Backstepping control for the optoelectronic stabilized platform based on adaptive fuzzy logic system and nonlinear disturbance observer

Backstepping sliding mode control of stabilized platform for fully rotary steerable drilling system based on nonlinear disturbance observer

“…Following the NDO form from Zhang et al, 27 Dutta and Kumar, 28 we have $$$\left\{\begin{array}{c}\hat{d}=z+p({\rm{x}}),\\ \dot{z}=L({\rm{x}})z+L({\rm{x}})[-p({\rm{x}})-f({\rm{x}})-g({\rm{x}})u],\end{array}\right.$$$where $$\hat{d}$$ is the observer estimate value of d , z is the internal state of the observer, p ( x ) is the nonlinear function to be designed, and L ( x ) is the gain of the nonlinear observer satisfying $$$L({\rm{x}})\cdot {\dot{x}}_{2}=\frac{dp({\rm{x}})}{dt}.$$$…”

Fuzzy compensation disturbance observer-based adaptive tracking control for pure-feedback systems with deferred output constraint

“…The disturbance in this paper is an unknown time-varying function, which is more general than the disturbance in [15][16][17]26]. Compared with [28][29][30], this paper designs an auxiliary system for the compensation term and independently proves the stability of the disturbance observer.…”

“…In [19,20], the authors used the parameter estimation methods to estimate external disturbances and enhance the disturbance attenuation ability of controllers. The disturbance observer-based control schemes were utilized to deal with disturbances in [18,[24][25][26][27][28][29][30]. Different from the other schemes used to handle the disturbance, the disturbance observer is a tool that can directly and quickly press the strong disturbance.…”

“…In [28], a fuzzy disturbance observer was proposed to estimate the disturbance and enhance the anti-disturbance performance of the system. A nonlinear disturbance observer was employed to design the adaptive fuzzy control scheme in [29,30]. However, the external disturbance under research in [15,16] changed slowly.…”

Design and Analysis of the Composite Stability Control of the Reflective Optoelectronic Platform

“…Nevertheless, the effectiveness of these research improvements is constrained by the low-frequency phase lag issue caused by filters lacking a zero point. Some other researchers have used adaptive algorithms to enhance the stability error compensation process for optoelectronic platforms and validated their approach through simulations [15,[17][18][19][20]. However, developing an adaptive algorithm model requires extensive empirical data and can be challenging to implement, raising questions about its practical utility in solving engineering problems.…”