• 전기의세계
• /
• v.29 no.7
• /
• pp.460-470
• /
• 1980

The design of a control unit for a playback-type industrial robot is studied. Implemented for the cylindrical-coordinate type industrial robot with 5 degrees of freedom, the control unit constructed for the study consists of (i) z-80 .mu.p-based .mu.-computer control system (ii) Teach-Box for work command, and (iii) various softwares for generating signals for servo driving unit and operating the robot as playback-type. Softwares are developed by using high level Basic Language and low level z-80 Assembly Language for ease of programming and speed of program execution. To show the effectiveness, and example is included.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.252-257
• /
• 1990

For the position control of BL-DC motors, 2.phi.-3.phi. conversion unit, hysteresis band device, and PWM pulse generation are required. By utilizing a single-chip processor INTEL 8097BH, we cover all required functions. As a result, no analogue device is employed in this control scheme, so that it makes BL-DC motor controller simple and flexible. Furthermore, the single-chip processor is utilized for the nonlinear coordinate transformation which is necessary for the linearization of the motor system.

• Journal of the Korean Society for Railway
• /
• v.10 no.6
• /
• pp.685-691
• /
• 2007

In this paper through Honan high-speed railroad which is planned with the north and south axis, we will verify the feasibility of the coordinate conversion using railroad control points after regarding current planned-railroad as the linear central axises. From analysis, distortion of Y axis varies 21 cm to 40 cm diminishing to a gentle straight line, distortion of X axis varies 14 cm to 29 cm. Through a revision, the deviation value between the coordinates were 6 mm to 9 mm and it satisfied the allowable error of national geographic information institute which is following ITRF (International Terrestrial Reference Frame) and cadastral boundary survey (10 cm). consequently the coordinate conversion is possible using railroad control points as common control points.

• International Journal of Aeronautical and Space Sciences
• /
• v.13 no.4
• /
• pp.484-490
• /
• 2012

This paper is devoted to investigate the feasibility of using a medium power ground-based laser to produce a torque on LEO satellites of various shapes. The laser intensity delivered to a satellite is calculated using a simple model of laser propagation in which a standard atmospheric condition and linear atmospheric interaction mechanism is assumed. The laser force is formulated using a geocentric equatorial system in which the Earth is an oblate spheroid. The torque is formulated for a cylindrical satellite, spherical satellites and for satellites of complex shape. The torque algorithm is implemented for some sun synchronous low Earth orbit cubesats. Based on satellites perigee height, the results demonstrate that laser torque affecting on a cubesat has a maximum value in the order of $10^{-9}$ which is comparable with that of solar radiation. However, it has a minimum value in the order of $10^{-10}$ which is comparable with that of gravity gradient. Moreover, the results clarify the dependency of the laser torque on the orbital eccentricity. As the orbit becomes more circular it will experience less torque. So, we can conclude that the ground based laser torque has a significant contribution on the low Earth orbit cubesats. It can be adjusted to obtain the required control torque and it can be used as an active attitude control system for cubesats.

• International Journal of Aeronautical and Space Sciences
• /
• v.16 no.1
• /
• pp.77-88
• /
• 2015

The dynamics of relative motion in a perturbed orbital environment are exploited based on Gauss' and Cowell's variational equations. The inertial coordinate frame and relative coordinate frame (Hill frame) are used, and a linear high fidelity model is developed to describe the relative motion. This model takes into account the primary gravitational and atmospheric drag perturbations. Then, this model is used in the design of a navigation, guidance, and control system of a chaser vehicle to approach towards and to depart from a target vehicle in proximity operations. Relative navigation uses an extended Kalman filter based on this relative model to estimate the relative position/velocity of the chaser vehicle with respect to the target vehicle. This filter uses the range and angle measurements of the target relative to the chaser from a simulated LIDAR system. The corresponding measurement models, process noise matrix, and other filter parameters are provided. Numerical simulations are performed to assess the precision of this model with respect to the full nonlinear model. The analyses include the navigation errors and trajectory dispersions.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.12
• /
• pp.1145-1151
• /
• 2013

Kinematic modeling is a prerequisite for motion planning and the control of mobile robots. In this paper, we proposed a new method of kinematic modeling for a type of mobile robot based on differential motion transformation. The differential motion implies a small translation and rotation in three-dimensional space in a small time interval. Thus, transformation of the differential motion gives the velocity relationship, i.e., Jacobian between two coordinate frames. Since the theory of the differential motion transformation is well-developed, it is useful for the systematic velocity kinematic modeling of mobile robots. In order to show the validity for application of the differential motion transformation, we obtained velocity kinematic models for a type of exemplar mobile robot including spherical ballbots.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.446-449
• /
• 1990

A Multi-Robot Control language (MRCL) is proposed to effectively control the multi-robot. MRCL has not only single-robot, command, but multi-robot command with multi-task OS, XINU. Concurrent motion, coordinate motion, and simple collision avoidance motion are implemented. This language is expected to act as a intelligent supporting tool for multi-robot system. To verify the effectiveness of the MRCL, a simple puzzle matching example is illustrated.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2481-2483
• /
• 1999

This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.195-198
• /
• 2003

Camera calibration is the method of finding the relationship between world coordinates and image coordinates with respect to camera coordinate. It is represented by PPM(Perspective Projection Mateix) compactly. And the PPM is effected by positions, intervals and distribution of control points. This paper presents to the relationship between PPMs and control points by experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.466-471
• /
• 1996

This work is concerned with the development of digital contouring controller formulti-axial servosystems. Digital optimal contouring controller is proposed to coordinate each of the controllers of multiple feed drives and specifically improve the controuring performance. The optimal control formulation includes the contour error explicity in the performance index to be minimized. The contouring control is exercised for straight line and circular contours. Substantial improvement in contouring perfomance is obtained for a range of contouring conditions. Both steady state and transient error measures have been considered. The simulation study presented has estiblished the potential of the proposed controller to improve contourning perfomance.