Design Of Stability Augmentation Systems Research Articles

On the design of command and stability augmentation systems for advanced technology aeroplanes

There exists an enormous wealth of published material describing the application of so called, 'modern control methods' to the design of fliglat control systems for piloted aeroplanes. It is also evident, with the exception of a very small number of recent applications, that there is a conspicuous lack of enthusiasm on the part of the airframe manufacturers to adopt this design technology, especially for the design of command and stability augmentation systems for piloted aeroplanes. It is possible to speculate on the reasons for this apparent lack of interest, but to do so might well result in a misplaced condemnation of modern control methods. Since evidence exists to suggest that some modern control system design strategies have overlooked important flight dynamics considerations, the discussion is turned around here by drawing attention to some of the more important considerations in command and stability augmentation system design. The object is, therefore, to inform the designer, of whatever persuasion, of the critically important aspects of command and stability augmentation system design for the advanced technology aeroplane.

Performance, Stability, Dynamics and Control of Airplanes

Performance, Stability, Dynamics and Control of Airplanes provides a comprehensive and integrated overview of several interrelated disciplines involving airplane performance. It contains all necessary background material on aerodynamics, dynamics, and control systems, discussing the fundamental principles with the use of sketches, solved examples, and design exercises. It is an ideal text for upper level undergraduates, graduate students, and professionals. Chapters 1 through 3 present basic principles of aerodynamics, aircraft performance, and static equilibrium and control in steady flight. Chapter 4 deals with aircraft dynamics and decoupled equations for longitudinal and lateral motion, and it introduces the concept of stability derivatives. Chapter 5 discusses design of stability augmentation systems and autopilots. Chapter 6 discusses aircraft response and methods of closed-loop control of aircraft, while Chapters 7 and 8 discuss problems of inertial coupling, aircraft spin, and high angle of attack. The third edition features updates throughout along with a new chapter 9 on stability, control issues, and challenges of unmanned aerial vehicles

Mixed linear-quadratic/eigenstructure strategy for design of stability augmentation systems

The problem of determining an optimal output-feedback controller that forces the aircraft dynamics to evolve as an ideal model with prescribed eigenvalues and eigenvectors is addressed. A mixed linear-quadratic/eigenstructure strategy is used, where the matrix gain is chosen by minimizing a standard quadratic performance criterion. This allows one to 1) keep under control the maximum value of the input demand and 2) take into account flying-quality requirements by imposing suitable constraints on the system eigenstructure. It is believed that this optimization procedure provides significant improvements to a standard eigenstructure strategy and that it is well suited in the design of aircraft stability augmentation systems. A discussion of three case studies demonstrates the effectiveness of this procedure by comparing the corresponding results with others given in the literature.

Design of Stability Augmentation Systems for Automotive Vehicles

The high-speed cruising stability of passenger vehicles may be enhanced with stability augmentation systems. These systems would modify the driver’s steering command to the vehicle’s front wheels, and steer the rear wheels according to measured vehicle conditions such as its yaw-rate. In this simulation study, an explicit driver model is used in the design of these stability augmentation systems. For ease of implementation, only low-order controllers are synthesized using parameter optimization. The high-speed, straight-line stability of a passenger vehicle in a cross-wind is simulated to evaluate steering performance with these controllers. Our results show that stability augmented steering has the potential to improve the directional stability of passenger vehicles.