Locomotion Characteristics Research Articles

Simulation and experimental testing of locomotion characteristics of a vibration-driven system with a solenoid-type actuator

Simulation and experimental testing of locomotion characteristics of a vibration-driven system with a solenoid-type actuator

A coati conundrum: how variation in levels of arboreality influences gait mechanics among three musteloid species.

The gait characteristics associated with arboreal locomotion have been frequently discussed in the context of primate evolution, wherein they present as a trio of distinctive features: a diagonal-sequence, diagonal-couplet gait pattern; a protracted arm at forelimb touchdown; and a hindlimb-biased weight support pattern. The same locomotor characteristics have been found in the woolly opossum, a fine-branch arborealist similar in ecology to some small-bodied primates. To further our understanding of the functional link between arboreality and primate-like locomotion, we present comparative data collected in the laboratory for three musteloid taxa. Musteloidea represents an ecologically diverse superfamily spanning numerous locomotor specializations that includes the highly arboreal kinkajou (Potos flavus), mixed arboreal/terrestrial red pandas (Ailurus fulgens) and primarily terrestrial coatis (Nasua narica). This study applies a combined kinetic and kinematic approach to compare the locomotor behaviors of these three musteloid taxa, representing varying degrees of arboreal specialization. We observed highly arboreal kinkajous to share many locomotor traits with primates. In contrast, red pandas (mixed terrestrial/arborealist) showed gait characteristics found in most non-primate mammals. Coatis, however, demonstrated a unique combination of locomotor traits, combining a lateral-sequence, lateral-couplet gait pattern typical of long-legged, highly terrestrial mammals, varying degrees of arm protraction, and a hindlimb-biased weight support pattern typical of most primates and woolly opossums. We conclude that the three gait characteristics traditionally used to describe arboreal walking in primates can occur independently from one another and not necessarily as a suite of interdependent characteristics, a phenomenon that has been reported for some primates.

Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection.

Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following spinal cord injury. The thoracic lateral hemisection represents an experimental model of an incomplete spinal cord injury, where connections between the brain and spinal cord are abolished on one side of the cord. To investigate the effects of such an injury on the operation of the spinal locomotor network, we used our computational model of cat locomotion recently published in eLife (Rybak et al., 2024) to investigate and predict changes in cycle and phase durations following a thoracic lateral hemisection during treadmill locomotion in tied-belt (equal left-right speeds) and split-belt (unequal left-right speeds) conditions. In our simulations, the "hemisection" was always applied to the right side. Based on our model, we hypothesized that following hemisection, the contralesional ("intact", left) side of the spinal network is mostly controlled by supraspinal drives, whereas the ipsilesional ("hemisected", right) side is mostly controlled by somatosensory feedback. We then compared the simulated results with those obtained during experiments in adult cats before and after a mid-thoracic lateral hemisection on the right side in the same locomotor conditions. Our experimental results confirmed many effects of hemisection on cat locomotion predicted by our simulations. We show that having the ipsilesional hindlimb step on the slow belt, but not the fast belt, during split-belt locomotion substantially reduces the effects of lateral hemisection. The model provides explanations for changes in temporal characteristics of hindlimb locomotion following hemisection based on altered interactions between spinal circuits, supraspinal drives, and somatosensory feedback.

Digital video analysis reveals gait parameters that predict performance in the jumping test phase of three-day eventing

In international equestrian sport, visual inspections assess gait and lameness to protect the welfare of performance horses during competition. Horses competing internationally in three-day eventing must pass two mandatory inspections (pre-competition and post-cross country) before attempting the final phase: the jumping test (JT). We hypothesized that digitally quantifying objective gait parameters captured during the two mandatory inspections will identify locomotor characteristics that predict success during the jumping test. Utilizing the DeepLabCut (DLC) software package for labeling of anatomical landmarks and a custom analysis pipeline we calculated gait parameters for 194 competition horses at the trot. During the pre-competition inspection, relative trot speed was significantly associated (P = 0.0060, GLMM), and the forelimb travel trended towards significance (P =0.0800, GLMM), with achieving a clear round in the later jumping test. Post-cross country, the forelimb travel significantly predicted JT results (P = 0.0188, GLMM). As our parameters are scaled for body size, these parameters may indicate conformational characteristics for superior jumping ability and overall athletic fitness. Within each competitive effort, comparisons of the post-cross country and pre-competition observations revealed that the change in speed and duty factor were significantly different in the group that accrued jumping faults (P = 0.00376 and P = 0.02430, GLMM), perhaps capturing locomotor signs of exercise fatigue. Further work employing these approaches to better understand competition performance will encourage the use of objective measures to protect sport horse welfare, as well as provide an advantageous tool for gait evaluation in the horse.

