• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.466-479
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• 2006

This paper addresses a formation navigation issue for a group of mobile robots passing through an environment with either static or moving obstacles meanwhile keeping a fixed formation shape. Based on Lyapunov function and graph theory, a NN formation control is proposed, which guarantees to maintain a formation if the formation pattern is $C^k,\;k\geq1$. In the process of navigation, the leader can generate a proper trajectory to lead formation and avoid moving obstacles according to the obtained information. An evolutionary computational technique using particle swarm optimization (PSO) is proposed for motion planning so that the formation is kept as $C^1$ function. The simulation results demonstrate that this algorithm is effective and the experimental studies validate the formation ability of the multiple mobile robots system.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.31-36
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• 2005

Intelligent Space (iSpace) is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment comes to have intelligence. In iSpace, the locations of multiple humans and other objects are obtained and tracked by using multiple camera and color-based method. In addition, we describe a context-aware information system which is based on Spatial-Knowledge-Tags (SKT). SKT system enables humans to access information and data by using spatial location of human and stored information in storage. The proposed tracking method is applied to the intelligent environment and its performance is verified by the experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1044-1047
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• 2005

In this paper, we present the strategy of object search for distributed autonomous robotic systems (DARS). The DARS are the systems that consist of multiple autonomous robotic agents to whom required functions are distributed. For instance, the agents should recognize their surrounding at where they are located and generate some rules to act upon by themselves. In this paper, we introduce the strategy for multiple DARS robots to search a hidden object at the unknown area. First, we present an area-based action making process to determine the direction change of the robots during their maneuvers. Second, we also present Q learning adaptation to enhance the area-based action making process. Third, we introduce the coordinate system to represent a robot's current location. In the end of this paper, we show experimental results using hexagon-based Q learning to find the hidden object.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1749-1752
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• 2005

For online high accurate reconstruction of an object from an visual information, a linear reconstruction method for multiple images is popular. Basically this method needs many cameras or many different screen shots from different view points. This method, however, has the benefit of less calculation and is adequate for a real time application by comparing other popular method. In this paper, online reconstruction system using more than three cameras is treated. An evaluation method of cameras' position, and of the number is derived for the linear reconstruction method. To decrease errors that are caused from skew of lens, positional error between corresponding points is taken into consideration on the evaluation. The proposed evaluation method enables estimation of the adequate number of cameras and then of feasible view locations. Additionally, repeating search of epipolar lines enables estimation of the hidden point. Comparing with result of an average error analysis, it was confirmed that the proposed methods works effectively.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1524-1529
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• 2005

Particle filter is a kind of conditional density propagation model. Its similar characteristics to both selection and mutation operator of evolutionary strategy (ES) due to its Bayesian inference rule structure, shows better performance than any other tracking algorithms. When a new object is entering the region of interest, particle filter sets which have been swarming around the existing objects have to move and track the new one instantaneously. Moreover, there is another problem that it could not track multiple objects well if they were moving away from each other after having been overlapped. To resolve reinitialization problem, we use competitive-AVQ algorithm of neural network. And we regard interfarme difference (IFD) of background images as potential field and give priority to the particles according to this IFD to track multiple objects independently. In this paper, we showed that the possibility of real-time object tracking as intelligent interfaces by simulating the deformable contour particle filters.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1192-1195
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• 2005

This paper presents the realization of a multiple-input maximum circuit, which is operated in a current-mode. The proposed circuit operates with bi-directional input current signal and employs 5n+4 transistors for n inputs. The realization method is suitable for fabrication using CMOS technology. The proposed circuit is useful building block for the real-time systems. The performances of the proposed bi-directional maximum circuit were studied using the PSPICE analog simulation program. The simulation results verified the circuit performances are agreed with the expected values.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.103.5-103
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• 2001

This paper presents a visual feedback system that controls a micromanipulator using multiple microscopic vision information. The micromanipulation stations basically have optical microscope. However the single field-of-view of optical microscope essentially limits the workspace of the micromanipulator and low dept-of-field makes it difficult to handle 3D-shaped micro objects. The system consists of a stereoscopic microscope, three CCD cameras, the micromanipulator and personal computer. The use of stereoscopic microscope which has long working distance and high depth-of-field with selective field-of-view improves the recognizability of 3D-shaped micro objects and provides a method for overcoming several essential limitations in micromanipulation. Thus, visual feedback information is very important in handling micro objects for overcoming those limitations and provides a mean for the ...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.100.3-100
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• 2002

This paper presents the method for detection and tracking of multiple humans robustly in mobile platform. The perception of human is performed in real time through the processing of images acquired from a moving stereo vision system. We performed multi-cue integration such as human shape, skin color and depth information to detect and track each human in moving background scene. Human shape is measured by edge-based template matching on distance transformed image. Improving robustness for human detection, we apply the human face skin color in HSV color space. And we could increase the accuracy and the robustness in both detection and tracking by applying random sampling stochastic estimati...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.50.5-50
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• 2002

In this paper, we propose a method using neural network (NN) to improve the motion control of a decentralized control system for cooperative transportation. In our former work, a decentralized control system for transporting a single object by multiple nonholonomic mobile robots has been developed. One of these mobile robots acts as a leader, who is assumed to be able to plan and to manipulate the omnidirectional motion of the object. Other robots, referred to as followers, cooperatively transport the object by keeping a constant position relative to the object. in this work, it is assumed that the leader can not only plan but also broadcast the local velocity of the object. Then...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.45.4-45
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• 2002

In EIT, an array of disjoint electrodes is attached on the boundary of the object and a set of small alternating electrical currents is injected into the object through these electrodes, and then the corresponding set of voltages is measured on the same array of the electrodes. The objective in EIT is to estimate the resistivity distribution inside the object based on the set of measured voltages and injected currents. In this paper, we proposed a new dynamic EIT reconstruction scheme based on the interacting multiple model (IMM) algorithm. The main contribution of the proposed scheme is that multiple models are employed for the state evolution to get around the modeling uncertainty. Extensi...