• Journal of the Institute of Convergence Signal Processing
• /
• v.10 no.2
• /
• pp.146-150
• /
• 2009

An Intelligent active roll angle controller design algorithm is discussed. The detailed mathematical formulation and analysis are discussed, and then modeling and design method for active roll angle controller are presented. This paper proposes a design method based upon intelligent robust controller design algorithm to control actively roll angle for improving cornering performance problems. The intelligent robust controller is designed for steady speed driving vehicle system model with representation of steering angle and yaw angular velocity parameters for cornering stability. And the detailed formulation and analysis for the objective vehicle system are investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.4
• /
• pp.34-42
• /
• 2004

In this paper, a double gimbal is used for roll/yaw attitude control of spacecraft and two feedback controllers are designed. One is a PD controller of no phase difference between roll and yaw control input. The other is a PD controller with a phase lag compensator about the yaw control input. The phase lag compensator is designed a first order system and a lag parameter is designed for the control of yaw angle. There are two case simulations for each of controllers; constant disturbance torques and initial errors of nutation. We obtain the results through simulations that a steady-state error and a rising time of yaw angle are developed by the compensator. In this paper, simulation parameters use the values of KOREASAT 1.

• 한국기계연구소 소보
• /
• s.15
• /
• pp.5-17
• /
• 1985

Dynamics of railway vehicles are strongly influenced by the wheel/rail contact forces. Wheel/rail contact geometric characteristics are important parameters to determining wheel/rail contact forces. In general, geometric relations between wheel and rail are represented by nonlinear functions of the wheelset lateral excursion and the relative yaw angle. There are some analytical and experimental studies to show the influences of the wheelset lateral displacement on wheel/rail geometric relations. Recently radial steering bogie which is designed to have flexible yaw motions of wheelsets was developed to improve curve negotiation performance. The radial steering bogie makes it important problem to study the effects of wheelset yaw motion on wheel/rail geometric relations. This paper describes the method to analyze 3-dimensional wheel/rail contact geometry considering wheelset yaw motion and describes also some computer simulation results.

• Journal of Mechanical Science and Technology
• /
• v.16 no.3
• /
• pp.338-343
• /
• 2002

In the autonomous vehicle, the reference lane is continually detected by machine vision system. And then the vehicle is steered to follow the reference yaw rates which are generated by the deviations of lateral distance and the yaw angle between a vehicle and the reference lane. To cope with the steering delay and the side-slip of vehicle, PI controller is introduced by yaw rate feedback and tuned from the simulation where the vehicle is modeled as 2 DOF and 79 DOF and verified by the results of an actual vehicle test. The lateral control algorithm by yaw rate feedback has good performances of lane tracking and passenger comfort.

• Wind and Structures
• /
• v.17 no.5
• /
• pp.553-564
• /
• 2013

By using the nonlinear aerostatic stability theory together with the method of mean wind decomposition, a method for nonlinear aerostatic stability analysis is proposed for long-span suspension bridges under yaw wind. A corresponding program is developed considering static wind load nonlinearity and structural nonlinearity. Taking a suspension bridge with three towers and double main spans as an example, the full range aerostatic instability is analyzed under wind at different attack angles and yaw angles. The results indicate that the lowest critical wind speed of aerostatic instability is gained when the initial yaw angle is greater than $0^{\circ}$, which suggests that perhaps yaw wind poses a disadvantage to the aerostatic stability of a long span suspension bridge. The results also show that the main span in upstream goes into instability first, and the reason for this phenomenon is discussed.

• Journal of Power System Engineering
• /
• v.10 no.4
• /
• pp.56-64
• /
• 2006

This paper shows the development process of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. The data reduction method using a bi-cubic curve-fitting program in a new calibration map was introduced in this study. This new calibration map can be applied up to the application angle, ${\pm}55^{\circ}$ of a probe. As a result, for the application angle of ${\pm}45^{\circ}$, an error for yaw and pitch angles appeared from $-1.76^{\circ}\;to\;1.83^{\circ}$ and from $-1.91^{\circ}\;to\;1.75^{\circ}$, respectively. Moreover, an error for a vector magnitude and a static pressure compared with a dynamic one showed from -7.83% to 4.87% and from -0.73 to 0.77, respectively. Even though this data reduction method showed unsatisfactory errors in a vector magnitude, it resulted in an easy and simple application method. Especially, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole. However, in order to obtain a better result, it is thought that a more sophisticated interpolation method needs to be introduced.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.35-36
• /
• 2019

Major influence factors for piercing depth of concrete against small caliber bullet are target's property such as compression strength of concrete and bullet's property such as the velocity and weight of it. In particular about the bullet's property, velocity and incidence angle could be controlled by specific position or distance between targets and shooter, but the angle of yaw of bullet dose not. Because the the angle of yaw of bullet causes lower piercing force of bullet, some errors on piercing depth of concrete could be appeared by live fire test for the evaluation of protective performance. Therefore, we have checked the error canceling effect on the piercing depth of concrete by single shot and barrage of small caiber bullets. As a result, we identified that the error of piercing depth by the angle of yaw of bullet could be cancelled by barrage.

• Journal of Wind Energy
• /
• v.13 no.4
• /
• pp.17-25
• /
• 2022

In this study, the response characteristics of two semi-submersible platforms with an IEA 15 MW reference wind turbine are compared. The nacelle acceleration, platform motion and generator power of FOWT applying a VolturnUS-S platform developed by the University of Maine and PentaSemi platform developed by the Korea Research Institute of Ships and Ocean Engineering are compared in operational conditions. Numerical simulations are performed based on the marine environmental conditions of the U.S east coast. In the FOWT to which the PentaSemi platform is applied, the nacelle acceleration and platform pitch angle are rather high, but the results of both platforms satisfied the design criteria at all operating wind speeds. The platform yaw angle of PentaSemi platform to which a yaw control catenary mooring system is applied is significantly smaller than the platform yaw angle of VolturnUS-S. Also, despite the relatively large nacelle acceleration and platform pitch angle, the generator power is higher on the PentaSemi platform. This means that the generator power dominates the control system rather than the nacelle and platform motion.

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

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.2109-2114
• /
• 2003

The vortex flow characteristics of a yawed LEX-delta wing at a high-angle of attack are studied using a computational analysis. The objective of the present study is to investigate and visualize the effects of the yaw angle, the development and interaction of vortices, the relationship between the suction pressure distributions and the vortex flow characteristics. Computations are applied to the three dimensional, compressible, Navier-Stokes Equations. In computations, the yaw angle is varied between 0 and 20 degree at a high-angle of attack. Computational predictions are compared with the previous experimental results.