基于介电弹性体的旋转步进柔性驱动器

Rotary stepping flexible actuator based on dielectric elastomer

为了适应未来小型自动化机器的驱动需求,设计并实现了一种基于单层介电弹性体薄膜的旋转步进柔性驱动器。相对于传统双轴拉伸装置,自制的八爪拉伸装置使介电弹性体薄膜的预拉伸更均匀。测试了不同预拉伸量下介电弹性体驱动器的最大形变量,确定了制作驱动单元所需的介电弹性体薄膜最佳的预拉伸量。最终通过合理的设计将棘轮机构和驱动单元相结合实现了旋转步进柔性驱动。由于介电弹性体驱动器存在迟滞现象,导致驱动器的步进频率会随着负载质量的增大而减小。通过调节驱动信号的频率,可以改变驱动器的负载能力及步进频率。试验结果表明,当驱动电压为4.53 kV,空载时驱动器步进频率最高可达2.3 Hz;负载时,最大负载为263 g,即峰值扭矩为13.15 mN·m,此时步进频率降至0.22 Hz。

In order to meet the driving requirements for small automatic machines in the future,a rotary stepping flexible actuator was designed and implemented based on a monolayer dielectric elastomer film.The device was designed in terms of eight claws,which makes the pre-stretching of dielectric elastomer film more uniform compared with the traditional biaxial stretched mechanism.The maximum deformation of dielectric elastomer actuator was measured under different pre-stretching quantities,and the optimum pre-stretching quantity was determined for dielectric elastomer film needed for the driving unit.Finally,through appropriate design,the rotary stepping flexible actuator was implemented by combining the ratchet and the driving unit.The stepping frequency of dielectric elastomer actuator decreases with the increase of load mass because of the hysteresis phenomenon.The load capacity and stepping frequency of the actuator can be changed by adjusting the frequency of the driving signal.The results show that when the driving voltage is 4.53 kV,the stepping frequency can reach 2.3 Hz with the actuator unloaded.When the actuator is loaded,the maximum load is 263 g,the peak torque is 13.15 mN·m,and the stepping frequency drops to 0.22 Hz.