Academic literature on the topic 'Locomotor mimicry'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Locomotor mimicry.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Locomotor mimicry"
1
Srygley, Robert B. "Locomotor mimicry in Heliconius butterflies: contrast analyses of flight morphology and kinematics." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1380 (January 29, 1999): 203–14. http://dx.doi.org/10.1098/rstb.1999.0372.
Full textAbstract:
Müllerian mimicry is a mutualism involving the evolutionary convergence of colour patterns of prey on a warning signal to predators. Behavioural mimicry presumably adds complexity to the signal and makes it more difficult for Batesian mimics to parasitize it. To date, no one has quantified behavioural mimicry in Müllerian mimicry groups. However, morphological similarities among members of mimicry groups suggested that pitching oscillations of the body and wing–beat frequency (WBF) might converge with colour pattern. I compared the morphology and kinematics of four Heliconius species, which comprised two mimicry pairs. Because the mimics arose from two distinct lineages, the relative contributions of mimicry and phylogeny to variation in the species' morphologies and kinematics were examined. The positions of the centre of body mass and centre of wing mass and wing shape diverged among species within lineages, and converged among species within mimicry groups. WBF converged within mimicry groups, and it was coupled with body pitching frequency. However, body–pitching frequency was too variable to distinguish mimicry groups. Convergence in WBF may be due, at least in part, to biomechanical consequences of similarities in wing length, wing shape or the centre of wing mass among co–mimics. Nevertheless, convergence in WBF among passion–vine butterflies serves as the first evidence of behavioural mimicry in a mutualistic context.
2
Shamble, Paul S., Ron R. Hoy, Itai Cohen, and Tsevi Beatus. "Walking like an ant: a quantitative and experimental approach to understanding locomotor mimicry in the jumping spider Myrmarachne formicaria." Proceedings of the Royal Society B: Biological Sciences 284, no. 1858 (July 12, 2017): 20170308. http://dx.doi.org/10.1098/rspb.2017.0308.
Full textAbstract:
Protective mimicry, in which a palatable species avoids predation by being mistaken for an unpalatable model, is a remarkable example of adaptive evolution. These complex interactions between mimics, models and predators can explain similarities between organisms beyond the often-mechanistic constraints typically invoked in studies of convergent evolution. However, quantitative studies of protective mimicry typically focus on static traits (e.g. colour and shape) rather than on dynamic traits like locomotion. Here, we use high-speed cameras and behavioural experiments to investigate the role of locomotor behaviour in mimicry by the ant-mimicking jumping spider Myrmarachne formicaria , comparing its movement to that of ants and non-mimicking spiders. Contrary to previous suggestions, we find mimics walk using all eight legs, raising their forelegs like ant antennae only when stationary. Mimics exhibited winding trajectories (typical wavelength = 5–10 body lengths), which resemble the winding patterns of ants specifically engaged in pheromone-trail following, although mimics walked on chemically inert surfaces. Mimics also make characteristically short (approx. 100 ms) pauses. Our analysis suggests that this makes mimics appear ant-like to observers with slow visual systems. Finally, behavioural experiments with predatory spiders yield results consistent with the protective mimicry hypothesis. These findings highlight the importance of dynamic behaviours and observer perception in mimicry.
3
WIPFLER, BENJAMIN, PETR KOČÁREK, ADRIAN RICHTER, BRENDON BOUDINOT, MING BAI, and ROLF GEORG BEUTEL. "Structural features and life habits of †Alienoptera (Polyneoptera, Dictyoptera, Insecta)." Palaeoentomology 2, no. 5 (October 31, 2019): 465–73. http://dx.doi.org/10.11646/palaeoentomology.2.5.10.
