arXiv subjects

Ketao Zhang

Publications and source records attributed to Ketao Zhang.

4 recordsLinked to original sources

arXiv2026

Soft Electroadhesive Feet for Micro Aerial Robots Perching on Smooth and Curved Surfaces

Electroadhesion (EA) provides electrically switchable adhesion and is a promising mechanism for perching micro aerial robots on smooth surfaces. However, practical implementations of soft and stretchable EA pads for aerial perching remain limited. This work presents (i) an efficient workflow for fabricating soft, stretchable electroadhesive pads with sinusoidal wave and concentric-circle electrodes in multiple sizes, (ii) a controlled experimental comparison of normal and shear adhesion under inactive (0 kV) and active (4.8 kV) conditions using an Instron-based setup, and (iii) a perching demonstration using a Crazyflie quadrotor equipped with electroadhesive feet on flat and curved substrates. Experimental results show that shear adhesion dominates, reaching forces on the order of 3 N with partial pad contact, while normal adhesion is comparatively small and strongly dependent on substrate properties. The Crazyflie prototype demonstrates repeatable attachment on smooth plastic surfaces, including curved geometries, as well as rapid detachment when the voltage is removed. These results highlight the potential of soft electroadhesive feet for lightweight and reliable perching in micro aerial vehicles (MAVs).

cs.RO↗

arXiv2024

Mathematical Tri-State Model for Bee Shimmering Propagation Dynamics

Bees undergo a self-organised process known as shimmering, where they form emergent patterns when they interact with each other on the nest surface as a defence mechanism in response to predator attacks. Many experimental studies have empirically investigated how the transfer of information to neighbouring bees propagates in various shimmering processes by measuring shimmering wave strength. However, there is no analytical modelling of the collective defence mechanism in nature. Here we introduce the first analytical tri-state Inactive-Active-Relapse (IAR) model to formulate the intrinsic process of bee shimmering. The major shimmering behaviour is shown to emerge under theoretical conditions which is demonstrated numerically and visually by simulating 1,000,000 bee agents, while the number of agents is scalable. Furthermore, we elaborate on these mathematical results to construct a wave strength function to demonstrate the accuracy of shimmering dynamics. The constructed wave strength function can be adapted to peak between 50-150ms which supports the experimental studies. Our results provide a foundation for further theoretical understanding of bee shimmering wave dynamics and could serve as inspiration for modelling other self-organised phenomena across scientific applications.

nlin.AO↗

arXiv2023

A Soft Robotic Gripper with Active Palm for In-Hand Object Reorientation

The human hand has an inherent ability to manipulate and re-orientate objects without external assistance. As a consequence, we are able to operate tools and perform an array of actions using just one hand, without having to continuously re-grasp objects. Emulating this functionality in robotic end-effectors remains a key area of study with efforts being made to create advanced control systems that could be used to operate complex manipulators. In this paper, a three fingered soft gripper with an active rotary palm is presented as a simpler, alternative method of performing in-hand rotations. The gripper, complete with its pneumatic suction cup to prevent object slippage, was tested and found to be able to effectively grasp and rotate a variety of objects both quickly and precisely.

cs.RO↗

arXiv2022

The Natural Robotics Contest: Crowdsourced Biomimetic Design

Biomimetic and Bioinspired design is not only a potent resource for roboticists looking to develop robust engineering systems or understand the natural world. It is also a uniquely accessible entry point into science and technology. Every person on Earth constantly interacts with nature, and most people have an intuitive sense of animal and plant behavior, even without realizing it. The Natural Robotics Contest is novel piece of science communication that takes advantage of this intuition, and creates an opportunity for anyone with an interest in nature or robotics to submit their idea and have it turned into a real engineering system. In this paper we will discuss the competition's submissions, which show how the public thinks of nature as well as the problems people see as most pressing for engineers to solve. We will then show our design process from the winning submitted concept sketch through to functioning robot, to offer a case study in biomimetic robot design. The winning design is a robotic fish which uses gill structures to filter out microplastics. This was fabricated into an open source robot with a novel 3D printed gill design. By presenting the competition and the winning entry we hope to foster further interest in nature-inspired design, and increase the interplay between nature and engineering in the minds of readers.

cs.RO↗