“The VSFS, which we built with MathWorks tools, enables engineering students to see and feel the direct effect of control design parameter changes on aircraft flight. That experiential component leads to major learning improvements for our students.”
Dr. Peter Gibbens, University of Sydney
Students in the University of Sydney’s School of Aerospace, Mechanical, and Mechatronic Engineering (SAMME) have a unique opportunity to experience the effects of design decisions on flight stability. Using a full-motion, three-degree-of-freedom flight simulator, they can feel how an aircraft responds to their controls under a range of environmental conditions, aircraft configurations, and control designs.
SAMME faculty and students built the Variable Stability Flight Simulator (VSFS) using the hydraulics, structure, and cockpit of a decommissioned QANTAS simulation trainer, replacing the original analog control system with a real-time system developed using MathWorks tools.
“With Simulink, the entire VSFS design is in a graphical format that is easy for students to understand,” says Dr. Peter Gibbens, senior lecturer at SAMME. “Simulink models also made it easy for us to architect and design the VSFS and then rapidly implement the system using Simulink Coder™ and xPC Target, which are effectively the core of the VSFS. Creating and prototyping control systems and observing their actual behavior is most effective with this setup.”
While engineering students understood control systems theory, they lacked the intuitive feel for flight stability that comes from practical flying experience.
Gibbens and his colleagues at SAMME needed tools sophisticated enough to enable them to design and implement the real-time VSFS system yet intuitive enough for students to learn quickly. “For students to come up to speed takes way too long when using C,” Gibbens explains.
With more than 200 students in the undergraduate program, in addition to graduate students and faculty working on VSFS, the school needed access to tools from numerous workstations.
University of Sydney acquired a Total Academic Headcount license, enabling students and faculty to use MATLAB®, Simulink®, Simulink Coder, and companion products campus-wide.
Gibbens and postgraduate student Alex Scamps used Simulink to design a control system model that took pilot yoke movements as input and drove the servo-actuators on the hydraulics to move the cockpit in response. After simulation, they used Simulink Coder to generate code, which they ran in real time using xPC Target™.
They used the same approach to develop VSFS modules for environmental conditions, such as turbulence, and for the aircraft itself, which included the complete equations of motion and the aerodynamic characteristics of the airplane.
SAMME faculty use the simulator to reinforce concepts taught in the classroom. In Flight Mechanics 1, for example, students use MATLAB to complete assignments on flight dynamics, aerodynamic effects on aircraft motion, flight stability, and aircraft modes of motion. Later in the course, they run aircraft simulations in the VSFS. As they perform maneuvers, instructors alter stiffness, damping, and other aerodynamic parameters to help students understand how these parameter changes affect handling.
For Flight Mechanics 2, students use MATLAB and Control System Toolbox™ to develop flight control systems and an autopilot system. Each instructor-approved control design is embedded into the VSFS. Students then fly a simulation to compare the performance and stability characteristics of their design with those of standard control designs.
Students who take Advanced Flight Mechanics learn the principles of flight test procedures. They use MATLAB and Signal Processing Toolbox™ to perform filtering and power spectrum analysis as they evaluate the characteristics of accelerometers and other test sensors. After simulating a flight test program and validating the aircraft model using regression techniques, they use Control System Toolbox to develop a flight control system and test it in the VSFS.
Many students use MathWorks products to complete their undergraduate and graduate thesis projects. These projects have included adding or improving models for the VSFS for Oblique Wing aircraft; lifting body aircraft, such as the NASA HL-10 and HL-20; and the F-16 fighter.
Provide aerospace engineering students with hands-on experience with the principles of flight dynamics
Use MathWorks tools to develop a full-motion flight simulator for students to use in lab exercises and thesis projects