• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.167-174
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• 2011

This paper proposed a smart-phone based user movement state identification algorithm. Then movement state of the user is identified by calculating the location and moving speed using the GPS sensor, and detailed movement methods are identified by analyzing the data from the Orientation sensor. In this study, two sensors of the smart-phone were used to implement the user movement status identification algorithm and to perform tests. The reference values of the speed and orientation required for the identification of the movement type were defined based on the experimental data. The results of this study showed that the movement type of a smart-phone user can be identified using the user movement state identification algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1915-1923
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• 2011

For automated guidance control of a magnetically guided-all wheel steered vehicle, it is necessary to have information about position and orientation of the vehicle, and deviations from the reference path in real time. The magnet reference system considered here consists of three magnetic sensors mounted on the vehicle and magnetic markers, which are non-equidistantly buried in the road. This paper presents an observer to estimate such position and orientation at the center of gravity of the vehicle. This algorithm is based on the simple kinematic model of vehicle and uses the data of wheel velocity, steering angle, and the discrete measurements of marker positions. Since this algorithm requires the exact values of initial states, we have also proposed an algorithm of determining the initial position and orientation from the 16 successive magnet pole data, which are given by the magnetic measurement system(MMS). The proposed algorithm is capable of continuing to estimate for the case that the magnetic sensor fail to measure up to three successive magnets. It is shown through experimental data that the proposed algorithm works well within permissible error range.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.89-98
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• 2005

Fingerprint segmentation and ridge orientation estimation algorithms with images from a mobile camera are proposed. The fingerprint images from a mobile camera are quite different from those from conventional sensor, called touch based sensor such as optical, capacitive, and thermal. For example, the images from a mobile camera are colored and the backgrounds or non-finger regions are very erratic depending on how the image capture time and place. Also the contrast between ridge and valley of a mobile camera image are lower than that of touch based sensor image. To segment fingerprint region, we first detect the initial region using color information and texture information. The LUT (Look Up Table) is used to model the color distribution of fingerprint images using manually segmented images and frequency information is extracted to discriminate between in focused fingerprint regions and out of focused background regions. With the detected initial region, the region growing algerian is executed to segment final fingerprint region. In fingerprint orientation estimation, the problem of gradient based method is very sensitive to outlier that occurred by scar and camera noise. To solve this problem, we propose a robust regression method that removes the outlier iteratively and effectively. In the experiments, we evaluated the result of the proposed fingerprint segmentation algerian using 600 manually segmented images and compared the orientation algorithms in terms of recognition accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1677-1680
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• 1991

Machining is a bottleneck in robot application technologies because of uncertainty of position/form, poor reliability of robot function and low reaction speed of robot to changes of surroundings, But in grinding automation with relatively low machining speed it is feasible to integrate of sensor signal in machining. In this paper strategy for robotic grinding with F/T sensor will be presented and with that the experimental results will be discussed. F/T sensor signal in grinding of strategy weld seam are transferred to PC, which plays a role as cell computer and transform F/T data to robot position and/or orientation, speed correction data according to programmed algorithm. The possibility and boundary of robotic grinding with F/T sensor intergration is discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.566-569
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• 1993

This paper presents the design and implementation of an industrial controller for an autonomous guided vehicle(AGV) with economic sensor. A guidance scheme provides accurate tracking and achieves faster minimizing oftracking error. A sensor at the center provides the position and orientation of the vehicle relative to the track. Control laws that make use of this information have been devised to achieve accurate and fast tracking. The gains are modified on-line to achieve proper tracking. The simulation and implementation results are provided for the illustration of the implemented controller.

• Journal of Power Electronics
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• v.10 no.3
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• pp.300-305
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• 2010

This paper presents a two Hall sensor method for rotor angle detection in permanent magnet synchronous motors (PMSM). To minimize the implementation complexity, the system is designed to measure the edge field of permanent magnet pieces. However, there are nonlinearities in the measured values of the edge field. In this work, an angle correction algorithm is proposed, and the improvements in accuracy are verified through experiments. Finally, a field orientation controller is constructed with the proposed angle detection algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.116.5-116
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• 2001

When inertial navigation system(INS) employ more sensors that mutually orthogonal sets to three, the redundant sensor system can have improved reliability and accuracy. For the redundant system the placement of redundant sensors is related to the system performance and also the number and proper orientation of sensors are important. We consider INS sensor configurations using two IMUs comprised mutually orthogonal sets of three. We suggest several configurations using two IMUs and analyze the system performance and the FDI(fault detection and isolation) properties from suggested configurations.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.219-224
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• 1996

By integrating the wired-glove and the position sensor using the magnetic fields, we developed the system which could measure the functional dimension of the hand and arm of the human. Magnetic position sensor traces the position and orientation of the arm while the wired-glove measures 18 phalangeal joint angles(including abduction between fingers, pitch and yaw of the wiist). The system could be used to monitor and quantify the functional dimension of the hand and arm and also could be used to test the product usability where the hand motion is important. Another important application lies in determining the degree of paralysis.

• Journal of Multimedia Information System
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• v.2 no.2
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• pp.233-240
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• 2015

Mobile devices are becoming increasingly sophisticated and the latest generation of smartphones now incorporates many diverse and powerful sensors. These sensors include acceleration sensor, magnetic field sensor, light sensor, proximity sensor, gyroscope sensor, pressure sensor, rotation vector sensor, gravity sensor and orientation sensor. The availability of these sensors in mass-marketed communication devices creates exciting new opportunities for data mining and data mining applications. In this paper, we describe and evaluate a system that uses phone-based accelerometers to perform activity recognition, a task which involves identifying the physical activity that a user is performing. To implement our system, we collected labeled accelerometer data from 10 users as they performed daily activities such as "phone detached", "idle", "walking", "running", and "jumping", and then aggregated this time series data into examples that summarize the user activity 5-minute intervals. We then used the resulting training data to induce a predictive model for activity recognition. This work is significant because the activity recognition model permits us to gain useful knowledge about the habits of millions of users-just by having them carry cell phones in their pockets.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.1
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• pp.106-117
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• 2006

The active vibration control of composite shell structure has been performed with the optimized sensor/actuator system. For the design of sensor/actuator system, a method based on finite element technique is developed. The nine-node Mindlin shell element has been used for modeling the integrated system of laminated composite shell with PVDF sensor/actuator. The distributed selective modal sensor/actuator system is established to prevent the effect of spillover. Electrode patterns and lamination angles of sensor/actuator are optimized using genetic algorithm. Continuous electrode patterns are discretized according to finite element mesh, and orientation angle is encoded into discrete values using binary string. Sensor is designed to minimize the observation spillover, and actuator is designed to minimize the system energy of the control modes under a given initial condition. Modal sensor/actuator for the first and the second mode vibration control of singly curved cantilevered composite shell structure are designed with the method developed on the finite element method and optimization. For verification, the experimental test of the active vibration control is performed for the composite shell structure. Discrete LQG method is used as a control law.