Robust Tracking Control using Integral Sliding Mode Observer for Quadrotors Considering Motor and Propeller Dynamics and Disturbances

Unknown System Dynamics Estimator-Based Anti-Disturbance Attitude Funnel Control for Quadrotors with Experimental Verifications

“…In order to recover the unknown perturbations and acquire an enhanced robustness, a great deal of advanced disturbance observers have been exploited for quadrotors by compensating for the negative impact in a feedforward manner, i.e., sliding mode observers (SMO) [5][6][7][8], extended state observers (ESO) [9][10][11], and function approximators [12][13][14]. To reinforce the tracking performance for quadrotors, a fixed-time-based SMO control rule was suggested in Zhou et al [5].…”

“…To reinforce the tracking performance for quadrotors, a fixed-time-based SMO control rule was suggested in Zhou et al [5]. In Heo et al [8], a robust tracking control strategy was proposed for quadrotors by incorporating an integral SMO. In Cui et al [9], with the aid of the estimated results of ESO, a super-twisting-based adaptive control method was designed for quadrotors to govern the trajectory tracking behaviors.…”

“…With the aid of the above observers, excellent disturbance identification can be ensured and the robustness can be improved. However, certain defects including the unexpected chattering phenomenon in [5][6][7][8] and complex argument selections impose restrictions on engineering practices to a certain extent. In addition, it is generally difficult to make a compromise between the peak phenomenon and the convergence speed of estimation errors by using ESO [9][10][11].…”

“…In Na et al [16], an USDE-based motion control was proposed for robotic systems to address the internal unknown dynamics and environmental disturbances. Compared to the aforementioned disturbance observers [5][6][7][8][9][10][11][12][13][14], the USDE possesses a convenient parameter tuning rule and a satisfied estimation accuracy; however, the existing USDE-based outcomes are oriented towards simple integral-chain systems, which cannot be directly applied to the quadrator attitude with obvious coupling and multiple variables, yielding to a more complicated controller development and stability analysis. Additionally, the key metrics, i.e., overshoot, convergence time and steady-state errors, are not actively considered during the above control developments.…”

“…Distinguishing it from the existing sliding mode observer [5][6][7][8]-based control strategies, where chattering cannot be efficaciously surmounted by raising the deployment of the sign function, the unknown system dynamics estimator (USDE) is presented for quadrotor attitude dynamics to identify the unmeasurable perturbations by utilizing an invariant manifold principle. In addition, differing from previous function approximator-based control schemes [12][13][14], by using simple filtering calculations for the available quadrotor states, a more concise design frame and a lower calculation burden could be guaranteed.…”