Download or read book Flight Control Design for an Autonomous Rotorcraft Using Pseudo sliding Mode Control and Waypoint Navigation written by Nicolas Joseph Mallory and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of robust automated flight control systems for aircraft of varying size and complexity is a topic of continuing interest for both military and civilian industries. By merging the benefits of robustness from sliding mode control (SMC) with the familiarity and transparency of design tradeoff offered by frequency domain approaches, this thesis presents pseudo-sliding mode control as a viable option for designing automated flight control systems for complex six degree-of-freedom aircraft. The infinite frequency control switching of SMC is replaced, by necessity, with control inputs that are continuous in nature. An introduction to SMC theory is presented, followed by a detailed design of a pseudo-sliding mode control and automated flight control system for a six degree-of-freedom model of a Hughes OH6 helicopter. This model is then controlled through three different waypoint missions that demonstrate the stability of the system and the aircraft's ability to follow certain maneuvers despite time delays, large changes in model parameters and vehicle dynamics, actuator dynamics, sensor noise, and atmospheric disturbances.

Download or read book Autonomous Hovering Controller Design Using Sliding Mode Control Theory and Its Flight Test Verification for Small scaled Unmanned Helicopter System written by 林建宏 and published by . This book was released on 2010 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Control of Autonomous Aerial Vehicles written by Andrea L'Afflitto and published by Springer Nature. This book was released on 2023-11-20 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Control of Autonomous Aerial Vehicles is an edited book that provides a single-volume snapshot on the state of the art in the field of control theory applied to the design of autonomous unmanned aerial vehicles (UAVs), aka “drones”, employed in a variety of applications. The homogeneous structure allows the reader to transition seamlessly through results in guidance, navigation, and control of UAVs, according to the canonical classification of the main components of a UAV’s autopilot. Each chapter has been written to assist graduate students and practitioners in the fields of aerospace engineering and control theory. The contributing authors duly present detailed literature reviews, conveying their arguments in a systematic way with the help of diagrams, plots, and algorithms. They showcase the applicability of their results by means of flight tests and numerical simulations, the results of which are discussed in detail. Control of Autonomous Aerial Vehicles will interest readers who are researchers, practitioners or graduate students in control theory, autonomous systems or robotics, or in aerospace, mechanical or electrical engineering.

Download or read book Application of Sliding Mode Methods to the Design of Reconfigurable Flight Control Systems written by Scott R. Wells and published by . This book was released on 2002 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. An overview of reconfigurable flight control is given, including a review of the current state-of-the-art within the subdisciplines of fault detection parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears promising due its property of invariance to matched uncertainty. An overview of SMC is given and its properties are demonstrated. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate SISO and MIMO designs. The third application is a linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.

Download or read book Robust Flight Control of Rotorcraft written by Adam Daniel Pechner and published by . This book was released on 2010 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fault tolerant Flight Control and Guidance Systems written by Guillaume J. J. Ducard and published by Springer Science & Business Media. This book was released on 2009-05-14 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a complete overview of fault-tolerant flight control techniques. Discussion covers the necessary equations for the modeling of small UAVs, a complete system based on extended Kalman filters, and a nonlinear flight control and guidance system.

Download or read book Quad Rotorcraft Control written by Luis Rodolfo García Carrillo and published by Springer Science & Business Media. This book was released on 2012-08-12 with total page 191 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 Investigations of Model free Sliding Mode Control Algorithms Including Application to Autonomous Quadrotor Flight written by Eric Schulken and published by . This book was released on 2017 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Sliding mode control is a robust nonlinear control algorithm that has been used to implement tracking controllers for unmanned aircraft systems that are robust to modeling uncertainty and exogenous disturbances, thereby providing excellent performance for autonomous operation. A significant advance in the application of sliding mode control for unmanned aircraft systems would be adaptation of a model-free sliding mode control algorithm, since the most complex and time-consuming aspect of implementation of sliding mode control is the derivation of the control law with incorporation of the system model, a process required to be performed for each individual application of sliding mode control. The performance of four different model-free sliding mode control algorithms was compared in simulation using a variety of aerial system models and real-world disturbances (e.g. the effects of discretization and state estimation). The two best performing algorithms were shown to exhibit very similar behavior. These two algorithms were implemented on a quadrotor (both in simulation and using real-world hardware) and the performance was compared to a traditional PID-based controller using the same state estimation algorithm and control setup. Simulation results show the model-free sliding mode control algorithms exhibit similar performance to PID controllers without the tedious tuning process. Comparison between the two model-free sliding mode control algorithms showed very similar performance as measured by the quadratic means of tracking errors. Flight testing showed that while a model-free sliding mode control algorithm is capable of controlling realworld hardware, further characterization and significant improvements are required before it is a viable alternative to conventional control algorithms. Large tracking errors were observed for both the model-free sliding mode control and PID based flight controllers and the performance was characterized as unacceptable for most applications. The poor performance of both controllers suggests tracking errors could be attributed to errors in state estimation, which effectively introduce unknown dynamics into the feedback loop. Further testing with improved state estimation would allow for more conclusions to be drawn about the performance characteristics of the model-free sliding mode control algorithms."--Abstract.

