• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.131-132
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• 2017

본 논문에서는 쿼드콥터 드론의 충돌방지를 위한 효율적인 자동제어 방법을 제안한다. 이 제어방법은 RC 조종기에서 노브를 이용하여 사용자가 제어하는 신호를 쿼드콥터의 리시버단에서 수신한 뒤 출력되는 PWM 신호들 중에서 쓰로틀, 피치, 롤 제어정보를 필요시 변경하는 방법으로 충돌을 방지한다. 충돌을 예측하기 위해서 전후, 좌우, 상하 6방향에 레이저 거리측정센서를 장착하고 주기적으로 거리를 측정한다. 그리고 측정 거리를 이용하여 장애물 유무를 판정하고 충돌이 예상되면 수신된 PWM 신호를 변경하여 쿼드콥터의 비행제어부로 전달함으로써 충돌을 방지하도록 한다. 본 논문에서 제안하는 충돌방지 방법을 쿼드콥터에 적용하여 실험을 통해 검증한 결과, 조종자 부주의 혹은 조종 미숙으로 인해 발생할 수 있는 충돌을 방지할 수 있어 안전성이 향상됨을 보였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.479-486
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• 2013

There exist two major difficulties in developing flight control system: nonlinear dynamic characteristics and time-varying properties of parameters of aircraft. Instead of the difficulties, many high reliable and efficient control methodologies have been developed. But, most of the developed control systems are based on the exact mathematical modelling of aircraft and, in the absence of such a model, it is very difficult to derive performance, robustness and nominal stability. From these aspects, recently, some approaches to utilizing the intelligent control theories such as fuzzy logic control, neural network and genetic algorithm have appeared. In this paper, one advanced intelligent lateral control system of a high speed fight has been developed utilizing type-2 fuzzy logic, which can deduce the uncertainty problem of the conventional fuzzy logic. The results will be verified through computer simulation.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.33-41
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• 2023

As seen in the case of the Boeing 737 Max accident, the proportion of aircraft software is rapidly increasing. However, it is vulnerable to safety issues. In case of domestic aircraft software, to operate a Light Unmanned Aerial Vehicle (LUAV) less than an empty weight of 150 kg, safety certification is required for an Ultra-Light Vehicle (ULV). However, software certification procedure is not included. Since the use of LUAVs has increased recently, software verification is required. This paper proposed a checklist of LUAV software that could be applied to LUAV referring DO-178C, an aviation software certification standard. A case study of applying the proposed checklist to the Model-based Development-based Helicopter Flight Control Computer (FCC) project currently used by domestic and foreign advanced companies and institutions was conducted.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.574-579
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• 2016

Unlike general unmanned aerial vehicles, the quad-rotor is attracting the attention of many people because of simple structure and very useful value. However, as the interest in drones increases, the safety and location of vehicles are becoming more important provide against aviation safety accidents or lost accidents. Therefore, in this paper, we propose a tracking system that stabilizes the model with a simple controller by linearized modeling and grasp tilt angle data from various sensor through the filter. The developed tracking system transmits the position of the quad-rotor in flight to the computer and shows it through the route, so it can check the flight path and various information such as flight speed and altitude at the same time. Then the sensor used in the actual quad-rotor can not measure exact sensor data for disturbance and vibration. So we use sensor fusion of Kalman filter and Complementary filter to overcome this problem and the stability of the quad-rotor hovering is realized by PID control. Through simulation, various information such as the speed, position, and altitude of the quad-rotor were confirmed in real time.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.57-64
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• 2021

In this paper, we propose a device that can control the primary control surface of an aircraft by recognizing speech commands. The speech command consists of 19 commands, and a learning model is constructed based on a total of 2,500 datasets. The training model is composed of a CNN model using the Sequential library of the TensorFlow-based Keras model, and the speech file used for training uses the MFCC algorithm to extract features. The learning model consists of two convolution layers for feature recognition and Fully Connected Layer for classification consists of two dense layers. The accuracy of the validation dataset was 98.4%, and the performance evaluation of the test dataset showed an accuracy of 97.6%. In addition, it was confirmed that the operation was performed normally by designing and implementing a Raspberry Pi-based control device. In the future, it can be used as a virtual training environment in the field of voice recognition automatic flight and aviation maintenance.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.112-119
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• 2004

