0 1 2 3 4 5 6 7 8 9 10
−4
−3
−2
−1 0 1 2 3 4
t[sec]
y(t)
Fig. 4.3: Response of the output y(t) = [y1(t), y2(t)]T for the periodic disturbance d1(t) = [sinπt+ 2sinπt]T
0 1 2 3 4 5 6 7 8 9 10
−3
−2.5
−2
−1.5
−1
−0.5 0 0.5 1 1.5 2
t[sec]
y(t)
Fig. 4.4: Response of the output y(t) = [y1(t), y2(t)]T for the periodic disturbance d2(t) = [sinπt+ 2sinπt]T
Chapter 5 Conclusions
This Chapter gives concluding remarks. Results of this thesis are summarized as follows:
Chapter 1 described the trend of a study on design methods for modified Smith predictor and the purpose of this thesis.
Chapter 2 proposed the parameterization of all stabilizing two-degree-of-freedom by feed-back control for modified Smith predictors for multiple-input/multiple-output time-delay plants that can specify the input-output characteristic and the feedback characteristic separately.
Next, the parameterization of all stabilizing two-degree-of-freedom modified Smith predictor for multiple-input/multiple-output unstable time-delay plants was also given. Move over, the modified Smith predictor is explained control input based on time domain. Finally, a numerical example was illustrated to show the effectiveness of the proposed method.
Chapter 3 examined a design method for modified Smith predictive control system to attenu-ate periodic disturbances that often appear in real time-delay plants using the parameterization of all stabilizing modified Smith predictors. This chapter is organized as follows: In section 3.2, modified Smith predictors are introduced briefly. In addition, the problem considered in this pa-per is described. In section 3.3, propose a design method for a modified Smith predictive control system to attenuate periodic disturbances effectively. However, the modified Smith predictive control system proposed in section 3.3 cannot specify the input-output characteristic and the disturbance attenuation characteristic separately. Moreover come this problem, section 3.4 was proposed a two-degree-of-freedom by feed-back control for modified Smith predictive control system to attenuate periodic disturbances effectively and specifies the input-output character-istic separately. In section 3.5, a numerical example was illustrated to show the effectiveness of the proposed design method. Section 3.6 gives concluding remarks.
Chapter 4 expanded the result in Chapter 3 and proposed a design method for modified Smith predictive control system for multiple-input/multiple-output time-delay plants to atten-uate periodic disturbances. Because many of actual plants are multiple-input/multiple-output plants, to consider for multiple-input/multiple-output time-delay plants is important. In addi-tion, a design method for stabilizing two-degree-of-freedom modified Smith predictive control system for multiple-input/multiple-output time-delay plants to attenuate periodic disturbances and to specify the input-output characteristic and the disturbance attenuation characteristic separately is presented. Finally, a numerical example was shown to illustrate the effectiveness of the proposed design method.
This thesis establishes guidelines for the design of two-degree-of-freedom modified Smith predictor. It shows clearly that it is good to use these methods which the method proposed in Chapter 2 to improve the input-output characteristic, in Chapter 3 and Chapter 4 to improve disturbance attenuation characteristic, and can expect to apply to many real systems.
Acknowledgements
I would like to acknowledge with sincere thanks and deep appreciation to Professor K. Yamada who had appropriate instruction, advice on accomplishing this study. Without his support, this study would not have come into completion.
I would also like to thank Prof. T. Yamaguchi, Professor Emeritus K. Watabe, Associate Prof. Y. Ando and Associate Prof. S. Hashimoto whose opinions and information have helped me very much throughout the production of this study.
I would like to express my gratitude respectfully.
And, I would like to express my gratitude to Assistant Prof. T. Sakanushi and Mr. T.
Kobayashi whose helped me to engaged in my study.
I also would like to thank laboratory members, Mr. T. Hoshikawa, Ms. J. Hu, Mr. Y. Zhao, Ms. Y. Tatsumi, Mr. Y. Karasawa, Mr. S. Tohnai, Mr. H. Huo, Ms. H. Wang, Ms. Y. Zhai, Ms. S. Natnari, Mr. T. Maruyama, Mr. R. Hirota, Mr. T. Noguchi and Mr. Y. Ri who often advised and encouraged me when I had some trouble in my study.
Finally, I would like to express my gratitude to my family who have supported me.
March 2014 Nghia Thi Mai
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