This paper presents the control of a two-degree-of-freedom piezoelectric actuator that exhibits hysteresis nonlinearity, creep nonlinearity, badly damped vibration, and cross couplings without using feedback sensors. The principle consists in compensating first the hysteresis, then the creep, and finally the vibration. The proposed compensation technique is multivariable and therefore is also able to reduce the cross couplings that are unwanted phenomena. The experimental tests demonstrate that the hysteresis that initially exceeds 19% is reduced to about 0.01%, while the creep is reduced from 5.5% to 0.04%. Regarding the vibration, the related overshoot that was initially 45% is completely removed. Note to Practitioners-This paper describes an approach to control and to automate dexterous precise positioning systems based on multiaxes piezoelectric actuators (PEAs). Two problems have motivated the approach investigated in this paper: 1) the presence of nonlinearities (hysteresis and creep), of badly damped vibration and of cross couplings in the multiaxes PEAs and 2) the lack of convenient sensors to feedback control them. Therefore, this paper proposes multivariable and complete feedforward control approach that does not require external sensors. This sensorless control architecture permits a low-cost and a high integration feature additionally to the fact that it is of great interest in applications at small scales where implementation of real-time measurement system is often difficult.

中文翻译：

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多轴压电执行器中的迟滞、蠕变、严重阻尼振动和交叉耦合的多变量补偿


本文介绍了二自由度压电执行器的控制，该执行器在不使用反馈传感器的情况下表现出磁滞非线性、蠕变非线性、严重阻尼振动和交叉耦合。其原理在于首先补偿滞后，然后补偿蠕变，最后补偿振动。所提出的补偿技术是多变量的，因此还能够减少不需要的现象的交叉耦合。实验测试表明，最初超过19%的滞后减少至约0.01%，而蠕变则从5.5%减少至0.04%。关于振动，最初 45% 的相关超调已完全消除。从业人员注意事项 - 本文描述了一种基于多轴压电执行器 (PEA) 的灵巧精确定位系统的控制和自动化方法。本文研究的方法有两个问题：1）多轴 PEA 中存在非线性（滞后和蠕变）、严重阻尼振动和交叉耦合；2）缺乏方便的传感器来反馈控制它们。因此，本文提出了不需要外部传感器的多变量、完全前馈控制方法。这种无传感器控制架构具有低成本和高集成度的特点，此外，它对于难以实现实时测量系统的小规模应用也很感兴趣。