This paper proposes an attitude determination GPS/INS integrated system scheme for a UAV and presents experimental flight test results. The proposed system is designed as a part of an autopilot system and comprises a GPS attitude determination receiver, an off-the-shelf inertial measurement unit (IMU), and a navigation computer unit (NCU). UAV requires accurate attitude information for stable automatic flight control. The proposed system can provide accurate attitude information for the flight control computer (FCC) so that stable automatic flight control can be achieved. In order to verify the performance of the proposed scheme, an integrated navigation system has been developed. In order to evaluate the developed navigation system, the flight test has been performed. In the flight test, the developed system was shown to provide the position, the velocity and the attitude satisfactorily enough for stable flight control. The accuracy of the attitude information of the developed system was confirmed by comparing attitude of vertical gyro.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.517-526
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• 2015

This paper presents the results of study for improving the reliability of quadrotor attitude control by applying a multi-sensor along with a data fusion algorithm. First, a mathematical model of the quadrotor dynamics was developed. Then, using the quadrotor mathematical model, simulations were performed using the improved reliability multi-sensor data as the inputs. From the simulation results, we designed a Gimbal-equipped quadrotor system. With the quadrotor in a hover state, we performed experiments according to the angle change of the user's specifications. We then calculated the attitude control data from the actual experimental data. Furthermore, with additional simulations, we verified the performance of the designed quadrotor attitude control system with multiple sensors.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.3
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• pp.109-116
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• 2022

A modular platform development technique was proposed to minimize development cost and development period by utilizing the already developed unmanned Aerial target AVT, which has been operated and verified for many years. New Mission Profile was designed and structural analysis was performed through finite element analysis (FEA) by analyzing mission requirements for visual short-range, non-visible mid-range, and long-range targets. The targets are used for guided missile anti-aircraft training. In addition, avionics systems including flight control computers for autonomous flights were developed to verify their conformance by performing launcher take-off tests with rapid acceleration changes and autonomous flight tests at a maximum speed of 300km per hour.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1081-1087
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• 2008

This paper describes limitations and solutions of the existing processor-monitoring concept for a military supersonics aircraft Flight Control Computer (FLCC) equipped with modern architecture processor to perform the system integration test. Safecritical FLCC integration test, which requires automatic test for thousands of test cases and real-time input/output test condition generation, depends on the processor-monitoring device called Processor Interface (PI). The PI, which relies upon on the FLCC processor's external address and data-bus data, has some limitations due to multi-fetching capability of the modern sophisticated military processors, like C6000's VLIW (Very-Long Instruction Word) architecture and PowerPC's Superscalar architecture. Several techniques for limitations were developed and proper monitoring approach was presented for modem processor-adopted FLCC system integration test.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1613-1616
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• 2010

본 논문은 실시간 운영체제인 Xenomai 를 사용하여, 회전익 무인항공기 소프트웨어 개발에 대한 내용을 설명하고 있다. 실시간 운영체제 사용하여 고정 순위 우선 스케줄링을 채택함으로써 데드라인의 타이밍(Timming) 결정성을 보장하였고, 이기종 시스템과의 호환성과 확장성을 고려하여 POSIX API 를 사용하여 멀티 쓰레드를 구현하였다. 또한 실시간 드라이버 모델(RTDM : Real-Time Driver Model)을 사용하여 획득한 데이터를 실시간 전송이 가능하도록 하였다. 본 논문은 실시간 운영체제를 무인항공기에 적용하고 구현된 비행제어 컴퓨터와 제어 소프트웨어를 비율 단조 스케줄링을 적용하여 무인항공기의 쓰레드들의 응답 속도 및 안정성을 보장하는 방안을 제시하였다.