Wu Jundong, Nie Xinyu, Wang Yawu, Su Chun-Yi, Sato Daiki, She Jinhua
IEEE Trans Cybern. 2025 Nov;55(11):5435-5444. doi: 10.1109/TCYB.2025.3586002.
The trajectory tracking control for the photothermal-driven liquid crystal elastomer (LCE) actuator presents a significant challenge due to its hysteresis nonlinear characteristic and its inherent complex deformation mechanism. To address this challenge, this article proposes a trajectory tracking control method for the LCE actuator utilizing a nonlinear compensator and a state observer. The proposed control is a multistep control, which includes temperature control from the input voltage to the LCE temperature and displacement control from the LCE temperature to the LCE displacement. In the proposed method, we design a non-Lipschitz continuous state-feedback controller to realize finite-time convergence control of the temperature. As for the displacement control, we design a state observer to estimate the change rate of the LCE displacement. Meanwhile, a nonlinear inverse compensator is designed to compensate for the hysteresis nonlinearity of the LCE dynamics, which simplifies the complex nonlinear control problem into a linear control problem. Hence, the pole placement method can be utilized to design a trajectory tracking controller to achieve the control objective. The proposed control method is validated by tracking control experiments with different target trajectories.
由于光热驱动液晶弹性体（LCE）致动器具有滞后非线性特性及其固有的复杂变形机制，其轨迹跟踪控制面临重大挑战。为应对这一挑战，本文提出了一种利用非线性补偿器和状态观测器的LCE致动器轨迹跟踪控制方法。所提出的控制是一种多步控制，包括从输入电压到LCE温度的温度控制以及从LCE温度到LCE位移的位移控制。在所提出的方法中，我们设计了一个非利普希茨连续状态反馈控制器来实现温度的有限时间收敛控制。对于位移控制，我们设计了一个状态观测器来估计LCE位移的变化率。同时，设计了一个非线性逆补偿器来补偿LCE动力学的滞后非线性，这将复杂的非线性控制问题简化为线性控制问题。因此，可以利用极点配置方法来设计轨迹跟踪控制器以实现控制目标。通过对不同目标轨迹的跟踪控制实验验证了所提出的控制方法。
