Browsing by Author "Huang, Ruei-Yu"

Now showing 1 - 5 of 5

A New Framework of Disturbance Observer with Vidyasagar's Structure
(2018-12-01)
Chen, Yu-Xian
;
Huang, Ruei-Yu
;
Chang, Shih-Chung
;
Pan, Yi-Ren
;
Lee, An-Chen
This paper proposes a novel two degree of freedom (TDOF) control structure: a combination of Vidyasagar's structure (VS) and the doubly coprime factorization based disturbance observer (DCFDOB). The DCFDOB-VS framework is aimed at providing a control structure and design procedure for a MIMO system with good characteristics of disturbance attenuation, tracking, and decoupling property. The structure can deal with stable/unstable and minimum phase/non-minimum phase plants. The advantage of the method is that two parameters can be designed for different purposes, independently. The parameter H stabilizes the system and improves tracking property. Once the parameter H has been designed, then the Q(Y) can be implemented via a parameter Q for rejecting disturbances and improving the system robustness.
Harmonic Elimination for PWM Inverter
(2017-01-01)
Wang, Bo-Han
;
Huang, Ruei-Yu
;
Lee, An-Chen
;
機械工程學系
;
Department of Mechanical Engineering
For a PWM inverter system, the output ac current is expected to be a sinusoidal waveform after filtering; however, PWM inverters have two drawbacks causing distortion of output waveform. One is the presence of harmonics, and the other is the variations of the system parameters. In this paper, a robust Doubly Coprime Factorization Disturbance Observer (robust DCFDOB) is applied to a dc-to-ac inverter. The proposed robust DCFDOB involves the H infinity -loop shaping method to guarantee the robust stability and robust performance. Experiment results are given to illustrate the effectiveness of the robust DCFDOB.
High speed tracking control of ball screw drives
(2017-01-01)
Liu, Chao-Yi
;
Huang, Ruei-Yu
;
Lee, An-Chen
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a new method to achieve the requirement of high speed and high precision for ball screw drive. First, a PI controller is adopted to increase the equivalent structural damping in the velocity loop. Next, the design of the position controller is implemented by a two-stage method. The Doubly Coprime Factorization Disturbance Observer (DCFDOB) is developed to suppress disturbance and resist modelling error in the inner loop, while the outer loop is then designed based on method to extend the system bandwidth over first resonant frequency so that high speed and high accuracy can be achieved. Finally, a feedforward controller is implemented to improve tracking performance. The experiment results showed that the proposed method has smaller tracking error and better performance for suppressing disturbance when compared to the conventional cascaded P-PI control.
Minimum Variance Run-to-Run Controller for General Stochastic Time-Series-Based Disturbances
(2020-08-01)
Lee, An-Chen
;
Huang, Ruei-Yu
;
Chen, Yu-Xian
;
Tsai, Te-Hsiu
;
Chang, Chen-Yu
Exponentially weighted moving average (EWMA) or double EWMA controllers are often employed to deal with various stochastic time-series disturbances for run-to-run control. If the disturbance model is known, then the best EWMA or double EWMA controller can be obtained by minimizing output variance with respect to controller parameters. However, from the theoretical view point, results are only sub-optimum because the control scheme may not be the best control scheme for the underlying stochastic disturbance. Therefore, investigating the best control scheme for the process disturbance following the general ARIMA time series process is worthwhile. In this paper, the predictive disturbance observer (PDOB) is developed based on minimum variance control for various ARIMA(p,r,q) stochastic disturbances. If the ARIMA(p,r,q) disturbance model is known, then the PDOB scheme generates one-step ahead prediction for this disturbance and then feeds it back to compensate the effect of stochastic disturbance on the system output; as a result, the system generates the minimum output variance or simply white noise variance.
NURBS Path Tracking Control of a Scanning Mirror System Based on EtherCAT Fieldbus
(2018-01-01)
Huang, Ruei-Yu
;
Cheng, Chung-Wei
;
Lee, An-Chen
;
機械工程學系
;
Department of Mechanical Engineering
In this paper, an EtherCAT scanning mirror system with function of NURBS path tracking control was investigated. By using EtherCAT protocol to connect master computer with a scanning mirror system, we did a first attempt to implement position control by the master computer, so that one can apply an advanced control algorithm to the system instead of applying a distributed control algorithm on the proprietary driver of the slave device. The technical issue of this configuration like commutation delay caused by the three-buffer-mode is addressed. A two-staged H-infinity with feed-forward controller is designed for the position control loop. Moreover, considering the widely used of non-uniform rational B-spline (NURBS) in the field of CAD/CAM, we added the function of NURBS path planning in the controller so that the system can deal with complex NURBS curves. The experiment results showed that the proposed method can reduce tracking error and have better performance when comparing with traditional distributed control strategy.