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51.
52.
Robust Adaptive Neural Control for a Class of Time‐Varying Delay Systems with Backlash‐like Hysteresis Input 下载免费PDF全文
Xiuyu Zhang Zhi Li Chun‐Yi Su Xinkai Chen Jianguo Wang Linlin Xia 《Asian journal of control》2016,18(3):1087-1101
This paper proposes a robust adaptive dynamic surface control (DSC) scheme for a class of time‐varying delay systems with backlash‐like hysteresis input. The main features of the proposed DSC method are that 1) by using a transformation function, the prescribed transient performance of the tracking error can be guaranteed; 2) by estimating the norm of the unknown weighted vector of the neural network, the computational burden can be greatly reduced; 3) by using the DSC method, the explosion of complexity problem is eliminated. It is proved that the proposed scheme guarantees all the closed‐loop signals being uniformly ultimately bounded. The simulation results show the validity of the proposed control scheme. 相似文献
53.
连接界面的黏滑、摩擦行为不仅是引起结构刚度和阻尼非线性的主要原因,而且是结构无源阻尼的主要来源.Iwan模型能够较好地复现连接界面的黏滑、摩擦行为.本文采用时频域交替法(Alternating Frequency/Time Domain Method,AFT)研究含Iwan非线性模型的单自由度振子系统的稳态响应.时频域交替法具有频域法求解线性系统响应的高效性和时域法判断非线性力的便捷性特点,采用离散傅里叶变换和傅里叶逆变换,在频域和时域内分别求解系统响应和对应的非线性恢复力,再反复迭代计算系统的稳态响应.将时频域交替法计算结果和中心差分法计算的结果进行对比,并研究激励幅值对系统非线性特征的影响.结果表明,时频域交替法计算的结果与中心差分计算的结果具有较好的一致性,且求解效率较高,计算耗时减少50%;随着激励幅值的增加,系统的能量耗散增加,刚度降低,固有频率降低. 相似文献
54.
行波型超声电机基于神经网络的逆模型辨识 总被引:1,自引:0,他引:1
行波型超声电机的动态特性受定子压电陶瓷迟滞和接触层非线性摩擦力的影响,表现出复杂的多值映射特征.通过引入动态迟滞逆算子,将存在于超声波电机逆系统中的多值映射在新的扩张输入空间上,转换为一一映射;然后使用神经网络建立超声波电机的逆模型,对迟滞和非线性摩擦力的影响进行补偿.所建立的模型结构简单,可以在线调整适应电机参数的非线性变化.实验仿真结果验证了该方法的有效性. 相似文献
55.
F. Zuo 《Journal of Superconductivity》1995,8(6):773-774
We report extensive magnetization measurements on single crystals of Tl2Ba2CuO6 superconductors. The fishtail magnetization is found to disappear above a characteristic temperature (60 K), which corresponds to a crossover temperature in the temperature dependence of the irreversibility line. Since the low temperature irreversibility field can be modeled by a Josephson coupled layered system, we propose that the fishtail magnetization in the Tl2Ba2CuO6 system is due to dimensional crossover. 相似文献
56.
57.
Chunliu Xu Weibo Hua Qinghua Zhang Yuan Liu Rongbin Dang Ruijuan Xiao Jin Wang Zhao Chen Feixiang Ding Xiaodong Guo Chao Yang Liangrong Yang Junmei Zhao Yong-Sheng Hu 《Advanced functional materials》2023,33(33):2302810
Na superionic conductor of Na3MnTi(PO4)3 only containing high earth-abundance elements is regarded as one of the most promising cathodes for the applicable Na-ion batteries due to its desirable cycling stability and high safety. However, the voltage hysteresis caused by Mn2+ ions resided in Na+ vacancies has led to significant capacity loss associated with Mn reaction centers between 2.5–4.2 V. Herein, the sodium excess strategy based on charge compensation is applied to suppress the undesirable voltage hysteresis, thereby achieving sufficient utilization of the Mn2+/Mn3+ and Mn3+/Mn4+ redox couples. These findings indicate that the sodium excess Na3.5MnTi0.5Ti0.5(PO4)3 cathode with Ti4+ reduction has a lowest Mn2+ occupation on the Na+ vacancies in its initial composition, which can improve the kinetics properties, finally contributing to a suppressed voltage hysteresis. Based on these findings, it is further applied the sodium excess route on a Mn-richer phosphate cathode, which enables the suppressed voltage hysteresis and more reversible capacity. Consequently, this developed Na3.6Mn1.15Ti0.85(PO4)3 cathode achieved a high energy density over 380 Wh kg−1 (based on active substance mass of cathode) in full-cell configurations, which is not only superior to most of the phosphate cathodes, but also delivers more application potential than the typical oxides cathodes for Na-ion batteries. 相似文献
58.
Ruichun Du Tianwei Bao Tangsong Zhu Jing Zhang Xinxin Huang Qi Jin Ming Xin Lijia Pan Qiuhong Zhang Xudong Jia 《Advanced functional materials》2023,33(30):2212888
Ionic conductive soft materials for mimicking human skin are a promising topic since they can be thought of as a possible basis for biomimetic sensing. In pursuit of devices with a long working range and low signal delay, conductive materials with low hysteresis and good stretchability are highly demanded. To overcome the challenges of highly stretchable conductive materials with good resilience, herein a chemical design is proposed where polyrotaxanes act as topological cross-linkers to enhance the stretchability by sliding-induced reduced stress concentration while the compatible ionic liquid is introduced as a dispersant for low hysteresis. The obtained ionogels exhibit versatile properties more than low hysteresis (residual strain = 7%) and good stretchability (550%), and also anti-fatigue, biocompatibility, and good adhesion. The low hysteresis is attributed to lower energy dissipation from the well-dispersed polyrotaxanes by compatible ionic liquids. The mechanism provides a new insight in fabricating highly stretchable and low-hysteresis slide-ring materials. Furthermore, the conductivity of the ionogels and their responses to strains and temperatures are measured. Benefiting from the good conductivity and low hysteresis, the ionogel is applied to develop a wireless communication system to realize rapid human-machine interactions. 相似文献
59.
To control a nonlinear system with both hysteresis and disturbance, it is necessary to establish a hysteresis model and improve the disturbance rejection ability. However, the input signal implicitly involved in the classical hysteresis model can lead to difficulty in constructing a compensator. In this study, a hysteresis model in explicit form is proposed with a bounded auxiliary variable. Then, a model-based inverse is constructed for approximate compensation for the hysteresis. Moreover, the compensation error, which is considered a part of the disturbance, is proved to be bounded. Disturbance estimation triggered control (DETC) is utilized to address the compensation error coupled with the external disturbance. According to the disturbance effect indicator (DEI), DETC can improve the system control performance by considering the disturbance effect judgment. Experimental results are presented to illustrate the potential of the proposed technique. 相似文献
60.
Since the hysteresis property inherently exists in the rubber material, it is necessary to deal with the control issues for the micro-hand by considering the hysteresis property. Therefore, in this paper, the robust tracking control for the micro-hand systems is discussed from the aspect of the Prandtl–Ishlinskii hysteresis property which is more applicable for the real applications. Firstly, a new model is obtained by combining the dynamic model of the micro-hand with Prandtl–Ishlinskii hysteresis property. Secondly, a new stability condition based on bounded input and bounded output stability is proposed for the Prandtl–Ishlinskii hysteresis modeled micro-hand system from two different cases. Thirdly, by designing the robust controllers based on the internal model control method, the tracking performance can be improved by eliminating the effect from the disturbance. Finally, simulation is used to further demonstrate the effectiveness of the proposed design scheme. 相似文献