In the presence of uncertainty, a closed-loop system must be able to maintain its stability and performance. Uncertainty can be categorized into two meanings, disturbance from external systems and perturbation in a dynamical system. In this paper, we will present a robust control design by considering a disturbance from external factors, and analyze its robustness using Structured Singular Value respect to parametric uncertainty and external disturbance. Beside that, every control system has their own region to operate, outside that region a performance degradation will occur, and led into unstability. One factor to that catastrophic is a fault in instrument reading, to anticipate it, this paper also implement Simplified Instrument Fault Detection method to detect a sensor fault in order to give an alarm for further action.