• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.32-37
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• 2017

For automated vehicles, the integrity and fault tolerance of environment perception sensor have been an important issue. This paper presents radar, vision, lidar(laser radar) fusion-based fault detection algorithm for autonomous vehicles. In this paper, characteristics of each sensor are shown. And the error of states of moving targets estimated by each sensor is analyzed to present the method to detect fault of environment sensors by characteristic of this error. Each estimation of moving targets isperformed by EKF/IMM method. To guarantee the reliability of fault detection algorithm of environment sensor, various driving data in several types of road is analyzed.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.465-468
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• 2003

In industry areas, a lot of factories and process plants need network for processing data acquired from field and for communicating between sensors or actuators or field controllers. Most of the industry networks are based on wired solutions. But, recently, a lot of factories and process plants are moving into wireless solutions since they have some advantages compared with wired one. In this paper we first review the characteristics of wired and wireless network technologies and introduce the new technique called wireless sensor network (WSN). And then we describe the wireless sensor node system designed by us for WSN which has the ability of small size, flexibility and low-power consumption and embedded into the Bar-code scanner to communicate each other. Finally, we conclude this paper by showing that wireless industry network can be constructed with wireless sensor network without large change of traditional wired topologies through experiment using wireless sensor nodes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.126-148
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• 2015

Different from the existing works on coverage problems in wireless sensor networks (WSNs), this paper considers the exposure-path prevention problem by using the percolation theory in three dimensional (3D) WSNs, which can be implemented in intruder detecting applications. In this paper, to avoid the loose bounds of critical density, a bond percolation-based scheme is proposed to put the exposure-path problem into a 3D uniform lattice. Within this scheme, the tighter bonds of critical density for omnidirectional and directional sensor networks under random sensor deployment-a 3D Poisson process are derived. Extensive simulation results show that our scheme generates tighter bounds of critical density with no exposure path in 3D WSNs.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.4
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• pp.33-40
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• 2005

This paper represents the stable path recognition by the ultrasonic sensor which gathers navigation environments and the monocular image sensor which generates the self localization information of mobile robot. The proposed ultrasonic sensor and vision camera system recognizes the target and extracts parameters for generating the world map and self localization. Therefore, this paper has developed an indoor mobile robot and has stably demonstrated in a corridor environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.395-402
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• 2007

This paper considers about the tilt measurement of lens module with multiple lenses. The tilt between lenses in lens module and barrel or between image sensor and barrel can be measured precisely with the proposed algorithm. The magnitude and direction of the tilt vector of lens and image sensor can be measured from the best focal surface. The selecting and setting of image sensor, test chart, image sensor centering to lens module, axis align, focus measure method are also explained to get highly precise tilt results. The proposed algorithm is verified with the lens module inspection system we developed, and the experimental results show that the tilt measure proposed in this paper is robust and precise. With the proposed tilt measurement algorithm, the tilt of an image sensor and any other lens which intermediates light can be measured.

• Journal of Korea Multimedia Society
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• v.18 no.12
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• pp.1538-1546
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• 2015

This paper proposes a virtual sleep sensor in order to monitor sleep disorder for an individual, and presents a therapy service model for the sleep management. PSQI score is usually used clinically to evaluate the levels of sleep disorder. However, The PSQI score which was only gleaned through an interview on a questionnaire can not be accurate because it is difficult to remember something about sleep during the last month. In order to resolve this problem, This paper presented the virtual sleep sensor that has a protocol to receive sleep information through physical sensors and smart algorithm. In addition, the virtual sleep sensor can be contributed to a service model for sleep therapy when it is combined with light therapy and aromatherapy. Finally, based on the findings of the experiment, its effectiveness was confirmed in the proposed model.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.14-23
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• 2005

In this paper we propose a sensor fusion method for the navigation algorithm which can be used to estimate state vectors such as position and velocity for its motion control using multi-sensor output measurements. The output measurement we will use in estimating the state is a series of known multi-sensor asynchronous outputs with measurement noise. This paper investigates the Extended Kalman Filtering method to merge asynchronous heading, heading rate, velocity of DVL, and SSBL information to produce a single state vector. Different complexity of Kalman Filter, with. biases and measurement noise, are investigated with theoretically data from MOERI's SAUV. All levels of complexity of the Kalman Filters are shown to be much more close and smooth to real trajectories then the basic underwater acoustic navigation system commonly used aboard underwater vehicle.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.3
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• pp.12-19
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• 2003

This paper describes the design of a robot's hand with two fingers for stably grasping an unknown object, and the development of a 3-axis force sensor for which is necessary to constructing the robot's fingers. In order to safely grasp an unknown object using the robot's fingers, they should measure the forces in the gripping and in the gravity directions, and control the measured forces. The 3-axis force sensor should be used for accurately measuring the weight of an unknown object in the gravity direction. Thus, in this paper, the robot's hand with two fingers for stably grasping an unknown object is designed, and the 3-axis force sensor is newly modeled and fabricated using several parallel-plate beams.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.146-151
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• 2001

The importance of sensing the force and torque with arbitrary direction and magnitude is becoming more crucial for robotic applications and manufacturing automations. Recently, several designs of a multi-axis force-torque sensor have been tried to sense this force and torque. This paper deals mainly with the signal processing of a six-axis force-torque sensor using cross-shaped elastic structures with circular holes. In this paper, we show principle of sensing force and torque, the signal processing methodology, and efficient methods of seeking strain gage positions in the sensor structure. The validity of the proposed method is shown via experiments.

• Journal of the Korea Society of Computer and Information
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• v.24 no.8
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• pp.131-136
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• 2019

A wireless sensor network (WSN) consists of several sensor nodes and usually one base station. In this paper, we propose a method to monitor topics using a wireless sensor network. Fire threatens people, animals, and plants, and it takes a lot of recovery time when a fire occurs. For this reason, it is necessary to use a fire monitoring system that is easy to configure and fast to avoid fire. In this paper, we propose a fast and easily reliable fire detection system using WSN. The wireless node of the WSN measures the temperature and brightness around the node. The measured information is transferred to the workstation and to the base station. The workstation analyzes current and historical data records to monitor the fire and notify the manager.