Once simulation is defined, the architecture that produces it can be specified.
Architecture compliance identifies the structural conditions a system must satisfy before fidelity can be measured. A system that does not meet these conditions cannot produce physics-accurate outputs regardless of software quality or motion range.
A compliant system must define motion using the standard aerospace body-axis coordinate system. This system anchors all three rotational axes to the vehicle's center of mass and defines their orientation relative to the vehicle body.
Extends forward through the vehicle nose. Rotation about this axis produces roll.
Extends from left to right across the vehicle. Rotation about this axis produces pitch.
Extends vertically through the vehicle center of mass. Rotation about this axis produces yaw.
All three axes must be mutually perpendicular and intersect at the vehicle's center of mass.
Each rotational axis must be driven and controlled independently. Roll, pitch, and yaw must resolve separately from one another. A system in which adjusting one axis produces unintended output on another does not satisfy this requirement.
The definition of axis independence and the structural consequences of coupling are provided on the independent degrees of freedom page.
The following table shows the rotational motion parameters observed in systems that satisfy the axis independence requirement. These values are not certification thresholds.
| Axis | Example Range of Motion | Example Max Angular Velocity | Example Peak Angular Acceleration |
|---|---|---|---|
| Roll (X-Axis) | 50° total (±25°) | 60 °/s | 2400 °/s² |
| Pitch (Y-Axis) | 25° total (±12.5°) | 60 °/s | 2400 °/s² |
| Yaw (Z-Axis) | 40° total (±20°) | 60 °/s | 2400 °/s² |
Example Performance Envelope. Values shown reflect observed capabilities of systems that satisfy the architectural requirements above. They are not mandatory specifications and should not be interpreted as framework minimums or certification thresholds.
Motion must be resolved relative to the vehicle's center of mass. All three rotational axes must intersect at this point. A system that resolves rotation at an arbitrary platform point, seat position, or external reference introduces positional error into every motion output.
The definition of center of mass as a framework criterion and the consequence of non-compliant reference points are provided on the rigid body dynamics page.
If the rotation origin is not the vehicle's center of mass, the system cannot produce geometrically correct motion cues.
Motion outputs, visual environment, and control inputs must remain temporally aligned. Latency between any two of these systems introduces timing error. When timing is wrong, the relationship between action and response is wrong regardless of the accuracy of any individual component.
Physical motion cues must be delivered without perceptible lag relative to the visual frame. Latency above the detection threshold breaks the coherence of the motion environment.
Motion outputs must correspond to control inputs without delay that exceeds real-world vehicle response times. Delayed motion trains incorrect anticipatory behavior.
When multiple axes are active simultaneously, their outputs must remain phase-coherent. Axes that drift out of phase with each other produce motion cues that do not correspond to any real vehicle state.
Synchronization must be maintained under full operational load. Systems that maintain timing at low demand but degrade under peak conditions do not satisfy this requirement.
A system that cannot maintain synchronization across motion, visual, and control channels cannot deliver valid training outputs.
Satisfying each individual architectural requirement is necessary but not sufficient. The coordinate system, axis independence, center of mass alignment, and synchronization must function together as a coherent whole in real time.
A system in which the physics engine, motion hardware, and visual environment operate as separate components that are loosely coupled after the fact does not satisfy this requirement. The architecture must be integrated from the physics layer outward, not assembled from independent subsystems and bridged at the output.
Systems that satisfy these requirements can be evaluated using the SFR measurement framework. Classification is determined after measurement is applied.
The measurement framework for evaluating architectural compliance is on the simulation fidelity metrics page. The classification outcomes are on the system classification page.
A system must satisfy the coordinate system, axis independence, center of mass alignment, synchronization, and integration requirements before fidelity measurement is meaningful.
If the architecture is wrong, no measurement score can correct the output.
The governing principle that physics must be the source layer for all simulation output.
View Physics First →Definition of axis independence and the structural consequence of coupling.
View Independent DOF →The definition of center of mass as the required rotational reference point.
View Rigid Body Dynamics →How the perceptual consequences of architecture manifest in the yaw axis.
View Yaw in Simulation →The measurement framework applied to systems that satisfy these architectural requirements.
View SFR Metrics →