Neuromotor decline is associated with gut dysbiosis following surgical decompression for Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) describes a spectrum of disorders that cause progressive and chronic cervical spinal cord compression. The clinical presentation can be complex and can include locomotor impairment, hand and upper extremity dysfunction, pain, loss of bladder and bowel function, as well as gastrointestinal dysfunction. Once diagnosed, surgical decompression is the recommended treatment for DCM patients with moderate to severe impairment.Our body is composed of a large community of microorganisms, known as the microbiota. Traumatic and non-traumatic spinal cord injuries (SCIs) can induce changes in the gut microbiota and gut microbiota derived metabolites. These changes have been reported as important disease-modifying factors after injury. However, whether gut dysbiosis is associated with functional neurological recovery after surgical decompression has not been examined to date.Here, DCM was induced in C57BL/6 mice by implanting an aromatic polyether material underneath the C5–6 laminae. The extent of gut dysbiosis was assessed by gas chromatography and 16S rRNA sequencing from fecal samples before and after decompression. Neuromotor activity was assessed using the Catwalk test.Our results show that DCM pre- and post- surgical decompression is associated with gut dysbiosis, without altering short chain fatty acids (SCFAs) levels. Significant differences in Clostridia, Verrumicrobiae, Lachnospiracea, Firmicutes, Bacteroidales, and Clostridiaceae were observed between the DCM group (before decompression) and after surgical decompression (2 and 5 weeks). The changes in gut microbiota composition correlated with locomotor features of the Catwalk. For example, a longer duration of ground contact and dysfunctional swing in the forelimbs, were positively correlated with gut dysbiosis. These results show for the first time an association between gut dysbiosis and locomotor deterioration after delayed surgical decompression. Thus, providing a better understanding of the extent of changes in microbiota composition in the setting of DCM pre- and post- surgical decompression.

Computational synthesis of locomotive soft robots by topology optimization.

Locomotive soft robots (SoRos) have gained prominence due to their adaptability. Traditional locomotive SoRo design is based on limb structures inspired by biological organisms and requires human intervention. Evolutionary robotics, designed using evolutionary algorithms (EAs), have shown potential for automatic design. However, EA-based methods face the challenge of high computational cost when considering multiphysics in locomotion, including materials, actuations, and interactions with environments. Here, we present a design approach for pneumatic SoRos that integrates gradient-based topology optimization with multiphysics material point method (MPM) simulations. This approach starts with a simple initial shape (a cube with a central cavity). The topology optimization with MPM then automatically and iteratively designs the SoRo shape. We design two SoRos, one for walking and one for climbing. These SoRos are 3D printed and exhibit the same locomotion features as in the simulations. This study presents an efficient strategy for designing SoRos, demonstrating that a purely mathematical process can produce limb-like structures seen in biological organisms.

DEVELOPMENT OF A MATHEMATICAL MODEL FOR DETERMINING TRACTION AND ENERGY PERFORMANCE INDICATORS OF A MANEUVERING LOCOMOTIVE