Download or read book Sliding mode Control Applied for Robust Control of a Highly Unstable Aircraft written by Travis Kenneth Vetter and published by . This book was released on 2002 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flight Control Design for Rotorcraft with Variable Rotor Speed written by Wei Guo and published by . This book was released on 2009 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flight control design issues for rotorcraft with variable rotor speed are investigated, and new design methodologies are developed to deal with the challenges of variable rotor speed. The benefits of using variable rotor speed for rotorcraft are explored with a rotor speed optimization study using a modified GENHEL model of UH-60A Blackhawk. The optimization results recommend to use the optimal rotor speed in each flight condition to improve the helicopter performance. The efforts are made to accommodate the optimal rotor speed schedule into the flight control system design and also address the stability issues due to the rotor speed variation. The rotor speed optimization results show significant performance improvements can be achieved with moderate reductions in rotor speed. The objective of the control design is to accommodate these rotor speed variations, while achieving desired flying qualities and maneuver performance. A gain scheduled model following/model inversion controller is used to control the roll, pitch, yaw, heave, and rotor speed degrees of freedom. Rotor speed is treated as a redundant control effector for the heave axis, and different control allocation schemes are investigated. The controllers are evaluated based on step responses and the ADS-33E height response requirement. Results show that dynamic variation in rotor speed can improve maximum climb rate and flying qualities for moderate to large commands in vertical speed, but that non-linear effects present significant challenges when integrating control of the aircraft and the engine. The effects of reduced rotor speeds on stability margins, torque required, and stability issues are also studied. A power command system in the vertical axis is designed to incorporate variable rotor speed while handling torque limits and other constraints. The vertical axis controller uses a fixed nonlinear mapping to find the combination of collective pitch and rotor speed to optimize performance in level flight, climbing/descending flight, and steady turns. In this scheme, the controller is open-loop, making it an inexpensive and reliable solution. The mapping is designed to produce a desired power level for a given pilot input. Thus the mapping can take into account the performance limits associated with the vertical axis such as power limits, torque limits, and maximum rate of descent. A model following controller is implemented for the pitch, roll, and yaw axes. The piloted simulation was performed to evaluate the controller. The impact of variable rotor speed on closed loop stability of rotorcraft is discussed. The model following controller can provide high bandwidth control and improve performance using variable rotor speed. However, reduction of rotor speed can result in rotor body coupling and even instability. A rotor state feedback control law can be designed independently and easily integrated into the baseline model following control architecture. Simulations were performed to verify the effectiveness of RSF control to stabilize the rotorcraft dynamics or improve the command tracking performance in the presence of reduced rotor RPM.

Download or read book Development of a Novel Method for Autonomous Navigation and Landing of Unmanned Aerial Vehicles written by David J. Grymin and published by . This book was released on 2009 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this work, control techniques for the autonomous navigation and landing of an Unmanned Aerial Vehicle (UAV) are developed and compared. Controllers were developed and implemented on two different aircraft models: the Lockheed-Martin F-16 and AAI Corporation/Israel Aircraft Industries RQ-2 Pioneer. Due to the expense of modifying the pre-existing F-16 flight control system, the controller is implemented outside of the closed loop. Proportional-integral-derivative and proportional-integral controllers are developed for holding the aircraft at a desired velocity and altitude. The aircraft are approximated as Dubins vehicles constrained to travel on a two-dimensional surface for decreased simulation time. Using the simplified model two control techniques are developed and then compared. the first uses a proportional feedback controller based on the Rhumb-line that the aircraft is traveling along. The second control technique uses a trajectory determined from an algorithm using the Dubins path determination for the shortest travel distance between the two points. A sliding mode controller is developed to guide the simplified model along the Dubins path trajectory. The advantage of the Dubins path trajectory is that it allows for a closed-form time estimate to reach the desired way-point. Comparison between the two navigation techniques using the simplified system shows a significant decrease in time to way-point for the Dubins curve trajectory controller. The Rhumb-line controller and a hybrid Rhumb-line/Dubins path controller are implemented on nonlinear models of both aircraft. Simulation of both controllers on the nonlinear model shows acceptable performance in guiding the aircraft between way-points. Also, the time to way-point for the nonlinear aircraft model guided by the hybrid controller is within 5% of the closed-form Dubins trajectory estimate. Autonomous landing is accomplished utilizing the path guidance and altitude controllers. The nonlinear simulated aircraft successfully followed the glideslope from way-point to runway."--Abstract.

