Dror A Levy, Shapiro Amir
Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
Heliyon. 2024 May 8;10(11):e30683. doi: 10.1016/j.heliyon.2024.e30683. eCollection 2024 Jun 15.
Piezoelectric elements (PEMs) are used in a variety of applications. In this paper, we developed a new simple sensorless method for a Piezoelectric Actuator (PEA), which includes piezostack elements and a three-stage amplification mechanism. This research focuses on a piezoelectric actuator that incorporates a three-stage amplification system, where the outcome of one stage serves as the input for the subsequent one. The actuator receives two types of inputs: the voltage applied to the piezoelectric elements and the mechanical load it carries. Its output is defined by the rotation angle observed at the end of the third amplification stage. To indirectly measure the actuator's displacement, a basic external circuit is utilized. The precise movement of these actuators is essential. To circumvent the high costs and limitations associated with highly accurate displacement sensors, there has been a growing interest in sensorless control methods. Certain electrical signals, when measured, can provide an estimation of displacement. However, induced voltage measurements are not effective for piezoelectric stacks. Two more promising measures are the voltage and current of the piezoelectric material. Given that the electrical charge on these actuators closely reflects their displacement with minimal hysteresis across a broad frequency spectrum, it's proposed that displacement can be effectively gauged through current measurements that assess charge. The core contribution of this paper is the introduction and validation, both theoretically and experimentally, of a hybrid algorithm that leverages these two electrical signals to enhance the accuracy of displacement estimates. This was confirmed using a laboratory setup. The primary benefit of this research is the presentation of a straightforward sensorless control algorithm, poised for further exploration within the realm of piezoelectric actuators. The simplicity of both the theoretical model and the sensorless technique facilitates their application across a diverse range of piezoelectric actuators and amplification systems, thereby streamlining the design, modeling, and control strategy development for various actuators. The innovation of this study stems from the application of an uncomplicated sensorless estimation algorithm, coupled with a system-level perspective on piezoelectric actuators. This approach utilizes a simple, adaptable model suitable for a wide array of applications and operational techniques.
压电元件（PEM）被应用于各种领域。在本文中，我们为一种压电致动器（PEA）开发了一种新的简单无传感器方法，该压电致动器包括压电叠堆元件和三级放大机构。本研究聚焦于一种包含三级放大系统的压电致动器，其中一级的输出作为后续一级的输入。该致动器接收两种类型的输入：施加到压电元件上的电压和其所承载的机械负载。其输出由在第三级放大末端观察到的旋转角度定义。为了间接测量致动器的位移，使用了一个基本的外部电路。这些致动器的精确运动至关重要。为了规避与高精度位移传感器相关的高成本和局限性，对无传感器控制方法的兴趣日益浓厚。某些电信号在测量时可以提供位移估计。然而，感应电压测量对于压电叠堆并不有效。另外两种更有前景的测量方法是压电材料的电压和电流。鉴于这些致动器上的电荷在很宽的频谱范围内以最小的滞后紧密反映其位移，建议通过评估电荷的电流测量来有效测量位移。本文的核心贡献是在理论和实验上引入并验证了一种混合算法，该算法利用这两种电信号来提高位移估计的准确性。这通过实验室装置得到了证实。本研究的主要益处是提出了一种简单的无传感器控制算法，准备在压电致动器领域进行进一步探索。理论模型和无传感器技术的简单性便于它们应用于各种压电致动器和放大系统，从而简化了各种致动器的设计、建模和控制策略开发。本研究的创新源于应用了一种简单的无传感器估计算法，并从系统层面看待压电致动器。这种方法使用了一个简单、适应性强的模型，适用于广泛的应用和操作技术。
