The best way for students to understand automatic flight control systems is through out-of-class assigments that involve building and interacting with flight control systems. The following project suggestions are designed to enable students to explore the various aspects of automatic flight control systems.
Basic Feedback Control
Demonstrating the effects of basic feedback control concepts such as pole placement, natural frequency, and damping is best done by setting up an out-of-class project that allows your students to experience the effect of these concepts on a simple, interactive aircraft model. As the students work on this project, they supply various values for placement of the poles, or various values of natural frequency and damping. Using the measurement tools available in AVDS, students can perform a simple "flight test" to determine what an "over-damped" response is, or what happens when a pair of poles cross the ____ axis into the right half plane. In this manner, students gain a better understanding of basic concepts, as well as how the "scientific method" is applied to testing flight systems. Other concepts can be demonstrated in the same manner, including feedforward gain, feedback gain, control integration, and control differentiation.
AVDS can also help students answer questions such as, "What are position, rate and acceleration feedback, and why would one be used instead of another?" Using AVDS, students can easily connect the output of any of the aircraft measurements to their own control systems. By working on a project where they "fly" their control systems through various tasks, again following a basic flight test scenario, students are able to experience the difference between commanding an aircraft to a particular pitch altitude versus a particular pitch rate. Students can perform various flight tasks in their "flight tests," including landing, terrain following, and drone tracking.
Standard Aircraft Control Systems
Using AVDS, you can develop other projects that enable your students to design longitudinal flight control systems such as altitude or velocity hold, flight path stabilization, and glide slope coupling with automatic flare. Not only can students become involved with designing these control systems, but they can fly the aircraft to an appropriate point, engage the control system, and observe its behavior.
You can also develop lateral flight control projects such as dutch roll damper, turn coordination and compensation, and lateral beam guidance, which allow students to experience the control systems firsthand. With AVDS, students can investigate the differences between using side acceleration, sideslip or computed yaw rate for turn coordination, or learn how a washout filter can alleviate the effects of the dutch roll mode without interfering with pilot commands.
Research
AVDS allows students to perform research on control systems that require sophisticated control and aircraft models. Following are examples of flight control systems and related phenomena that your students can investigate with AVDS:
C* or Mixed Feedback Model Following Control Fault/Damage Tolerant Robust Control Simulated Flight Test Dynamic Inversion Adaptive Control systems Inertial Coupling Guidance Systems Ride Control Formation Flight Systems Flexible/Structural Effects Pilot Compensation Linear Quadratic Gaussian Since AVDS facilitates the introduction of full nonlinear six degree-of-freedom models with three dimensional look-up tables, research students can develop and explore sophisticated aircraft and flight control system models. Through the use of AVDS's interactive simulation capability, the researcher can easily simulate flight profiles that are extremely difficult or close to impossible to simulate with non-interactive simulations. Because AVDS's terrain database is based on U.S. geological survey maps and satellite photos, research can include subjects like terrain following and avoidance, and terrain-based guidance.
