ℌ ∞ probabilistic robust control of Hard Disk Drive

This paper presents a ℌ ∞ probabilistic robust track following output feedback controller for Hard Disk Drive (HDD) servo systems. Such a controller benefits from the sequential approximation method based on gradient iteration. In probabilistic framework, randomization is used to handle uncertainty and convex optimization to find the design parameters. In this approach, uncertainty is considered as random variable; hence, due to this stochastic nature, the probability of performance function can be estimated. Simulation results reveal that by allowing a very small violation of cost function, we can achieve much better performance compared to classical deterministic approach.