液驱多维力加载系统的CMAC-PID复合控制

CMAC-PID Compound Control of Hydraulic Driving Multi-dimensional Force Loading System

液驱并联机构多维力加载系统是多维力加载环境模拟的重要设备,然而在多维力加载过程中存在强耦合力导致动态响应差的问题。为此提出一种新型CMAC-PID复合控制方法,用于抑制耦合力,提高力加载动态跟踪性能。通过构建多维力加载系统动力学模型与液压动力元件模型,分析研究耦合力产生机理。利用小脑模型神经网络控制器具有较强的自适应性,能够实现快速学习非线性函数等优点,将多维力加载时产生的耦合力视为干扰,引入CMAC-PID复合控制器不仅补偿了耦合力干扰,并且显著提高多维力加载跟随性能。实验结果表明,在CMAC-PID复合控制器作用下,多维力跟踪曲线幅值衰减最小降低84.9%,相位滞后最小降低35.1%,耦合力降低66.6%。验证了CMAC-PID复合控制器在降低各通道间耦合力,提高多维力加载控制精度的有效性。

The multi-dimensional loading system of hydraulic drive parallel mechanism is an important equipment for the simulation of multi-dimensional loading environment.However,strong coupling force lead to poor dynamic response during the multi-dimensional force loading.Therefore,a new CMAC-PID compound control method is proposed to restrain coupling force and improve dynamic tracking performance of the force loading.By constructing the dynamic model of multi-dimensional force loading system and the hydraulic power component model,we analyze the mechanism of coupling force generation.The CMAC has strong self-adaptability and can achieve fast learning of nonlinear functions.Based on this,we consider the coupling force generated by multi-dimensional force loading as interference and introduce the CMAC-PID compound controller,which not only compensates the coupling force interference,but also significantly improves the following performance of multi-dimensional force loading.The experimental results show that the amplitude attenuation of the multi-dimensional tracking curve is reduced by 84.9%,the phase lag is reduced by 35.1%and the coupling force is reduced by 66.6% under the action of the CMAC-PID compound controller,and the effectiveness of CMAC-PID compound controller in reducing the coupling force between channels and improving the control precision of multi-dimensional force loading is verified.