This paper investigates the vibration suppression of an all-clamped plate based on an electromagnetic inertial actuator. A dynamic sliding mode controller combined with a model-assisted extended state observer (DSMC+MAESO) is developed to address strong electromechanical coupling, external disturbances, and nonlinearities of the vibration system. An electromechanical coupling dynamic model is established to capture the intrinsic nonlinearities induced by the inertial actuator’s electromagnetic force called control force. The model-assisted extended state observer (MAESO), employing the experimental setup, is developed to more accurately estimate the system states and total disturbances including strong coupling, nonlinearity and external disturbances, while avoiding bandwidth increase. Considering the influence of total disturbances on the all-clamped plate, a disturbance-compensated dynamic sliding surface is designed by incorporating the disturbance estimation from MAESO. The dynamic sliding mode controller (DSMC) optimizes the control voltage and reduces the high-frequency chattering phenomenon of conventional sliding mode control, thereby protecting the inertial actuator. The experiments are carried out on the basis of the National Instruments Peripheral Component Interconnect Express 6343 (NI PCIe-6343) acquisition card. Experimental results demonstrated that the proposed DSMC+MAESO method significantly suppressed vibration of the all-clamped plate, reducing the amplitude from 15.1 dB to 0.2 dB. This performance clearly outperformed dynamic sliding mode controller combined with an extended state observer (DSMC+ESO) and sliding mode controller combined with an extended state observer(SMC+ESO), confirming the superiority and practical applicability of the proposed method for vibration control in such structures.

Aiming to attenuate the total disturbances of a DC-DC buck converter, i.e., the mid-to-low frequency voltage ripple, load fluctuations, and input voltage variations, a novel fractional-order active disturbance rejection controller (FOADRC) is proposed in this paper. First, a novel fractional-order reduced-order extended state observer (FORESO) is developed to estimate and compensate the total disturbances through a feedforward channel. Second, the method of reducing order to achieve phase compensation is proposed to address the phase lag limitation and enhance the estimation accuracy of conventional fraction-order extended state observer (FOESO). Third, a theoretical basis for adjusting fractional order and observer bandwidth is provided by transforming FORESO into an equivalent FOTDE form in the frequency domain. Finally, the comparison of several experimental results demonstrates that the proposed FORESO exhibits better output voltage tracking performances compared to FOESO. The experimental results indicate that FORESO achieves a 16.7% improvement in RMSE, a 15% reduction in overshoot and a 10% enhancement in response speed compared to FOESO.

To address the degradation of speed regulation performance in the permanent magnet synchronous motor (PMSM) transmission system caused by the gearbox broken tooth fault and disturbances, a fault model-assisted active disturbance rejection control (FMA-ADRC) algorithm is proposed in this paper. First, an electromechanical coupling model of the motor–gearbox transmission system is established based on the dynamic model of the tooth fault. Secondly, a fault model-assisted extended state observer (ESO) in the active disturbance rejection controller is designed, where the periodic torque disturbances caused by the fault are compensated to reduce the estimation burden on the observer. In addition, the observer is nonlinearized to improve the accuracy of tracking disturbances. The observer error of the nonlinear ESO (NESO) is proven to converge to a bounded region within finite time by using the Lyapunov stability proof theory. Finally, the speed regulation performance of the proposed FMA-ADRC controller is verified under different degrees of fault using an experimental platform based on DSP28335 and MATLAB/SIMULINK R2023b. The reliability and superiority of the proposed controller are verified by the experiment results.

This paper proposes an improved nonlinear extended state observer (NLESO)-based dynamic sliding mode control strategy to address total disturbances, including modeling uncertainties, higher-order harmonics, external excitations, and random noise in an all-clamped piezoelectric plate. Modal analysis is conducted using a laser vibrometer to identify the natural frequencies and mode shapes for optimal actuator and sensor placement. An improved NLESO with a new nonlinear error feedback function xal ( xal -ESO) is developed for accurate state and disturbance estimation with enhanced noise suppression. A dynamic sliding mode surface (DSMC) based on the xal -ESO is designed to reduce high-frequency chattering and enhance vibration suppression performance. Simulation results show that the proposed xal -ESO outperforms traditional ESOs in estimation accuracy and noise suppression. Finally, experimental comparisons of vibration control performance are conducted on a MATLAB/Simulink real-time platform with an NI PCIe-6343 data acquisition card among the xal -ESO + DSMC, fal -ESO + DSMC, and LESO + DSMC schemes. The results demonstrate that the proposed xal -ESO + DSMC exhibits strong disturbance rejection capability.