Second, a novel SMC that employs extended disturbance observer (EDO) to counteract the effect of uncertainties using a new sliding surface which includes the estimation error is integrated to address the tracking error stabilization issues in the attitude and angular rate loop, respectively.  In addition, new results associated with EDO are examined in terms of dynamic response and noise-tolerant performance, as well as estimation accuracy.  Based on finite time convergence stability theory, the stability of the resulting closed-loop system is well established. 
EDO
First, fewer control consumption is achieved using nonlinear tracking differentiator (TD) in the attitude loop. 
TD
Sliding mode based trajectory linearization control for hypersonic reentry vehicle via extended disturbance observer.This paper proposes a novel hybrid control framework by combing observer-based sliding mode control (SMC) with trajectory linearization control (TLC) for hypersonic reentry vehicle (HRV) attitude tracking problem.  Second, a novel SMC that employs extended disturbance observer (EDO) to counteract the effect of uncertainties using a new sliding surface which includes the estimation error is integrated to address the tracking error stabilization issues in the attitude and angular rate loop, respectively. 
SMC
Sliding mode based trajectory linearization control for hypersonic reentry vehicle via extended disturbance observer.This paper proposes a novel hybrid control framework by combing observer-based sliding mode control (SMC) with trajectory linearization control (TLC) for hypersonic reentry vehicle (HRV) attitude tracking problem. 
TLC