• Journal of Aerospace System Engineering
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• v.15 no.4
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• pp.11-20
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• 2021

The estimation of hovering flight time of multicopters using the battery power propulsion system is important for the development and design of the aircraft and its operation. For a given operational weight, the maximum possible battery weight can be decided using both a conventional energy density method and a new Peukert law. In the present study, the hovering flight time is predicted using both methods. The specific data of multicopters in the published literatures were employed for the computation of the hovering flight time. The results were validated with the measured data. The effect of figure of merit of propeller, battery discharging process on the hovering flight time was evaluated, Finally, the effect of the battery cell and package connection types on the hovering time was investigated. It was found that the combination of serial battery cell connections and parallel package connection is the bast in the endurance maximization aspect. As the cell number increases in a package, the hovering flight time is increased. There exists the max. battery ratio for the given takeoff gross weight.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.4
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• pp.318-322
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• 2016

A quad-copter or quad rotor system is an unmanned flying machine having four engines, which their thrust force is produced by four propellers. Its stable control is very important and has widely been studied. It is a typical example of a nonlinear system. So, it is difficult to get a desired control performance by conventional control algorithms. In this paper, we propose the design of a vectored sum defuzzification based fuzzy logic system for the hovering control of a quad-copter. We first summarize its dynamics and introduce a vectored sum defuzzification scheme. And then we design a vectored sum defuzzification based fuzzy logic system. for the hovering control of the quad-copter. Finally, in order to check the feasibility of the proposed system we present some simulation examples.

• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.218-224
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• 2013

This paper describes the design and control of a hovering AUV test-bed and analyzes the dynamic performance of the vehicle using simulation programs. The main purpose of this vehicle is to carry out fundamental tests of its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general appearance of an ROV for underwater operations, and its dimensions are $0.75m{\times}0.5m{\times}0.5m$. It has four 450-W thrusters for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring the water depth and a magnetic compass for measuring its heading angle. The navigation of the vehicle is controlled by an onboard Pentium III-class computer, which runs with the help of the Windows XP operating system. This provides an appropriate environment for developing the various algorithms needed for developing and advancing a hovering AUV.

• Journal of Institute of Control, Robotics and Systems
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• v.1 no.1
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• pp.25-32
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• 1995

Nonlinear depth control algorithms for the hovering system of underwater vehicles are presented. In this paper, a nonlinear effect in heave motion for underwater vehicles, a deadzone effect of the flow control valve in the hovering tank and an impact disturbance are considered. In this situation, in order to choose a desirable controller, sliding mode controller and fuzzy sliding mode controller are designed and compared. The computer simulation results show that the fuzzy sliding mode control system is more suitable in order to maintain a desirable depth of an underwater vehicle with a deadzone and impact disturbance.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1399-1411
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• 1994

A model helicopter has more versatile flight capability than the fixed-wing aircraft and it can be used as an unmaned vehicle in hazardous area. A helicopter, similar to other aircrafts, is an unstable, multi-input multi-output nonlinear system exposed to strong disturbance. So it should be controlled by robust control theories that can be applied to multivariable systems. In this study, motion equations of hovering are established, linearized and transformed into a state equation form. Various parameters are measured and calculated in other to obtain the stability derivatives in the state equation. Hovering flight controller is designed using the digital LQG/LTR(Linear Quadratic Gaussian/Loop Transfer Recovery) control theory. The designed controller is tested by the nonlinear simulations and implemented on an IBM-PC/386. Experiments were carried out on a model helicopter attached to the 3-DOF gimbal. The designed controller showed satisfactory hovering capability to maintain the hovering for more than 40 seconds.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.4
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• pp.361-370
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• 1992

A controller of the hovering VTOL aircraft with four fan is constructed by SRFIMF(State Rate Feedback Implicit Model-Following)theory, in which feedback state are angle acceleration, angle velocity and angle position of the aircraft during hover With yaw control of the system, characteristics of the hovering aircraft can be analyzed by changing states feedback gain and sponse provides robust stable hovering system.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.3
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• pp.165-171
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• 2014

In this paper, we propose the hardware and software of a test-bed of a hovering AUV (autonomous underwater vehicle). Test-bed to develop as the underwater robot for the hovering -type is planning to apply for marine resource development and exploration for deep sea. The RTU that controls a azimuth thruster and a vertical thruster of test-bed is a intergrated-type thruster. The main control unit that collects sensor's data and performs high-speed processing and controls a movement of test-bed is a underwater hybrid navigation system. Also it transfers position, posture, state information of test-bed to the host PC of user using a wireless communication. The host PC checks a test-bed in real time by using a realtime monitoring system that is implemented by LabVIEW.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.9
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• pp.797-804
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• 2013

In this paper, a study of a new hovering six dof underwater robot with redundant horizontal thrusters, titled HAUV (hovering AUV), is presented. The results of study on the structure design, deployment of thrusters, and development of the developed control system of the AUV was presented. For the HAUV structure, a structure design and an analysis of the thrusting system was performed. For navigation, a sensor fusion board which can proceed various sensor signals to identify correct positions and speeds was developed and a total control system including EKF (Extended Kalman Filter) was designed. Rolling, pitching and depth control tests of the HAUV have been performed, and relatively small angle error and depth tracking error results were shown.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.580-585
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• 2005

A QRT(Quad-Rotor Type) hovering robot system is developed for quick detection and observation of the circumstances under calamity environment such as indoor fire spots. The UAV(Unmanned Aerial Vehicle) is equipped with four propellers driven by each electric motor, an embedded controller using a DSP, INS(Inertial Navigation System) using 3-axis rate gyros, a CCD camera with wireless communication transmitter for observation, and an ultrasonic range sensor for height control. The developed hovering robot shows stable flying performances under the adoption of RIC(Robust Internal-loop Compensator) based disturbance compensation and the vision based localization method. The UAV can also avoid obstacles using eight IR and four ultrasonic range sensors. The VTOL(Vertical Take-Off and Landing) flying object flies into indoor fire spots and sends the images captured by the CCD camera to the operator. This kind of small-sized UAV can be widely used in various calamity observation fields without danger of human beings under harmful environment.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.185-188
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• 1993

The goal of this paper is to develop an on-board controller for a model helicopter's hovering attitude control, using i8096 one-chip microcontroller. Required controller algorithm is programmed in ASM-96 assembly language and downloaded into an i8096 microcontroller. The performance of hovering flight using this system is verified by experiments with the model helicopter mounted on an instrumented flight stand where 3 potentiometers and an optical proximity sensor measure te attitude and main rotor speed of the helicopter.