Download or read book Design of a Helicopter Automatic Hover Controller for Stabilization and Tracking Using Eigenstructure Assignment written by Jeffrey L. Newcomer and published by . This book was released on 1989 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Helicopter Flight Control Systems for Hover and Low Speed Using Eigenstructure Assignment written by Eicher Low and published by . This book was released on 1991 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 34 (thesis year 1989) a total of 13,377 theses titles from 26 Canadian and 184 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 34 reports theses submitted in 1989, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Download or read book Linear and Nonlinear Control of Small Scale Unmanned Helicopters written by Ioannis A. Raptis and published by Springer Science & Business Media. This book was released on 2010-09-28 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been significant interest for designing flight controllers for small-scale unmanned helicopters. Such helicopters preserve all the physical attributes of their full-scale counterparts, being at the same time more agile and dexterous. This book presents a comprehensive and well justified analysis for designing flight controllers for small-scale unmanned helicopters guarantying flight stability and tracking accuracy. The design of the flight controller is a critical and integral part for developing an autonomous helicopter platform. Helicopters are underactuated, highly nonlinear systems with significant dynamic coupling that needs to be considered and accounted for during controller design and implementation. Most reliable mathematical tools for analysis of control systems relate to modern control theory. Modern control techniques are model-based since the controller architecture depends on the dynamic representation of the system to be controlled. Therefore, the flight controller design problem is tightly connected with the helicopter modeling. This book provides a step-by-step methodology for designing, evaluating and implementing efficient flight controllers for small-scale helicopters. Design issues that are analytically covered include: • An illustrative presentation of both linear and nonlinear models of ordinary differential equations representing the helicopter dynamics. A detailed presentation of the helicopter equations of motion is given for the derivation of both model types. In addition, an insightful presentation of the main rotor's mechanism, aerodynamics and dynamics is also provided. Both model types are of low complexity, physically meaningful and capable of encapsulating the dynamic behavior of a large class of small-scale helicopters. • An illustrative and rigorous derivation of mathematical control algorithms based on both the linear and nonlinear representation of the helicopter dynamics. Flight controller designs guarantee that the tracking objectives of the helicopter's inertial position (or velocity) and heading are achieved. Each controller is carefully constructed by considering the small-scale helicopter's physical flight capabilities. Concepts of advanced stability analysis are used to improve the efficiency and reduce the complexity of the flight control system. Controller designs are derived in both continuous time and discrete time covering discretization issues, which emerge from the implementation of the control algorithm using microprocessors. • Presentation of the most powerful, practical and efficient methods for extracting the helicopter model parameters based on input/output responses, collected by the measurement instruments. This topic is of particular importance for real-life implementation of the control algorithms. This book is suitable for students and researches interested in the development and the mathematical derivation of flight controllers for small-scale helicopters. Background knowledge in modern control is required.
Download or read book Helicopter Flight Control System Design Using the Linear Quadratic Regulator for Robust Eigenstructure Assignment written by and published by . This book was released on 1992 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis applied modern, multi-variable control design techniques, via a FORTRAN computer algorithm, to U.S. Army helicopter models in hovering flight conditions. Eigenstructure assignment and Linear Quadratic Regulator (LQR) theory are used to achieve enhanced closed loop performance and stability characteristics with full state feedback. The addition of cross coupling weights to the standard LQR performance index is specifically addressed. A desired eigenstructure is chosen with a goal of reduced pilot workload via performance qualities requirements. Cross coupling weighting is shown to provide greater flexibility in achieving a desired closed loop eigenstructure. While the addition of cross coupling weighting is shown to eliminate stability margin guarantees associated with LQR methods, the modified algorithm can achieve a closer match to a desired eigenstructure than previous versions of the program while maintaining acceptable stability characteristics.
Download or read book Modeling Control and Coordination of Helicopter Systems written by Beibei Ren and published by Springer Science & Business Media. This book was released on 2012-02-02 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved.
Download or read book Micro Coaxial Helicopter Controller Design written by Zelimir Husnic and published by . This book was released on 2015 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the advantages of the micro coaxial helicopter is in its maneuverability. It can perform some flight maneuvers that a fixed-wing aircraft cannot do - like hovering, perching, vertical take-off and landing, flying backwards, or moving sideways to the left or to the right. It is also more agile than the conventional helicopter with a counter-gyro effect rotor at the tail of the fuselage. However, due to its small size and sensitivity to disturbances, the micro coaxial helicopter is more challenging to control than a full-scale helicopter. \In this work, the flight dynamics of the micro coaxial helicopter were investigated and a simplified model for the autonomous flight control system design was constructed. System identification techniques as used in full-scale helicopters have been successfully applied to the micro coaxial unmanned helicopter. The essential parts of system identification include model theory, experimental data acquisition, parameter estimation, and model validations. The multivariable tracking and H2 control theory were employed to design a flight control system that would provide desired stability and performance for autonomous flight of a variety of maneuvers mentioned above. With a well-designed autonomous flight control system, the micro coaxial helicopter can be deployed for battle field awareness in battle fields, surveillance for search and rescue, border patrol, counter-terrorism operations, etc.
