This paper introduces a novel strategy for the specification of certification of airworthiness (CoA) categories for Unmanned Aircraft systems (UAS). Logical approach in this classification based on determination of allowable risk for an UAS supposing of operational scenario that using from this parameter as alone criteria for segregation of manned and Unmanned airworthiness. In this research, for issuance of CoA in scope of UAS, is proposed regular matrix according to risk table of mil-std-882 that based on, level of airworthiness control on the design & construction of UAS’s with various missions, is specified. Referral point of the present work, is validation on proposed matrix with statistical work upon greater than 500 kinds of military and civil UAS that has been accomplish in two stage and with computation of two criteria as maximum kinetic energy and hazard area from physical, performance and aerodynamic specification each UAS with aim of determination of risk. For this intent in first step, attention to introduced various level of injury in references, is specified limits for kinetic energy that respect to their current UAS in archive is categorized and is conformed with introduced categories in proposed matrix. In next step, with creation of statistical algorithm is defined limits for hazard area parameter that in beside limits of kinetic energy, meanwhile increase the precision in proposed categorization for UAS in certification matrix, this matrix is validated again. Such after determination of certification category on the proposed matrix, this certification issue on what limitation of requirements and design & construction regulations, is subject that will implement in next issuance. Important point correspond to this technique, is degeneration and no confliction of introduced methodology for determination of CoA category of an UAV with regulations framework of part 21.

The feasibility of using a stand alone Fluidic Thrust- Vectoring (FTV) system for the purpose of longitudinal trim of an Unmanned aerial vehicle is the focus of the research presented in this paper. Since the fluidic thrust vectoring requires high pressure secondary air to deflect the engine exhaust gases, this research also provides an analytical toolset for the preliminary sizing of a suitable secondary air supply. The study is based on a conceptual model of a Vertical Take-Off and Landing (VTOL) Tail-sitter type Unmanned aerial vehicle in three common phases of flight named as Hovering, Transition and Cruise. A relationship is finally presented between the thrust-vectoring angle and the required secondary mass flow rate.It is found that, just by use of FTV system the Aircraft trim is possible. In addition, the mathematical model developed in this study can be used as a preliminary tool for overall performance evaluation of such a conceptual Aircraft, especially for sensitivity analysis of thrust-vectoring control and finding the optimum values of the parameters like centre of gravity and engine location.

Due to the drastic change in aerodynamic parameters, the problem of controlling the landing mode will be much more complicated than the high altitude flight. On the other hand, the presence of obstacles in the way of the bird's landing is another condition that should be considered in the design of the controller. Thus, according to the above, it is necessary to use the predictive controller to solve the problem. This controller inherently has a high resistance to model change. Also, if this controller is used in a restricted manner, it can be used to bypass obstacles in the path of movement during landing. The aim of this paper is to control the system for automatic landing by means of model-based pre-interlinear control. The reason for using the pre-interlinear controller is the presence of obstacles in the path of movement and the fulfillment of the constraints in the environment to remove the obstacles. As a final result, this controller is designed in such a way that the effect of external disturbances on the bird is minimized and the stability of the system is not jeopardized by the emergence of model uncertainties. Also, in this method, the effect caused by the delay of the external navigation system is taken into account in the closed loop system and the stability of the system is guaranteed. Finally, the proposed controller design is calculated for a real bird model and its performance simulation in the presence of obstacles, lateral and longitudinal wind is presented.

In this paper, modeling and feedback linearization controller for trajectory tracking of a novel sixrotor UAV (Unmanned Aerial Vehicle) is developed. Because of the very simple structure and high maneuverability, quadrotors are one of the most preferred types of UAVs but the main problem in using them is their small payload. In the proposed novel model, two coaxial propellers are added to the center of vehicle to improve the ability of lifting heavier payloads, and to surpass anticrosswind capability of quadrotor, while the dynamic and steering principle is preserved. The dynamic model is obtained via Newton Euler approach. Model is under actuated, nonlinear, and has strongly coupled terms. Also, two types of nonlinear controllers are presented. The first is a conventional input-output feedback linearization controller which involves high-order derivative terms and turns out to be quite sensitive to sensor noise as well as modeling uncertainty. The second controller is a feedback linearization based on the hierarchical control strategy that yields easier controller. To compensate actuator’s dynamic and moreover, to avoid complexity of controller, a two-stage algorithm is utilized. The obtained simulation results confirm that the performance of hierarchical controller is more convenient in terms of position tracking and disturbance rejection than conventional controller.

This paper proposes a switching adaptive control for trajectory tracking of Unmanned Aircraft systems. The switching adaptive control method is designed to overcome the wind disturbance and achieve a proper tracking performance for control systems. In the suggested system, the wind disturbance is regarded as a finite set of uncertainties; a controller is designed for each uncertainty, and a performance signal is obtained for switching between controllers through a set of visualizers. Each sub-system is robustly stable and the hysteresis logic-based switching is used to obtain the stabilization of a general system. The new system indicates more appropriate results for overcoming the air disturbance compared with the back-stepping adaptive controllers. Finally, the modeling results for the performance of the designed controller are presented.

This article explores the potential use of fire extinguishing balls in conjunction with drone and remote-sensing technology as a supplement to traditional firefighting methods. The proposed system involves three components: a scouting Unmanned Aircraft system (UAS) to detect fires and monitor wildfire risk, a communication UAS to facilitate communication between the scouting UAS and firefighting UAS, and a firefighting UAS that drops heat-activated, environmentally friendly fire extinguishing balls at designated locations. The system is currently being developed as part of a multi-institutional project. The article provides a general overview of the design and discusses experiments that have been conducted to evaluate the effectiveness of the fire extinguishing balls. The results indicate that while smaller-sized balls may not be useful for building fires, they can be effective in extinguishing short grass fires (a ball with the weight of 0. 5 kg extinguished a 1-meter circle of short grass). As a result, the authors are focusing on wildfire fighting rather than building fires. The article also discusses the development of heavy payload drones (about 15 kg of load) and the progress of creating an apparatus that can carry fire-extinguishing balls and be attached to drones.