共查询到19条相似文献,搜索用时 171 毫秒
1.
针对压电叠堆作动器的率相关迟滞非线性特性,该文提出了一种基于asymmetric unilateral backlash(aubacklash)算子的BP神经网络率相关迟滞建模方法。首先提出了改进的aubacklash算子,改善了Prandtl-Ishlinskii(PI)模型backlash算子在原点处残余位移及严格中心对称的问题;其次分析了压电叠堆作动器迟滞的率相关记忆特性,提出了率相关BP神经网络迟滞模型;最后搭建了迟滞建模精度评估系统,采用Levenberg-Marquardt(L-M)算法辨识aubacklash算子模型参数,确定了BP神经网络模型最优结构参数。实验结果表明,在高、低单一频率及混合频率下,BP神经网络模型较PI模型均方误差降低了70.90%~89.98%,相对误差降低了70.69%~89.84%,验证了该模型的精度与频率适应性。 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
为达到在脉动气流激励下抑制风洞模型振动的目的,该文提出了基于压电陶瓷作动器神经网络模型的风洞模型主动振动控制方法,并进行了实验研究。首先,分析了风洞模型系统振动特性,建立了内嵌式压电陶瓷作动器的主动振动控制系统,通过模型质心加速度推算出压电陶瓷作动器期望输出抑振力。然后,建立了压电陶瓷作动器期望输出抑振力 激励电压的神经网络模型,并根据该模型设计了一种实时解算加速度为激励电压的控制方法。最后,通过地面试验对控制方法的有效性进行验证。实验结果表明,该控制方法具有良好的实时性和鲁棒性,在锤击试验中,振动加速度衰减时间相比于压电方程线性控制时减小了54.46%,系统阻尼比增大了1.58倍,取得了良好的控制效果。 相似文献
10.
11.
The hysteretic behavior of a plant with a non-negative input, referred to as one-sided hysteresis, is characterized by an initial ascending curve and hysteresis loops. It is observed that the widely-used classical Preisach hysteresis model and its modifications cannot represent such one-sided hysteresis due to the limitation of the Preisach hysteresis operator. To address this issue, a novel hysteresis operator modified from the Preisach hysteresis operator is proposed in this study and on this basis, a rate-independent hysteresis model and a rate-dependent hysteresis model are developed with methods to estimate their parameters. An algorithm to invert the rate-independent hysteresis model and its application to tracking control are also presented. The models and control schemes developed were verified experimentally on a commercially-available piezoelectric actuator. The results obtained show that the models developed are promising to represent the one-sided hysteresis of the piezoelectric actuator and that the inverting algorithm of the rate-independent hysteresis model is effective as applied to the tracking control of piezoelectric actuators. 相似文献
12.
Tracking control of a piezoceramic actuator with hysteresis compensation using inverse Preisach model 总被引:6,自引:0,他引:6
G. Song Jinqiang Zhao Xiaoqin Zhou J.A. De Abreu-Garcia 《Mechatronics, IEEE/ASME Transactions on》2005,10(2):198-209
This paper presents the classical Preisach hysteresis modeling and tracking control of a curved pre-stressed piezoceramic patch actuator system with severe hysteresis. The actuator is also flexible with very small inherent damping. It has potential applications in active antennas. A series of tests are conducted to study the hysteresis properties of the piezoceramic actuator system. The numerical expressions of the classical Preisach model for different input variations are presented. The classical Preisach model is applied to simulate the static hysteresis behavior of the system. Higher order hysteresis reversal curves predicted by the classical Preisach model are verified experimentally. The good agreement found between the measured and predicted curves showed that the classical Preisach model is an effective mean for modeling the hysteresis of the piezoceramic actuator system. Subsequently, the inverse classical Preisach model is established and applied to cancel the hysteresis the piezoceramic actuator system for the real-time microposition tracking control. In order to improve the control accuracy and to increase damping of the actuator system, a cascaded PD/lead-lag feedback controller is designed with consideration of the dynamics of the actuator. In the experiments, two cases are considered, control with major loop hysteresis compensation, and control with minor loop hysteresis compensation. Experimental results show that RMS tracking errors are reduced by 50% to 70% if the hysteresis compensation is added in the feedforward path in both cases. Therefore, hysteresis compensation with the feedback controller greatly improves the tracking control accuracy of the piezoceramic actuator. 相似文献
13.
为了辨识压电驱动器中固有的迟滞特性,提出了一种基于区间二型Takagi Sugeno(T S)模糊系统的建模方案。首先,引用垂直距离公式替换传统的误差计算公式,使聚类算法与所辨识的超平面结果直接相关联,并提出了改进的区间二型模糊C回归模型(FCRM)聚类算法用于模糊空间的划分,提高了区间划分精度。其次,针对超球型高斯隶属度函数与超平面型聚类算法结构不匹配的问题,引入了与超平面相匹配的超平面隶属度函数完成模糊前件参数的辨识,并利用最小二乘法完成模糊后件参数的辨识。最后,利用上述方案完成了压电驱动器迟滞特性的建模。实验结果证明该方案是有效的。 相似文献
14.
This paper investigates the influence of hysteresis present in the ferromagnetic core of a variable reluctance actuators on the force reproducibility. To reduce this influence and to boost reproducibility, a hysteretic inverse actuator model is derived and used to linearize a current-driven reluctance actuator. Furthermore, an identification procedure for identifying the parameters of the hysteresis model and the remaining actuator non-linearities is presented. Two actuators are experimentally tested with the proposed compensator and a linearization error smaller than 0.05% of the maximum force is achieved, which is an order of magnitude improvement over single-valued inverse compensators. A comparably small error is obtained for non-trivial, non-periodic inputs when higher order reversal curves of the actuator hysteresis have to be reproduced as well. The simple structure of the compensator allows a fast implementation in digital controllers. 相似文献
15.
