Analytical Investigation of Acceleration Restrictiion in a Fighter Airplane with an Automatic Control System

Analytical Investigation of Acceleration Restrictiion in a Fighter Airplane with an Automatic Control System
Author: James T. Matthews
Publisher:
Total Pages: 726
Release: 1958
Genre: Acceleration (Mechanics)
ISBN:

A theoretical analysis was made to investigate the performance and acceleration-restriction capabilities of a normal-acceleration command control system in a fighter airplane. Several combinations of pitching velocity and pitching acceleration were investigated as feedback quantities in combination with normal acceleration.

A Longitudinal Control Feel System for In-flight Research on Response Feel

A Longitudinal Control Feel System for In-flight Research on Response Feel
Author: Stanley Faber
Publisher:
Total Pages: 36
Release: 1961
Genre:
ISBN:

An adjustable feel system connected to the longitudinal control system of a transonic fighter airplane has been developed and has been evaluated in flight. Variable control feel including response feel is provided from the following five sources: control position, control rate, normal acceleration, pitching velocity, and pitching acceleration. This system provides a very flexible tool for more detailed study of longitudinal control feel characteristics than has previously been possible. The evaluation program for the variable-feel system yielded flight time histories which illustrate effects on the stability of airplane and control-system response modes of large amounts of response feel. These results illustrate the need for balancing the amounts of feel from normal acceleration and pitching acceleration to maintain the stability of the short-period and control-system modes. At the frequency of the short-period mode, large amounts of normal-acceleration feel cause the control system to oscillate and excite the airplane short-period mode of oscillation. At the same frequency the pitching acceleration component of feel, which leads the normal-acceleration component by 180 deg, is almost equivalent to viscous damping on the stick. However, at slightly frequencies the lag of the response-feel components increases by 90 deg or more so that a large pitching-acceleration component excites an oscillation of the control system at 4 cycles per second. These results by confirming and supplementing the conclusions of previous observers indicate that the adjustable feel system is operating properly.

Theoretical Investigation of Longitudinal Response Characteristics of a Swept-wing Fighter Airplane Having a Normal-acceleration Control System and a Comparison with Other Types of Systems

Theoretical Investigation of Longitudinal Response Characteristics of a Swept-wing Fighter Airplane Having a Normal-acceleration Control System and a Comparison with Other Types of Systems
Author: Fred H. Stokes
Publisher:
Total Pages: 50
Release: 1954
Genre: Airplanes
ISBN:

A theoretical investigation of the longitudinal response characteristics of a swept-wing fighter airplane using a normal-acceleration control system has been made. The system has been evaluated with normal-acceleration plus pitch-rate feedback and normal-acceleration plus pitch-rate feedback with a lag network placed in the forward loop. The effects of Mach number and altitude upon the response characteristics of the system and the effects of varying the parameter settings are determined. Also discussed are the elevator deflections and pitching velocities encountered at various parameter settings and flight conditions when an approximate step command in normal acceleration is impressed on the system. A comparison has been made between the normal-acceleration system and pitch-attitude sysetm when control of the flight path is desired, and, for further comparison, an angle-of-attack control and a pitch-rate control are discussed briefly.

A Feasibility Study of Self-learning Adaptive Flight Control for High Performance Aircraft

A Feasibility Study of Self-learning Adaptive Flight Control for High Performance Aircraft
Author: Stephen G. Hoppe
Publisher:
Total Pages: 258
Release: 1967
Genre: Automatic pilot (Airplanes)
ISBN:

A study of the feasibility of a self-learning adaptive system for the flight control of high performance aircraft has been performed. A flight control system was developed for the investigation of the stability augmentation of the longitudinal axis of the F101B aircraft using self-learning adaptive control. The learning adaptive controller developed employs a three-loop concept. The innermost loop comprises a linear feedback control system in which a set of control gains is adjusted by a second (adaptive) loop employing a parameter identifier and a trainable function generator (automation). The automation provides the correct values of feedback gain in response to patterns derived from the identified aircraft parameters. The third loop (the learning loop) measures control system performance, and continually retrains the automation to improve the performance. Experiments were performed with a digital simulation of the aircraft and the learning adaptive control system. Results of the experiments indicate that learning adaptive control is feasible. However, a number of significant technical problems must be overcome prior to the use of such a control system in tactical aircraft. Studies of sensitivity must be performed to assess the effect of small perturbations in the identification parameters on system performance. Extended studies of property extraction from the identified parameters is required, and means for further simplifying the control structure is of importance in a real system. (Author).

Automatic Flight Control Systems

Automatic Flight Control Systems
Author: Mohammad Sadraey
Publisher: Morgan & Claypool Publishers
Total Pages: 175
Release: 2020-02-14
Genre: Technology & Engineering
ISBN: 1681737299

This book provides readers with a design approach to the automatic flight control systems (AFCS). The AFCS is the primary on-board tool for long flight operations, and is the foundation for the airspace modernization initiatives. In this text, AFCS and autopilot are employed interchangeably. It presents fundamentals of AFCS/autopilot, including primary subsystems, dynamic modeling, AFCS categories/functions/modes, servos/actuators, measurement devices, requirements, functional block diagrams, design techniques, and control laws. The book consists of six chapters. The first two chapters cover the fundamentals of AFCS and closed-loop control systems in manned and unmanned aircraft. The last four chapters present features of Attitude control systems (Hold functions), Flight path control systems (Navigation functions), Stability augmentation systems, and Command augmentation systems, respectively.

Aircraft Control and Simulation

Aircraft Control and Simulation
Author: Brian L. Stevens
Publisher: John Wiley & Sons
Total Pages: 768
Release: 2015-10-05
Genre: Technology & Engineering
ISBN: 1118870999

Get a complete understanding of aircraft control and simulation Aircraft Control and Simulation: Dynamics, Controls Design, and Autonomous Systems, Third Edition is a comprehensive guide to aircraft control and simulation. This updated text covers flight control systems, flight dynamics, aircraft modeling, and flight simulation from both classical design and modern perspectives, as well as two new chapters on the modeling, simulation, and adaptive control of unmanned aerial vehicles. With detailed examples, including relevant MATLAB calculations and FORTRAN codes, this approachable yet detailed reference also provides access to supplementary materials, including chapter problems and an instructor's solution manual. Aircraft control, as a subject area, combines an understanding of aerodynamics with knowledge of the physical systems of an aircraft. The ability to analyze the performance of an aircraft both in the real world and in computer-simulated flight is essential to maintaining proper control and function of the aircraft. Keeping up with the skills necessary to perform this analysis is critical for you to thrive in the aircraft control field. Explore a steadily progressing list of topics, including equations of motion and aerodynamics, classical controls, and more advanced control methods Consider detailed control design examples using computer numerical tools and simulation examples Understand control design methods as they are applied to aircraft nonlinear math models Access updated content about unmanned aircraft (UAVs) Aircraft Control and Simulation: Dynamics, Controls Design, and Autonomous Systems, Third Edition is an essential reference for engineers and designers involved in the development of aircraft and aerospace systems and computer-based flight simulations, as well as upper-level undergraduate and graduate students studying mechanical and aerospace engineering.