A Dielectric Elastomer Actuator-Driven Vibro-Impact Crawling Robot

Abstract

Over the last decade, many bio-inspired crawling robots have been proposed by adopting the principle of two-anchor crawling or anisotropic friction-based vibrational crawling. However, these robots are complicated in structure and vulnerable to contamination, which seriously limits their practical application. Therefore, a novel vibro-impact crawling robot driven by a dielectric elastomer actuator (DEA) is proposed in this paper, which attempts to address the limitations of the existing crawling robots. The novelty of the proposed vibro-impact robot lies in the elimination of anchoring mechanisms or tilted bristles in conventional crawling robots, hence reducing the complexity of manufacturing and improving adaptability. A comprehensive experimental approach was adopted to characterize the performance of the robot. First, the dynamic response of the DEA-impact constraint system was characterized in experiments. Second, the performance of the robot was extensively studied and the fundamental mechanisms of the vibro-impact crawling locomotion were analyzed. In addition, effects of several key parameters on the robot's velocity were investigated. It is demonstrated that our robot can realize bidirectional motion (both forward and backward) by simple tuning of the key control parameters. The robot demonstrates a maximum forward velocity of 21.4 mm/s (equivalent to 0.71 body-length/s), a backward velocity of 16.9 mm/s, and a load carrying capacity of 9.5 g (equivalent to its own weight). The outcomes of this paper can offer guidelines for high-performance crawling robot designs, and have potential applications in industrial pipeline inspections, capsule endoscopes, and disaster rescues.

The effects of compliant support on the dynamics of a dielectric elastomer actuator: a parametric study

“…For instance, a soft robot/device can have an actual performance well below the design expectation (e.g. oscillation amplitude of the DEA in field being significantly below that in the lab tests due to resonant frequency shifts, as have been observed in the authors' previous work in [30]) or behave differently from expectation (e.g. a different resonant mode is triggered in field due to the introduced DoFs).…”

“…This is due to that, despite that the other motion modes of the cone DEAs can be utilized in novel applications such as acoustic devices [22], the majority of research focuses on the first mode (i.e. vertical translation considered in this work) which exert the highest stroke and power outputs for soft robotic locomotion [7,30] or highperformance miniature soft pumps [25,28]. The equations of motion for this two-DoF system are developed in the rest of this subsection where the nonlinear dynamic model for the double cone DEA (m 1 ) applies to both cases while the equation of motion for the compliant support (m 2 ) in two cases will be given separately.…”

“…Nguyen et al have developed a series of double cone DEA driven dynamically crawling hexapod robots [26,27]. The authors have also conducted a series of works on resonating double cone DEA driven soft robots or devices, including a miniature flexible pneumatic pump [28], an insect-inspired flapping mechanism [7], a soft hopping robot [29], and a vibro-impact driven pipe crawler [30].…”

Design Analysis and Actuation Performance of a Push-Pull Dielectric Elastomer Actuator

“…Similarly to the push-pull DEA, the double conical actuation design integrates two conical DEA back-to-back via rigid support or magnets [ 28 , 29 ]. Bionic vehicles [ 30 ], binary actuation [ 31 ], and pipeline robots [ 32 ] have been implemented in a double conical actuator. Theoretical and experimental studies have been conducted to evaluate the actuation performance of conical DEAs, as reported in references [ 22 , 23 , 33 , 34 , 35 ].…”

Nonlinear Dynamics of a Resonant-Impact Dielectric Elastomer Actuator

“…Therefore, utilizing a vibro-impact mechanism and a DEA, we proposed a soft actuatorbased resonant-impact DEA system in our previous study [37]. This system mainly consists of a resonant DEA and an elastic constraint as the output to any payloads.…”