Full textAbstract:
Structural features and life habits of described species of the extinct †Alienoptera are evaluated based on previously published studies on the group. Head structures and feedings habits are addressed, as are the locomotor organs, especially the wings and adhesive devices. Suggested pollen feeding habits and the possible role as pollinators are discussed, as well as hypothesized ant and wasp mimicry and myrmecophily. Species of †Alienoptera were likely predators, in the case of †Caputoraptor elegans Bai, Beutel et Wipfler, 2018 with a unique cephalo-prothoracic prey grasping mechanism. They were likely strong fliers with anatomical dipterism with functional hind wings. Wing joints protected by scale-like sclerotized fore wings probably allowed them to move very efficiently in dense foliage of trees or shrubs and to prey upon smaller insects. Ant mimicry, myrmecophily and “weevil mimicry” are rejected. †Meilia Vršanský et Wang, 2018 is a possible case of wasp mimicry but more evidence is required. Other suggested cases of mimicking wasps are unfounded.
4
Golding, Y. C., A. R. Ennos, and M. Edmunds. "Similarity in flight behaviour between the honeybee Apis mellifera (Hymenoptera: apidae) and its presumed mimic, the dronefly Eristalis tenax (Diptera: syrphidae)." Journal of Experimental Biology 204, no. 1 (January 1, 2001): 139–45. http://dx.doi.org/10.1242/jeb.204.1.139.
Full textAbstract:
It is generally accepted that the dronefly Eristalis tenax is a Batesian mimic of the honeybee Apis mellifera. Previous work has established that the foraging behaviour of droneflies is more similar to that of its model than to that of other more closely related flies, suggesting that behaviour may be important in the mimicry. Locomotor mimicry has been demonstrated in mimetic Heliconius butterflies but not in hoverflies. This study therefore investigated aspects of the flight behaviour of Eristalis tenax, Apis mellifera and two other flies, Syrphus ribesii and a Musca sp. Insects were filmed foraging on Helichrysum bracteum flowers, and flight sequences were analysed to determine flight velocities, flight trajectories and the percentage of time spent hovering. It was found that the flight behaviour of droneflies was more similar to that of honeybees than to that of the other flies. This suggests that the flight behaviour of Eristalis tenax may be mimetic.
5
Shine, Richard, David O'Connor, and Robert T. Mason. "Female mimicry in garter snakes: behavioural tactics of "she-males" and the males that court them." Canadian Journal of Zoology 78, no. 8 (August 1, 2000): 1391–96. http://dx.doi.org/10.1139/z00-089.
Full textAbstract:
Red-sided garter snakes (Thamnophis sirtalis parietalis) in central Manitoba court and mate in early spring soon after emerging from communal overwintering dens. Some males ("she-males") produce female-like skin pheromones, and hence attract courtship from other males. Studies at a den near Inwood, Manitoba, support and extend results from work at other dens. She-males were males that had recently emerged from hibernation and had not yet regained full locomotor capacity or muscle strength. She-males resembled "he-males" rather than females in their antipredator responses, including the thermal threshold at which they fled from a simulated predator (a plastic crow) rather than remaining stationary and displaying. Males courting she-males were cooler than those courting females; nonetheless they were more likely to flee when we approached them. Compared with courting groups focussed on females, groups around she-males were smaller, consisted predominantly of smaller he-males, and were found over a more restricted time of day (early afternoon). Arena trials confirmed that she-males are disproportionately courted by small rather than large he-males, and clarified other aspects of she-male attractiveness and behaviour. She-males attracted more intense courtship when large females were absent. She-males courted less vigorously when large he-males were present, especially when they were vigorously courted themselves. Overall, our data reveal hitherto-unsuspected complexity in the behavioural tactics of reproducing garter snakes.
6
Nelson, Ximena J., and Ashley Card. "Locomotory mimicry in ant-like spiders." Behavioral Ecology 27, no. 3 (December 20, 2015): 700–707. http://dx.doi.org/10.1093/beheco/arv218.
Full text
7
Bertels, Hannah, Guillem Vicente-Ortiz, Khadija El Kanbi, and Aya Takeoka. "Neurotransmitter phenotype switching by spinal excitatory interneurons regulates locomotor recovery after spinal cord injury." Nature Neuroscience 25, no. 5 (May 2022): 617–29. http://dx.doi.org/10.1038/s41593-022-01067-9.
