• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.26-26
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• 1998

다련장 로켓과 같이 무유도로서 대량 발사하는 탄을 설계함에 있어서 탄의 성능을 예측하기 위해서는 사거리와 고도 해석을 통해 체계 성능을 분석하고 탄의 특성 및 외부요소의 변화 가능성을 고려하여 탄착 정확도에 대한 해석을 수행하여야 한다. 탄착 정확도는 설계하고자하는 무기체계의 신뢰성을 평가하는 최종단계이므로 매우 중요한 factor이다. 다련장 로켓과 같은 무유도 로켓의 탄착 정확도를 평가하는 가장 좋은 방법은 많은 발수의 시료를 발사하여 획득한 데이터를 바탕으로 평가하는 것이다. 그러나 이 방법은 예비 설계시에는 적용할 수 없으며 제작이 되었다 하더라도 비용이 많이 들기 때문에 적용하기 무척 어렵다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.1
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• pp.41-51
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• 2018

Downwash from helicopter rotor blades and external winds from various maneuvering make an unguided rocket change its trajectory and range. For the prediction of the trajectory and range, it is essential to consider the downwash effect. In this study, an algorithm was developed to calculate 6-Degree-Of-Freedom(6 DOF) forces and moments exerting on the rocket, and total flight trajectory of a 2.75-inch unguided rocket in a helicopter downwash flow field. Using Actuator Disk Model(ADM) analysis result, the algorithm could analyze the entire trajectory in various initial launch condition such as launch angle, launch velocity, and external wind. The algorithm that considered the interference between a fuselage and external winds could predict the trajectory change more precisely than inflow model analysis. Using the developed algorithm, the attitude and trajectory change mechanism by the downwash effect were investigated analyzing the effective angle of attack change and characteristics of pitching stability of the unguided rocket. Also, the trajectory and range changes were analyzed by considering the downwash effect with external winds. As a result, it was concluded that the key factors of the rocket range change were downwash area and magnitude which effect on the rocket, and the secondary factors were the dynamic pressure of the rocket and the interference between a fuselage and external winds. In tailwind case which was much influential on the range characteristics than other wind cases, the range of the rocket rose as increasing the tailwind velocity. However, there was a limit that the range of the rocket did not increase more than the specific tailwind velocity.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.58-65
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• 2020

In this paper, the combat effectiveness of ship guidance rockets to counter the threat of multiple USV(Unmanned Surface Vehicle) was analyzed in three cases. The probability of sinking a number of USVs approaching by distance was compared using various weapon systems and guided rocket systems installed on the naval vessels. As a result of the analysis, it was found that the combat effectiveness of the guided rocket was improved compared to the close defense system of the anti-ship missile installed on the naval vessels.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.315-327
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• 2017

In this paper, we present a method for estimating of position and velocity of a moving target by using the range and the bearing measurements from multiple sensors of aiming unit. In many cases, conventional low cost gyro sensor and a portable laser range finder(LRF) degrade the accuracy of estimation. To enhance these problems, we propose two methods. The first is background image tracking and the other is principal component analysis (PCA). The background tracking is used to assist the low cost gyro censor. And the PCA is used to cope with the problems of a portable LRF. In this paper, we prove that our method is robust with respect to low-frequency, biased and noisy inputs. We also present a comparison between our method and the extended Kalman filter(EKF).

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.4
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• pp.74-80
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• 2014

This paper describes the development of the dual-thrust flight motor for enhancing the hit probability of unguided rockets. We designed dual-thrust flight motor by shape modification of the double base propellant with high burning rate, and confirmed the dual-thrust performance by static firing tests. The test results showed the thrust ratio of about 1:7.6 between sustaining phase and boosting phase, and had a quietly normal dual-thrust characteristics. And the results showed that there was not the fire extinction phenomenon of propellant due to the pressure drop.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.47-60
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• 2018

In this paper, we proposed a method for eliminating aiming error of unguided anti-tank rocket using improved target tracking. Since predicted fire is necessary to hit moving targets with unguided rockets, a method was proposed to estimate the position and velocity of target using fire control system. However, such a method has a problem that the hit rate may be lowered due to the aiming error of the shooter. In order to solve this problem, we used an image-based target tracking method to correct error caused by the shooter. We also proposed a robust tracking method based on TLD(Tracking Learning Detection) considering characteristics of the FCS(Fire Control System) devices. To verify the performance of our proposed algorithm, we measured the target velocity using GPS and compared it with our estimation. It is proved that our method is robust to shooter's aiming error.