobatics and dogfights, but the motion platform operation does not match to plane's position on the screen. It is also recommend to use Body Roll Intermittent over Body Roll Sustained for VR applications.

Lateral G-Force Sustained is there to simulate constant lateral force that appears during uncoordinated turns. Basically during clean turn (coordinated turn), this force is close to zero and the motion platform roll (caused by this component is zero). If you plan with the rudder during the turn, this force will cause the motion platform to roll, but depending on the forces distribution, it might cause rotation in the direction of the turning curve or opposite to it. If the latter occurs, the motion platform will roll in the opposite direction than the plane is doing on the screen. With extensive use of rudder, this might cause really huge amount of motion.

4.1 Recommendations

1. For passenger type flight and flights that do not include inverted flights, use Body Roll Sustained and Lateral G-Force Sustained and reduce Body Roll Intermittent to zero.
2. For aerobatics/dogfight and flights that do include inverted flights, use Body Roll Intermittent and Lateral G-Force Sustained and reduce Body Roll Sustained to zero.
3. For VR and closed cabin setups, use Body Roll Intermittent and Lateral G-Force Sustained and reduce Body Roll Sustained to zero.

5 Pitch

Summary pitch of the motion platform is a combined result of the following components

• Body Pitch Sustained
• Body Pitch Intermittent
• Longitudinal G-Force Sustained
• Vertical G-Force Sustained

Body Pitch Sustained is a relative constant angle relative to horizon. Usually it is easy to interpret as the motion platform matches plane position on the screen. It works correctly for passenger flight but quickly become troublesome in inverted flights, aerobatics and dogfights due to limited motion platform's work envelope (most of the motion platforms cannot perform 360 degree rotation).

Body Pitch Intermittent, as defined by the Classical Washout principles, simulates changes in pitch rate (changes in angular velocity). It shows only the beginning and ending of the maneuver (changes in angular velocity) and returns the motion platform to neutral position during the maneuver (when angular velocity is constant or zero). It is very good for dynamics flights like aerobatics and dogfights, but the motion platform operation does not match to plane's position on the screen. It is also recommended to use Body Pitch Intermittent over Body Pitch Sustained for VR applications.

Longitudinal G-Force Sustained is there to simulate constant lateral force that appears during acceleration and deceleration. Sometimes it might be confused with vertical acceleration as usually acceleration is reduced when you move the plane's nose up and increased when you move the plane's nose down.

Vertical G-Force Sustained is there to simulate G force during turning and all high G maneuver. Since it uses pitch to generate a feeling of sustained force, it can easily eat work envelope if tuned incorrectly. It also very often conflicts with Body Pitch Sustained, Body Pitch Intermittent and Longitudinal G-Force Sustained so it is recommended to tune each component individually and start with low Gain factors values.

5.1 Recommendations

1. For passenger type of flight and flights that do not include inverted flights, use Body Pitch Sustained and Longitudinal G-Force Sustained and reduce Body Pitch Intermittent and Vertical G-Force Sustained to zero.
2. For aerobatics/dogfight and flights that do include inverted flights, use Body Pitch Intermittent, Longitudinal G-Force Sustained and Vertical G-Force Sustained and reduce Body Pitch Sustained to zero.
3. For VR and closed cabin, use Body Pitch Intermittent, Longitudinal G-Force Sustained and Vertical G-Force Sustained and reduce Body Pitch Sustained to zero.