A Mixed Sensitivity H∞ Control Method Based on Active Magnetic Bearing

H∞ control theory, as a popular active magnetic suspension control method in recent years, has the advantages of directly handling system uncertainties and disturbances in the frequency domain, and strong system robustness. However, traditional <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{\infty}$</tex> control methods often focus on optimizing a single performance metric, such as stability or disturbance rejection capability, while neglecting the mutual influence and balance between different internal system components. To overcome this difficulty, this paper proposes a hybrid sensitivity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{\infty}$</tex> control method. The hybrid sensitivity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{\infty}$</tex> control method can not only effectively deal with the uncertainty of internal parameters in the system, but also fully consider the interaction between external disturbances and internal dynamics during the controller design stage, thereby designing a controller that better meets the actual application requirements. This article derives the mixed sensitivity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{\infty}$</tex> control method, analyzes the selection of weight functions, and demonstrates its significant advantages in improving system robustness, dynamic performance, and anti-interference capability through theoretical analysis and simulation verification.