Precision tracking control of shape memory alloy actuators using neural networks and a sliding-mode based robust controller
Precision tracking control of shape memory alloy actuators using neural networks and a sliding-mode based robust controller
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DOI：
10.1088/0964-1726/12/2/310
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发表时间：
2003-04-01
影响因子：
4.1
通讯作者：
Batur, C
中科院分区：
文献类型：
--
作者：
Song, G;Chaudhry, V;Batur, C
本文提出了一种新的方法来控制形状记忆合金（SMA）驱动器的滞后补偿，通过使用神经网络前馈控制器和滑模鲁棒反馈控制器。SMA致动器表现出严重的滞后，这通常是导致调节或跟踪系统中的位置不准确的原因，并且在某些情况下甚至可能导致不稳定。在这项研究中使用了一个单一的SMA线驱动器。一个测试系统，其中包括一个线架，直线轴承，偏置弹簧，位置传感器，可编程电流放大器和基于PC的数字数据采集和实时控制系统，被用来测试SMA线驱动器在开环和闭环的方式。所提出的控制包括两个主要部分：一个前馈神经网络控制器，这是用来消除或减少滞后，和基于滑模的鲁棒反馈控制器，这是用来补偿不确定性，如滞后消除误差，并确保系统的稳定性。根据钢丝绳作动器的开环试验结果，设计了前馈神经网络控制器。与所提出的控制，SMA驱动器以下的正弦命令具有不同的频率和幅度的测试进行。实验结果表明，SMA驱动器的实际位移与建议的控制密切遵循所需的正弦命令。
This paper presents a new approach to controlling shape memory alloy (SMA) actuators with hysteresis compensation by using a neural network feedforward controller and a sliding-mode based robust feedback controller. SMA actuators exhibit severe hysteresis, which is often responsible for position inaccuracy in a regulation or tracking system and may even cause instability in some cases. A single SMA wire actuator is used in this research. A testing system, which includes a wire stand, a linear bearing, a bias spring, a position sensor, a programmable current amplifier and a PC-based digital data acquisition and real-time control system, is used to test the SMA wire actuator in both open- and closed-loop fashions. The proposed control includes two major parts: a feedforward neural network controller, which is used to cancel or reduce the hysteresis, and a sliding-mode based robust feedback controller, which is employed to compensate uncertainties such as the error in hysteresis cancellation and ensures the system's stability. The feedforward neural network controller is designed based on the experimental results of open-loop testing of the wire actuator. With the proposed control, tests of the SMA actuator following sinusoidal commands with different frequencies and magnitudes are conducted. The experiments show that the actual displacement of the SMA actuator with the proposed control closely followed that of the desired sinusoidal command.