• 한국군사과학기술학회지
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• 제18권2호
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• pp.181-188
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• 2015

This paper present, the result of the guidance and control law for a course correction munitions(CCM) with 2sets of canards positioned in the rotating nose section. The nonlinear simulation model of the CCM was developed based on 7DOF equation of motion. The ability of correcting position was verified by open-loop control input with nonlinear model. The guidance and control command was constructed by reference trajectory which can be obtained with no control. Finally, the performance of the guidance and control law was evaluated through Monte-carlo simulation. The CEP(Circular Error Probability) was obtained by considering the errors in muzzle velocity, aerodynamic coefficient, wind, elevation and azimuth angle and density.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권2호
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• pp.346-363
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• 2015

We have performed integrated dynamics modeling for a supercavitating vehicle. A 6-DOF equation of motion was constructed by defining the forces and moments acting on the supercavitating body surface that contacted water. The wetted area was obtained by calculating the cavity size and axis. Cavity dynamics were determined to obtain the cavity profile for calculating the wetted area. Subsequently, the forces and moments acting on each wetted part-the cavitator, fins, and vehicle body-were obtained by physical modeling. The planing force-the interaction force between the vehicle transom and cavity wall-was calculated using the apparent mass of the immersed vehicle transom. We integrated each model and constructed an equation of motion for the supercavitating system. We performed numerical simulations using the integrated dynamics model to analyze the characteristics of the supercavitating system and validate the modeling completeness. Our research enables the design of high-quality controllers and optimal supercavitating systems.

• Structural Monitoring and Maintenance
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• 제7권2호
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• pp.125-147
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• 2020

Damage detection of structures is one of the most important topics in structural health monitoring. In practice, the response is not available at all structural degrees of freedom, and due to the installation of sensors at some degrees of freedom, responses exist only in limited number of degrees of freedom. This paper is investigated the damage detection of structures by applying two approaches, AllDOF and Dynamic Condensation Method (DCM), based on the Modified Modal Strain Energy Method (MMSEBI). In the AllDOF method, mode shapes in all degrees of freedom is available, but in the DCM the mode shapes only in some degrees of freedom are available. Therefore by methods like the DCM, mode shapes are obtained in slave degrees of freedom. So, in the first step, the responses at slave degrees of freedom extracted using the responses at master degrees of freedom. Then, using the reconstructed mode shape and obtaining the modified modal strain energy, the damages are detected. Two standard examples are used in different damage cases to evaluate the accuracy of the mentioned method. The results showed the capability of the DCM is acceptable for low mode shapes to detect the damage in structures. By increasing the number of modes, the AllDOF method identifies the locations of the damage more accurately.

• 대한조선학회논문집
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• 제29권3호
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• pp.125-130
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• 1992

실제 해상에서 운항중인 선박의 6자유도 운동 및 해상의 파도를 계측할 수 있는 시스템을 개발하였다. 이 시스템은 Miles의 방법에 따라 7개의 가속도계로 선체의 운동을 계측하고, 초음파 파고계를 이용하여 선수부에서의 상대운동을 계측하여 상대운동에서 선체운동을 소거함으로써 해상에서의 파랑에 관한 정보(파고 및 주기)를 해석할 수 있다. 모형시험을 수행하여 개발된 시스템의 우수성을 확인하였으며, 원격조종 모형시험시 운동계측기로의 적용가능성도 발견하였다.

• 전기학회논문지
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• 제66권7호
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• pp.1123-1130
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• 2017

This paper deals with the dynamic surface control based tracking control for a drone equipped with a 2-DOF manipulator. First, the dynamics of drone and 2-DOF manipulator are derived separately. And we obtain the combined model of a drone equipped with a manipulator considering the inertia and the reactive torque generated by a manipulator. Second, a dynamic surface control based attitude and altitude control method is presented. Also, multiple sliding mode control based position control method is presented. The system stability and convergence of tracking errors are proven using Lyapunov stability theory. Finally, the simulation results are given to verify the effectiveness of the proposed control method.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.502-507
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• 2016

In this paper, we propose a tracking control method for a quadrotor equipped with a 2-DOF manipulator, which is based on the multiple sliding surface control (MSSC) method. To derive the model of a quadrotor equipped with a 2-DOF manipulator, we obtain the models of a quadrotor and a 2-DOF manipulator based on the Lagrange-Euler formulation separately - and include the inertia and the reactive torque generated by a manipulator when these obtained models are combined. To make a quadrotor equipped with a manipulator track the desired path, we design a double-loop controller. The desired position is converted into the desired angular position in the outer controller and the system's angle tracks the desired angular position through the inner controller based on the MSSC method. We prove that the position-tracking error asymptotically converges to zero based on the Lyapunov stability theory. Finally, we demonstrate the effectiveness of the proposed control system through a computer simulation.

• 한국정밀공학회지
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• 제18권12호
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• pp.66-72
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• 2001

In this paper, by using pseudo-inverse matrix of the spatial redundant flexible manipulators, a position control method and its effect in vibration suppression was presented. Vibration suppression control was developed using lumped mass spring model of the flexible manipulators. With 2 elastic links and 7 rotory joint manipulator ADAM, (1)position control for no redundancy, and (2)position control for one redundant DOF(degree of freedom) were tested. The objective of this experiment is to show the effect of position control, using pseudo-inverse matrix. toward the improvement of operation, and at the same time, to reduce the vibration of the link and the magnitude of the joint torque.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.87-96
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• 2013

This paper shows how the performance of an ESC(Electronic Stability Control) system can be affected by the selection of in-vehicle network protocols such as CAN or FlexRay. The vehicle control performance under ESC operation is analyzed by EILS(ECU-In-the-Loop Simulation). The experimental set-up for the EILS of the ESC system consists of two 32-bit microcontroller boards communicated with CAN or FlexRay protocols. A 7-DOF vehicle model and an ESC algorithm with 2-DOF reference vehicle model are implemented on each microcontroller respectively. It is shown by experimental results that the ESC system using the FlexRay protocol can achieve better performance than that using the CAN protocol for a fast and accurate lane changing.

• 동력기계공학회지
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• 제7권3호
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• pp.61-68
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• 2003

Steering characteristics is an important factor in the evaluation of vehicle quality. To estimate steering characteristics in the vehicle conceptual design stage, vehicle dynamics simulation methods are very efficient. However, it is often difficult to simulate vehicle dynamics for the specific driving scenarios in open-loop driving environment. An efficient driver-in-the-loop vehicle model will be efficient for this job. A good tire model is also very important for the accurate vehicle dynamics simulation. In this research, a driver model is used to simulate vehicle steering dynamics for a 8-dof vehicle model with STI(Systems Technology, Inc.) tire model. For the demonstration of this model, a SUV(sports utility vehicle) and a sedan were simulated.

• 대한기계학회논문집A
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• 제32권7호
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• pp.549-555
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• 2008

Analytical method to analyze the tolerance effect on the vehicle ride comfort is suggested in this paper. Ride comfort is one of the most important performance indices which decide the vehicle design quality. In general, the ride comfort is affected by the variations of parameters of a vehicle model. Therefore, the effects of the parameters on the ride comfort need to be evaluated statistically based on the whole-body vibration of the vehicle. In this paper, weighted RMS values of the acceleration PSD of a seat position are used to define the ride comfort. The equations of motion and the sensitivity equations are derived based on a 5-DOF vehicle model. By employing the sensitivity information of the acceleration at the seat position, the tolerance effect on the vehicle ride comfort could be effectively analyzed.