Robust Control of Precision Nano-Positioning System for Microsurgical Applications

Nano-positioning systems can be used in drug delivery systems, lab-on-a-chip devices, biomedical research, microsurgery and minimally invasive procedures, nanoscale imaging and diagnostics, and nanoscale object control and manipulation. Diagnostic devices and algorithms allow doctors to swiftly and accurately diagnose a wide range of medical conditions, making them essential in modern healthcare. Practical implementation requires robustness. Creep, hysteresis and friction in linear actuators reduce output motion precision and system stability. Piezoelectric actuator tracking control and Bouc-Wen hysteresis models are investigated in this work and its robustness can be improved with the application of Sliding Mode Control technique. Due to its tiny size and high-resolution displacement, the actuator can be employed in optical systems, microscope stages, nano-positioning platforms and other precision positioning systems. The system's static and dynamic behaviour is analysed using a modified Bouc-Wen non-symmetric model. Because it matches anticipated and actual curves, the Bouc-Wen model simulates piezoelectric actuator system hysteresis. MATLAB's parameter optimisation toolbox optimises Hysteresis model parameters. The system's tracking performance and hysteresis improve with SMC control. A control approach employing higher-order sliding mode techniques to address uncertainty in nonlinear systems is presented in this study.