Modeling and Robust Attitude Controller Design for a Small Size Helicopter

This paper addresses the design and application controller for a small-size unmanned aerial vehicle (UAV). In this work, the main objective is to study the modeling and attitude controller design for a small size helicopter. Based on a non-simplified helicopter model, a new robust attitude control law, which is combined with a nonlinear control method and a model-free method, is proposed in this paper. Both wind gust and ground effect phenomena conditions are involved in this experiment and the result on a real helicopter platform demonstrates the effectiveness of the proposed control algorithm and robustness of its resultant controller.Comment: 6 page

Survey of computer vision algorithms and applications for unmanned aerial vehicles

This paper presents a complete review of computer vision algorithms and vision-based intelligent applications, that are developed in the field of the Unmanned Aerial Vehicles (UAVs) in the latest decade. During this time, the evolution of relevant technologies for UAVs; such as component miniaturization, the increase of computational capabilities, and the evolution of computer vision techniques have allowed an important advance in the development of UAVs technologies and applications. Particularly, computer vision technologies integrated in UAVs allow to develop cutting-edge technologies to cope with aerial perception difficulties; such as visual navigation algorithms, obstacle detection and avoidance and aerial decision-making. All these expert technologies have developed a wide spectrum of application for UAVs, beyond the classic military and defense purposes. Unmanned Aerial Vehicles and Computer Vision are common topics in expert systems, so thanks to the recent advances in perception technologies, modern intelligent applications are developed to enhance autonomous UAV positioning, or automatic algorithms to avoid aerial collisions, among others. Then, the presented survey is based on artificial perception applications that represent important advances in the latest years in the expert system field related to the Unmanned Aerial Vehicles. In this paper, the most significant advances in this field are presented, able to solve fundamental technical limitations; such as visual odometry, obstacle detection, mapping and localization, et cetera. Besides, they have been analyzed based on their capabilities and potential utility. Moreover, the applications and UAVs are divided and categorized according to different criteria.This research is supported by the Spanish Government through the CICYT projects (TRA2015-63708-R and TRA2013-48314-C3-1-R)

Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones

Helicopter Autonomous Ship Landing System

This research focuses on developing a helicopter autonomous ship landing algorithm based on the real helicopter ship landing procedure which is already proven and currently used by Navy pilots. It encompasses the entire ship landing procedure from approach to landing using a pilot-inspired vision-based navigation system. The present thesis focuses on the first step towards achieving this overarching objective, which involves modeling the flight dynamics and control of a helicopter and some preliminary simulations of a UH-60 (Blackhawk) helicopter landing on a ship. The airframe of the helicopter is modeled as a rigid body along with rotating articulated blades that can undergo flap, lag and pitch motions about the root. A UH-60 helicopter is used for a representative model due to its ample simulation and flight test data. Modeling a UH-60 helicopter is based on Blade Element Momentum Theory (BEMT), rotor aerodynamics with the Pitt-Peters linear inflow model, empennage aerodynamics and rigid body dynamics for fuselage. For the blade dynamics, the cyclic (1/rev) and collective pitch motions are prescribed and the blade (1/rev) flap and lag motions are obtained as a response to the aerodynamic and inertial forces. The helicopter control inputs and translational and attitude dynamics obtained from the model are validated with flight test data at various speeds and attitude. A linearized model is extracted based on a first-order Taylor series expansion of the nonlinear system about an equilibrium point for the purpose of determining the stability of the dynamic system, investigating sensitivity to gusts, and designing a model-based flight control system. Combined vision-based navigation and Linear Quadratic Regulator (LQR) for set-point tracking is used for disturbance rejection and tracking states. A rotatable camera is used for identifying the relative position of the helicopter with respect to the ship. Based on the position, a corresponding trajectory is computed. Considering the trade-off between transient responses and control efforts, gains for the LQR controller are chosen carefully and realistically. A fully autonomous flight is simulated from approach to landing on a ship. It consists of initial descent, steady forward flight, steady coordinated turn, deceleration, and final landing. Corresponding to each maneuver, relevant linearized model is used and gains are tuned. By using X-plane flight simulator program, the simulation data which include fuselage attitude and position at each time step are visualized with a single flight deck ship. This method allows an aircraft to land on a ship autonomously while maintaining high level of safety and accuracy without the need to capture the ship deck motions, however, by using a camera, and any other additional sensors, which will provide the accurate location of the ship relative to the helicopter. This method is not only relevant for a particular helicopter, but for any types of VTOL aircraft, manned or unmanned. Hence, it can improve the level of safety by preventing human errors that may occur during landing on a ship

Helicopter Autonomous Ship Landing System

This research focuses on developing a helicopter autonomous ship landing algorithm based on the real helicopter ship landing procedure which is already proven and currently used by Navy pilots. It encompasses the entire ship landing procedure from approach to landing using a pilot-inspired vision-based navigation system. The present thesis focuses on the first step towards achieving this overarching objective, which involves modeling the flight dynamics and control of a helicopter and some preliminary simulations of a UH-60 (Blackhawk) helicopter landing on a ship. The airframe of the helicopter is modeled as a rigid body along with rotating articulated blades that can undergo flap, lag and pitch motions about the root. A UH-60 helicopter is used for a representative model due to its ample simulation and flight test data. Modeling a UH-60 helicopter is based on Blade Element Momentum Theory (BEMT), rotor aerodynamics with the Pitt-Peters linear inflow model, empennage aerodynamics and rigid body dynamics for fuselage. For the blade dynamics, the cyclic (1/rev) and collective pitch motions are prescribed and the blade (1/rev) flap and lag motions are obtained as a response to the aerodynamic and inertial forces. The helicopter control inputs and translational and attitude dynamics obtained from the model are validated with flight test data at various speeds and attitude. A linearized model is extracted based on a first-order Taylor series expansion of the nonlinear system about an equilibrium point for the purpose of determining the stability of the dynamic system, investigating sensitivity to gusts, and designing a model-based flight control system. Combined vision-based navigation and Linear Quadratic Regulator (LQR) for set-point tracking is used for disturbance rejection and tracking states. A rotatable camera is used for identifying the relative position of the helicopter with respect to the ship. Based on the position, a corresponding trajectory is computed. Considering the trade-off between transient responses and control efforts, gains for the LQR controller are chosen carefully and realistically. A fully autonomous flight is simulated from approach to landing on a ship. It consists of initial descent, steady forward flight, steady coordinated turn, deceleration, and final landing. Corresponding to each maneuver, relevant linearized model is used and gains are tuned. By using X-plane flight simulator program, the simulation data which include fuselage attitude and position at each time step are visualized with a single flight deck ship. This method allows an aircraft to land on a ship autonomously while maintaining high level of safety and accuracy without the need to capture the ship deck motions, however, by using a camera, and any other additional sensors, which will provide the accurate location of the ship relative to the helicopter. This method is not only relevant for a particular helicopter, but for any types of VTOL aircraft, manned or unmanned. Hence, it can improve the level of safety by preventing human errors that may occur during landing on a ship

Unmanned Aerial Systems Guidance and Control Utilizing Instantaneous Screw Motion Invariants

M.S