• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.376-381
• /
• 2001

This paper presents a methodology of machining error compensation by using Artificial Neural Network(ANN) model based on the inspection database of On-Machine-Measurement(OMM) system. First, the geometric errors of the machining center and the probing errors are significantly reduced through compensation processes. Then, we acquire machining error distributions from a specimen workpiece. In order to efficiently analyze the machining errors, we define two characteristic machining error parameters. These can be modeled by using an ANN model, which allows us to determine the machining errors in the domain of considered cutting conditions. Based on this ANN model, we try to correct the tool path in order to effectively reduce the errors by using an iterative algorithm. The iterative algorithm allows us to integrate changes of the cutting conditions according to the corrected tool path. Experimentation is carried out in order to validate the approaches proposed in this paper.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.4
• /
• pp.413-419
• /
• 1998

A novel order-reduction technique for model predictive control(MPC) is proposed based on the singular value decomposition(SVD) of a pulse response circulant matrix(PRCM) of a concerned system. It is first investigated that the PRCM (in the limit) contains a complete information of the frequency response of a system and its SVD decomposes the information into the respective principal directions at each frequency. This enables us to isolate the significant modes of the system and to devise the proposed order-reduction technique. Though the primary purpose of the proposed technique is to diminish the required computation in MPC, the clear frequency decomposition of the SVD of the PRCM also enables us to improve the robustness through selective excitation of frequency modes. Performance of the proposed technique is illustrated through two numerical examples.

• Journal of KSNVE
• /
• v.4 no.1
• /
• pp.71-82
• /
• 1994

We propose a systematic method to select the master states, which are retained in the reduced model after the order reduction process. The proposed method is based on the fact that the range space of right eigenvector matrix is spanned by orthogonal base vectors, and tries to keep the orthogonality of the submatrix of the base vector matrix as much as possible during the reduction process. To quentify the skewness of that submatrix, we define "Absolute Singularity Factor(ASF)" based on its singular values. While the degree of observability is concerned with estimation error of state vector and up to n'th order derivatives, ASF is related only to the minimum state estimation error. We can use ASF to evaluate the estimation performance of specific partial measurements compared with the best case in which all the state variables are identified based on the full measurements. A heuristic procedure to find suboptimal master states with reduced computational burden is also proposed. proposed.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.31.4-31
• /
• 2001

This paper deals with a control technique of eliminating the transient vibration of a waist axis of an articulated robot. This technique is based on a model-based control in order to establish the damping effect on the mechanical part. The control model is composed of reduced-order electrical and mechanical parts. This model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically and is added to the velocity command to suppress the transient vibration of a waist axis of the arm. This control model is easily obtained from design or experimental data and can be easily integrated into a DSP. This control technique is applied to a waist axis of an articulated robot composed of a harmonic drive ...

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.11
• /
• pp.2010-2016
• /
• 2007

PID control is windely used to control stable processes, However, its application to integrating processes is less common. In this paper, we proposed a stable PID controller tuning method for integrating processes with time delay using model reduction method. For proposed model reduction method, it disconnect an integrating factor from integrating processes and reduces separate process using reduction method. and it connect an integrating factor to reduced model. We can obtain stable integrating processes using P controller in inner feedback loop and PID tuning is then used to cancel the pole of the feedback loop. This guarantees both robustness and performance. Simulation examples are given to show the good performance of the proposed tuning method comparing with other methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.6
• /
• pp.176-182
• /
• 2004

This paper proposes a frequency transfer function synthesis for simplifying a high-order model with time delay to a low-order model. The model reduction is based on minimizing the m function weighted by the numerator polynomial of reduced systems. The proposed methods provide a better fitness within low frequency. Four examples are given to illustrate the feasibilities of the suggested schemes.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.8
• /
• pp.421-431
• /
• 2004

Line constants are composed by impedances and susceptances. A paper which was published estimated only impedances of line constants. Therefore, this paper estimates susceptances as well as impedances of equivalent five-conductors model using the reduced equivalent method. In order to verify estimated line constants, we measured line constants of real railway system. And we compared calculated results with measured data on 60Hz∼3000Hz. For the other verification, the calculation results from the proposed model and the measurement data from the test are compared focused on the amplification of harmonic current in the paper.

• Proceedings of the KIEE Conference
• /
• 1995.11a
• /
• pp.178-181
• /
• 1995

In this paper, on-line adaptive friction compensation scheme for the precise position control is presented. 2 DOF system with compliance and friction is used for the plant model. In order to reduce the calculation time for the parameter estimation, 1 DOF estimation model is used. The computer simulation and experimental results show the validity of the supposed scheme.

• Journal of the military operations research society of Korea
• /
• v.24 no.1
• /
• pp.58-67
• /
• 1998

This paper studies on physical strength measurement utilized for selecting military sportsmen. In order to estimate physical potential capability of a volunteer for a sportsmen, scores of physical strength factors are used and a regression model is developed. And then the results of this model and current physical strength measurement are compared. This paper shows that the model developed here is more effective than current measurement, since measurable physical strength factors are reduced and physical strength factors are quantified by comparing each other.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.5
• /
• pp.27-34
• /
• 1998

This paper is on the discrete model reduction method over disc-type analytic domains. We define hankel singular value over the disc that is mapped by standard bilinear mapping. And the generalized singular perturbation approximation and the direct truncation are generalized to GSPA and DT over a disc. Furthermore, it is shown that the reduced order model over a smaller domaing has a smaller .inf.-norm error bound. And the poposed reduction method is used to obtain the regional pole placement property.