Design and Locomotion Studies of a Miniature Centipede-Inspired Robot

Many applications, such as search and rescue missions, hazardous environment exploration, and surveillance, call for miniature robots capable of agile locomotion in a variety of unpredictable environments. Recent advances in meso-scale fabrication techniques and an understanding of biological insect locomotion have enabled the creation of multiple miniature legged robots to meet this demand. Nearly all insect-scale legged robots take inspiration from rigid-body hexapods; however, another unique body morphology found in nature is that of the centipede, characterized by its many legs and flexible body. These characteristics are expected to offer performance benefits in terms of agility, stability, robustness, and adaptability.Engineering and Applied Science

Non-inertial Undulatory Locomotion Across Scales

Locomotion is crucial to behaviors such as predator avoidance, foraging, and mating. In particular, undulatory locomotion is one of the most common forms of locomotion. From microscopic flagellates to swimming fish and slithering snakes, this form of locomotion is a remarkably robust self-propulsion strategy that allows a diversity of organisms to navigate myriad environments. While often thought of as exclusive to limbless organisms, a variety of locomotors possessing few to many appendages rely on waves of undulation for locomotion. In inertial regimes, organisms can leverage the forces generated by their body and the surrounding medium's inertia to enhance their locomotion (e.g., coast or glide). On the other hand, in non-inertial regimes self-propulsion is dominated by damping (viscous or frictional), and thus the ability for organisms to generate motion is dependent on the sequence of internal shape changes. In this thesis, we study a variety of undulating systems that locomote in highly damped regimes. We perform studies on systems ranging from zero to many appendages. Specifically, we focus on four distinct undulatory systems: 1) C. elegans, 2) quadriflagellate algae (bearing four flagella), 3) centipedes on terrestrial environments, and 4) centipedes on fluid environments. For each of these systems, we study how the coordination of their many degrees of freedom leads to specific locomotive behaviors. Further, we propose hypotheses for the observed behaviors in the context of each of these system's ecology.Ph.D

Locomotion of Low-DoF Multi-legged Robots

Multi-legged robots inspired by insects and other arthropods have unique advantages when compared with bipedal and quadrupedal robots. Their sprawled posture provides stability, and allows them to utilize low-DoF legs which are easier to build and control. With low-DoF legs and multiple contacts with the environment, low-DoF multi-legged robots are usually over constrained if no slipping is allowed. This makes them intrinsically different from the classic bipedal and quadrupedal robots which have high-DoF legs and fewer contacts with the environment. Here we study the unique characteristics of low-DoF multi-legged robots, in terms of design, mobility and modeling. One key observation we prove is that 1-DoF multi-legged robots must slip to be able to steer in the plane. Slipping with multiple contacts makes it difficult to model these robots and their locomotion. Therefore, instead of relying on models, our primary strategy has been careful experimental study. We designed and built our own customized robots which are easily reconfigurable to accommodate a variety of research requirements. In this dissertation we present two robot platforms, BigAnt and Multipod, which demonstrate our design and fabrication methods for low-cost rapidly fabricated modular robotic platforms. BigAnt is a hexapedal robot with 1-DoF legs, whose chassis is constructed from foam board and fiber tape, and costs less than 20 USD in total; Multipod is a highly modular multi-legged robot that can be easily assembled to have different numbers of 2-DoF legs (4 to 12 legs discussed here). We conducted a detailed analysis of steering, including proposing a formal definition of steering gaits grounded in geometric mechanics, and demonstrated the intrinsic difference between legged steering and wheeled steering. We designed gaits for walking, steering, undulating, stair climbing, turning in place, and more, and experimentally tested all these gaits on our robot platforms with detailed motion tracking. Through the theoretical analyses and the experimental tests, we proved that allowing slipping is beneficial for improving the steering in our robots. Where conventional modeling strategies struggle due to multi-contact slipping, we made a significant scientific discovery: that multi-legged locomotion with slipping is often geometric in the sense known from the study of low Reynolds number swimmers and non-holonomic wheeled snake robots which have continuous contact with the environment. We noted that motion can be geometric ``on average'', i.e. stride to stride, and can be truly instantaneously geometric. For each of these we developed a data-driven modeling approach that allowed us to analyze the degree to which a motion is geometric, and applied the analysis to BigAnt and Multipod. These models can also be used for robot motion planning. To explore the mechanism behind the geometric motion characteristics of these robots, we proposed a spring supported multi-legged model. We tested the simulation based on this model against experimental data for all the systems we studied: BigAnt, Multipod, Mechapod (a variant of 6-legged Multipod) and cockroaches. The model prediction results captures many key features of system velocity profiles, but still showed some systematic errors (which can be alleviated ad-hoc). Our work shows the promise of low-DoF multi-legged robots as a class of robotic platforms that are easy to build and simulate, and have many of the mobility advantages of legged systems without the difficulties in stability and control that appear in robots with four or fewer legs.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169985/1/danzhaoy_1.pd

