• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.340-343
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• 1992

Fundamental positioning characteristics of a dual-axis Sawyer linear motor are described. The Sawyer motor is capable of high positional accuracy. An electronic control unit of the motor whose velocity is proportional to the frequency of the electric current was produced in our laboratory. The positioning system was constructed using two Sawyer motors, an air bearings suspension unit and an electronic control unit. The stable motion of the motor was confirmed on the open loop operation. The adjustable operating conditions were the live load of 1 kg, the maximum acceleration of 1.2G and the maximum velocity of 350 mm/s. Absolute positioning accuracy was improved within .+-.5.mu.m, on microstep operating conditions of dividing one pitch of 508.mu.m into 508 steps. The following two conclusions were obtained. An accelerating-cruising-decelerating control is effective for reduction in the travel time required. Also, microstep operation is effective for improving the resolution of position.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.247-250
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• 1996

In this paper, we have examined the impedance characteristics of a tipper link of human being in a positioning motion. Firstly, we have shown the characteristics of the human arm using a bilinear model. From the bilinear model, we have observed that both the driving torque of the forearm and the visco-elasticity of the elbow joint can be controlled by muscles, respectively. Then, we have defined several indexes to show the impedance characteristics. Using the proposed indexes, we have examined the impedance characteristics in the positioning operation. As a result, we can not observe the difference of the impedance characteristics, even if the ease of the positioning motion is varied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2054-2061
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• 2010

This paper suggests an algorithm for optimal positioning individuals(or observations) with p-dimensional measurements into coordinates of a two dimensional space. A criterion for optimizing the rotation is taken as the consistency of the grouping result obtained by the cluster analysis. This paper introduces the criterion and a transformation matrix for the orthogonal rotation. The criterion of the optimal positioning is that standard groups are placed in each quadrant of the positioning. An optimal angle of the orthogonal rotation is investigated and found by this criterions.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.795-800
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• 2008

The paper presents research for the established experiment environment of multi vehicle robot, localization algorithm that is based on vehicle control, and path tracking. The established experiment environment consists of ultrasonic positioning system, vehicle robot, server and wireless module. Ultrasonic positioning system measures positioning for using ultrasonic sensor and generates many errors because of the influence of environment such as a reflection of wall. For a solution of this fact, localization algorithm is proposed to determine a location using vehicle kinematics and selection of a reliable location data. And path tracking algorithm is proposed to apply localization algorithm and LOS, finally, that algorithms are verified via simulation and experimental

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.66.6-66
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• 2001

In this paper, we studied the error compensation using an error budget method for repeatability improvement of the precision positioning system. The precision positioning system is developed for micro-pressing machine. We performed the force and displacement analysis about parts of the system. Proposed system determines the position and orientation of the materials manufactured by micro-pressing machine. It is consisted of x-y-z linear stages setting the position, and the gripper system setting the orientation. We executed kinematic and dynamic modeling of the whole precision positioning system. By generalizing the design variables, precision positioning system has the flexibility of material dimension. As we tried an error compensation using ...

• Electronics and Telecommunications Trends
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• v.38 no.3
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• pp.11-19
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• 2023

Drones, which were early operated by remote control, have evolved to enable autonomous flight by combining various sensors and software tools. In particular, autonomous flight of drones was possible since the application of GNSS-RTK (global navigation satellite system with real-time kinematic positioning), a precision satellite navigation technology. For instance, unmanned drone delivery based on GNSS-RTK data was demonstrated for pizza delivery in Korea for the first time in 2021. However, the vulnerabilities of GNSS-RTK should be overcome for delivery drones to be commercialized. In particular, jamming in the navigation system and low positioning accuracy in urban areas should be addressed. Solving these two problems can lead to stable flight, takeoff, and landing of drones in urban areas, and the corresponding solutions are expected to establish a hybrid positioning technology. We discuss current trends in hybrid positioning technology that can either replace or complement GNSS-RTK for stable drone autonomous flight.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.782-785
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• 1988

A two-dimensional positioning system by use of an M-array is proposed. An M-array pattern, which is known as one of the two-dimensional pseudorandom array, is attached on an object to be positioned. The M-array pattern is observed by a TV camera and crosscorrelated with the reference M-array. The maximum of the two-dimensional crosscorrelation function is sought by two-dimensional servo system. This method of positioning can be used in very noisy circumstances.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1196-1199
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• 1990

The authors proposed a new two-dimensional(2D) positioning system by use of M-array suitable for noisy environment in '88KACC and its revised version in '89KACC. This 2D positioning system is further improved to be used in practice; the computation time is improved by use of vector signal processor and the focussing process is improved by use of an electrically controlled zoom lense. It is shown that this system is robust to noise and also to misalignment of devices.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.146-146
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• 2000

This paper presents field test results of the GPS precise positioning using carrier phase observable. The Least-squares AMBiguity Decorrelation Adjustment(LAMBDA) method is implemented to resolve integer ambiguity problem for two epoch Ll carrier phase measurement data. Field test results show that the GPS precise positioning of cm-level accuracy is obtainable with conventional low cost, single frequency C/A code GPS receivers.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.606-608
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• 2003

This paper investigates the accuracy of three-dimensional positioning for EROS A stereo pairs when different numbers of ground control points are employed. The major works of the proposed schemes include: (1) initialization of orientation parameters (2) preliminary orbit fitting, (3) orbit refinement using the least squares filtering technique, and (4) space intersection. The experiment includes validation of positioning accuracy for an EROS A in-track stereo pair when different number of check points are employed.