Full textAbstract:
AbstractSevere spinal cord injury in adults leads to irreversible paralysis below the lesion. However, adult rodents that received a complete thoracic lesion just after birth demonstrate proficient hindlimb locomotion without input from the brain. How the spinal cord achieves such striking plasticity remains unknown. In this study, we found that adult spinal cord injury prompts neurotransmitter switching of spatially defined excitatory interneurons to an inhibitory phenotype, promoting inhibition at synapses contacting motor neurons. In contrast, neonatal spinal cord injury maintains the excitatory phenotype of glutamatergic interneurons and causes synaptic sprouting to facilitate excitation. Furthermore, genetic manipulation to mimic the inhibitory phenotype observed in excitatory interneurons after adult spinal cord injury abrogates autonomous locomotor functionality in neonatally injured mice. In comparison, attenuating this inhibitory phenotype improves locomotor capacity after adult injury. Together, these data demonstrate that neurotransmitter phenotype of defined excitatory interneurons steers locomotor recovery after spinal cord injury.
8
Romero Núñez, Eunice, Tonali Blanco Ayala, Gustavo Ignacio Vázquez Cervantes, Gabriel Roldán-Roldán, Dinora Fabiola González Esquivel, Saé Muñiz-Hernández, Alelí Salazar, et al. "Pregestational Exposure to T. gondii Produces Maternal Antibodies That Recognize Fetal Brain Mimotopes and Induces Neurochemical and Behavioral Dysfunction in the Offspring." Cells 11, no. 23 (November 29, 2022): 3819. http://dx.doi.org/10.3390/cells11233819.
Full textAbstract:
The activation of the maternal immune system by a prenatal infection is considered a risk factor for developing psychiatric disorders in the offspring. Toxoplasma gondii is one of the pathogenic infections associated with schizophrenia. Recent studies have shown an association between high levels of IgG anti-T. gondii from mothers and their neonates, with a higher risk of developing schizophrenia. The absence of the parasite and the levels of IgGs found in the early stages of life suggest a transplacental transfer of the anti-T. gondii IgG antibodies, which could bind fetal brain structures by molecular mimicry and induce alterations in neurodevelopment. This study aimed to determine the maternal pathogenic antibodies formation that led to behavioral impairment on the progeny of rats immunized with T. gondii. Female rats were immunized prior to gestation with T. gondii lysate (3 times/once per week). The anti-T. gondii IgG levels were determined in the serum of pregestational exposed females’ previous mating. After this, locomotor activity, cognitive and social tests were performed. Cortical neurotransmitter levels for dopamine and glutamate were evaluated at 60 PND in the progeny of rats immunized before gestation (Pregestational group). The maternal pathogenic antibodies were evidenced by their binding to fetal brain mimotopes in the Pregestational group and the reactivity of the serum containing anti-T. gondii IgG was tested in control fetal brains (non-immunized). These results showed that the Pregestational group presented impairment in short and long-term memory, hypoactivity and alteration in social behavior, which was also associated with a decrease in cortical glutamate and dopamine levels. We also found the IgG antibodies bound to brain mimotopes in fetuses from females immunized with T. gondii, as well as observing a strong reactivity of the serum females immunized for fetal brain structures of fetuses from unimmunized mothers. Our results suggest that the exposure to T. gondii before gestation produced maternal pathogenic antibodies that can recognize fetal brain mimotopes and lead to neurochemical and behavioral alterations in the offspring.
9
Silva, Naiane Arantes, Gabriel Henrique de Oliveira Caetano, Pedro Henrique Campelo, Vitor Hugo Gomes Lacerda Cavalcante, Leandro Braga Godinho, Donald Bailey Miles, Henrique Monteiro Paulino, et al. "Effects of Caudal Autotomy on the Locomotor Performance of Micrablepharus Atticolus (Squamata, Gymnophthalmidae)." Diversity 13, no. 11 (November 4, 2021): 562. http://dx.doi.org/10.3390/d13110562.
