• 전자공학회논문지B
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• 제33B권11호
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• pp.11-21
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• 1996

Robot manipulators constituing multi-robot system must exert the desired motion force on an object to preserve tghe fine motion of it. The forces exerte on an object by the end-effectors of multi-inducing force and the internal force. Here, motion-inducing force effects the motion of an object, but internal force as lies in the null space of an object coordinate can't effect it. The motion of an object can't track exactly the desired motion by the effect of an object, but internal force as lies in the null space of the effect of internal force component, therefore internal force component must be considered. In this paper, first, under assumption that we can estimate exactly the parameter of dynamics, we constitute paper, first, under assumption that we can estimate exactly the parameter of dynamics, we constitute the controller concerning internal force. And we obtain the internal force as projecting force sensor readings onto the space spanned by null basis set of jacobian matrix. Using the resolved acceleration control method and the fact that internal force lies in the null space of jacobian matrix, we construct the robust control law to preserve the robustness with respect to the uncertainty of mainpulator parameters.

• IEIE Transactions on Smart Processing and Computing
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• 제1권3호
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• pp.125-132
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• 2012

This paper proposes an automatic object segmentation and background composition method for video communication over consumer mobile phones. The object regions were extracted based on the motion and color variance of the first two frames. To combine the motion and variance information, the Euclidean distance between the motion boundary pixel and the neighboring color variance edge pixels was calculated, and the nearest edge pixel was labeled to the object boundary. The labeling results were refined using the morphology for a more accurate and natural-looking boundary. The grow-cut segmentation algorithm begins in the expanded label map, where the inner and outer boundary belongs to the foreground and background, respectively. The segmented object region and a new background image stored a priori in the mobile phone was then composed. In the background composition process, the background motion was measured using the optical-flow, and the final result was synthesized by accurately locating the object region according to the motion information. This study can be considered an extended, improved version of the existing background composition algorithm by considering motion information in a video. The proposed segmentation algorithm reduces the computational complexity significantly by choosing the minimum resolution at each segmentation step. The experimental results showed that the proposed algorithm can generate a fast, accurate and natural-looking background composition.

• 한국멀티미디어학회논문지
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• 제19권4호
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• pp.774-779
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• 2016

The conventional methods using color signal for tracking the movement of the object require a lot of calculation and the performance is not accurate. In this paper, we propose a method to effectively track the moving objects using the depth information from a depth camera. First, it separates the background and the objects based on the depth difference in the depth of the screen. When an object is moved, the depth value of the object becomes blurred because of the phenomenon of Motion Blur. In order to solve the Motion Blur, we observe the changes in the characteristics of the object (the area of the object, the border length, the roundness, the actual size) by its velocity. The proposed algorithm was implemented in the simulation that was applied directly to the tracking of a golf ball. We can see that the estimated value of the proposed method is accurate enough to be very close to the actual measurement.

• 한국지능시스템학회논문지
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• 제21권1호
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• pp.106-111
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• 2011

영상 기반의 움직이는 객체의 검출 및 추적은 실시간 감시 시스템이나 영상회의 시스템 등에서 널리 사용되어지고 있다. 또한 인간-컴퓨터 상호 작용(Human-Computer Interface)이나 인간-로봇 상호 작용(Human-Robot Interface)으로 확장되어 사용할 수 있기 때문에 움직이는 객체의 추적 기술은 중요한 핵심 기술 중에 하나이다. 특히 다중 객체의 움직임 환경에서 특정 객체의 움직임만을 추적할 수 있다면 다양한 응용이 가능할 것이다. 본 논문에서는 파티클 필터를 이용한 특정 객체의 움직임 추적에 관하여 연구 하였다. 실험 결과들로부터 파티클 필터를 이용한 단일 객체의 움직임 추적과 다중 객체의 움직임 환경에서 특정 객체의 움직임 추적에서 좋은 결과를 얻을 수 있었다.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.81-85
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• 1991

In this paper, we present a motion compensated video compression method based on both block and object motions. A simplified objectoriented motion parameter is estimated from the block based motion vectors. A decision rule for the global or local MCP modes is established. Simulation results show that the proposed method has lower bit-rates than the BMA based method at the same reconstruction errors.

