Download or read book Real time Optimal Trajectory Smoothing for Unmanned Aerial Vehicle in Three Dimensions written by Saideepthi Malisetty and published by . This book was released on 2011 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a dynamically feasible and real-time trajectory path generation algorithm for unmanned aerial vehicles (UAVs) flying through a sequence of a random N number of waypoints (WPs) in three dimensions. Pontryagin's minimum principle was used to show that the straight-line path segments connecting the sequence of waypoints are time optimal [1]. An algorithm was designed so that the total trajectory path length of a UAV is approximately equal to the straight-line path of the waypoints. The trajectory path obtained was also compared with the one-circle method, and it was found that the proposed method has less path length. Issues related to this algorithm are explained in detail. Simulation results show the efficiency of the method.

Download or read book Real time Trajectory Planning for Ground and Aerial Vehicles in a Dynamic Environment written by Jian Yang and published by . This book was released on 2008 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, a novel and generic solution of trajectory generation is developed and evaluated for ground and aerial vehicles in a dynamic environment. By explicitly considering a kinematic model of the ground vehicles, the family of feasible trajectories and their corresponding steering controls are derived in a closed form and are expressed in terms of one adjustable parameter for the purpose of collision avoidance. A collision-avoidance condition is developed for the dynamically changing environment, which consists of a time criterion and a geometrical criterion. By imposing this condition, one can determine a family of collision-free paths in a closed form. Then, optimization problems with respect to different performance indices are setup to obtain optimal solutions from the feasible trajectories. Among these solutions, one with respect to the near-shortest distance and another with respect to the near-minimal control energy are analytical and simple. These properties make them good choices for real-time trajectory planning. Such optimal paths meet all boundary conditions, are twice differentiable, and can be updated in real time once a change in the environment is detected. Then this novel method is extended to 3D space to find a real-time optimal path for aerial vehicles. After that, to reflect the real applications, obstacles are classified to two types: "hard" obstacles that must be avoided, and "soft" obstacles that can be run over/through. Moreover, without losing generality, avoidance criteria are extended to obstacles with any geometric shapes. This dissertation also points out that the emphases of the future work are to consider other constraints such as the bounded velocity and so on. The proposed method is illustrated by computer simulations.

Download or read book Trajectory Generation for a Quadrotor Unmanned Aerial Vehicle written by Douglas Conover and published by . This book was released on 2018 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of multirotor unmanned aerial vehicles (UAVs) has seen substantial progression in the past decade. Trajectory generation and control has been a main focus in this domain, with methods that enable the performance of complex three-dimensional maneuvers through space. Efforts have been made to execute these maneuvers using concepts of nonlinear control and differential flatness. However, a lack of theory for the estimation of higher-order dérivatives of a multirotor UAV has prevented the experimental application of several of these techniques concentrated on trajectory control. This work firstly explores the existing control approach of sequential composition for the execution of quadrotor manoeuvres through narrow windows. This technique involves the combination of several theoretically simple controllers in sequence in order to produce a complex result. Experimental results conducted in the Mobile Robotics and Automated Systems Laboratory (MRASL) at Polytechnique demonstrate the validity of this approach, producing precise and repeatable manoeuvres through narrow windows. However, they also show the limitations of such a method in real world applications, notably its initial inaccuracy and lack of feasibility evaluation. This thesis then focuses on the development of a state-estimation architecture based on linear Kalman filter techniques in order to provide a real-time value of a quadrotor UAV's second and third derivatives (referred to as acceleration and jerk, respectively). Filters of different complexities are developed with the goal of incorporating all available system information into the resulting estimate. A full-state estimator is produced that uses a quadrotor's position and acceleration measurements as well as control inputs in order to be usable for feedback. A jerk-augmented controller based off of optimal control theory is then developed in order to validate this estimator. It is designed in such a way to use the UAV's jerk, acceleration, velocity and position as design parameters and to be unstable without feedback in each of these terms. Tests are conducted in order to examine the performance of both the estimator and controller. Firstly, the quadrotor is commanded to track various reference inputs in 3D space to ensure its stability. The controller tracks these references very closely to simulated responses. The controller is then asked to follow a changing reference in order to evaluate the precision of the developed estimator. Results show that the real-time estimation of the jerk follows offline values adequately. To the best of our knowledge, this is the first application to implement the feedback of a multirotor UAV's jerk in real-world experimentation.