Fuel consumption for traction significantly depends on the locomotive's operating mode, and by selecting a rational mode during station maneuvers or transit, it is possible to reduce fuel consumption. Previous works on this topic do not provide sufficient analysis of locomotive motion with varying numbers of connected engines. To optimize energy resource consumption, a combination of methods for the rational use of the locomotive is necessary. The traction and energy performance indicators for the maneuvering work of the ČME3 locomotive are calculated by performing traction calculations. In this paper, a mathematical model has been developed to determine these indicators when operating with 4 and 2 parallel-connected traction electric motors. Graphs were constructed to illustrate the relationship between traction force and locomotive speed, the time required to cover a given distance, fuel consumption for a specified distance, and the temperature rise above ambient conditions concerning 6 parallel-connected traction electric motors for the 3rd, 4th, and 5th positions of the engineer's controller. The locomotives were compared while covering the same stretch of track with the same train weight, considering wheel-rail adhesion constraints.Analyzing the obtained dependencies allows the conclusion that using different configurations of connected engines can result in fuel savings of up to 15 % during maneuvering operations, depending on operational conditions. Furthermore, the engine temperature remains within acceptable limits for insulation class F, based on the results of approximating existing locomotive characteristics and deriving analytical expressions (6, 7, 8, 24). Mathematical models of the motion of the ЧМЕ3 locomotive were created for various engine connection scenarios using the obtained mathematical formulas (9, 10, 11, 13, 20, 21, 22, 23, 24).

A model-based proportional-integral observer design for adhesion estimation in the wheel-rail interface: LMI approach

Adhesion estimation in wheel and rail interface is a crucial element as it has a direct effect on the locomotive characteristics and performance. Since the adhesion condition depends on unpredictable factors and dynamic models, its estimation is a complex task. In this paper, a dynamic model for a single wheelset including parameters in detail is developed to improve the accuracy of the model. Then, a model-based Proportional–Integral Observer (PIO) is designed to estimate adhesion during uncertainties and nonlinear parameters. The stability of the proposed PI observer is proved with Lyapunov theory and Linear Matrix Inequality (LMI). Finally, the performance of the method is evaluated via numerical simulation in MATLAB software, and it is validated with a model set-up in the SIMPACK Multibody Simulation (MBS) software.

Adaptive Gait Acquisition through Learning Dynamic Stimulus Instinct of Bipedal Robot.

Standard alternating leg motions serve as the foundation for simple bipedal gaits, and the effectiveness of the fixed stimulus signal has been proved in recent studies. However, in order to address perturbations and imbalances, robots require more dynamic gaits. In this paper, we introduce dynamic stimulus signals together with a bipedal locomotion policy into reinforcement learning (RL). Through the learned stimulus frequency policy, we induce the bipedal robot to obtain both three-dimensional (3D) locomotion and an adaptive gait under disturbance without relying on an explicit and model-based gait in both the training stage and deployment. In addition, a set of specialized reward functions focusing on reliable frequency reflections is used in our framework to ensure correspondence between locomotion features and the dynamic stimulus. Moreover, we demonstrate efficient sim-to-real transfer, making a bipedal robot called BITeno achieve robust locomotion and disturbance resistance, even in extreme situations of foot sliding in the real world. In detail, under a sudden change in torso velocity of -1.2 m/s in 0.65 s, the recovery time is within 1.5-2.0 s.

Analyzing Lower Limb Dynamics in Human Gait Using Average Value-Based Technique

The motivation of this study is to develop effective and economical assistive technologies for people with physical disabilities. The novelty in this manuscript is the application of the average value-based technique to accurately represent the involved biomechanics of the lower limb joints during the human gait cycle. This mathematical formulation of lower limb joints’ biomechanics forms the first objective for modeling and final exoskeleton prototype development. To account for modeling the characteristics of human locomotion, the nth-order linear differential equation with constant coefficients is considered with appropriate modification. The physical characteristics of an individual are represented by the constant coefficients (P0, P1, P2, and P3) of the modified infinite series, which are obtained by processing experimental data collected using an optical technique. The differential terms of the infinite series are replaced by difference terms (δbavg, δ2bavg, and δ3bavg) since the data were captured as a set of digital values. The work presented here is based on the experimental results of individuals suitably categorized according to their physical nature like age and other physical structure. The optically monitored positional values of the lower limb joints of the individual subjects while they are completing the gait cycles are used for getting values of different terms of the model. The data collected through the conduct of experiments are used for finding the values of the terms of the differential equation. The model is effectively validated through experimental results. It was determined that the representation’s accuracy fell within the ±5% acceptable tolerance limit. The model is prepared for healthy as well as disabled persons, through which the disability is quantified. The resulting model can be used to develop assistive devices for people with physical disabilities. This results in the rehabilitation process and thereby helps the reintegration into society, subsequently allowing them to lead a normal life.