Full textAbstract:
Caudal autotomy is a striking adaptation used by many lizard species to evade predators. Most studies to date indicate that caudal autotomy impairs lizard locomotor performance. Surprisingly, some species bearing the longest tails show negligible impacts of caudal autotomy on sprint speed. Part of this variation has been attributed to lineage effects. For the first time, we model the effects of caudal autotomy on the locomotor performance of a gymnophthalmid lizard, Micrablepharus atticolus, which has a long and bright blue tail. To improve model accuracy, we incorporated the effects of several covariates. We found that body temperature, pregnancy, mass, collection site, and the length of the regenerated portion of the tail were the most important predictors of locomotor performance. However, sprint speed was unaffected by tail loss. Apparently, the long tail of M. atticolus is more useful when using undulation amidst the leaf litter and not when using quadrupedal locomotion on a flat surface. Our findings highlight the intricate relationships among physiological, morphological, and behavioral traits. We suggest that future studies about the impacts of caudal autotomy among long-tailed lizards should consider the role of different microhabitats/substrates on locomotor performance, using laboratory conditions that closely mimic their natural environments.
10
Benthall, Katelyn N., Ryan A. Hough, and Andrew D. McClellan. "Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury." Journal of Neurophysiology 117, no. 1 (January 1, 2017): 215–29. http://dx.doi.org/10.1152/jn.00544.2016.
Full textAbstract:
Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3–5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. NEW & NOTEWORTHY In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the experimental results. Thus, after disruption of long-axon projections from RS neurons in the lamprey, descending propriospinal (PS) neurons appear to be a viable compensatory mechanism for indirect activation of spinal locomotor networks.
Dissertations / Theses on the topic "Locomotor mimicry"
1
Card, Ashley. "Locomotory mimicry in ant-like jumping spiders (Salticidae)." Thesis, University of Canterbury. Biological Sciences, 2012. http://hdl.handle.net/10092/7680.
Full textAbstract:
The jumping spider genus Myrmarachne (Salticidae) contains many different morphological ant mimics that resemble a wide variety of ant species. This mimicry enables Myrmarachne to evade ant-averse predators that confuse the spiders with ants. A conspicuous trait of Myrmarachne, which is frequently mentioned in the literature but has been overlooked experimentally, is locomotory mimicry. In this thesis, I quantified, for the first time, the locomotory pattern of non-ant-like salticids, Myrmarachne, and their presumed models. Indeed, I found that the locomotion of the mimics resembles that of ants, but not of other salticids. I then attempted to identify whether this behavioural mimicry enhances the morphological component of the mimicry signal. The locomotion component was tested by modelling a 3D computer animation based on the morphology of Myrmarachne, and then applying either non-ant-like salticid motion characteristics or ant-like locomotion to the models. These animations were presented to ant-eating salticid predators, which are known to have acute vision, in order to identify any differences in how the predators reacted to each virtual prey type based solely on differences in locomotory behaviour. No significant effect was identified for enhancing the deception, but there was a non-significant trend that hinted at an enhancement of the mimicry signal, suggesting that a more robust finding would be found with a larger sample size. Additionally, ant mimics are unusual in their relationship to their model organism, as the ant models are also potential predators of the mimic. Predation by visual ant species may exert selection pressure on Myrmarachne across some aspects of morphological or behavioural mimicry. In turn, this may select for traits that improve Myrmarachne’s survival in close proximity to their highly aggressive models. Consequently, I investigated whether ant-like locomotion is salient to a visual ant species, Oecophylla smaragdina. I found that the locomotion typical of ants and Myrmarachne is more attractive to ants than non-ant-like salticid locomotion. This suggests that the trade-off of increased resemblance to ants is not just towards being categorised as prey by ant-eating species, but also by being more attractive to ant species. This may place them at greater risk of predation by the model. As a whole, these results suggest that there is selection pressure on Myrmarachne for increased resemblance to a model by locomotory mimicry, despite associated costs when faced with ant-eating predators and when living in proximity to models that are both aggressive and visual.
Books on the topic "Locomotor mimicry"
1
Kruusmaa, Maarja. From aquatic animals to robot swimmers. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.003.0044.
Full textAbstract:
Fish and other aquatic animals have developed a diverse repertoire of locomotion and sensing strategies in an environment that is 800 times denser than air. This chapter explains the underlying principles of aquatic locomotion and describes some landmark biomimetic robots based on those principles. Biological underwater swimmers face the trade-off between speed and manoeuvrability and it is argued that the same trade-off exists also with biomimetic vehicles. Biomimetic underwater vehicles mostly mimic carangiform and subcarangiform swimmers which are fast swimmers. The highly manoeuvrable fish species (lampreys, rays, etc.) are a less popular choice of bioinspiration arguably because of their higher complexity and limitations posed by current technology of electromechanical devices. A unique sensing organ, the lateral line, is utilized by all fish species. Artifical lateral lines for sensing flow are briefly discussed as well as the potential of robot control with the help of flow sensing.
