• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.4
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• pp.193-203
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• 2014

This paper implements a weather monitoring system based on wireless sensor network. The wireless sensor network protocol proposed in this paper adopts a TDMA styled MAC. The protocol is designed to balance the energy consumption among sensor nodes. Other purposes of the protocol are to avoid the hidden terminal problem in 2-hop star topology, and to allow a CSMA styled communication in a given time slot to support emergent messages. Also, this paper develops the hardware of sensor node, gateway and electric generator based on solar and windy energy. The test results on the implemented system show that the time slot of each node is shifted in circular manner to balance the waiting time for transmission, and the reliability of wireless communication is over 99%.

• Journal of Sensor Science and Technology
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• v.26 no.5
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• pp.353-359
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• 2017

This paper describes the design and manufacture of a ankle two-axis force sensor of a walking assist robot for hemiplegic leg patient. The walking assist robot for the hemiplegic leg patient can safely control the robot by detecting whether the foot wearing the walking assist robot is in contact with the obstacle or not. To do so, a two-axis force sensor should be attached to the robot's ankle. The sensor is used to measure the force of a patient's ankle lower part. The two-axis force sensor is composed of a Fx force sensor, a Fy force sensor and a pulley, and they detect the x and y direction forces, respectively. The two-axis force sensor was designed using by FEM(Finite Element Method), and manufactured using by strain-gages. The characteristics experiment of the two-axis force sensor was carried out respectively. The test results indicated that the interference error of the two-axis force sensor was less than 1.2%, the repeatability error and the non-linearity of the two-axis force sensor was less than 0.04% respectively. Therefore, the fabricated two-axis force sensor can be used to measure the force of ankle lower part in the walking assist robot.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.325-332
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• 2017

The engine cooling system is a device that maintains the temperature in the engine room at an appropriate level by driving a cooling fan when the temperature in the engine room generated during the vehicle operation occurs over a certain temperature. In recent years, the vehicle cooling system has changed to an electronic system. Therefore, in this paper, we design and develop a hall sensor based electronic engine cooling system. In this paper, a hall sensor module and an actuator module for engine cooling control system are designed. In order to verify the performance of the designed module, the magnetic field control was verified through the simulation of the diameter and the head of the coil.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.6
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• pp.331-338
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• 2012

This paper presents a wireless sensor network protocol aimed for artificial structure monitoring. The proposed protocol enables the sensor network to operate at a low duty cycle for reducing power consumption with a high degree of synchronization accuracy. It also enables event-triggered measurement of environmental information with a high sampling rate and the transmission of the measured data with a low latency. The feasibility of the proposed protocol is demonstrated through experiments involving three sensor nodes and a sink node. Though a tunnel health monitoring was considered in the paper, the proposed protocol can be easily adopted in other areas.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.608-613
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• 2002

In this paper we developed the MPC sensor for steering control and steering control of the AGVDS(Autonomous Guided Vehicle Driving System) for Durability test. Among durability tests, the accelerated durability test has been widely used to evaluate the durability of vehicle structure and chassis parts in a short period of time on the designed road that has severe surface conditions. However it increased the drivers fatigue mainly caused by the severe driving conditions. The driver's difficulty to maintain the constant speed and control the steering wheel reduces the reliability of test results. In addition to the general detecting sensor for steering control was restricted by surrounding condition. So we need to develop steering control sensor was robust in the bad driving condition. In this paper we developed steering control sensor using magnetic induction which is robust in the bad driving condition and implemented the AGVDS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.229-232
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• 2002

This paper describes the development of robot's finger 3-axis force sensor that detects the Fx, Fy, and Fz simultaneously fur stably grasping an unknown object. In order to safely grasp an unknown object using the robot's fingers, they should detect the force of gripping direction and the force of gravity direction, and perform the force control using the detected farces. The 3-axis force sensor that detects the Fx, Fy, and Fz simultaneously should be used for accurately detecting the weight of an unknown object of gravity direction. Thus, in this paper, robot's finger for stably grasping an unknown object is developed. And, the 3-axis farce sensor that detects the Fx, Fy, and Fz simultaneously fur constructing a robot's finger is newly modeled using several parallel-plate beams, and is fabricated. Also, it is calibrated, and evaluated.

• Tribology and Lubricants
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• v.24 no.1
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• pp.34-43
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• 2008

In this paper, an actively controlled aerostatic bearing is studied to overcome the defects of air bearing such as low stiffness and damping coefficients. The actively controlled aerostatic bearing is composed of aerostatic bearings, non-contact type of displacement sensors, piezoelectric actuators and controllers. The cylindrical capacitance sensor (CCS) is used as the displacement sensor. The reason for using CCS instead of the commercial gap sensor is that it can give us the pure error motion of the spindle because it removes the roundness error or the geometric errors in the spindle. The controller is designed by the state space equation and quadratic optimal control theory. The characteristic data of the actively controlled aerostatic bearing system in the frequency domain are presented and the stiffness and damping coefficients of the bearing are mentioned. This paper shows the possibility to reduce the motion error up to 6000 rpm.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.4
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• pp.167-174
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• 2018

Presently, the exploration of an unknown environment is an important task for the development of mobile robots and mobile robots are navigated by means of a number of methods, using navigating systems such as the sonar-sensing system or the visual-sensing system. To fully utilize the strengths of both the sonar and visual sensing systems, In mobile robotics, multi-sensor data fusion(MSDF) became useful method for navigation and collision avoiding. Moreover, their applicability for map building and navigation has exploited in recent years. In this paper, as the preliminary step for developing a multi-purpose autonomous carrier mobile robot to transport trolleys or heavy goods and serve as robotic nursing assistant in hospital wards. The aim of this paper is to present the use of multi-sensor data fusion such as ultrasonic sensor, IR sensor for mobile robot to navigate, and presents an experimental mobile robot designed to operate autonomously within indoor environments. Simulation results with a mobile robot will demonstrate the effectiveness of the discussed methods.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.206-208
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• 2005

Wireless sensor network's value has increased greatly in recent years in the fields of Ubiquitous Computing that function as solution to reduce both the limitation and collision about RFID Technology. The research for wireless sensor network technology is proceeding with the research for various sensor nodes, powerful routing algorithms, securities for data transmission, and valid applications. This paper suggests that we make the new multi-hop routing algorithm using RSS in order to implement enhanced multi-hop routing algorithm. This paper should demonstrate that the routing algorithm using suggested RSS is superior to routing algorithm based on established BSDV(Destination Sequenced Distance Vector).

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.375-377
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• 2009

This paper researched the algorithm of robot's walking and action on the basis of robot studied and made at our laboratory and studied how to efficiently control the robot joints by developing wireless Digital Servo Motor using Zigbee Sensor Network Module which is using at wide part recently. I realized the stable walking by adopt Press Sensor at the bottom of robot foot to get stability of walking. Also I let the algorithm calculate the robot movement to make the joint motion and monitored the robot walk to its motion. At this Paper, I studied the method organizing the motion by the each robot walking and measuring the torque applying to the joint. And I also knew that it is possible to make its control and construct hardware more conveniently than them of the existing studied and controling 2Legs Walking Robot by applying it at walking robot and developing wireless servo motor by Zirbee Sensor Network.