Download or read book Unmanned Aircraft Systems written by Ella Atkins and published by John Wiley & Sons. This book was released on 2017-01-17 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: UNMANNED AIRCRAF T SYSTEMS UNMANNED AIRCRAF T SYSTEMS An unmanned aircraft system (UAS), sometimes called a drone, is an aircraft without a human pilot on board ??? instead, the UAS can be controlled by an operator station on the ground or may be autonomous in operation. UAS are capable of addressing a broad range of applications in diverse, complex environments. Traditionally employed in mainly military applications, recent regulatory changes around the world are leading to an explosion of interest and wide-ranging new applications for UAS in civil airspace. Covering the design, development, operation, and mission profiles of unmanned aircraft systems, this single, comprehensive volume forms a complete, stand-alone reference on the topic. The volume integrates with the online Wiley Encyclopedia of Aerospace Engineering, providing many new and updated articles for existing subscribers to that work. The chapters cover the following items: Airframe configurations and design (launch systems, power generation, propulsion) Operations (missions, integration issues, and airspace access) Coordination (multivehicle cooperation and human oversight) With contributions from leading experts, this volume is intended to be a valuable addition, and a useful resource, for aerospace manufacturers and suppliers, governmental and industrial aerospace research establishments, airline and aviation industries, university engineering and science departments, and industry analysts, consultants, and researchers.

Download or read book Modelling and Simulation for Autonomous Systems written by Jan Mazal and published by Springer. This book was released on 2018-03-06 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed post-workshop proceedings of the 4th International Workshop on Modelling and Simulation for Autonomous Systems, MESAS 2017, held in Rome, Italy, , in October 2017. The 33 revised full papers included in the volume were carefully reviewed and selected from 38 submissions. They are organized in the following topical sections: M&S of Intelligent Systems – AI, R&D and Applications; Autonomous Systems in Context of Future Warfare and Security – Concepts, Applications, Standards and Legislation; Future Challenges and Opportunities of Advanced M&S Technology.

Download or read book Real Time Trajectory Generation for Autonomous Nonlinear Flight Systems written by and published by . This book was released on 2006 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unmanned aerial vehicle and smart munition systems need robust, real-time path generation and guidance systems to avoid terrain obstructions, navigate in hazardous weather conditions, and react to mobile threats such as radar, jammers, and unfriendly aircraft. In Phase 1 of this STTR project, real-time path planning and trajectory generation techniques for two dimensional flight were developed and demonstrated in software simulation. In Phase 2 these algorithms were refined, extended and were demonstrated in flight on a unique low-cost micro-air vehicle with a payload which included three optical flow sensors, a laser ranger, and a video camera. This report is a comprehensive technical summary of the significant work completed in Phase 2 to enable development of autonomous flight control systems which are capable of accomplishing the complex task of path and trajectory planning in dynamic and uncertain environments.

Download or read book Bio inspired Computation in Unmanned Aerial Vehicles written by Haibin Duan and published by Springer Science & Business Media. This book was released on 2014-01-02 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bio-inspired Computation in Unmanned Aerial Vehicles focuses on the aspects of path planning, formation control, heterogeneous cooperative control and vision-based surveillance and navigation in Unmanned Aerial Vehicles (UAVs) from the perspective of bio-inspired computation. It helps readers to gain a comprehensive understanding of control-related problems in UAVs, presenting the latest advances in bio-inspired computation. By combining bio-inspired computation and UAV control problems, key questions are explored in depth, and each piece is content-rich while remaining accessible. With abundant illustrations of simulation work, this book links theory, algorithms and implementation procedures, demonstrating the simulation results with graphics that are intuitive without sacrificing academic rigor. Further, it pays due attention to both the conceptual framework and the implementation procedures. The book offers a valuable resource for scientists, researchers and graduate students in the field of Control, Aerospace Technology and Astronautics, especially those interested in artificial intelligence and Unmanned Aerial Vehicles. Professor Haibin Duan and Dr. Pei Li, both work at Beihang University (formerly Beijing University of Aeronautics & Astronautics, BUAA). Prof Duan's academic website is: http://hbduan.buaa.edu.cn