Omega motion, rolling, and active standing of a worm-inspired robot under the action of the magnetic field

With the rapid development of origami technologies, worm-inspired robots have attracted a great deal of attention due to their flexible locomotion characteristics. In the present work, we have prepared a soft robot inspired by the worms, which can achieve various locomotion patterns under the actuation of magnetic field. First, the origami technique is used to form the backbone of the robot, and two NdFeB discs are adhered on its two ends. Next, the experiments for controlling the Omega motion and rolling of the robot are performed, and the mechanical analyses are given. In the experiments, the Omega locomotion speed and rolling speed can reach ∼5 mm/s and 2π rad/s, respectively. Then, two typical examples on the composite motion, including the Omega motion and rolling, are demonstrated, where the robot can realize the tasks of sweeping objects and obstacle crossing in unstructured environments. We further design a system to mimic the situation when the worm-like robot detects and responds to the dangerous signal, and the power of the electromagnet can be accurately controlled. These findings cast a new light on engineering intelligent robots and devices originating from the inspirations of living creatures.

Equilibrium and locomotion characteristics of multi-modular magnetic millirobots with different magnet patterns

This paper investigated a multi-modular magnetic microrobot/millirobot (MMM) with a serial chain structure consisting of multiple identical modules. Depending on the magnet pattern used for the MMM’s modules, an MMM can have different equilibrium postures under an external magnetic field, such as assembled ring and disassembled straight-line postures. In this study, we investigated the equilibrium and locomotion characteristics of the MMM by applying two different representative magnet patterns, considered to be effective for magnetic actuation, to the robots. We established various equations to determine and control the assembly, disassembly, and locomotion of the MMM with each magnet pattern. We also conducted various experiments demonstrating the assembly, disassembly, and cargo delivery capabilities of the MMM under different external magnetic fields. Results confirmed that each MMM and their magnet pattern have distinctive and useful characteristics, demonstrating that the two magnet patterns can be selectively and effectively used as MMM in different applications.

Улучшение тягово-энергетических характеристик автономных локомотивов за счет применения модульного исполнения элементов тяговой системы

Purpose: The priority direction of strategic programs for the development of railway transport is the design and introduction into operation of new rolling stock, which is characterized by high technical and economic indicators. In this regard, the goal is to formulate scientifically based technical solutions to reduce the costs of production, maintenance and repair of traction rolling stock and improve its traction and energy characteristics. Methods: To achieve the stated goal, the following methods have been applied: structural analysis; statistical processing of large arrays of experimental data; computer simulation; theory of locomotive traction. Results: Priority directions for improving traction rolling stock have been identified. A set of scientifically based technical solutions has been developed to improve the traction and energy characteristics of selfcontained locomotives, which may allow the transition to a single platform for diesel and electric locomotives. As a result, the reduction in costs for the production, maintenance and repair of traction rolling stock and an improvement in the traction and energy characteristics of locomotives will be achieved. Practical significance: Economic effect obtained due to reducing the costs of production, maintenance and repair of traction rolling stock and the consumption of fuel and energy resources for train traction.

Magnetic Mesoporous Janus Microrollers for Combined Chemo‐ and Photothermal Ablation Therapy

AbstractMobile microrobots have been proposed as a promising approach to overcome the limitations of traditional drug/gene delivery systems. Magnetically actuated surface rolling microrobots, or magnetic surface microrollers, have shown potential for navigation in physiologically relevant environments due to their robust locomotion characteristics. Although much is known about their locomotion abilities in various environments, the full extent of their potential in medical applications has yet to be fully explored. Here, the potential of surface microrollers for combined chemo‐ and photothermal ablation therapy under medical imaging modalities is demonstrated. The surface microrollers are half‐coated with magnetic material, allowing for photothermal heating and magnetic locomotion, and loaded with a biopharmaceutics classification system (BCS) class IV anti‐cancer drug, Docetaxel (DTX), for combined therapy. Synergistic action of on‐demand photothermal ablation and the controlled release of DTX result in the efficient elimination of cancer cells. Furthermore, microrollers can be detected ex vivo with magnetic resonance imaging (MRI) and photoacoustic imaging (PA), highlighting the potential of surface microrollers for future targeted medical applications.

