• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.508-513
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• 2003

This paper is concerned with a mixed control with aerodynamic fin and side thrusters applied to an agile missile using two-time scale dynamic inversion and linear time-varying control technique. The nonlinear dynamic inversion method with the weighting function allocates the desired control inputs (aerodynamic fin and side thrusters) to track a reference trajectory, and the time-varying control technique guarantees the robustness for the uncertainties. Closed-loop stability is achieved by the assignment of the extended-mean of these linear time-varying eigenvalues to the left half complex plane. The proposed schemes are validated by nonlinear simulations.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.148.4-148
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• 2001

This paper shows an autopilot design example with simulation results for a medium range surface-to-air missile used to intercept fast maneuver targets. The missile is assumed to use both aerodynamic fins and side thrusters to achieve fast time response. The steady-state maneuver capability of the missile is assumed to be enough at high altitude to engage usual maneuvering targets. Side thruster is used to get an extremely rapid acceleration response at high altitude where the missile´s aerodynamic control effectiveness is weak. The strategy of control design is firstly to employ side thrusters to achieve a rapid response and then to hand-over the control to the aerodynamic fins to maintain the desired acceleration command in the steady state ...

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.1-6
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• 2017

In this paper, we present a study concerning the design of a 400 N class side thruster for small ships. The side thrusters used in Korea are imported from abroad. The performance and durability of the imported products employed in Korea are not adequate, therefore the side thrusters which will be suitable for Korean domestic needs to be re-designed. The strength calculation of the side thruster was performed by KS standard. Strength calculation and design were made to meet design requirements. Structural analysis and safety factor analysis were carried out to confirm the validity of strength calculations and design. After manufacturing the bevel gear, a back lash test was conducted. We also conducted a no-load test, a rated load, and an overload test for a performance test and a durability test of the design while satisfying the design conditions.

• Bulletin of the Society of Naval Architects of Korea
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• v.14 no.2
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• pp.11-25
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• 1977

• Journal of Ocean Engineering and Technology
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• v.8 no.2
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• pp.56-63
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• 1994

This paper presents a design method of multivariable robust servo system for tracking control system for AUV(Autonomous Underwater Vehicle). In order to obtain the basic data for the design of the tracking control system, the control algorithm is evaluated in the view of computer simulation results. The tracking control is carried out for an AUV with 2 main thrusters, 2 side thrusters and 2 thrusters for the movement to up-down direction. The results of computer simulation show that the proposed multivariable servo system design method is an efficient method for the control performance of tracking control system of AUV under severe underwater environment.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.347-360
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• 2014

The auto-berthing of a ship requires excellent control for safe accomplishment. Crabbing, which is the pure sway motion of a ship without surge velocity, can be used for this purpose. Crabbing is induced by a peculiar operation procedure known as the push-pull mode. When a ship is in the push-pull mode, an interacting force is induced by complex turbulent flow around the ship generated by the propellers and side thrusters. In this paper, three degrees of freedom equations of the motions of crabbing are derived. The equations are used to apply the adaptive backstepping control method to the auto-berthing controller of a cruise ship. The controller is capable of handling the system non-linearity and uncertainty of the berthing process. A control allocation algorithm for a ship equipped with two propellers and two side thrusters is also developed, the performance of which is validated by simulation of auto-berthing.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.56-64
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• 2013

Crabbing motion is the pure sway motion of a ship without surge velocity. Thus, it can be applied to a berthing operation. Crabbing motion is induced by a peculiar operation method called the push-pull mode. The push-pull mode is induced by using a combination of the main propeller and side thruster. Two propellers generating the same amounts of thrust and rotating in opposite directions produce some yawing moment on a vessel but do not induce longitudinal motion. With the additional operation of side thrusters, the push-pull mode is used to induce a large amount of lateral force. In this paper, three-degree-of-freedom equations of motion such as for the surge, sway, and yaw are constructed for the crabbing motion. Based on these equations of motion, a feedback linearization control method is applied to auto-berthing control for a twin-screw ship with side thrusters. The controller can deal with the nonlinearity of a system, which is present in the berthing maneuver of a twin screw ship. A simulation of the auto-berthing of a ship is performed to validate the performance of the designed controller.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.961-964
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• 2016

This paper describes the implementation of AUSV system for Sonar Image acquisition. The system be controlled by FF-PID algorithm for the thrusters using motion sensor and DGPS. As experimental results, the control performance is that the error distance from the destination positions are under 5m in total survey track of 1km, and the image deviation is under 12 pixel from the manned survey method, which the comparison with the total image quality is almost the same as the manned survey one. Thus the AUSV system is a new method of system can be utilized on the limited survey area as the surveyor should not be able to approach on sea surface.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.581-586
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• 2008

The MEMS solid propellant thrusters have very low thrust level for applying to the propulsion system of micro/nano satellites or the side jet thruster of smart bombs. In this research, the fabrication possibility of planar type MEMS solid propellant thrusters that have enlarged burning surface area was examined and the safety of the structure of thruster during the firing test was confirmed. The performance of a micro igniter which is the key component of the MEMS solid propellant thruster was estimated by the ANSYS Icepak and evaluated by the experiment. Finally, the thrust was measured by the micro force sensor. The levels of thrust were 300, 600 mN in the case of K=15, 20.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.208-213
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• 2016

This paper proposes a potential field-based guidance law for docking a USV (unmanned surface vehicle). In most cases, a USV without side thrusters is an under-actuated system. Thus, there are undockable regions near docking stations where a USV cannot dock to a docking station without causing a collision or backward motion. This paper suggest a guidance law that prevents a USV from enter such a region by decreasing the lateral error to the docking station at the initial stage of the docking process. A Monte-carlo simulation was performed to validate the performance of the proposed method. The proposed method was compared to conventional guidance laws such as pure pursuit guidance and pure/lead pursuit guidance. As a result, the collision angle and lateral distance error of proposed method tended to have lower values compared to conventional methods.