2
Prescott, Tony J., Nathan Lepora, and Paul F. M. J. Verschure, eds. Living machines. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.001.0001.
Full textAbstract:
Biomimetics is the development of novel technologies through the distillation of ideas from the study of biological systems. Biohybrids are formed through the combination of at least one biological component—an existing living system—and at least one artificial, newly engineered component. These two fields are united under the theme of Living Machines—the idea that we can construct artifacts that not only mimic life but also build on the same fundamental principles. The research described in this volume seeks to understand and emulate life’s ability to self-organize, metabolize, grow, and reproduce; to match the functions of living tissues and organs such as muscles, skin, eyes, ears, and neural circuits; to replicate cognitive and physical capacities such as perception, attention, locomotion, grasp, emotion, and consciousness; and to assemble all of these elements into integrated systems that can hold a technological mirror to life or that have the capacity to merge with it. We conclude with contributions from philosophers, ethicists, and futurists on the potential impacts of this remarkable research on society and on how we see ourselves.
3
Mehta, Gautam, and Bilal Iqbal. Clinical Medicine for the MRCP PACES. Oxford University Press, 2010. http://dx.doi.org/10.1093/oso/9780199542550.001.0001.
Full textAbstract:
Volume 1 of a two volume MRCP text, this book includes cases which mimic the style and approach of the MRCP PACES exam. Clinical Medicine for MRCP PACES will equip the candidate attempting the MRCP examination with the skills and knowledge necessary for success, and will also provide an overview of evidence-based medicine for competency-based training. Throughout this and Volume 2, the authors explore all aspects of the candidate's performance, from clinical examination, to presentation, communication and medical ethics and up-to-date clinical evidence. Volume 1 includes over 150 cases and covers Stations 1, 3 and 5: Station 1 covers the respiratory and abdominal systems; Station 3 covers the cardiovascular and central nervous systems; Station 5 includes 20 Brief Clinical Consultations and supplementary cases covering ophthalmology, dermatology, endocrine and locomotor presentations. Throughout the book, the cases begin with the case presentation, followed by extensive clinical notes for each case. Each case also includes questions commonly asked by the examiners with suggested evidence-based answers and relevant bibliography. Station 5 Brief Clinical Consultations include a standardized approach to preparation and provide a concise summary of the focused history, examination, diagnosis and guidance on how to feedback to both the patient and the examiner. Visit our website for details of our range of titles for MRCP and more in the Oxford Specialty Training series at www.oup.com/uk/medicine/ost http://www.oup.com/uk/medicine/ost Advance praise for Clinical Medicine for MRCP PACES: "The authors have produced two volumes packed with the information needed to pass PACES and to practise high quality medicine. While written specifically for those aspiring to be physicians these volumes deserve to be widely read by all with an interest in clinical medicine. Candidates in particular and patients have good reason to welcome these volumes." Sir Graeme Catto
Conference papers on the topic "Locomotor mimicry"
1
Blanch, Ian G., Duane W. Storti, Rhonda L. Anderson, Mark A. Ganter, and Per G. Reinhall. "Novel Autonomous Underwater Vehicle Based Upon Jellyfish Locomotion." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34440.