Emerging Roles of Microrobots for Enhancing the Sensitivity of Biosensors

To meet the increasing needs of point-of-care testing in clinical diagnosis and daily health monitoring, numerous cutting-edge techniques have emerged to upgrade current portable biosensors with higher sensitivity, smaller size, and better intelligence. In particular, due to the controlled locomotion characteristics in the micro/nano scale, microrobots can effectively enhance the sensitivity of biosensors by disrupting conventional passive diffusion into an active enrichment during the test. In addition, microrobots are ideal to create biosensors with functions of on-demand delivery, transportation, and multi-objective detections with the capability of actively controlled motion. In this review, five types of portable biosensors and their integration with microrobots are critically introduced. Microrobots can enhance the detection signal in fluorescence intensity and surface-enhanced Raman scattering detection via the active enrichment. The existence and quantity of detection substances also affect the motion state of microrobots for the locomotion-based detection. In addition, microrobots realize the indirect detection of the bio-molecules by functionalizing their surfaces in the electrochemical current and electrochemical impedance spectroscopy detections. We pay a special focus on the roles of microrobots with active locomotion to enhance the detection performance of portable sensors. At last, perspectives and future trends of microrobots in biosensing are also discussed.

DVT: a high-throughput analysis pipeline for locomotion and social behavior in adult Drosophila melanogaster

BackgroundDrosophila melanogaster is excellent animal model for understanding the molecular basis of human neurological and motor disorders. The experimental conditions and chamber design varied between studies. Moreover, most previously established paradigms focus on fly trace detection algorithm development. A comprehensive understanding on how fly behaves in the chamber is still lacking.ResultsIn this report, we established 74 unique behavior metrics quantifying spatiotemporal characteristics of adult fly locomotion and social behaviors, of which 49 were newly proposed. By the aiding of the developed analysis pipeline, Drosophila video tracking (DVT), we identified siginificantly different patterns of fly behavior confronted with different chamber height, fly density, illumination and experimental time. Meanwhile, three fly strains which are widely used as control lines, Canton-S(CS), w1118 and Oregon-R (OR), were found to exhibit distinct motion explosiveness and exercise endurance.ConclusionsWe believe the proposed behavior metrics set and pipeline should help identify subtle spatial and temporal differences of drosophila behavior confronted with different environmental factors or gene variants.

Development and investigation of the vibration-driven in-pipe robot

Vibratory machines are widely used for monitoring and cleaning various tubes, pipelines, intestines, vessels, etc. The problems of ensuring the prescribed dynamic characteristics of such equipment and simultaneous optimizing the power consumption are currently being solved by numerous researchers. The main purpose of this study is to investigate the locomotion characteristics of the novel vibration-driven design of the pipeline inspecting and cleaning robot actuated by an electromagnetic exciter and equipped with the size-adapting and self-locking mechanisms. The research methodology consists of four main stages: an overview of the enhanced robot design; constructing its dynamic diagram and deriving the differential equations of motion; performing the numerical modeling with the help of the Mathematica software and studying the robot’s kinematic characteristics; conducting virtual experiments by computer simulation of the robot motion in the SolidWorks software. The research results present the time dependencies of the robot’s displacement, speed, and acceleration at different working regimes (excitation forces, disturbing frequencies, etc.). The novelty of the performed investigations consists in substantiating the efficient locomotion conditions of the enhanced vibration-driven in-pipe robot. Further investigations can be focused on developing the full-scale laboratory prototype of the robot and conducting experimental studies. The obtained research results can be interesting for engineers and scientists who deal with similar vibration-driven pipeline robots.

