• 제어로봇시스템학회논문지
• /
• 제10권10호
• /
• pp.947-955
• /
• 2004

This paper is concerned with a mixed control with aerodynamic fin and side thrust control applied to an agile missile using a dynamic inversion and a time-varying control technique. The nonlinear dynamic inversion method with the weighting function allocates the desired control inputs(aerodynamic fin and side thrust control) to achieve a reference command, and the time-varying control technique plays the role to guarantee the robustness for the uncertainties. The proposed schemes are validated by nonlinear simulations with aerodynamic data.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 A
• /
• pp.255-257
• /
• 1995

In this paper, a new speed estimation method of induction motors based on the very quick torque control is proposed to realize speed sensorless control. The proposed method can be realized very simply by detecting primary motor current and voltage command at every sampling time. As the method need not the differential value of primary current in a arithmetic of voltage command, it can be expected to promote the precision of speed estimation in low speed area, especially. Through the numerical simulation, the validity of the proposed method was successfully confirmed.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
• /
• pp.164-168
• /
• 1988

This paper utilizes an optimal control law for the accurate tracking servo system design. The devivation of a simple control law implementing microprocessor is made to minimize position and speed error of the controller. The 16 bit microprocessor receives command angular position and calculate the control algorithm for accurate tracking and provides control system gain scheduling to achieve very short settling time. Simulation results and some experimental results of the position controlled tracking using 4.5Kw DC servo motor are shown.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1997년도 전력전자학술대회 논문집
• /
• pp.341-344
• /
• 1997

This paper suggests the modified delay compensation scheme under the control input saturation in order to improve the control performance. This scheme uses the real estimated control input instead of the direct command control input. The simulation results show that this scheme can improve the current control performance under the delay time and the limited control input.

• 한국추진공학회지
• /
• 제15권1호
• /
• pp.55-62
• /
• 2011

본 연구에서는 하이브리드 로켓의 추력 제어 연소실험을 통하여 추력 제어 성능 향상을 위한 연구를 진행하였다. 추력 제어 명령에 따라 니들밸브와 결합된 스텝모터의 구동을 제어함으로써 산화제 유량을 조절하는 시스템을 구축하였다. 하이브리드 로켓 연소실험에서 사용된 산화제로는 기체산소($GO_2$)를 사용하였으며 추진제는 PE(Polyethylene)와 PC(Polycarbonate)를 사용하였다. 추력 제어 연소실험 초기에 발생되었던 추력섭동(Thrust Oscillation) 현상의 개선과 낮은 응답속도의 향상을 위해 연소실험 과정에서 산화제 배관의 유속 변화를 측정하고 원인을 분석하였다. 이를 보완한 연소 실험을 통하여 추력명령의 ${\pm}1$ N 이내에서 추력이 안정적으로 제어되었다.

• 제어로봇시스템학회논문지
• /
• 제14권11호
• /
• pp.1117-1123
• /
• 2008

This paper implements dual-kernel system using standard Linux and real-time embedded Linux for the real-time control of intelligent robot systems. Such system provides more useful services including standard Linux thread that is easy to implement complicated tasks and real-time tasks for the deterministic response to velocity control. Here, an open source real-time embedded Linux, XENOMAI, is ported on embedded target board. And for interfacing with motor controller we adopted a real-time serial device driver. The real-time task was implemented with a priority to keep the cyclic control command for trajectory control. In order to validate deterministic response of the proposed system, the performance measurement of the delay in performing trajectory control with feedback loop is evaluated with non real-time standard Linux. The proposed software architecture is anticipated to take advantage of features in both standard Linux and real-time operating systems for the intelligent robot systems.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.179-181
• /
• 2003

Conventional P/PI speed controller of today's servo drives should be manually tuned the controller switching set-point by trial-and-errors, which may translate the drive system down-time and loss of productivity. The adjustable drive performance is heavily dependent on the qualify of the expert knowledge and becomes inadequate in applications where the operating conditions change in a wide range, i.e., tracking command, cceleration/deceleration time, and load disturbances. In this paper, the demands on simple controls/setup are discussed for industry servo drives. Analyzing the frequency content of motor torque command, P/PI control mode switching is automatically peformed with some prior knowledge of the mechanical dynamics. The dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time over the whole operating conditions. For comprehensive comparison of traditional P/PI control scheme, extensive test is carried out on actual servo system.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.195-198
• /
• 1997

This paper proposes the effective compensation method of the rotor time constant of induction motor. An indirect vector control method is highly dependent on the motor parameters. To solve the problem of performance degradation due to parameter variation in an indirect vector control of induction motor, we compensate the rotor time constant by current error feedback. The proposed method is a simple on-line rotor time constant compensation method using the information from terminal voltages and currents. As the current error, difference between current command and estimated current, approaches to zero, the value of rotor time constant in an indirect vector controller follows the real value of induction motor. This scheme is valid transient region as well as steady state region regardless of low or high speed. This method is verified by computer simulation. For this, we constructed the simulation model of induction motor, indirect vector controller and current regulated PWM (CRPWM) voltage source inverter (VSI) using SIMULINK in MATLAB.

• 대한전기학회논문지
• /
• 제45권3호
• /
• pp.365-373
• /
• 1996

This paper presents the effects of rotor time constant variation and the on-line tuning algorithm of the rotor time constant. If the value of the rotor time constant is set incorrectly, the IFOC (Indirect Field Oriented Control)scheme exhibits deteriorated performance according to the wrong slip command. These variation effects of the rotor time constant are caused by the slip calculator where it is known that the rotor time constant play an important role in the aligned rotor flux. Using the two torque angles (stationary torque angle, rotating torque angle), the variation of the rotor time constant is identified, and the rotor time constant of the controller is tuned to the proper value of the machine. As the result, with the proposed algorithm, the dynamics of the deteriorated IFOC system, where the rotor time constant is varied, is improved. For the purpose of the validity of this proposed algorithm, the computer simulations and the experiments have been performed and the explanation of the results is presented. (author). refs., figs., tab.

• 제어로봇시스템학회논문지
• /
• 제10권8호
• /
• pp.689-695
• /
• 2004

This paper presents a robot system that combines computer network and an autonomous mobile robot where RTOS is installed. We propose a wireless communication protocol, and also implement it on the RTOS of the robot system. Main controller of the robot processes the control program as a task type in the real-time operating system. Peripheral devices are driven by the device driver functions with the dependency of the hardware. Because the client and server program was implemented to support the multi-platforms by Java SDK and Java JMF, it is easy to analyze programs, maintain system, and correct the errors in the system. End-user can control a robot with a vision showing remote sight over the Internet in real time, and the robot is moved keeping away from the obstacles by itself and command of the server received from end-user at the local client.