• IEIE Transactions on Smart Processing and Computing
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• 제5권6호
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• pp.375-382
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• 2016

This paper realizes control of the motion of a swimming robot fish in order to implement an underwater robot fish aquarium. And it implements positional control of a two-axis trajectory path of the robot fish in the aquarium. The performance of the robot was verified though certified field tests. It provided excellent performance in driving force, durability, and water resistance in experimental results. It can control robot motion, that is, it recognizes an object by using an optical flow object-detecting algorithm, which uses a video camera rather than image-detecting sensors inside the robot fish. It is possible to find the robot's position and control the motion of the robot fish using a radio frequency (RF) modem controlled via personal computer. This paper proposes realization of robot fish motion-tracking control using the optical flow object-detecting algorithm. It was verified via performance tests of lead-lag action control of robot fish in the aquarium.

• International Journal of Control, Automation, and Systems
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• 제2권2호
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• pp.228-237
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• 2004

This paper provides a motion analysis of soft-fingertip object manipulation tasks by presenting a dynamic model of multi-fingered object manipulations with soft fingertips. It is fundamentally observed that soft fingertips employed in a multi-fingered hand generate some deformation effects during the manipulation process and also that those effects are closely related to the behavior of the manipulated object. In order to analyze the motion of using soft fingertips, a dynamic manipulation control scheme is presented. Simulation and experimental results demonstrate the motion of soft-fingertips applied in object manipulating tasks and are further used to discuss the characteristics of soft-fingertip motions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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• pp.231-234
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• 2002

This paper proposes a new approach to extract contour of moving object from compressed video stream. We segment the area of moving object by using motion vector and extract the motion object block from it. And then we describe the connectivity direction of outline moving block, detect the edge related to connectivity direction in the block and finally obtain the contour by connecting the edges. This can divide the moving object only with motion vector and detect the exact contour on the basis of the edge automatically. Also, we can reduce spending time using motion block and remove the noise with directional edge. The experimental results demonstrate the accurate and effective qualify of the proposed method.

• 전기학회논문지
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• 제62권12호
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• pp.1737-1743
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• 2013

This paper proposes the range and velocity of the object estimation method using a moving camera. Structure and motion (SaM) estimation is to estimate the Euclidean geometry of the object as well as the relative motion between the camera and object. Unlike the previous works, the proposed estimation method can relax the camera and object motion constraints. To this end, we arrange the dynamics of moving camera-moving object relative motion model in an appropriate form such that the nonlinear observer can be employed for the SaM estimation. Through both simulations and experiments we have confirmed the validity of the proposed estimation algorithm.

• 한국산학기술학회논문지
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• 제6권4호
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• pp.349-354
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• 2005

컴퓨터 비전에 관한 연구는 인간의 시각 능력을 대신할 시스템을 구축하고자 하는 것으로 특히 이동 객체추적 시스템은 최근 중요한 연구 분야로 대두되고 있다. 본 연구에서는 움직임 추정에 기반 한 단일 이동객체를 추적할 수 있는 시스템을 제안하였다. 추적 시스템은 차영상 기법을 이용하여 객체의 움직임을 추정하곤 카메라의 Pan/Tilt를 제어함으로서 이동 객체를 추적할 수 있도록 하였다. 구현된 시스템은 영상획득 및 전처리 단계, 움직임 추정 단계, 객체 추적 단계로 구성하였다. 실시간 추적 실험을 실시한 결과 이동 객체의 움직임을 추정할 수 있었고, 추적 과정에서도 객체를 일어버리지 앉고 정상적으로 추적할 수 있었다.