Charge Controller with a Novel Hysteresis Disturbance Observer for High-Accuracy Trajectory Tracking of Piezoelectric Actuators

Piezoelectric hysteresis poses a major challenge for achieving high-accuracy motion in piezo-actuators. While charge control has emerged as a promising sensorless and model-free solution, the complexity of hysteresis often limits the tracking performance of existing charge controller designs. To address this challenge, we have developed a novel charge controller that integrates a hysteresis disturbance observer (HDOB). Such an observer is inspired by model-based hysteresis decomposition techniques and consists of two essential components: hysteresis decomposition and control signal regulation. By reconstructing the control signal, the controller circuit allows for fine-tuning to handle complex tracking errors, thus enabling superior tracking performance compared to existing designs. Furthermore, the diode-based dc stabilization scheme expands the controller's operating bandwidth, making it suitable for applications with wide bandwidth requirements. The proposed design, with its improved tracking performance, has broad implications for various applications, such as precision positioning systems, nanopositioning devices, and scanning probe microscopy.