Nonsingular Integral Terminal Sliding Mode Control for Resonant Frequency Tracking of Electromagnetic Acoustic...

Area of Science:

• Control Systems Engineering
• Materials Science
• Acoustics

Background:

• Electromagnetic acoustic transducers (EMATs) face challenges in maintaining stable resonant frequency and conversion efficiency due to environmental variations.
• Drifting working frequencies in EMATs lead to reduced performance and reliability in various applications.

Purpose of the Study:

• To develop a robust and precise resonant frequency tracking control strategy for EMATs.
• To enhance the convergence speed and tracking accuracy of EMATs operating frequency to its natural resonant frequency.
• To improve the overall performance and stability of EMAT systems under changing environmental conditions.

Main Methods:

• Implementation of a fixed-time nonsingular integral terminal sliding mode (FT-NITSM) control strategy.
• Design of a specialized resonant frequency tracking controller for EMATs.
• Analysis of system stability using Lyapunov functions and validation through numerical simulations.

Main Results:

• The FT-NITSM control strategy demonstrated precise tracking of EMATs' operating frequency to its natural resonant frequency in under 3 seconds.
• Achieved a tracking error of less than 0.01 × 10⁴ Hz, showcasing high accuracy.
• Ensured the control system's impedance angle remained consistent and bounded within -5 to 5° at steady state, with limited overshoot variation.

Conclusions:

• The proposed FT-NITSM control strategy offers a robust solution for precise resonant frequency tracking in EMATs.
• This method significantly improves convergence speed and tracking accuracy, enhancing EMAT performance.
• The study provides a valuable control framework for advancing EMAT technology and applications.