Motion Control and Cueing Software

The Moog FCS Motion Control Software (FMCS) is responsible for the control of the motion system during normal operational conditions, test conditions, and for failure detection and handling i.e.:

Interfaces with the Host by Ethernet.
Interfaces with all hardware components including interlocks and the ramp.
Control of the operational state of the motion system at system level.
Execution of the Motion Cueing Model.
Execution of the Motion Actuator Control Software (servo loops), which controls the actuator such that the demanded platform motion is realized.
Execution of several monitoring and safety functions at system and actuator level.
Reporting status, warning and error messages to the Host and Moog FCSExplorer sessions.
Execution of test-modes at platform level or at actuator level.

The FMCS makes a number of services available to the Host and Moog FCSExplorer session and can handle multiple requests for these services while performing the above time-critical tasks.

Moog FCS Motion Drive Software

The Moog FCS Motion Drive Software (FMDS) is a model within the FMCS. The FMDS algorithm is driven by the simulated vehicle linear accelerations, rotational accelerations, rotational velocities and linear buffet accelerations (used for high frequent vibrations; optional). Other control variables may be added depending on the type of vehicle, training task, and maneuvres to be simulated. The FMDS is an adaptive optimal control algorithm that translates the input vehicle accelerations into acceleration, velocity, and position set points for the motion platform. A kinematic transformation results in the acceleration, velocity, and position set point for each individual actuator controller.

While the Moog FCS motion platform is designed to provide a large kinematic motion envelope (large single DOF and combined DOF excursions), the FMDS is designed to maximize the Dynamic motion envelope. The Dynamic motion envelope represents that part of the kinematic motion envelope that is actually used during simulation, or, the Dynamic motion envelope refers to the collection of vehicle manoeuvres that can be represented by the motion system with acceptable fidelity to the pilot (driver). The FMDS makes the motion system feel ‘larger’ than it really is.

The main features of the FMDS are the following:

Complementary low frequent and high frequent motion filters
Specific force error correction
Simultaneous adaptive motion cue attenuation and washout in 6 degrees of freedom. This allows sensitive tuning for small and average dynamic inputs that occur 95% of the time. The filters automatically adapt to rare large and violent dynamic inputs.
Dynamic offset or pre-positioning of the motion system. Sometimes the software can predict the vehicle accelerations in the near future. Based on this prediction, the platform is moved to an optimal position within the workspace with accelerations below perception threshold. Example: platform movement to full aft position prior to full stop (end of braking effect)
Advanced Platform Kinematics (APK). APK allows low frequent platform rotations (for sustained cues) to take place about a non-fixed rotation point, which is optimal from a kinematic viewpoint. Only high frequent rotations take place about the pilot's (driver's) eye-point. APK also handles the translational washout and constantly drives the platform to the optimal translational position
Support for special effects. Special effects are customer specific and are, amongst others, used to compensate for deficiencies in the vehicle dynamic model. Example: high pass gain scheduling based on vehicle velocity
The FMDS can be tuned to the dynamics of the vehicle by over 250 categorized tuning parameters by means of the Moog FCSExplorer. Of course the motion cueing parameters can be changed during simulation, so the effect is directly noticeable
Support of multiple training- or flight condition specific tuning sets. For example to support different vehicle conditions of training tasks.