• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.706-711
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• 2015

The fighter aircraft uses several different loading configurations for air-to-surface and air-to-air combat missions. To maintain wings-level flight with an asymmetric weapon configuration, a pilot controls a roll trim system. However, it is difficult to apply an accurate roll trim input for wings-level flight in the actual flight under disturbance. The inaccurate roll trim input degrades the performance of the roll autopilot system. In this paper, to solve this problem, an integrator was additionally designed in the command part of the roll autopilot system. The initial transient response was improved by scheduling the limiter to restrict the roll attitude error. As a result of the evaluation of the simulation for the designed flight control law, the roll attitude following performance was found to be improved in the autopilot system operation under the inaccurate roll trim condition.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1509-1512
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• 1996

This paper presents an intelligent autopilot for STT missiles with multiple controllers. The mixed H$_{2}$/H$_{\infty}$ control technique is applied for each controller and implemented by using the genetic searching algorithm. To facilitate automatic switching of multiple controllers under different operating conditions, an error based switching scheme is also combined with the multiple controllers at the higher level, which constitutes a hierarchical intelligent control system. It is shown via computer simulation that the proposed autopilot outperforms the conventional one..

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.139-144
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• 2004

The flight control system designed for an unmanned airship, which is under development by KARI, is in reduced. First, the dynamic characteristics of the airship are addressed, which are fairly different from those of the nominal aircraft. In order to implement autonomous flight for the unmanned airship, flight control logic is designed including autopilot and guidance law. The autopilot is designed under consideration of the velocity region of the unmanned airship. The guidance laws are implemented in main operational modes such as point navigation, station keeping and spiral up/down for emergency return. Their simulation results are also presented in order to validate performances of the flight control system.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.699-703
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• 2004

The autopilot system targets decreasing labor, working environment, service safety security and elevation of service efficiency. Ultimate purpose is minimizing number of crew for guarantee economical efficiency of shipping service. Recently, being achieving research about Course Keeping Control, Track Keeping Control, Roll-Rudder Stabilization, Dynamic ship Positioning and Automatic Mooring Control etc. which compensate nonlinear characteristic using optimizing control technique. And application research is progressing using real ship on actual field. Relation of Rudder angle which adjusted by Steering Machine and ship-heading angle are non-linear. And, Load Condition of ship acts as non-linear element that influence to Parameter of ship. Also, because the speed of a current and direction of waves, velocity and quantity of wind etc. that id disturbance act in non-linear form, become factor who make service of shipping painfully. Therefore, service system of shipping requires robust control algorithm that can overcome nonlinearity. In this paper, Using GA algorithm,design autopilot system of ship that could overcome the non-linear factor of ship and disturbance and examined result through simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.11
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• pp.1104-1111
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• 2008

The supersonic advanced trainer based on digital flight-by-wire flight control system uses aircraft flight information such as altitude, calibrated airspeed and angle of attack to calculate flight control law, and this information is measured by IMFP(Integrated Multi-Function Probe) equipment. The information has triplex structure using three IMFP sensors. Final value of informations is selected by mid-value selection logic to have more flight data reliability. As the result of supersonic flight test, pitch oscillation is occurred due to IMFP noise when altitude hold autopilot mode is engaged. This tendency may affect stability and handling quality of an aircraft during autopilot mode. This paper addresses autopilot control law design to remove pitch oscillation and these control laws are verified by non-real time simulation and flight test. Also, pitch response characteristics of pitch attitude hold autopilot mode is improved by upgrading the control law structure and feedback gain tuning during bank turn.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.525-530
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• 2003

This paper is concerned with a control allocation strategy using the dynamic inversion which generates the nominal control input trajectories, and autopilot design using the time-varying control technique which is time-varying version of pole placement of linear time-invariant system for an agile missile with aerodynamic fin and thrust vectoring control. Dynamic inversion can decide the amount of the deflection of each control effector, aerodynamic fin and thrust vectoring control, to extract the maximum performance by combining the action of them. Time-varying control technique for autopilot design enhance the robustness of the tracking performance for a reference command. Nonlinear simulations demonstrates the dynamic inversion provides the effective nominal control input trajectories to achieve the angle of attack command, and time-varying control technique exhibits good robustness for a wide range of angle of attack.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.74-81
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• 2014

This article documents the design of a novel two-loop acceleration autopilot based on $\mathcal{L}_1$ adaptive output feedback control for tail-controlled missiles. The inner loop is an adaptive angle-of-attack tracking loop and the outer loop is the traditional PI controller for error compensation. A systematic low-pass filter design procedure is provided for minimum phase system and is applied to the inner loop design while the parameters of the outer loop are obtained from the multi-objective optimization problem. The effectiveness of the proposed autopilot is verified through numerical simulations under various conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.4
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• pp.458-463
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• 1998

This paper presents an autopilot design method for STT missiles using the intelligent control technique and multiple controllers. The mixed $H_2/H_{\infty}$ control technique is applied for each controller design and the control gains are implemented by using the genetic searching algorithm. To facilitate automatic switching of multiple controllers under different operating conditions, an error based switching scheme is also combined with the multiple controllers at a higher level, which constitutes a hierarchical intelligent control system. It is shown via computer simulation that the proposed autopilot outperforms the conventional one.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1995.04a
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• pp.65-92
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• 1995

The final aim of our research project is a study on assessment of automatic steering system of ships in open seas. In order to achieve this aim we need to know the characteristics of each component of the system and also to know the characteristics of disturbance to ship dynamcis. In this paper we provide calculation method of irregular disturbance to ships in autopilot navigation in open seas and also show calculation examples about two kinds of ship ore carrier and fishing boat. The disturbance consists of irregular wave and random wind, The disturbance is calculated as equivalent yaw angular velocity. Each spectrum and time history of disturbance are reasonably evaluated. Further investigation concerning to performance index of autopilot system and energy loss related to automatic course keeping will be dealt with in another paper,

• Journal of the Korean Institute of Navigation
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• v.19 no.2
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• pp.1-12
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• 1995

The final aim of our research project is a study on assessment of automatic steering system of ships in open seas. In order to achieve this aim, we need to know the characteristics of each component of the system, and also to know the characteristics of disturbance to ship dynamics. In this paper, we provide calculation method of irregular disturbance to ships in autopilot navigation in open seas, and also show calculation examples about two kinds of ship, ore carrier and fishing boat. The disturbance consists of irregular wave and random wind. The disturbance is calculated as equivalent yaw angular velocity. Each spectrum and time history of disturbance are reasonably evaluated. Further investigation concerning to performance index of autopilot system and energy loss related to automatic course keeping, will be dealt with in another paper.