摘要
压电宏纤维(marco fiber composite,MFC)具有柔性好、变形能力强的优点,但MFC致动器驱动的柔性臂的迟滞非线性严重影响系统定位精度。提出一种具有非对称性的改进Prandtl-Ishlinskii(PI)迟滞模型,解决经典PI迟滞模型的缺陷(对称性);该模型基于经典PI迟滞模型,叠加一系列不同权重、不同阈值的双边死区算子获得,基于最小二乘法的迟滞模型辨识结果表明,改进PI迟滞模型对MFC致动器的迟滞建模误差从PI迟滞模型误差的16.06%降到5.58%。另外,建立系统的离散传递函数模型来描述系统的线性动态特性,并与改进PI迟滞模型串联得到组合模型,解决纯迟滞模型仅能描述低频、准静态情况下的迟滞特性问题。在前馈补偿下,对MFC致动的柔性臂进行正弦波轨迹跟踪试验,测得补偿后实测位移与期望跟踪位移基本吻合,跟踪精度达到93.62%以上。试验结果证明,所提出的改进PI迟滞模型、离散传递函数模型及补偿方法的有效性。
Piezoelectric macro fiber composite(MFC)has the advantages of good flexibility and strong deformability.However,the hysteresis and nonlinearity of the flexible arm driven by the MFC actuator seriously affect the positioning accuracy of the system.An improved Prandtl-Ishlinskii(PI)hysteresis model with asymmetry was proposed to solve the defects(symmetry)of the classic PI hysteresis model.The model was obtained by superimposing a series of bilateral dead zone operators with different weights and different thresholds based on the classic PI hysteresis model.The hysteresis model identification results based on the least square method show that the improved PI hysteresis model can reduce the modeling error of the MFC actuator from 16.06%to 5.58%.Besides,a discrete transfer function model of the system was established to describe the linear dynamic characteristics of the system.The discrete transfer function model and the improved PI hysteresis model were connected in series to obtain a combined model.It solves the problem that the pure hysteresis model can only describe the hysteresis characteristics under low-frequency and quasi-static conditions.Under feedforward compensation,a sinusoidal wave trajectory tracking experiment was performed on the flexible arm actuated by the MFC actuator.The measured displacement after compensation is basically consistent with the expected tracking displacement,and the tracking accuracy is over 93.62%.The experimental results demonstrate the effectiveness of the proposed improved PI hysteresis model,discrete transfer function model and compensation method.
作者
卢荣华
陈特欢
娄军强
崔玉国
LU Ronghua;CHEN Tehuan;LOU Junqiang;CUI Yuguo(School of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 315211,China;State Key Laboratory of Industrial Control Technology,Zhejiang University,Hangzhou 310027,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第10期301-308,共8页
Journal of Vibration and Shock
基金
国家自然科学基金项目(61703217,51505238)
浙江省自然科学基金项目(LY21F030003)
宁波市自然科学基金项目(2019A610112)
宁波市科技创新2025重大专项(2019B10100)
浙江省教育厅科研项目(Y201839158)。