多足類の形態学的特徴を模擬したロボットの実現とそのロコモーションに関する考察

岡山理科大学202

Zur Mechanik vibrationsgetriebener Roboter für terrestrische und aquatische Lokomotion

This thesis discusses the mechanics of mobile robots for terrestrial and aquatic locomotion. Vibration-driven locomotion systems are characterised by an internal periodic excitation, which is transformed to a directed motion due to asymmetric properties of the system. To perform a two-dimensional and controllable locomotion, mechanical properties of robots are investigated dependent on the frequency of the internal excitation. The mechanical description of the robots is done using analytical and numerical methods and supported by experimental studies. The applicability of the results in mobile robots is proved by prototypes.On the basis of mechanical fundamentals, terrestrial and aquatic locomotion principles are discussed and classified. Actuators are reviewed. The purpose is to evaluate the performance as vibration sources for terrestrial and aquatic systems. Piezoelectric bending elements are particular suitable for it. An extensive overview on the state of the art shows the great potential of vibration-driven locomotion systems for miniaturised applications in technics.Systems with bristles can perform unidirectional terrestrial locomotion. Different working principles of bristles are studied based on a rigid body model and experimental investigations. A prototype for the locomotion in tubes is presented. To perform a controllable two-dimensional locomotion with only one actuator, it is needed to overcome the limits of rigid body systems. The applied approach uses the frequency-dependent vibration behaviour of elastic systems, like beams and plates. Models of continuum mechanics and finite element methods are used and supported by experiments. Based on the investigations, a programmable and remote controlled prototype is developed. The locomotion of it can be controlled on different surfaces by a change of the excitation frequency. The velocity of the prototype is up to 100 mm/s and it can support five times its own weight.Concluding, an innovative prototype with a single piezoelectric actuator for a controllable locomotion on flat ground and floating in fluids is developed. The terrestrial and aquatic locomotion behaviour of the robot is investigated. The carrying capacity of it is calculated using a hydrostatic model.Die Mechanik von mobilen Robotern für terrestrische und aquatische Lokomotion ist der Gegenstand der Arbeit. In den untersuchten Systemen wird die periodische Erregung eines inneren Antriebs durch nicht symmetrische Systemeigenschaften in eine gerichtete Fortbewegung gewandelt. Durch die Nutzung des frequenzabhängigen Schwingungsverhaltens von elastischen Systemen, wie Balken oder Platten, werden Systeme realisiert, die durch nur einen Antrieb eine steuerbare zweidimensionale Lokomotion auf festem Untergrund und an der Oberfläche von Flüssigkeiten durchführen können. Der Schwerpunkt der Arbeit liegt auf der mathematisch-mechanischen Beschreibung der Roboter mittels analytischer und numerischer Methoden sowie ihrer experimentellen Untersuchung. Prototypen mobiler Roboter dienen dem funktionellen Nachweis.Auch im Buchhandel erhältlich: Zur Mechanik vibrationsgetriebener Roboter für terrestrische und aquatische Lokomotion / Felix Becker Ilmenau : Univ.-Verl. Ilmenau, 2015. - XIX, 149 S. ISBN 978-3-86360-124-9 URN urn:nbn:de:gbv:ilm1-2015000338 Preis (Druckausgabe): 21,30