基于灰色预测-模糊控制提高PZT的运动精度

Improvement of Movement Precision of PZT Based on Grey Prediction-Fuzzy Control

压电陶瓷由于其可以实现纳米级的定位精度,被广泛应用于高精度定位系统和微精细加工等领域。但压电陶瓷微位移系统的固有特性、制造缺陷以及如噪声、振动等使用环境的影响,使得其微动精度难以达到预期的理论要求。为了提高微位移系统的运动的精度,采用灰色预测控制和模糊控制的联合控制方式的方法,分别以输入步进电压10 mv和100 mv的情况下对压电陶瓷微位移系统的运动位移进行实验。灰色预测控制可以在任何环境和未知因素的情况下,可以实现未来态势的控制,属于超前控制,再而模糊控制根据之前采集的数据制定模糊规则和算法,进一步对输入量和反馈量的精确控制,结合各自的优势特点,从而提高压电陶瓷微位移系统的运动精度。通过反复的实验研究,结果使得系统的平均运动精度在两种输入下分别提高了3.5倍和2.7倍。该方法方案大大地改善了压电陶瓷微位移系统的运动精度,具有实际的可行性。

Due to the realization of nano-scale position precision, piezoelectric ceramic are widely used in the fields, such as high precision positioning system, micro-fine process and so on. But the inherent features and the manufacturing defects of piezoelectric displacement systems, as well as the impacts of circumstances such as noise, vibration and so on, make the micro-displacement precision hardly meet the expected theoretical requirement. In order to improve the accuracy of micro-displacement system movement, the method of the grey predictive control and fuzzy control is adopted, experiments of movement displacement of piezoelectric micro displacement system by step 10 mv and 100 mv are conducted respectively. Grey prediction control, in any environment or under the condition of unknown factors, can realize the control of the future situation, belonging to the advanced control, furthermore the fuzzy control, according to the data pre-collected, establishes fuzzy rules and algorithm, and then controls the inputs and feedbacks precisely, combining with their respective advantages, so as to improve the motion precision of piezoelectric micro-displacement system. Through repeated experiments and researches, the average motion precision of the system increases 3.5 times and 2.7 times respectively with two kinds of inputs. This solution greatly improves the movement accuracy of piezoelectric micro-displacement system and has validated practical feasibility.