• Title/Summary/Keyword: Guidance law

Search Result 332, Processing Time 0.026 seconds

Trajectory Tracking Controller Design using L1 Adaptive Control for Multirotor UAVs (L1 적응 제어 기법을 이용한 멀티로터 무인 항공기의 궤적 추종 기법 설계)

  • Jung, Yeundeuk;Cho, Sungwook;Shim, Hyunchul
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.42 no.10
    • /
    • pp.842-850
    • /
    • 2014
  • This paper presents a trajectory tracking controller for rotorcraft UAVs to improve the tracking performances in the presence of various uncertainties. The proposed tracking method consists of a velocity guidance law based on the relative distance and L1 adaptive augmentation loop for tracking the velocity commands. In the proposed structure, the desired velocity generated by the guidance law is the reference value of the adaptive controller for accurate path tracking. In the guidance law, the desired acceleration is generated based on the relative distance and its derivatives, and then the velocity command of the inner control loop is calculated by integrating the accelerations. $L_1$ augmentation loop supplements the linear controller to guarantee the flight performances such as a tracking accuracy in the presence of the uncertainties. The proposed controller was validated in actual flight tests to successfully demonstrate its capability using a quadrotor UAV.

Development of AUV's Waypoint Guidance Law and Verification by HILS (무인잠수정의 경로점 유도 법칙 설계 및 HILS 검증)

  • Hwang, Jong-Hyon;Yoo, Tae-Suk;Han, Yongsu;Kim, Hyun Wook
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.24 no.11
    • /
    • pp.1417-1423
    • /
    • 2020
  • This paper proposes a waypoint guidance algorithm for the Autonomous Underwater Vehicle(AUV). The proposed simplified guidance algorithm is presented, which is combined LOS guidance and cross-track guidance for path following. Cross-track error is calculated using the position of the AUV and reference path. LOS guidance and cross-track guidance are appropriately changed according to cross-track error. And the stability of the system has been improved using variable cross-track control gain by cross-track error. Also, in this paper, navigation hardware in-the loop simulation(HILS) is implemented to verify navigation algorithm of AUV that performs combined navigation using inertial navigation device and doppler velocity log(DVL). Finally, we design integrated system HILS (including navigation HILS) for performance verification of guidance algorithm of the autonomous underwater vehicle. By comparing the sea test result with HILS result, the proposed guidance algorithm and HILS configuration were confirmed be correct.

Necessity of revision of the mandatory medication guidance regulation under the Pharmaceutical Affairs Act (약사법상 복약지도의무 규정의 개정 필요성)

  • Dawoon Jung
    • The Korean Society of Law and Medicine
    • /
    • v.24 no.2
    • /
    • pp.119-145
    • /
    • 2023
  • The Pharmaceutical Affairs Act stipulates medication counseling as an obligatory requirement in the case of preparation of medicine. In fact, there are many cases where pharmacists only tell patients the dose and time and do not properly guide them on taking medications. However, in light of the current situation where non-face-to-face treatment is being attempted, there is a high possibility of drug-taking accidents due to insufficient medication guidance. In addition, as an aging society progresses, the need for explanations on pharmaceuticals is increasing. If a pharmacist causes damage to a patient by failing to give appropriate medication guidance, the patient can claim compensation for damages. In addition, if a drug accident occurs due to a conflict between the pharmacist's duty to guide medication and the doctor's duty to explain, a joint tort is established between the pharmacist and the doctor. Nevertheless, there are cases in which only doctors are judged to bear the tort liability. However, the Pharmaceutical Affairs Act includes providing information for the selection of over-the-counter drugs in the medication guidance as part of the medication guidance obligation. Therefore, in order to reconsider the importance of the medication-taking guidance duty, it is necessary to define the medicationaking information provision method and the medication-taking guidance duty as separate concepts. In addition, it is necessary to amend related regulations centered on patients so that medication guidance, such as side effects of medicines and interactions with concomitant medications, can be made in detail.

A Study on the Improvement of Technical Guidance Fee for Preventing Accidents at Small-Medium Construction Sites (중·소규모 건설현장 재해예방 기술지도 대가 개선에 관한 연구)

  • Lim, Se-Jong;Shin, Seung-Hyeon;Won, Jeong-Hun;Yoon, Young-Cheol
    • Journal of the Korea Institute of Building Construction
    • /
    • v.21 no.5
    • /
    • pp.469-481
    • /
    • 2021
  • Under Korean law, small-to-medium-sized construction projects with budgets of more than 100 million won and less than 12 billion won must receive technical guidance by a visiting technician belonging to a specialized institution. This study proposed a method for calculating the technical guidance fee to prevent the potential inadequacy of technical guidance when the responsibility providing the technical guidance fee is changed from a contractor to a client. The method simplified the construction works which should receive technical guidance into four sections according to the construction amount. For each section, the number of instances of technical guidance per day provided by the visiting technician and the minimum technical grade of the visiting technician were limited, and the guideline for estimating engineering services fees was applied to calculate the fee per instance of technical guidance. The results show that the proposed method can be applied to the establishment of a technical guidance fee guideline since it well reflects the current fee distribution and K2B analysis results.