Download or read book On Line Trajectory Optimization for Autonomous Air Vehicles written by and published by . This book was released on 2007 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successful operation of next-generation unmanned air vehicles will demand a high level of autonomy. Autonomous low-level operation in a complex environment dictates a need for onboard, robust, reliable and efficient trajectory optimization. In this report, we develop and demonstrate an innovative combination of traditional analytical and numerical solution procedures to produce efficient, robust and reliable means for nonlinear flight path optimization in the presence of time-varying obstacles and threats. The trajectory generation problem is first formulated as an optimization problem using reduced-order dynamics that result from the natural time-scale separation that exists in the aircraft dynamics. Terrain information is incorporated directly into the formulation of the reduced-order dynamics, which significantly reduces the computational load and leads to a path planning solution that can be implemented in real-time. Various cases of terrain, pop-up obstacles/threats, and targets are simulated. A representative optimal trajectory is generated with in a high fidelity full-order nonlinear aircraft dynamics and compared with a solution obtained from a reduced-order optimization. The developed algorithm is flight demonstrated with a fixed-wing unmanned aircraft test-bed in which a neural network-based adaptive autopilot is integrated with the on-line trajectory optimization algorithm.

Download or read book Zwen und dreissig Artickel die allgemeinen Religion und Glauben belangend von den Theologen der hohen schul zu L ven gantz newlich aussgangen written by and published by . This book was released on 1545 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Communications Signal Processing and Systems written by Wei Wang and published by Springer Nature. This book was released on with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Path Planning for Unmanned Aerial Vehicle UAV Based on Quantum Behaved Particle Swarm Optimization written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Trajectory Planning for Flights in Multiagent and Dynamic Environments written by Jesus Tordesillas Torres and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: While efficient and fast trajectory planners in static worlds have been extensively proposed for UAVs (Unmanned Aerial Vehicles), a 3D real-time planner for environments with static obstacles, dynamic obstacles, and other planning agents still remains an open problem. The dynamic nature of these environments demands high replanning rates, making this problem especially hard on computationally limited platforms. Existing state-of-the-art planners reduce the computational complexity at the expense of more conservative results by relying on three main simplifications or assumptions: First, the collision avoidance constraints are imposed using the Bernstein and B-Spline polynomial bases, which do not tightly enclose a given interval of a polynomial trajectory. Second, multiagent planners usually make centralized and/or synchronized computation assumptions, which lead to poor scalability with the number of agents or can degrade the overall performance. Finally, position and yaw are decoupled when optimizing perception-aware trajectories, which produces highly conservative results. This thesis addresses the aforementioned limitations with the following contributions: First, it presents the MINVO basis, a polynomial basis that generates the simplex with minimum volume enclosing a polynomial curve, therefore reducing the conservativeness in the obstacle avoidance constraints. Leveraging the MINVO basis, this thesis then proposes a tractable way to avoid dynamic obstacles by imposing linear separability constraints between the polyhedral enclosures of the intervals of the trajectories. This is then extended to multiagent scenarios, and a decentralized and asynchronous obstacle avoidance algorithm among many replanning agents is presented. Real-time perception-aware planning is achieved by implicitly imposing the underactuated dynamics of the UAV through the Hopf fibration while jointly optimizing the full pose. Finally, a reduction of two orders of magnitude in the computation time is obtained by learning a policy that imitates the optimization-based planner. These proposed contributions are extensively evaluated in simulation, showing up to 32 agents planning in real time, and in real-world experiments, showcasing flights up to 5.8 m/s in unknown dynamic environments with only onboard computation.