Download or read book Helicopter Mathematical Modelling and Optimal Controller Design written by Said Ifkirne and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this bachelor thesis, a nonlinear mathematical model simulation and linear controller design for the U1-H1 helicopter was achieved. This thesis is divided into two parts. In the first part, the nonlinear dynamic model is developed using the Matrix Laboratory Software and Heli-Dyn R Software, which is a modeling and simulation tool for rotorcraft developed by Dr. Ilkay Yavrucuk at Middle East Technical University. The non-linear model consists in a contribution of main rotor, tail rotor, fuselage, gravitational model, horizontal and vertical tail rotor. The U1-H1 main rotor non-linear mathematical model was build by use of blade element momentum theory, inflow dynamics and flapping dynamics. The total forces and moments are used in 6 degrees of freedom equations of motion model and helicopter states are obtained for hover conditions and forward flight. Trim and linearization process was done by Heli-Dyn R Software. The second part consists in a stability augmentation systems (SAS) followed by a set of automatic flight control systems (AFCS) designed by use of PID controllers. The AFCS main objective is to ease the pilot by decreasing the workload. The stability augmentation systems was designed by use of optimal control, especially Linear Quadratic Tracking Controller (LQT) and Linear Quadratic Regulator Controller (LQR). The automatic flight control systems implemented are heading hold, attitude, hold altitude acquire and hold mode for hover condition and heading hold, attitude hold, altitude acquire and hold mode and airspeed hold for forward flight condition. Furthermore, in order to check the robustness of the controllers and directory modes, disturbances were added to the model. The nonlinear model in trim mode simulations shown that the U1-H1 has achieved hovering conditions and forward flight successfully. Furthermore, the controllers and directory modes shown a successful dynamic behavior towards perturbations.
Download or read book Quad Rotorcraft Control written by Luis Rodolfo García Carrillo and published by Springer. This book was released on 2016-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quad Rotorcraft Control develops original control methods for the navigation and hovering flight of an autonomous mini-quad-rotor robotic helicopter. These methods use an imaging system and a combination of inertial and altitude sensors to localize and guide the movement of the unmanned aerial vehicle relative to its immediate environment. The history, classification and applications of UAVs are introduced, followed by a description of modelling techniques for quad-rotors and the experimental platform itself. A control strategy for the improvement of attitude stabilization in quad-rotors is then proposed and tested in real-time experiments. The strategy, based on the use low-cost components and with experimentally-established robustness, avoids drift in the UAV’s angular position by the addition of an internal control loop to each electronic speed controller ensuring that, during hovering flight, all four motors turn at almost the same speed. The quad-rotor’s Euler angles being very close to the origin, other sensors like GPS or image-sensing equipment can be incorporated to perform autonomous positioning or trajectory-tracking tasks. Two vision-based strategies, each designed to deal with a specific kind of mission, are introduced and separately tested. The first stabilizes the quad-rotor over a landing pad on the ground; it extracts the 3-dimensional position using homography estimation and derives translational velocity by optical flow calculation. The second combines colour-extraction and line-detection algorithms to control the quad-rotor’s 3-dimensional position and achieves forward velocity regulation during a road-following task. In order to estimate the translational-dynamical characteristics of the quad-rotor (relative position and translational velocity) as they evolve within a building or other unstructured, GPS-deprived environment, imaging, inertial and altitude sensors are combined in a state observer. The text give the reader a current view of the problems encountered in UAV control, specifically those relating to quad-rotor flying machines and it will interest researchers and graduate students working in that field. The vision-based control strategies presented help the reader to a better understanding of how an imaging system can be used to obtain the information required for performance of the hovering and navigation tasks ubiquitous in rotored UAV operation.