Full textAbstract:
This paper describes the process of developing a novel biomimetic autonomous underwater vehicle (AUV) inspired by jellyfish locomotion. Our interest in an AUV that mimics jellyfish locomotion stems from the jellyfish’s simplistic and robust physiology and neurological makeup. Jellyfish swimming gates are controlled by a neural architecture consisting of an outer nerve ring and an inner nerve ring. The inner nerve ring is responsible for incorporating the sensory input from the outer ring and innervating the subumbrellar swimming muscles. Additionally, cells in the inner ring generate endogenous rhythms and act as pacemakers. The system of pacemakers generates the highly maneuverable swimming gates that can be observed in jellyfish; swimming vertically, turning and hovering. The swimming gates have been shown to correspond to the dynamics of the response of a system of coupled identical van der Pol oscillators. These oscillators are capable of creating in-phase, out-of-phase and “asymmetric” phase-locked dynamics that are plausibly related to the basic modes of jellyfish locomotion of coordinated bout swimming, hovering, and turning, respectively. In addition, the system of oscillators is fault tolerant; if the modeled system of oscillators is disrupted, analogous to sections of the jellyfish being damaged, the oscillators adjust and maintain effective swimming gates allowing the jellyfish to remain mobile. The simplicity and fault tolerance of the oscillatory system makes it an ideal model for a locomotion control system for an AUV. The objective of the Jellyfish AUV project is to emulate the locomotion and control mechanisms of the biological jellyfish to create a simple and robust AUV, which is both highly maneuverable and low in cost. The iterative design process that resulted in a working Jellyfish AUV is detailed in this paper. Numerous designs were created, exploring different combinations of actuator mechanisms, body types and control systems. Different actuators were evaluated for their ability to meet our design requirements. These actuators ranged from off the shelf servos to the more exotic shape memory alloys (SMAs) and ionic polymer metal composites (IPMCs.) By the completion of the prototyping phase of the Jellyfish AUV project we had created a low cost AUV using off the shelf components including, servos, linkages and a microprocessor based control system. The input to the servos was derived from a system of coupled oscillators which were tuned to mimic the observation jellyfish gates. In addition, using the Jellyfish AUV prototype, we showed that the identified servo input patterns roughly translate to swimming, hovering, and turning.
2
Orki, Omer, Offer Shai, Amir Ayali, and Uri Ben-Hanan. "A Model of Caterpillar Locomotion Based on Assur Tensegrity Structures." In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-47708.
Full textAbstract:
This paper presents an ongoing project aiming at building a robot composed of Assur tensegrity structures, which mimics caterpillar locomotion. Caterpillars are soft-bodied animals capable of making complex movements with astonishing fault-tolerance. In our model, each caterpillar segment is represented by a 2D tensegrity triad consisting of two bars connected by two cables and a strut. The cables represent the major longitudinal muscles of the caterpillar, while the strut represents hydrostatic pressure. The control scheme in this model is divided into localized low-level controllers and a high-level control unit. The unique engineering properties of Assur tensegrity structures, which were mathematically proved last year, together with the suggested control algorithm provide the model with robotic softness. Moreover, the degree of softness can be continuously changed during simulation, making this model suitable for simulation of soft-bodied caterpillars as well as other types of soft animals.
3
Orki, Omer, Offer Shai, Itay Tehori, Michael Slavutin, and Uri Ben-Hanan. "Employing Assur Tensegrity Structures Methods for Simulating a Caterpillar Locomotion." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28687.
Full textAbstract:
The paper presents an ongoing project aiming to build a robot, composed of Assur tensegrity structures, that mimics the caterpillar locomotion. Caterpillars are soft bodied animals capable of making complex movements with an astonishing fault-tolerance. In this model, a caterpillar segment is represented as a 2D tensegrity triad, consists of two cables and a linear actuator which are connected between two bars. The unique engineering properties of Assur tensegrity structures which were mathematically proved only this year, together with the suggested control algorithm share several analogies with the biological caterpillar. It provides each triad with an adjustable structural softness. Therefore, the proposed robot has a fault-tolerance and can adjust itself to the terrain roughness. This algorithm also reduces the control demands of the non-linear model of the triad by enabling simple motion control for the linear actuator and one of the cables, while the other cable is force controlled.
4
Hubbard, Joel J., Maxwell Fleming, Kam K. Leang, Viljar Palmre, David Pugal, and Kwang J. Kim. "Characterization of Sectored-Electrode IPMC-Based Propulsors for Underwater Locomotion." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5155.