Download or read book Real time Trajectory Design for UAVs Using RHC written by Yoshiaki Kuwata and published by . This book was released on 2003 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Trajectory Optimization for Helicopter Unmanned Aerial Vehicles UAVs written by Benjamin Thomas Gatzke and published by . This book was released on 2010 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores the numerical methods and software development for optimal trajectories of a specific model of Helicopter Unmanned Aerial Vehicle (UAV) in an obstacle-rich environment. This particular model is adopted from the UAV Laboratory of the National University of Singapore who built and simulated flights for an X-Cell 60 small-scale UAV Helicopter. The code, which allowed the team to simulate flights, is a complex system of non-linear differential equations-5 state variables and four control variables-used to maneuver the state trajectories. This non-linear model is incorporated into a separate optimization algorithm code, which allows the user to set initial and final time conditions together with various constraints, and, using the same variable scheme, optimize a trajectory. The optimal trajectory is defined by using a cost function-the performance measure-and the system is subject to a set of constraints (such as mechanical limitations and physical three-dimensional obstacles). Simulations conclude that solutions are readily obtained; however, it is still very difficult to derive trajectories that are truly optimal, and our work calls for more future research in computational programs for optimal trajectory planning. All simulations in this thesis are modeled using the MATLAB program.

Download or read book Efficient and Robust Aircraft Landing Trajectory Optimization written by Yiming Zhao and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses the challenges in the efficient and robust generation and optimization of three-dimensional landing trajectories for fixed-wing aircraft subject to prescribed boundary conditions and constraints on maneuverability and collision avoidance. In particular, this thesis focuses on the airliner emergency landing scenario and the minimization of landing time. The main contribution of the thesis is two-fold. First, it provides a hierarchical scheme for integrating the complementary strength of a variety of methods in path planning and trajectory optimization for the improvement in efficiency and robustness of the overall landing trajectory optimization algorithm. The second contribution is the development of new techniques and results in mesh refinement for numerical optimal control, optimal path tracking, and smooth path generation, which are all integrated in a hierarchical scheme and applied to the landing trajectory optimization problem. A density function based grid generation method is developed for the mesh refinement process during numerical optimal control. A numerical algorithm is developed based on this technique for solving general optimal control problems, and is used for optimizing aircraft landing trajectories. A path smoothing technique is proposed for recovering feasibility of the path and improving the tracking performance by modifying the path geometry. The optimal aircraft path tracking problem is studied and analytical results are presented for both the minimum-time, and minimum-energy tracking with fixed time of arrival. The path smoothing and optimal path tracking methods work together with the geometric path planner to provide a set of feasible initial guess to the numerical optimal control algorithm. The trajectory optimization algorithm in this thesis was tested by simulation experiments using flight data from two previous airliner accidents under emergency landing scenarios. The real-time application of the landing trajectory optimization algorithm as part of the aircraft on-board automation avionics system has the potential to provide effective guidelines to the pilots for improving the fuel consumption during normal landing process, and help enhancing flight safety under emergency landing scenarios. The proposed algorithms can also help design optimal take-off and landing trajectories and procedures for airports.

Download or read book Proceedings of the International Conference on Intelligent Computing Communication and Information Security written by Vladan Devedzic and published by Springer Nature. This book was released on 2023-07-03 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains high quality research papers accepted and presented at the International Conference on Intelligent Computing, Communication and Information Security (ICICCIS 2022), organized by Swami Keshvanand Institute of Technology, Management & Gramothan (SKIT), Jaipur, India during 25-26, November 2022. It presents the solutions of issues and challenges in intelligent computing, communication and information security domains. This book provides a background to problem domains, considering the progress so far, assessing the potential of such approaches, and exploring possible future directions as a single readily accessible source.

Download or read book Multi UAV Planning and Task Allocation written by Yasmina Bestaoui Sebbane and published by CRC Press. This book was released on 2020-03-27 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-robot systems are a major research topic in robotics. Designing, testing, and deploying aerial robots in the real world is a possibility due to recent technological advances. This book explores different aspects of cooperation in multiagent systems. It covers the team approach as well as deterministic decision-making. It also presents distributed receding horizon control, as well as conflict resolution, artificial potentials, and symbolic planning. The book also covers association with limited communications, as well as genetic algorithms and game theory reasoning. Multiagent decision-making and algorithms for optimal planning are also covered along with case studies. Key features: Provides a comprehensive introduction to multi-robot systems planning and task allocation Explores multi-robot aerial planning; flight planning; orienteering and coverage; and deployment, patrolling, and foraging Includes real-world case studies Treats different aspects of cooperation in multiagent systems Both scientists and practitioners in the field of robotics will find this text valuable.