• Journal of Mechanical Science and Technology
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• v.16 no.6
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• pp.745-756
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• 2002

The re-entry problem consists of guidance design and trajectory control. This paper summarizes the detailed relationships between the velocity, drag acceleration and altitude in determining reference trajectories. The computational issues are also addressed, and the performance of the proposed simple nonlinear control of a bank angle for the longitudinal/ lateral trajectory is demonstrated. In particular, the fixed bank angle methods that can reduce the drag acceleration errors at low-speeds are proposed. The importance of bank reversals with respect to the azimuth errors Is also elucidated.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.3
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• pp.231-238
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• 2002

In this paper, we present a new approach to autopilot design for skid-to-turn missiles which may have severe aerodynamic cross-couplings and nonlinearities with angle of attack. The model of missile motion is derived in the maneuver plane and, based on that model, pitch, yaw, and roll autopilot are designed. They are composed of a nonlinear term which compensates for the aerodynamic couplings and nonlinearities and a linear controller driven by the measured outputs of missile accelerations and angular rates. Besides the outputs, further information such as Mach number, dynamic pressure, total angle of attack, and bank angle is required. With the proposed autopilot and simple estimators of bank angle and total angle of attack, it is shown by computer simulations that the induced moments and some aerodynamic nonlinearities are properly compensated and that the performance is superior to that of the conventional ones.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.1
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• pp.1-8
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• 2012

The hydrodynamic interaction between ship and bank can't be neglected when a vessel is app- roached toward the tip of a wedge-shaped bank in restricted waterways, such as in a harbor, near some fixed obstacles, or in a narrow channel. In this paper, the characteristic features of the hydrodynamic interaction acting on a slowly moving vessel in the proximity of a wedge-shaped bank are described and illustrated, and the effects of water depth and the spacing between ship and wedge-shaped bank are summarized and discussed based on the slender body theory. From the theoretical results, it indicated that the hydrodynamic interactions decrease as wedge-shaped bank of angle ${\beta}$ in-creases. For water depth to draft ratio less than about 2.0, the hydrodynamic interactions between ship and bank in-crease sharply as h/d decreases, regardless of the wedge-shaped bank of angle ${\beta}$. Also, for lateral separation more than about 0.2L between ship and wedge-shaped bank, it can be concluded that the bank effects decrease largely as the separation increases.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.355-360
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• 1991

A method of autopilot gain-scheduling is presented for missiles which have heavy aerodynamic coupling between pitch and yaw channels due to high maneuverability. Pitch and yaw, autopilot are cross-coupled, and their feedback gains are scheduled by total acceleration and bank angle for given Mach number and height. Bank angle information is obtained by using a simple estimator. By computer simulation, it is shown that the proposed method is superior to other existing methods.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.412-417
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• 1992

In this paper, we present a method to design a coupled autopilot for STT missiles which have severe aerodynamic cross-coupling. The aerodynamic model is derived in the meneuver plane and, based on that model, an autopilot scheduled by the normal acceleration and the estimated bank angle is designed. Bank angle is obtained by a simple estimator. With the proposed autopilot, it is shown by computer simulations that induced moments are properly compensated and the performance is supiorior to the conventional autopilot.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.106-111
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• 2017

When a substrate with a pixel-defining layer (bank) is coated, there arises capillary force due to surface tension and adhesive forces between a solvent and the bank layer. It brings in a degradation of film thickness and emission uniformities within pixels. With an attempt to suppress it, we have performed fluid flow simulations of capillary arise by varying the contact angle of bank and the bank structure. We have first demonstrated that the fluid flow model can reproduce the capillary phenomenon that was observed experimentally. It has been found that capillary arise can be suppressed using a hydrophobic material for the bank layer. Furthermore, it was suppressed by tilting the sidewalls outwardly (i.e., using a positive photoresistor). We can obtain very uniform films when the slope is $50^{\circ}$ with the contact angle of $40^{\circ}$.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.2
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• pp.137-144
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• 2006

The objective of this paper is to present trajectory guidance and control system with a dynamic inversion for a small unmanned aerial vehicle (UAV). The UAV model is expressed by fixed-mass rigid-body six-degree-of-freedom equations of motion, which include the detailed aerodynamic coefficients, the engine model and the actuator models that have lags and limits. A trajectory is generated from the given waypoints using cubic spline functions of a flight distance. The commanded values of an angle of attack, a sideslip angle, a bank angle and a thrust, are calculated from guidance forces to trace the flight trajectory. To adapt various waypoint locations, a proportional navigation is combined with the guidance system. By the decision logic, appropriate guidance law is selected. The flight control system to achieve the commands is designed using a dynamic inversion approach. For a dynamic inversion controller we use the two-timescale assumption that separates the fast dynamics, involving the angular rates of the aircraft, from the slow dynamics, which include angle of attack, sideslip angle, and bank angle. Some numerical simulations are conducted to see the performance of the proposed guidance and control system.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.04a
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• pp.157-165
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• 2007

Restoration behavior of folded Korea bank note was studied. The variables were folding radii (0.5, 1, 3, 5. 7, 9 mm) and folding time. Initially, bank note was completely folded to make $180^{\circ}$ against predetermined radius panel, and restored angles were measured according to allowed restoration time. We found as folding radius was smaller and as folding time was longer, restoration speed of folding angle became slower and the amount of final restoration was smaller, respectively. Initial restoration angles were related to the elastic moduli of the bank notes, and final restoration angles were inversely related to the TEA of the bank notes, respectively.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.111-117
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• 2007

The nonlinear characteristics of a suspension is directly related to the ride quality of a passenger car. In this study, the nonlinear characteristics of a spring and a damper of a passenger car is analyzed by dynamic experiments using the MTS single-axial testing machine. Also, a mathematical nonlinear dynamic model for the suspension is devised to estimate the ride quality using the K factor. And the effect on the variation of the parameters of the suspension is examined. The results showed that the dynamic viscosity of the oil in a damper was the parameter that most influeced the ride quality of a passenger car for the ride quality of a passenger car.

• Journal of electromagnetic engineering and science
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• v.13 no.3
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• pp.151-157
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• 2013

Marine radars are affected by sea and rain clutters, which can make target discrimination difficult. The clutter standard deviation and improvement factor are applied using multiple parameters-moving speed of radar, antenna speed, angle, etc. When a radar signal is processed, a Data Matrix Bank (DMB) filter can be applied to remove sea clutters. This filter allows detection of a target, and since it is not affected by changes in adjacent clutters resulting from a multi- target signal, sea state clutters can be removed. In this paper, we study the level for clutter removal and the method for target detection. In addition, we design a signal processing algorithm for marine radars, analyze the performance of the DMB filter algorithm, and provide a DMB filter algorithm design. We also perform a DMB filter algorithm analysis and simulation, and then apply this to the DMB filter and cell-average constant false alarm rate design to show comparative results.