<p>In this paper, we have designed a robust optimal fault-tolerant controller which is assured the integrity in the presence of sensor faults as well as actuator faults, respectively, based on the mathematical model of time-delay system with parameter uncertainties and disturbances. The proposed robust optimal fault-tolerant control algorithm with state feedback is obtained using Lyapunov's stability theory and linear quadratic (LQ) control method. First, we formulate the state equations representing the influences of disturbances as well as the time-varying parameter uncertainties of state matrix, control matrix, interrelation terms, and control delay time. Then, existence conditions of fault-tolerant controller were introduced. Next, we extend the robust optimal control problem to the problem of sensor and actuator faults, derive it in linear matrix inequality (LMI) form, and then design the robust optimal fault-tolerant controller using Lyapunov's stability theory and LQ control method. The proposed robust optimal fault-tolerant controller neither needs to estimate the boundary values of an actuator fault and a sensor fault and nor depends on fault detection and diagnostic devices. Finally, the effectiveness of designed robust optimal fault-tolerant controller is demonstrated through numerical simulations and application experiments for Quadrotor Unmanned Aerial Vehicle (UAV).</p>