Retraction notice

At the request of the authors, the article

Zhan L and Zhou K, Synchronous disturbance attenuation in a power magnetically levitated spindle based on parameter-scheduled H_∞ control, Transactions of the Institute of Measurement and Control, Epub ahead of print 23 June 2014. DOI: 10.1177/0142331214538999 has been retracted. The authors of the paper have recently brought to our attention that some of the experimental results presented were incorrect:

 (1) According to our recent research, some experimental results in this article cannot be repeated. The problem relates to a damaged displacement sensor. These experiments affected are mainly the unbalance tests at high speeds. We carried out the experimental research mentioned in this article at different times. The static suspension experiments (the step response experiments) shown in Figures 17 and 18, and the unbalance tests at low speeds (such as Figure 19) were done earlier than those unbalance tests at higher speeds. When we carried out the unbalance experiments at higher speeds (shown in Figures 21 and 24), the sensors used on that platform might already have been damaged, producing incorrect data. Then, recently we found that we couldn’t get the same or similar experimental results as shown in Figures 21, 22 and 24. Since the experimental results were not correct, the corresponding analysis based on the experimental results and the corresponding conclusions must be wrong. We realized that this is a big accident.

 (2) Some other minor mistakes in this article include: 1) the spelled out form of DSP on Page 2 should be ‘digital signal processor’, rather than ‘digital signal processing’; 2) the symbol Ws on Page 8 should be W1; 3) the symbol Wt on Page 8 should be W3.