scholarly journals Formation of unmanned aircraft trajectory when flying around prohibited areas

Author(s):  
A. A. Lobaty ◽  
A. Y. Bumai ◽  
A. M. Avsievich

Considered the problem of flying over restricted areas by an unmanned aerial vehicle (UAV), which have various shapes and restrictions, set on the basis of the international airspace classification system for aviation in accordance with the Chicago Convention and the recommended principles for the formation of forbidden zones, rules for creating a flight route along forbidden zones and actions in case of border violations of restricted areas. The problem of analytical synthesis of the control acceleration of an unmanned aerial vehicle (UAV) is solved during its flight along a route passing along the boundaries of the forbidden zone of a given shape, along a given trajectory, which consists of subsequent segments located at the same height relative to the earth’s surface, in a given coordinate system. The optimal control synthesis problem is solved as an analytical definition of the optimal control of a linear non-stationary system based on the quadratic quality functional. A mathematical model of UAV motion in the horizontal plane is proposed, in the form of a system of ordinary differential equations in the Cauchy form. A law for measuring the control acceleration of the UAV’s center of mass is obtained on the basis of specifying the minimized quality functional and the corresponding constraints, which is a feature of the considered method of solving the problem. The proposed quality functional takes into account the parameters of coordinates and speed of the UAV, which correspond to the given points in the airspace, which characterize the necessary trajectory for flying around the restricted area. The derived mathematical dependences make it possible to implement them on board a UAV and minimize energy costs when guiding a UAV moving through specified points in space. Computer modeling of the derived analytical results, mathematical dependencies representing the optimal trajectory of the UAV flight along the boundaries of the forbidden zone, as well as the corresponding processes of changing the control acceleration and speed of the UAV movement was carried out, which made it possible to draw conclusions about the efficiency of the proposed method and the feasibility of its further use as a basis. for the initial stage of the synthesis of the UAV control system.

2021 ◽  
Vol 20 (4) ◽  
pp. 338-344
Author(s):  
A. A. Lobaty ◽  
A. Y. Bumai ◽  
S. S. Prohorovith

. The problem of analytical synthesis of the control acceleration for an unmanned aerial vehicle (UAV) during its flight along a complex trajectory, consisting of sequentially located horizontal flight sections, located at different heights relative to the earth's surface has been solved in the paper. The problem has been solved as an analytical definition of the  optimal control of a linear non-stationary system for a specified minimized quality functional. The mathematical model  of the system is presented in the form of differential equations of UAV motion in the vertical plane of a fixed coordinate  system related to the earth's surface. A feature of the proposed methodology for solving the problem is the substantiation  of the original form of the minimized functional and parameters included in the law of variation of the control acceleration obtained by known methods. As the components of the quality functional, the values of coordinates and velocity of the UAV are considered and they are specified at the corresponding points in space through which the UAV path must pass, in order  to obtain the optimal curvature of the trajectory. The derived mathematical dependences make it possible to implement them on board of an aircraft and, ultimately, solve the problem of ensuring the minimum energy consumption when controlling  an object (UAV). Computer simulation of the analytically obtained results in the form of the UAV flight trajectory and  the processes of changing its acceleration and speed have shown the efficiency of the proposed technique and the prospects  of its use at the initial stage of the synthesis of the UAV control system.


Author(s):  
A. A. Lobaty ◽  
A. Y. Bumai ◽  
S. S. Prohorovith

The problem of the stage-by-stage synthesis of the mathematical model of the autopilot of an unmanned aerial vehicle (UAV) is considered. At the first stage, an analytical synthesis of the control acceleration applied to the center of mass of the UAV is performed to form a specified trajectory of its flight. On the basis of the results received at the first stage, at the subsequent stages, the problem of synthesizing a mathematical model of the UAV autopilot is solved with the specified requirements for ensuring the stability and dynamic accuracy of UAV control. Under actual assumptions about the corresponding nature of changes in the trajectory parameters and variables that characterize the motion of the UAV in space, the use of a linear mathematical model of the evolution of the state vector of the UAV and its control system is substantiated. When synthesizing a mathematical model of the UAV autopilot, the method of modal control of the system was used for a specified mathematical model of the object. For a specified model of motion and aerodynamic characteristics of the UAV, the law of deviation of the control steering surface is analytically received, which depends on the parameters of the translational and rotational movement of the UAV. Computer simulation of the analytically received results of control synthesis for the specified characteristics of UAVs and specific using conditions was carried out, which clearly showed the efficiency and prospects of using this approach for the synthesis of control systems for UAVs of various purposes and design.


Author(s):  
Nicolas Michel ◽  
Zhaodan Kong ◽  
Xinfan Lin

Abstract Electric multirotor aircraft with vertical-take-off-and-landing capabilities are emerging as a revolutionary transportation mode. This paper studies optimal control of a multirotor unmanned aerial vehicle based on a system-level multiphysical model. The model considers aerodynamics of the rotor-propeller assembly, electro-mechanical dynamics of the motor and motor controller, and rigid-body dynamics of the vehicle, as control based on a system-level model incorporating all these dynamics and their coupling is missing in literature. A forward flight operation is considered for time-optimal and energy-optimal control, as well as battery voltages of 25 V and 21 V. Energy-optimal control is shown to reduce the energy required for the operation by 38.5% at 25 V, while reducing the battery voltage increases the minimum operation time by 19.8%. The energy-optimal cruise velocity is also examined, demonstrating that the optimal velocity predicted without considering rotor aerodynamics uses 35.2% more energy per meter travelled than is required at the true optimal velocity.