Growth rate affects blood flow rate to the tibia of the dinosaur Maiasaura

AbstractFossil bones were once living tissues that demanded internal blood perfusion in proportion to their metabolic requirements. Metabolic rates were primarily associated with bone growth (modeling) in the juvenile stages and with alteration and repair of existing bone affected by weight bearing and locomotion (remodeling) in later stages. This study estimates blood flow rates to the tibia shafts of the Late Cretaceous hadrosaurid Maiasaura peeblesorum, based on the size of the primary nutrient foramina in fossil bones. Foramen size quantitatively reflects arterial size and hence blood flow rate. The results showed that the bone metabolic intensity of juveniles (ca. 1 year old) was greater than fourfold higher than that of 6- to 11-year-old adults. This difference is much greater than expected from standard metabolic scaling and is interpreted as a shift from the high metabolic demands for primary bone modeling in the rapidly growing juveniles to a lower metabolic demand of adults to remodel their bones for repair of microfractures accumulated during locomotion and weight bearing. Large nutrient foramina of adults indicate a high level of cursorial locomotion characteristic of tachymetabolic endotherms. The practical value of these results is that juvenile and adult stages should be treated separately in interspecific analyses of bone perfusion in relation to body mass.

Sensor-Based Locomotion Data Mining for Supporting the Diagnosis of Neurodegenerative Disorders: A Survey

Locomotion characteristics and movement patterns are reliable indicators of neurodegenerative diseases (NDDs). This survey provides a systematic literature review of locomotion data mining systems for supporting NDD diagnosis. We discuss techniques for discovering low-level locomotion indicators, sensor data acquisition and processing methods, and NDD detection algorithms. The survey presents a comprehensive discussion on the main challenges for this active area, including the addressed diseases, locomotion data types, duration of monitoring, employed algorithms, and experimental validation strategies. We also identify prominent open challenges and research directions regarding ethics and privacy issues, technological and usability aspects, and availability of public benchmarks.

Locomotion characteristics of a wheeled vibration-driven robot with an enhanced pantograph-type suspension.

Introduction: The paper considers the improved design of the wheeled vibration-driven robot equipped with an inertial exciter (unbalanced rotor) and enhanced pantograph-type suspension. The primary purpose and objectives of the study are focused on mathematical modeling, computer simulation, and experimental testing of locomotion conditions of the novel robot prototype. The primary scientific novelty of the present research consists in substantiating the possibilities of implementing the enhanced pantograph-type suspension in order to improve the robot's kinematic characteristics, particularly the average translational speed. Methods: The simplified dynamic diagram of the robot's oscillatory system is developed, and the mathematical model describing its locomotion conditions is derived using the Euler-Lagrange differential equations. The numerical modeling is carried out in the Mathematica software with the help of the Runge-Kutta methods. Computer simulation of the robot motion is performed in the SolidWorks Motion software using the variable step integration method (Gear's method). The experimental investigations of the robot prototype operating conditions are conducted at the Vibroengineering Laboratory of Lviv Polytechnic National University using the WitMotion accelerometers and software. The experimental data is processed in the MathCad software. Results and discussion: The obtained results show the time dependencies of the robot body's basic kinematic parameters (accelerations, velocities, displacements) under different operating conditions, particularly the angular frequencies of the unbalanced rotor. The numerical modeling, computer simulation, and experimental investigations present almost similar results: the smallest horizontal speed of about 1mm/s is observed at the supplied voltage of 3.47V when the forced frequency is equal to 500rpm; the largest locomotion speed is approximately 40mm/s at the supplied voltage of 10V and forced frequency of 1,500rpm. The paper may be interesting for designers and researchers of similar vibration-driven robotic systems based on wheeled chassis, and the results may be used while implementing the experimental and industrial prototypes of vibration-driven robots for various purposes, particularly, for inspecting and cleaning the pipelines. Further investigation on the subject of the paper should be focused on analyzing the relations between the power consumption, average translational speed, and working efficiency of the considerer robot under various operating conditions.