The flight control interface has several primary functions.
Control law and gain selection: Each of the different control laws have different characteristics, and an experienced operator may wish to choose the one that best suits the particular situation.
Trajectory control: Selectable trajectory modes allow the operator to fly the vehicle directly, or to fly the desired position. The desired position may be controlled in a resolved rate mode where the hand controller inputs command the rotation rate of the desired vehicle attitude, or in a spacecraft dynamics mode where the desired attitude is specified by a spacecraft flight simulator. Trajectory control also provides a means for commanding rotational steps of various sizes, along with specification of sinusoidal trajectories of selectable magnitude and frequency.
Filter parameter control: The interface allows specification of parameters controlling the filtering of incoming sensor data.
Attitude error displays: Strip charts display different elements of the attitude error. These elements may also be plotted against each other in a plane to give more information about the path of convergence.
Advanced 3D displays: A three dimensional graphic model of Ranger NBV is used to indicate the estimated attitude, and a wireframe display represents the desired attitude. These models are updated real time as the information is returned from the vehicle to the control station.
Sensor data displays: The sensor data may be directly displayed in x-y, or strip charts.
Data acquisition and playback: The flight control system data stream may be recorded for future examination.
Figure 3-1 An overview of one of the main control interfaces discussed in this chapter
The sections that follow describe the details of each section of the flight control system interfaces.