2018 ◽  
Vol 92 (3) ◽  
pp. 318-328
Author(s):  
Marcin Chodnicki ◽  
Katarzyna Bartnik ◽  
Miroslaw Nowakowski ◽  
Grzegorz Kowaleczko

Purpose The motivation to perform research on feedback control system for unmanned aerial vehicles, a fact that each quadrocopter is unstable. Design/methodology/approach For this reason, it is necessary to design a control system which is capable of making unmanned aerial vehicle vertical take-off and landing (UAV VTOL) stable and controllable. For this purpose, it was decided to use a feedback control system with cascaded PID controller. The main reason for using it was that PID controllers are simple to implement and do not use much hardware resources. Moreover, cascaded control systems allow to control object response using more parameters than in a standard PID control. STM32 microcontrollers were used to make a real control system. The rapid prototyping using Embedded Coder Toolbox, FreeRTOS and STM32 CubeMX was conducted to design the algorithm of the feedback control system with cascaded PID controller for unmanned aerial vehicle vertical take-off and landings (UAV VTOLs). Findings During research, an algorithm of UAV VTOL control using the feedback control system with cascaded PID controller was designed. Tests were performed for the designed algorithm in the model simulation in Matlab/Simulink and in the real conditions. Originality/value It has been proved that an additional control loop must have a full PID controller. Moreover, a new library is presented for STM32 microcontrollers made using the Embedded Coder Toolbox just for the research. This library enabled to use rapid prototyping while developing the control algorithms.


2018 ◽  
Vol 161 ◽  
pp. 03021 ◽  
Author(s):  
Vinh Nguyen ◽  
Oksana Solenaya ◽  
Petr Smirnov

Adding an onboard manipulation system to an unmanned aerial vehicle (UAV) significantly complicates framework, functioning algorithms, and leads to an increase in overall dimensions. The physical interaction of the manipulator with objects influences to unstabilization of UAV, which in turn leads to difficulties in positioning the UAV and reduces the accuracy of gripper motion. In addition, the physical interaction of the manipulator with objects requires increased power resources of UAVs. The article analyzes modern research of UAVs with a manipulator, including flight control problems, avoidance of contact with the earth, surrounding space, as well as manipulations with the captured object. On the basis of the analysis, a list of new problems arising in the physical interaction of UAVs with objects through an embedded manipulator is formulated.


2020 ◽  
Vol 14 (1) ◽  
pp. 61-68
Author(s):  
L. A. Marchenko ◽  
M. V. Myzin ◽  
I. V. Kuznetsov ◽  
T. V. Mochkova ◽  
A. Yu. Spiridonov

Digital agricultural production is based on robotic agricultural technologies for the use of pesticides and fertilizers using unmanned aerial systems, which are based on unmanned aerial vehicles for monitoring agricultural land, the pesticides application, fertilizers and other agrochemicals. (Research purpose) To develop an unmanned helicopter based aircraft for applying pesticides and fertilizers, and to substantiate its technological parameters. (Materials and methods) The authors used methodological recommendations on the use of chemicals in the precision farming system, regulatory and technical documentation for unmanned aircraft systems. (Results and discussion) The authors determined the unmanned aerial vehicle main flight technical and technological parameters for the implementation of the applying pesticides and fertilizers process. They established the dependences of its productivity on the norms of introducing working fluids of pesticides and fertilizers, the agricultural field length, and the approach distance to the field. (Conclusions) The authors developed a helicopter-type unmanned aerial vehicle of a coaxial design with a take-off mass of 280 kilograms and a payload of 50-80 kilograms, a rotor diameter of 5.3 meters, a constructive boom width with sprayers of 5 meters, a working flight height of 1-5 meters, a working speed of 40-60 kilometers per hour, the rate of working fluid of pesticides application 10-20 liters per hectare and nitrogen fertilizers 30-120 liters per hectare. They established rational values for the application rates of pesticides – 10-20 liters per hectare, the agricultural field length – at least 0.8 kilometers, ensuring maximum productivity in flight hour when processing the agricultural field. They showed that the flight distance minimizing from the runway to the field significantly increased the productivity of applying pesticides and fertilizers.


Doklady BGUIR ◽  
2019 ◽  
pp. 50-57
Author(s):  
A. A. Lobaty ◽  
A. Y. Bumai ◽  
Du Jun

The purpose of the scientific research, results are determinated in the article, is to analytically synthesize the control law of an unmanned aerial vehicle while guiding one along the trajectory that specified by the reference points of space in an inertial coordinate system. The analysis of various existing approaches of the formation of a given flight path of an unmanned aerial vehicle based on various mathematical formulations of the problem is carried out. To achieve the goal, the flight path is considered as separate intervals, where the control optimization problem is solved. The optimization criterion in general form is substantiated and its presentation in the form of a minimized quadratic quality functional is convenient for analytical control synthesis. As components of the functional, the parameters of the deviation of the flight path of the aircraft from the specified points of space are considered, as well as the predicted parameters of the velocity vector and the control normal acceleration. Moreover, at each specified point in space, the direction of the trajectory to the subsequent point is taken into account, that ensures optimal curvature of the trajectory by specified flight speed of the unmanned aerial vehicle. As a result of analytical synthesis, mathematical dependences are obtained to determine control acceleration, which allow us to get a specified optimal control law on board an unmanned aerial vehicle, which ultimately ensures minimum energy consumption. The validity of the proposed theoretical provisions is confirmed by a clear example, where for a simplified mathematical problem statement the optimal laws of change in control acceleration and the trajectory parameters of an unmanned aerial vehicle are calculated by computer simulation.


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