针对压电叠堆迟滞带来的非线性效应严重制约系统控制精度提升的问题,该文提出了一种基于复合控制的压电驱动器控制方法,对系统非线性误差进行建模补偿,并基于数控芯片实现了嵌入式驱动设计。采用广义PI模型对被控压电促动器进行建模,利用指数函数作为密度函数,并基于粒子群算法对包络函数和密度函数进行参数寻优,最终得到压电促动器的前馈补偿逆模型,结合比例积分控制率实现系统的复合控制。同时采用数字信号处理结合现场可编程门阵列(DSP+FPGA)的数控架构,既保证了逆模型求解过程在DSP中实现的便捷性,又保证了采样及闭环控制在FPGA中实现的实时性及快速性。实验结果证明了所提设计方法的正确性及有效性。 相似文献
16.
为了提高空间天文望远镜精密稳像系统中大口径压电快摆镜机构(Fast Steering Mirror,FSM)的控制精度,采用迟滞前馈补偿和最优PID控制算法相结合的复合控制策略。针对基于广义Play算子的Prandtl-Ishlinskii(PI)模型可逆性受约束条件限制以及求逆过程中模型参数估计误差累加的问题,提出了一种基于广义Stop算子的PI逆模型进行压电执行器(Piezoelectric Actuator,PZT)迟滞补偿。针对逆迟滞模型的不确定性和直接前馈控制抗干扰能力差的问题,在控制系统中加入最优PID闭环控制器。采用自适应差分进化算法(Adaptive Differential Evolution,ADE)对迟滞逆模型参数和PID控制器参数进行寻优并引入混沌搜索机制来提高ADE算法的性能。实验结果表明:与传统PI模型解析求逆方法相比,基于广义Stop算子的PI逆模型能够更好描述逆迟滞曲线,拟合频率为1 Hz的迟滞曲线,拟合精度提高78.04%;实时跟踪频率分别为1、10、20 Hz的大口径快摆机构目标摆动位移,复合控制策略的跟踪精度相比于直接前馈控制分别提高了38.56%,22.92%和13.5%。 相似文献
17.
This paper introduces a novel concept termed Smart Mesoflaps for Aeroelastic Recirculation Transpiration (SMART) to render mass and momentum transfer for controlling shock/boundary-layer interactions in supersonic jet inlets. The SMART concept consists of a matrix of small flaps designed to undergo local aeroelastic deflection to achieve proper mass bleed or injection when subjected to shock loads. To optimize the performance of this system, NiTi shape memory alloy is used as an actuator for the flaps to control the amount of recirculation. The focus of this paper will be the subsystem modeling and control of a single flap. After a relatively detailed model is developed, a simpler model is generated, and it is experimentally shown that this approximation is adequate for control purposes. Next, the control strategy for this subsystem, subject to hysteresis and actuator saturation, is presented. A basic proportional integral derivative (PID) controller is enhanced using a hysteresis compensator (HC) and an error governor (EG). A generalized error governing scheme for PID controllers to compensate for actuator saturations is also developed. This EG method is generalizable to any stable process controlled by a PID. Finally, the PID with HC and the error governing method is experimentally applied to a benchtop SMART subsystem. 相似文献
18.
Feedforward Controller of Ill-Conditioned Hysteresis Using Singularity-Free Prandtl–Ishlinskii Model
Cheng Yap Shee U-Xuan Tan Riviere C.N. Wei Tech Ang Win Tun Latt 《Mechatronics, IEEE/ASME Transactions on》2009,14(5):598-605
Piezoelectric, magnetostrictive, and shape memory alloy actuators are gaining importance in high-frequency precision applications constrained by space. Their intrinsic hysteretic behavior makes control difficult. The Prandtl-Ishlinskii (PI) operator can model hysteresis well, albeit a major inadequacy: the inverse operator does not exist when the hysteretic curve gradient is not positive definite, i.e., ill condition occurs when slope is negative. An inevitable tradeoff between modeling accuracy and inversion stability exists. The hysteretic modeling improves with increasing number of play operators. But as the piecewise continuous interval of each operator reduces, the model tends to be ill-conditioned, especially at the turning points. Similar ill-conditioned situation arises when these actuators move heavy loads or operate at high frequency. This paper proposes an extended PI operator to map hysteresis to a domain where inversion is well behaved. The inverse weights are then evaluated to determine the inverse hysteresis model for the feedforward controller. For illustration purpose, a piezoelectric actuator is used. 相似文献
19.
介绍了一种新型压电驱动器含金属芯压电陶瓷纤维(MPF),推导了MPF的驱动电压与位移关系,运用ABAQUS软件对MPF进行了有限元仿真,并将MPF在不同驱动电压下的位移进行了理论值和仿真值的对比,验证了所推导公式中响应位移和驱动电压关系的正确性。通过实验测试了MPF的迟滞特性,并设计了迟滞逆模型开环控制、迟滞逆模型结合比例、积分和微分(PID)的两种控制方法对MPF进行了迟滞补偿控制。实验表明,复合控制的效果较好,MPF迟滞得到了很好补偿,使输入和输出呈线性,实现了高于10nm的高精度定位。复合控制的实验结果也进一步验证了MPF位移公式的正确性。 相似文献