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A actuator fault estimation algorithm based on adaptive iterative learning is proposed for a class of nonlinear periodic systems with actuator fault and disturbances. Firstly, the proposed method designs a state observer and a fault estimator based on adaptive iterative learning. The Lyapunov stability theory and the optimization theory are employed to prove the convergence of the method. Then the LMI toolbox is utilized to obtain the results of the observer gain matrix and fault estimator parameter matrix. The method combines the iterative learning strategy with the adaptive algorithm, and utilizes not only the state error signals of the last iteration learning, but also the output error signals of this time. It makes the estimated fault approximate to the real fault gradually and realizes the accurate estimation of the time-varying fault and the intermittent fault. Finally, the validity and accuracy of the proposed method are verified by the simulation of a single-link robotic arm mold.

Purpose The aim of study was to explore the overall efficacy and safety of ultrasound-guided quadratus lumborum block combined with general anesthesia in patients undergoing percutaneous nephrolithotomy (PCNL). Methods The study included 76 patients who underwent PCNL at our hospital between October 2018 and October 2019. The patients were randomly divided into the study group (ultrasound-guided quadratus lumborum block combined with general anesthesia, 38 cases) and the control group (general anesthesia, 38 cases). The intraoperative estimated blood loss, operative time and intraoperative anesthetic usage were recorded. Moreover, the effective pressing times of the posterior cerebral artery (PCA), the dosage of sufentanil in patient controlled intravenous analgesia (PCIA) were observed within 48 hours after operation. Results The dosage of propofol and remifentanil, the time of intestinal exhaust recovery time and the hospital study in the study group were lower than those in the control group. The HR and MAP of the two groups, with a trend towards gradual decrease at T0 and T1, were lower than those at T0. At 2 h, 6 h, 8 h and 24 h after operation, the visual analogue scale/score (VAS) score of the study group was lower than that of the control group. The analgesic rescue rate, the dosage of sufentanil and the effective PCA compression times in the study group were lower than those in the control group. The total incidence of adverse reactions in postanesthesia care unit (PACU) in the study group was significantly lower than that in the control group (8/38 vs. 18/38). Conclusion The combination of ultrasound-guided quadratus lumborum block and general anesthesia effectively exerts beneficial outcomes in terms of validly reducing the dose of tranquilizers and anesthetic analgesics during PCNL, which is able to treat patients with anesthetic mode of low opioids.