压电陶瓷迟滞非线性前馈补偿器

为了有效补偿压电陶瓷的迟滞非线性,提出了基于STOP算子的改进PI模型以改善传统基于PLAY算子的PI模型解析求逆的复杂过程以及通过插值算法求逆的大量耗时。介绍了传统的基于PLAY算子和基于STOP算子的PI模型,然后基于STOP算子的叠加形式建立了以预期位移为输入,以控制电压为输出的PI模型,并将这一模型直接作为前馈控制器补偿压电陶瓷的迟滞效应。为了更好地平衡全局寻优与局部寻优能力,对粒子群优化算法进行了改进,利用其辨识出各算子的权值。最后,利用实验的方法验证了改进的PI模型对迟滞非线性的补偿效果。进行了两组实验测试,结果显示:无论对于规律变化还是随机变化的输入,提出的改进PI模型都可以很好补偿迟滞非线性,跟踪误差可控制在1%以内。因此,基于STOP算子的改进PI模型在压电陶瓷控制领域中具有很好的实用价值。

Compensating controller for hysteresis nonlinerity of piezoelectric ceramics

To effectively compensate the hysteresis nonlinearity of piezoelectric ceramics, a modified PI model based on STOP operator was proposed to avoid the complex processing in solving inverse model and time consuming in interpolating method of the traditional PI model based on PLAY operator. Firstly, traditional PI models based on PLAY operator or STOP operator were introduced. Then, modified PI model based on STOP operator was established by taking an expecting displacement as the input and a control voltage as the output, and the model was used as a feedback controller to compensate the hysteresis effect of piezoelectric ceramics. To balance the ability of local optimization and global optimization, the particle swarm optimization algorithm was improved to identify the weights of operators with different thresholds. Finally, the modified PI model was used to verify experimentally the compensating effects for the hysteresis nonlinearity. Two groups of experiments were carried out, and the results show that the hysteresis has been compensated well by modified PI model with the error no more than 1% no matter the input is continuous or random. It concludes that, the modified PI model based on STOP operator is of great value in the field of piezoelectric ceramic control.