Download or read book Aircraft Control Using Sliding Mode Control written by Christian Tournes and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Rapid Prototyping of Flight Control and Navigation System for an Unmanned Aerial Vehicle written by Bock Aeng Lim and published by . This book was released on 2002-03-01 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in this thesis is in support of a larger research effort to implement a cluster of autonomous airborne vehicles with the capability to conduct coordinated flight maneuver planning and to perform distributed sensor fusion, Specifically, it seeks to design and implement an onboard flight control and navigation system for NPS FROG UAV, which will be used as the autonomous airborne vehicle for the research, using the newly marketed xPC Target Rapid Prototyping System from The Mathworks, Inc Part I briefly introduces the aircraft and explains the necessity for an onboard computer for the UAV. Part II describes the construction of the miniature aircraft computer, INS/GPS and air data sensor integration implementation as well as the rapid prototyping process. Part III covers the process to create a 6DOF model for the aircraft and the design of the aircraft autopilot, while Part IV presents a vision-based navigation algorithm that can be implemented on the UAV to give it some form of autonomous flight trajectory planning capability. Preliminary ground test results are presented in Part V to conclude this study.

Download or read book Flight Control System Design for Autonomous UAV Carrier Landing written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The challenge of integrating the UAV fleet into the carrier landing operational structure with respect to navigation and control strategies is addressed. A simulation model was developed which includes an aircraft model, an atmosphere model and an aircraft carrier motion model. The six degree of freedom non-linear aircraft model is based on the aerodynamic characteristics of the Mk 4a Jindivik extended to include rudder, spoiler and thrust vectoring controls, and an undercarriage model. The atmosphere model includes a carrier landing atmospheric disturbance model. The six degree of freedom aircraft carrier motion model is based on the ship motion simulation program SEAWAY. A Navigation System was developed which conforms to current operational procedures and future military navigation goals. This Navigation System continuously predicts the position in space where touchdown on the carrier deck will take place, based on aircraft position, the relative velocity between the aircraft and carrier, and the motion time history of the carrier. A reference flight path to the predicted touchdown point is continuously defined. The aircraft deviation from this flight path is determined and input to the autoland control system. For the purposes of this study perfection prediction is assumed. Automatic flight control systems were developed to assess three control strategies for suitability to the carrier landing task. The focus of this assessment was on vertical glide path deviation control. Direct Lift Control was compared to conventional control and was found to have superior performance, especially in turbulence. As UAV planforms tend to be tailless, and therefore lateral and pitch control are generated by a common aerodynamic surface, thrust vectoring was investigated as a means of alleviating aerodynamic pitch control requirements in the carrier landing task. An Adaptive Approach Speed Controller was developed as an extension of the Navigation System. This system synchronises.

Download or read book A Model free Control Algorithm Based on the Sliding Mode Control Method with Applications to Unmanned Aircraft Systems written by Adarsh Raj Kadungoth Sreeraj and published by . This book was released on 2019 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Control methods require the use of a system model for the design and tuning of the controllers in meeting and/or exceeding the control system performance objectives. However, system models contain errors and uncertainties that also may be complex to develop and to generalize for a large class of systems such as those for unmanned aircraft systems. In particular, the sliding control method is a superior robust nonlinear control approach due to the direct handling of nonlinearities and uncertainties that can be used in tracking problems for unmanned aircraft system. However, the derivation of the sliding mode control law is tedious since a unique and distinct control law needs to be derived for every individual system and cannot be applied to general systems that may encompass all classifications of unmanned aircraft systems. In this work, a model-free control algorithm based on the sliding mode control method is developed and generalized for all classes of unmanned aircraft systems used in robust tracking control applications. The model-free control algorithm is derived with knowledge of the system’s order, state measurements, and control input gain matrix shape and bounds and is not dependent on a mathematical system model. The derived control law is tested using a high-fidelity simulation of a quadrotor-type unmanned aircraft system and the results are compared to a traditional linear controller for tracking performance and power consumption. Realistic type hardware inputs from joysticks and inertial measurement units were simulated for the analysis. Finally, the model-free control algorithm was implemented on a quadrotor-type unmanned aircraft system testbed used in real flight experimental testing. The experimental tracking performance and power consumption was analyzed and compared to a traditional linear-type controller. Results showed that the model-free approach is superior in tracking performance and power consumption compared to traditional linear-type control strategies."--Abstract.

Download or read book Formalizing a Robust Flight Control Design Technique with Application to a Highly Flexible Aircraft written by Cheng Peng and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With many of the modern aircraft designed to be larger and lighter, there have been increasing interests in incorporating the structure mode when designing flight control system. Sliding mode control (SMC) is an approach to the design of control systems that shows significant robustness in the presence of large uncertainties in plant dynamics. In this study, formalized Multi-Input Mult-Output (MIMO) SMC based robust fight control system design procedure was introduced and presented. The study vehicle was selected to be the B-1 bomber, a highly flexible aircraft. The multi-input multi-output SMC design procedure was carried out using the study vehicle model. The structure modes of the aircraft was addressed. Finally, a pilot model was included to evaluate the robustness of the SMC design.

Download or read book Smart Autonomous Aircraft written by Yasmina Bestaoui Sebbane and published by CRC Press. This book was released on 2015-11-18 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the extraordinary growth of Unmanned Aerial Vehicles (UAV) in research, military, and commercial contexts, there has been a need for a reference that provides a comprehensive look at the latest research in the area. Filling this void, Smart Autonomous Aircraft: Flight Control and Planning for UAV introduces the advanced methods of flight contr