Full textAbstract:
Ionic polymer-metal composite (IPMC) actuators with sectored (patterned) electrodes have been fabricated for realizing bending and twisting motion. Such IPMCs can be used to create next-generation artificial fish-like propulsors that can mimic the undulatory, flapping, and complex motions of real fish fins. Herein, a thorough experimental study is performed on sectored IPMCs to characterize their performance. Specifically, results are presented to show (1) the achievable twisting response; (2) blocking force and torque; (3) power consumption and effectiveness; and (4) propulsion characteristics. The results can be utilized to guide the design of practical marine systems driven by IPMC propulsors. The design of an example underwater robotic system is also described which employs the IPMC actuators, and the performance of the robotic system is reported.
5
Yuan, Sichen, Wuming Jing, and Hao Jiang. "A Deployable Tensegrity Microrobot for Minimally Invasive Interventions." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-67009.
Full textAbstract:
Abstract Micro-, and milli-scale robots have emerged as next generation of intelligent technology for minimally invasive diagnosis and treatment. Recent minimally invasive interventions call for robots that work as tiny “surgeons” or drug delivery “vehicles” to achieve inner body diagnostic, surgical, and therapeutic practices, without any trauma or discomfort. Most traditional medical robots are large, and lack effective locomotion design, which prevent them from entering small entrances and moving smoothly in small working areas, such as long and narrow passages. Presented in this paper is a design of an innovative milli-scale deployable tensegrity microrobot for minimally invasive interventions. The robot is made of a deployable tensegrity structure integrated by self-stress. A folded size of the robot is small for easily entering a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damages when burrowing through tightly packed tissues or high-pressure environments. Locomotion of the tensegrity microrobot is designed to mimic a crawling motion of an earthworm, which grants the robot an ability to move well through small working areas. The robot is also an untethered agent. Morphing for deployment and locomotion of the robot is actuated by magnetic forces generated by its active members that serve as electromagnetic coils.
6
Cen, Lejun, and Alper Erturk. "Fish-Like Self Propulsion Using Flexible Piezoelectric Composites." In ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-8167.
Full textAbstract:
The capacity of humankind to mimic fish-like locomotion for engineering applications depends mainly on the availability of suitable actuators. Researchers have recently focused on developing robotic fish using smart materials, particularly Ionic Polymer-Metal Composites (IPMCs), as a compliant, noise-free, and scalable alternative to conventional motor-based propulsion systems. In this paper, we investigate fish-like self propulsion using flexible bimorphs made of Macro-Fiber Composite (MFC) piezoelectric laminates. Similar to IPMCs, MFCs also exhibit high efficiency in size, energy consumption, and noise reduction. In addition, MFCs offer large dynamic forces in bending actuation, strong electromechanical coupling as well as both low-frequency and high-frequency performance capabilities. The experimental component of the presented work focuses on the characterization of an MFC bimorph propulsor for thrust generation in a quiescent fluid as well as the development of a preliminary robotic fish prototype incorporating a microcontroller and a printed-circuit-board (PCB) amplifier to generate high actuation voltage for battery-powered free locomotion. From the theoretical standpoint, a reliable modeling framework that couples the actuator dynamics, hydroelasticity, and fish locomotion theory is essential to both design and control of robotic fish. Therefore, a distributed-parameter electroelastic model with fluid effects and actuator dynamics is coupled with the elongated body theory. Both in-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated body theory to predict the thrust output. Experiments are conducted to validate the electrohydroelastic modeling approach employed in this work and to characterize the performance of an MFC bimorph propulsor. Finally, a battery-powered preliminary robotic fish prototype is developed and tested in free locomotion.
7
Fatehiboroujeni, Soheil, Arvind Gopinath, and Sachin Goyal. "Follower Forces in Pre-Stressed Fixed-Fixed Rods to Mimic Oscillatory Beating of Active Filaments." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85449.