Download or read book Helicopter Flight Control System Design Using the Linear Quadratic Regulator for Robust Eigenstructure Assignment written by Dempsey D. Solomon (CAPT, USA.) and published by . This book was released on 1992 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of a Multivariable Helicopter Flight Control System for Handling Qualities Enhancement written by and published by . This book was released on 1990 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: New handling qualities specifications are currently being developed for attack helicopters. Most unaugmented helicopters will not meet these specifications and feedback control is necessary to improve handling qualities so that safe operation close to the earth in poor weather conditions and/or at night is possible. In this paper a methodology for the direct design of helicopter flight control systems which meet handling qualities specifications is presented. This methodology uses full state feedback to place closed loop eigenvalues to achieve bandwidth specifications and to shape closed loop eigenvectors to decouple lateral and longitudinal responses to control inputs. Full state feedback requires that all state variables be known; however, only angular rates and normal acceleration are measured by sensors. Thus, a state estimator is required in the feedback loop in order to convert sensor outputs to control inputs. This estimator is designed using eigenstructure assignment so as to achieve loop transfer recovery. Design of a feedback system for use in precise hovering control for a modern attack helicopter is used to illustrate the method. Control law synthesis is accomplished using an eighth order model which includes only rigid body modes. Control law performance is evaluated using a 37th order model which includes rigid body, actuator, rotor, sensor, and flexure dynamics. It is found that a notch filter must be added to the design in order to eliminate a high frequency instability. Once this is accomplished, both the time and frequency response characteristics of the augmented helicopter are much improved compared with the unaugmented helicopter.
Download or read book A Study of Helicopter Stability and Control Including Blade Dynamics written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: A linearized model of rotorcraft dynamics has been developed through the use of symbolic automatic equation generating techniques. The dynamic model has been formulated in a unique way such that it can be used to analyze a variety of rotor/body coupling problems including a rotor mounted on a flexible shaft with a number of modes as well as free-flight stability and control characteristics. Direct comparison of the time response to longitudinal, lateral and directional control inputs at various trim conditions shows that the linear model yields good to very good correlation with flight test. In particular it is shown that a dynamic inflow model is essential to obtain good time response correlation, especially for the hover trim condition. It also is shown that the main rotor wake interaction with the tail rotor and fixed tail surfaces is a significant contributor to the response at translational flight trim conditions. A relatively simple model for the downwash and sidewash at the tail surfaces based on flat vortex wake theory is shown to produce good agreement. Then, the influence of rotor flap and lag dynamics on automatic control systems feedback gain limitations is investigated with the model. It is shown that the blade dynamics, especially lagging dynamics, can severly limit the useable values of the feedback gain for simple feedback control and that multivariable optimal control theory is a powerful tool to design high gain augmentation control system. The frequency-shaped optimal control design can offer much better flight dynamic characteristics and a stable margin for the feedback system without need to model the lagging dynamics. Zhao, Xin and Curtiss, H. C., Jr. Unspecified Center BLADES; HELICOPTER CONTROL; ROTOR AERODYNAMICS; STABILITY; CONTROL SYSTEMS DESIGN; HOVERING; ROTOR BODY INTERACTIONS; TRANSLATIONAL MOTION...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Control Law Design Using Eigenstructure Assignment written by Stuart James Griffin and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimal Design of Helicopter Precision Hover Control Systems written by N. N. Purl and published by . This book was released on 1973 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1-F-162202-AA-9713(*helicopters, hovering), (*flight control systems, helicopters), stability, equations of motion, accuracy, optimizationcomputer aided analysisModern Control Theory is employed to analytically determine the limit of positional precision with which a helicopter can be hovered. Approaches based on Liapunov's Second Method and a Squared Root Locus Method are formulated to this optimal control problem. Both of these methods avoid iterative solution of the Matrix Riccati Equation. The Squared Root Locus Method is developed as a computer algorithm which generates optimal control designs as a function of performance index and helicopter stability/control derivatives. Practical design constraints can readily be interpreted from the results of this formulation. (Author).
Download or read book Design of a Model Reference Adaptive Controller for a Twin Rotor MIMO System written by Ikechukwu Okanu and published by . This book was released on 2012 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a helicopter has the ability to hover, it is used to carry out many flight operations such as combat, security missions, rescue, humanitarian missions, surveillance and traffic monitoring. Helicopters are difficult to hover, hence making it difficult to control in the hover mode. A helicopter is dynamically unstable when it is hovering without moving forward. This work investigates the stability of a helicopter in hover mode using dynamically changing physical properties. In particular, a Model Reference Adaptive Control system is proposed to stabilize the helicopter system in the hover mode while the mass of the helicopter changes.
Download or read book Modeling and Flight Control Design of a Tandem Rotor Helicopter Using the Eigenstructure Assignment Method written by Ming Rao and published by . This book was released on 1990 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:
