• Proceedings of the KIEE Conference
• /
• 1989.11a
• /
• pp.258-263
• /
• 1989

The configuration of Brushless DC moter is similar to the permanent magnet Synchronous moter. Power transistors are oftenly used to supply the switching by feedback signals of rotor positioning sensors. Brushless DC moter have been used in Aerospace and Robotics where the electromagnetic noise or the sparking of the commutator contact can not be tolerated and long - lived maintenance - free operation is required. This paper describes the design of the microprocessor - based controller for the Brushless DC moter. The controller is designed to operate for the constant torque generation and variable speed control using sinusoidal PWM inverters and resolvers as rotor positioning sensors.

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.658-662
• /
• 1986

In the microcomputer-based velocity control for an electro-hydraulic servo system, the effects of control methods and control hardware on the performance of the system were investigated. Experiments were carried out with PID and deadbeat controllers using 8 or 16 bit microprocessor and 8 or 12 bit A/D and D/A converters. It is found that the transient response of the system is better with PID controller than with deadbeat controller. When the number of bits of the microprocessor and converters are small, it is also found that amplitude quantization due to limited wordlength gives significant effects on transient responses of the system. Analytically predicted step-responses are in good agreement with experimental ones.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.4
• /
• pp.517-524
• /
• 1998

This paper discusses the development of a reactive power controller using digital signal processing. Digital Signal Processing is the technique of using digital devices to Process continuous signals or data, often in real-time. And DSP algorithms are associated with a discrete time interval between input samples. When one designs a digital filter, one can use a Laplace transform to determine the continuous time frequency response. The corresponding discrete time transform is called Z transform and depends upon discrete samples of the input spaced equally in time. The objectives of this paper are to minimize real power losses and improve the power factor of a given system. Also, the implementation of a direct-form non recursive filter on the TMS320C31 has been described. The application of this microprocessor-based controller using DSP on test system reveals its numerous advantages. Performance and features of the controller for the reactive power control are analyzed.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.527-529
• /
• 1987

This paper presents a study on the driving characteristics or delta inverter driving induction motor control systems based on the microprocessor. Delta inverter is a novel circuit which uses only three power transistor. Requiring approximately hair the components or a conventional bridge inverter it therefore has a merit of coat and Simplicity. The basic operating principles of the delta inverter and conventional bridge inverter are argued, using resistive and inductive load. Sinusoidal PWM method uses to reduce the harmonic components of its output waveform to acceptable levels.

• Journal of Biomedical Engineering Research
• /
• v.10 no.1
• /
• pp.53-58
• /
• 1989

An arbitrary waveform generator was developed for the experiment of electro-physiology and the electrical stimulator. This system has been constructed three parts. (1 ) Data input parts (2) Data processing and control parts (3) Analog signal output parts The system characteristics were as follows. (1) System based on Microprocessor (2) Input using Thumbwheel switch (3) Isolated output signal (4) System flexibility

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.5
• /
• pp.11-19
• /
• 2017

In this paper, we propose a hypervisor for embedded systems based on ARM microprocessor. The proposed hypervisor makes it possible to run several real-time kernels concurrently on a single embedded system by virtualizing its microprocessor. With assistance of MMU, it supports virtual memory which enables each guest operating system has its own address space. Exploiting the fact that most embedded systems use memory-mapped I/O device, it provides a mechanism to distribute an external interrupt to virtual machines properly. It also achieves load balancing through live migration which moves a running virtual machine to other embedded system. Unlike other para-virtualization techniques, minor modifications are needed to run it on the hypervisor. Extensive performance measurement studies are conducted to show that the proposed hypervisor has enough potentiality of its real-world application.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.4
• /
• pp.67-73
• /
• 2015

Recently in the evaluation of physical properties of a material, its surface friction characteristics is much required. This study treats the development of portable and affordable friction coefficient tester, which includes utensil design and application, measurement circuit design and layout, and microprocessor based firmware building. Also, real applicability of the present portable friction coefficient tester has been shown via performance comparisons with the existing standard tester.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.36 no.2
• /
• pp.80-87
• /
• 1987

This paper describes a new approach to control the two-phase servomotor driven with microprocessor based inverter. Conventional 6-step driving system has some shortcomings such as vibration and loss caused by the harmonic voltage. An attempt has been made to eliminate the harmonic content of output waveform by PWM technique and to simplify the control system by phase control method. In realizing the phase control by PWM technique proposed by this paper, control circuit and algorithm has been suggested. The proposed method has been applied to the speed control system with PI controller to confirm the adaptation of the servo system and experimental results has been compared with the computer simulation.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.7-9
• /
• 2007

If used to drive the minicar, the BLDC Motor has advantages of weightless, efficient, small-size and credibleness. In this paper at first the position detecting method for BLDC was introduced, secondly the simulation of control algorithm was done and at last the prototype controller based one chip processor MEGA48 was fabricated. The controller proposed has characteristic of cheap cost, reliable performance and totally meeting demands of minicar control.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.303-305
• /
• 1993

Walsh function and transform are important analytical tools for control theory and signal processing and have wide applications in those fields, especially in the field of digital communications. Therefore there is a need for a Walsh function generator in order to realize certain applications. And a number of different desists are known. But desist and implementation of such a generator through hardware logic nay give rise to orthogonality error. To develop Walsh function generator which gets rid of orthogonality error, this paper presents a microprocessor based design and implementation method.