Impact Angle Control for Non-maneuvering Target with Look Angle Measurements and Line of Sight (지향각, 시선각 정보를 이용한 이동표적의 충돌각 제어)

  • Park, Jang-Seong;Lee, Dong-Hee;Park, Sang-Hyuk;Kim, Yoon-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.47 no.7
    • /
    • pp.508-516
    • /
    • 2019
  • In this paper, we propose a guidance law to control Impact Angle in consideration of look angle limit of the missile with strapdown seeker on the non-maneuvering target. The proposed law is based on sliding mode algorithm and generates acceleration commands using look angle and line of sight information provided by the strapdown seeker and navigation system. And, target velocity and target path angle are provided by like TADS (Target Acquisition and Designation System) at launch time. We can confirm that the target interception and impact angle control are possible through the convergence of the proposed sliding surface. In addition, it is possible to confirm that the sign of derivative result of the look angle at the maximum and minimum look angle is opposite to the sign of the look angle, so the look angle limit is not exceeded.

Rendezvous Maneuver of an Unmanned Aerial Vehicle Using Lyapunov-based Variable Pursuit Guidance (르야프노프 기반 가변 추적유도법칙을 이용한 무인항공기 랑데부 기동 기법)

  • Kim, Mingu
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.48 no.10
    • /
    • pp.765-772
    • /
    • 2020
  • A lot of studies to overcome the limitation of flight time have been studied, since the requirement of complicated mission achievement of aircraft including Unmanned Aerial Vehicles(UAVs) has been increased. The fuel limitation could bring about not enough flight time to accomplish missions. For this reason, the rendezvous maneuver is required to accomplish aerial refueling missions. The rendezvous guidance law based on variable pursuit guidance is designed using Lyapunov stability theory in this study. Numerical simulation is performed to demonstrate the performance of the proposed rendezvous guidance.

Design of Autolanding Guidance and Control Algorithm Using Singular Perturbation (특이섭동법을 이용한 비행체 자동착륙 유도제어 알고리즘 설계)

  • Ha, Cheol-Keun;Choi, Hyoung-Sik
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.11 no.8
    • /
    • pp.726-732
    • /
    • 2005
  • This paper proposes an autolanding guidance and control algorithm with the lateral guidance law. This algorithm is basically formulated and designed in feedback linearization based on singular perturbation. Main features of this algorithm are two facts. One of those is that when a certain situation happens that airplane must realign to the runway suddenly assigned due to unexpected environment change around the landing site, the heading guidance in this algorithm is very valuable, and the other is the fact that the inner loop control of this algorithm is able to be designed directly based on the Handling Quality Requirements that most flight control systems must be satisfied with. To illustrate the potential of this algorithm, 6-DOF nonlinear simulation based on the nonlinear airplane model shown in Ref.[11] is carried out. The simulation results showed that the altitude response to the given landing trajectory is accurate, and the airplane heading alignment to the assigned runway from the lateral deviation is successful. It is noted that this algorithm is also applicable to unmanned aerial vehicle, which can be retrieved in autolanding technique, where the runway far retrieving the vehicle is in any direction for example at war field.

Investigation on Media Literacy of China Government Officials: Under the View of Public Opinion Guidance

  • Yang, Ting;Seo, Sangho
    • International Journal of Contents
    • /
    • v.14 no.4
    • /
    • pp.10-17
    • /
    • 2018
  • China media environment has drastically changed leading to the an inevitable change of public opinion ecology. Empirical studies have focused less on public opinion guidance, which forms an important component of the government officials' media literacy. This study applied quantitative method in the investigation of media literacy in China. Ideally, media literacy is measured from media cognition, media contact, media usage under the view of public opinion guidance. The findings reveal that the existing problem on 1) incorrect media cognition and public opinion guidance; 2) insufficient contact of personal social media 3) improper tendencies in the use of media to guide the public opinion, especially, on confidential information. Consequently, in order to improve media literacy in China government officials, enhancement of their basic knowledge on news diffusion and public opinion is necessary. Secondly, to effectively deal with "agenda settings", it is important for the government to consider the provision of valuable information and platforms to effectively spread information. So they need to learn how to personally and officially use social media platforms such as Weiboa and Wechat. This ensures they have maximized their potential to acquire valuable information and spread them on valuable platforms. Thirdly, government officials should be able to analyze and understand public opinion trends for official and personal use. Finally, they should understand the development of public opinion and the how online public opinion laws are formed and the target group.

Design of Guidance Law and Lateral Controller for a High Altitude Long Endurance UAV (고고도 장기체공 무인기의 유도 및 방향축 제어 알고리즘 설계)

  • Koo, Soyeon;Lim, Seunghan
    • Journal of Aerospace System Engineering
    • /
    • v.13 no.2
    • /
    • pp.1-9
    • /
    • 2019
  • This paper elaborates on the directional axis guidance and control algorithm used in mission flight for high altitude long endurance UAV. First, the directional axis control algorithm is designed to modify the control variable such that a strong headwind prevents the UAV from moving forward. Similarly, the guidance algorithm is designed to operate the respective algorithms for Fly-over, Fly-by, and Hold for way-point flight. The design outcomes of each guidance and control algorithm were confirmed through nonlinear simulation of high altitude long endurance UAV. Finally, the penultimate purpose of this study was to perform an actual mission flight based on the design results. Consequently, flight tests were used to establish the flight controllability of the designed guidance and control algorithm.