| Author Name | Affiliation | | HeZhen | Dept. of Control Science and Engineering,Harbin Institute of Technology,Harbin 150001,China | | MENG Fan-wei | Dept. of Control Science and Engineering,Harbin Institute of Technology,Harbin 150001,China | | Zhou Di | Dept. of Control Science and Engineering,Harbin Institute of Technology,Harbin 150001,China | | WANG Guang-xiong | Dept. of Control Science and Engineering,Harbin Institute of Technology,Harbin 150001,China |
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| Abstract: |
| For the control of unstable plants,it is required that the Nyquist locus of the system should encircle anticlockwise the point-1+j0,and the performance weighting function must be selected based on the specific requirement of the mid-frequency gain. Besides,the performance limitation imposed by the Bode’s integral also must be considered. Therefore the H∞ design for unstable plants is different from that in the regular case. It is pointed out that the sensitivity function for unstable plants must remain constant over the mid-frequency range to ensure a robust design. The selection of weighting functions to meet these requirements in the H∞ design is discussed in detail in the paper. A mixed sensitivity H∞ design example is also given to demonstrate the special considerations of the design. |
| Key words: unstable plant H∞ design mixed sensitivity electromagnetic levitation |
| DOI：10.11916/j.issn.1005-9113.2010.03.020 |
| Clc Number:TP273 |
| Fund: |