Full textAbstract:
Flagella and cilia are examples of actively oscillating, whiplike biological filaments that are crucial to processes as diverse as locomotion, mucus clearance, embryogenesis and cell motility. Elastic driven rod-like filaments subjected to compressive follower forces provide a way to mimic oscillatory beating in synthetic settings. In the continuum limit, this spatiotemporal response is an emergent phenomenon resulting from the interplay between the structural elastic instability of the slender rods subjected to the non-conservative follower forces, geometric constraints that control the onset of this instability, and viscous dissipation due to fluid drag by ambient media. In this paper, we use an elastic rod model to characterize beating frequencies, the critical follower forces and the non-linear rod shapes, for pre-stressed, clamped rods subject to two types of fluid drag forces, namely, linear Stokes drag and non-linear Morrison drag. We find that the critical follower force depends strongly on the initial slack and weakly on the nature of the drag force. The emergent frequencies however, depend strongly on both the extent of pre-stress as well as the nature of the fluid drag.
8
Rios, Oscar, Takeyuki Ono, and Hidenori Murakami. "Development of Active Mechanical Models for Flexible Robots to Duplicate the Motion of Inch Worms and Snakes." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65550.
Full textAbstract:
Due to the advent of pneumatic actuators, tendon-actuation mechanisms, and artificial muscles, an increasing number of robot engineers are developing flexible and soft robots. The emergence of soft and flexible robotics has offered new methods of locomotion that have applications in a wide variety of sectors. The research presented here focuses on developing mechanical models for such flexible robots. Two models are developed that will aid the modeling of soft robotics: (i) a discrete multi-body model consisting of jointed cylindrical segments and (ii) a thorough continuous beam model with internal actuation. The mechanical models serve as indicators of the necessary internal actuation for soft robots to reproduce or mimic the observed or necessary motion.
9
Venkateswaran, Swaminath, Damien Chablat, and Pol Hamon. "Design of a Piping Inspection Robot by Optimization Approach." In ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/detc2020-22021.
Full textAbstract:
Abstract This article presents an optimization approach for the design of an inspection robot that can move inside variable diameter pipelines having bends and junctions. The inspection robot uses a mechanical design that mimics the locomotion of a caterpillar. The existing prototype developed at LS2N, France is a rigid model that makes it feasible for working only inside straight pipelines. By the addition of a tensegrity mechanism between motor units, the robot is made reconfigurable. However, the motor units used in the prototype are oversized to pass through pipe bends or junctions. An optimization approach is employed to determine the dimensions of motors and their associated leg mechanisms that can overcome such bends. Two optimization problems are defined and solved in this article. The first problem deals with the determination of motor sizing without leg mechanisms. The second problem deals with the determination of sizing of the leg mechanism with respect to the dimensions of motor units obtained from the first problem. A 3D model of the optimized robot design is then realized using CAD software.
10
Ficanha, Evandro, Guilherme Aramizo Ribeiro, Lauren Knop, and Mohammad Rastgaar Aagaah. "Estimation of the 2-DOF Time-Varying Impedance of the Human Ankle." In 2017 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dmd2017-3328.
Full textAbstract:
The human ankle plays a major role in locomotion as it the first major joint to transfer the ground reaction torques to the rest of the body while providing power for locomotion and stability. One of the main causes of the ankle impedance modulation is muscle activation [1, 2], which can tune the ankle’s stiffness and damping during the stance phase of gait. The ankle’s time-varying impedance is also task dependent, meaning that different activities such as walking at different speeds, turning, and climbing/descending stairs would impose different profiles of time-varying impedance modulation. The impedance control is commonly used in the control of powered ankle-foot prostheses; however, the information on time-varying impedance of the ankle during the stance phase is limited in the literature. The only previous study during the stance phase, to the best of the authors knowledge, reported the human ankle impedance at four points of the stance phase in dorsiflexion-plantarflexion (DP) [1] during walking. To expand previous work and estimate the impedance in inversion-eversion (IE), a vibrating platform was fabricated (Fig. 1) [3]. The platform allows the ankle impedance to be estimated at 250 Hz in both DP and IE, including combined rotations in both degrees of freedom (DOF) simultaneously. The results can be used in a 2-DOF powered ankle-foot prosthesis developed by the authors, which is capable of mimicking the ankle kinetics and kinematics in the frontal and sagittal planes [4]. The vibrating platform can also be used to tune the prosthesis to assure it properly mimics the human ankle dynamics. This paper describes the results of the preliminary experiments using the vibrating platform on 4 male subjects. For the first time, the time-varying impedance of the human ankle in both DP and IE during walking in a straight line are reported.