摘要
软体驱动器由于具有可实现大变形、柔性接触、人体友好等特性,在机器人、生物医学器件、驱动器件等领域具有重要的应用价值.然而,目前的软体驱动器大多基于弯曲、伸缩、扭转等变形形式,无法实现连续旋转运动.本文从无肢动物获得灵感,提出一种基于压电振动驱动的新型可旋转软体驱动器,通过圆形压电双晶片为硅胶软体结构提供激励力,诱导软体结构底部倾斜触角阵列与地面摩擦产生圆周方向的转矩,驱动该软体结构实现快速旋转运动.结合理论和有限元模拟分析旋转软体驱动器在激励作用下的受力及运动机理,并通过实验研究频率和电压对其旋转性能的影响.结果显示,在压电双晶片产生的激励力作用下,该驱动器可实现连续旋转运动,最高旋转速度可达到118.3 r/min,高于目前报道的软体驱动器的旋转速度,有望应用于驱动机械手和移动机器人等.
The soft actuator is a soft driving device exhibiting large-deformation ability,which is significantly different from the traditional rigid actuator usually composed of rigid components such as motors,bearings,gears,hinges and so on.Soft actuators are usually made of soft materials;theoretically,they have the advantages of infinite motion freedom,continuous deformation,and compliant contact.Therefore,the soft actuator shows remarkable advantages in grasping and handling of fragile objects or motion in complex unstructured environments.However,most of the previous soft actuators are usually made of the forms of bending,stretching,and twisting deformation,for which it is hard to achieve continuous rotation.Some limbless creatures,such as snakes and worms,have bristles arranged periodically at a certain angle in nature.When sliding between the bristles and ground caused by vibration of the bristles or deformation of the soft body,the asymmetrical friction force is generated which can drive their forward motion.Based on this idea,an initiative rotating soft actuator,comprised of a piezoelectric bimorph and a soft rotating structure,which is driven by piezoelectric vibration is proposed in this paper.This actuator is composed of a piezoelectric bimorph and a soft rotary structure.The soft rotary structure is an array of inclined bristles arranged uniformly along the circumferential direction,fabricated by 3 D printing and injection molding technology.By analyzing the friction force of a single bristle during vibration,the formula of the rotation moment is given.In addition,through finite element analysis of the deformation of the bristles,the contact force and friction force of the actuator in one vibration period are obtained.It shows that the static friction force generated during the downward motion of the bristles is larger than the sliding friction generated during the upward motion of the bristles,so that a net driving rotation moment is gotten.Besides,the effects of the actuation amplitude and frequency of the applied actuation force on the rotation speed of the actuator are studied by finite element analysis,based on which an optimized bristle geometry ofθ=60°,l=7 mm,and d=1.6 mm is selected for subsequent experiments.The effects of voltage and frequency on the rotation performance of the rotary soft actuator are analyzed through experiments,which show that the rotation speed increases first and then decreases with the increasing of actuation frequency when the applied frequency exceeds 700 Hz.Furthermore,when the applied voltage VP-Pis 400 V and frequency is 1400 Hz,the rotation speed can reach 118.3 r/min,which is larger than the rotation speed of the soft actuator reported so far.
作者
徐聪
闫英博
刘思雨
诸骏
刘益伦
吴化平
Cong Xu;Yingbo Yan;Siyu Liu;Jun Zhu;Yilun Liu;Huaping Wu(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310014,China;School of Aerospace Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2020年第32期3585-3592,共8页
Chinese Science Bulletin
基金
国家自然科学基金(11972323)
浙江省自然科学基金(LR20A020002)
浙江省省属高校基本科研业务费专项资金(RF-B2019004)资助。
关键词
软体驱动器
压电双晶片
振动
旋转
运动机制
soft actuator
piezoelectric bimorph
vibration
rotation
movement mechanism
