Effects of speed on pheasant gaits and hindlimb joint angles

2019 ◽  
Vol 69 (3) ◽  
pp. 293-306
Author(s):  
Rui Zhang ◽  
Dianlei Han ◽  
Qiaoli Ji ◽  
Guoyu Li ◽  
Xian Li ◽  
...  
Keyword(s):  
Kinematic Analysis ◽  
High Speed ◽  
Stride Length ◽  
Joint Angle ◽  
Duty Factor ◽  
Joint Angles ◽  
Walking Gait ◽  
Intermittent Flight ◽  
Lift Off ◽  
Intertarsal Joint

Abstract When studying the gait of pheasants, an intermittent-flight bird, it is necessary to take into account changes in the gaits and hindlimb joint angles resulting from increases of speed. In this study, pheasant locomotion postures were recorded on a speed-variable treadmill with high-speed cameras. Firstly, kinematic analysis showed that the stride cycle of pheasants decreased and the stride length increased with increasing speed. The duty factor also decreased, but was less than 0.5 in only about 10% of measurements. Thus, pheasants are more inclined to choose the grounded running or walking gait in laboratory situations. Secondly, changes in the tarsometatarso-phalangeal joint angle and the intertarsal joint angle at touch-down, mid-stance and lift-off concomitant with speed variation were studied. Tarsometatarso-phalangeal joint angle was found not to be significantly affected by changes in speed, but changed over larger ranges than the intertarsal joint angle. Thirdly, the continuous changes in the joint angles were studied during a complete stride cycle. The curves shifted leftward with increasing speed. Finally, the changes at four main positions were analyzed with increasing speed.

A Three-Dimensional Cinematographic Analysis of the Fastball and Curveball Pitches in Baseball

1986 ◽  
Vol 2 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Bruce Elliott ◽  
J. Robert Grove ◽  
Barry Gibson ◽  
B. Thurston
Keyword(s):  
Motion Analysis ◽  
Linear Transformation ◽  
Kinematic Analysis ◽  
High Speed ◽  
Stride Length ◽  
Three Dimensional ◽  
High Speed Photography ◽  
Anatomical Features ◽  
Balance Point

Three-dimensional (3-D) high speed photography was used to record the fastball (FB) and curveball (CB) actions of six members of the Australian National pitching squad. The direct linear transformation (DLT) method of motion analysis for 3-D space reconstruction from 2-D images was used to record the movement of selected anatomical features. Laterally positioned phase-locked cameras operating at 200 fps and a front-on camera operating at 300 fps were used to record the pitching action. Mean pitching velocities for the FB and the CB were recorded. A kinematic analysis of the two pitching motions from the first balance point following the completion of the pump and pivot to follow through are presented. The actions are very similar for the two pitches, as would be expected if disguised to confuse the batter. Minor differences were noted, however, for stride length, forearm action prior to release, and wrist action at release.

scholarly journals Analysis of Spiders’ Joint Kinematics and Driving Modes under Different Ground Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Hao ◽  
Wenxing Ma ◽  
Chunbao Liu ◽  
Yilei Li ◽  
Zhihui Qian ◽  
...  
Keyword(s):  
High Speed ◽  
Gait Pattern ◽  
Joint Kinematics ◽  
Duty Factor ◽  
Joint Angles ◽  
3D Tracking ◽  
Biomimetic Systems ◽  
Transmission Mechanisms ◽  
Movement Characteristics ◽  
Ground Conditions

Although the hydraulic transmission system in spider legs is well known, the spider’s mechanism of locomotion during different terrain conditions still need to be explored further. In this study, spider locomotion was observed in detail on three pavement test platforms: horizontal hard pavement, horizontal soft pavement, and sloped soft pavement. The movement characteristics and joint kinematics of Grammostola rosea legs were captured by high-speed cameras and Simi Motion 3D tracking software. These observations showed that the gait pattern was basically consistent with an alternating tetrapod gait; however, the pattern observed on the sloped soft pavement was slightly different from that of the two horizontal pavements. In particular, the duty factor of the spiders was 0.683 when walking on the horizontal hard pavement, 0.668 on the horizontal soft pavement, and 0.630 on the sloped soft pavement. The duty factor was greater than 60% in all three pavement environments, which was minimal when walking on the sloped soft pavement. This pattern showed that spiders might have superior stability when walking, but their stability decreased in the sloped soft pavement environment. The ranges of joint angles through the spiders’ gait cycles in every pavement environment were also analysed and compared. The findings showed that the hydraulically driven femur-patella and tibia-metatarsal joint angles varied widely, which confirmed that hydraulically driven joints had major functions and obvious effects on the walking process. The kinematic patterns identified in this study provide improved understanding of the hydraulic transmission mechanisms, the factors that affect motion stability, and the design of biomimetic systems.

scholarly journals Genome-Wide Association Studies Based on Equine Joint Angle Measurements Reveal New QTL Affecting the Conformation of Horses

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 370 ◽  
Author(s):  
Annik Imogen Gmel ◽  
Thomas Druml ◽  
Rudolf von Niederhäusern ◽  
Tosso Leeb ◽  
Markus Neuditschko
Keyword(s):  
Joint Angle ◽  
Association Studies ◽  
Genome Wide Association ◽  
Cranial Morphology ◽  
Genome Wide Association Studies ◽  
Joint Angles ◽  
Mineral Density ◽  
Mixed Effect ◽  
Stifle Joint ◽  
Genome Wide

The evaluation of conformation traits is an important part of selection for breeding stallions and mares. Some of these judged conformation traits involve joint angles that are associated with performance, health, and longevity. To improve our understanding of the genetic background of joint angles in horses, we have objectively measured the angles of the poll, elbow, carpal, fetlock (front and hind), hip, stifle, and hock joints based on one photograph of each of the 300 Franches-Montagnes (FM) and 224 Lipizzan (LIP) horses. After quality control, genome-wide association studies (GWASs) for these traits were performed on 495 horses, using 374,070 genome-wide single nucleotide polymorphisms (SNPs) in a mixed-effect model. We identified two significant quantitative trait loci (QTL) for the poll angle on ECA28 (p = 1.36 × 10−7), 50 kb downstream of the ALX1 gene, involved in cranial morphology, and for the elbow joint on ECA29 (p = 1.69 × 10−7), 49 kb downstream of the RSU1 gene, and 75 kb upstream of the PTER gene. Both genes are associated with bone mineral density in humans. Furthermore, we identified other suggestive QTL associated with the stifle joint on ECA8 (p = 3.10 × 10−7); the poll on ECA1 (p = 6.83 × 10−7); the fetlock joint of the hind limb on ECA27 (p = 5.42 × 10−7); and the carpal joint angle on ECA3 (p = 6.24 × 10−7), ECA4 (p = 6.07 × 10−7), and ECA7 (p = 8.83 × 10−7). The application of angular measurements in genetic studies may increase our understanding of the underlying genetic effects of important traits in equine breeding.

scholarly journals Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2690
Author(s):  
Bo Pan ◽  
Xuguang Wang ◽  
Zhenyang Xu ◽  
Lianjun Guo ◽  
Xuesong Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Joint Angle ◽  
Simulation Software ◽  
Dissipated Energy ◽  
Energy Structure ◽  
Joint Angles ◽  
Crack Penetration ◽  
Before And After ◽  
The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

Kinematic analysis of a novel feeding mechanism in the brook trout Salvelinus fontinalis (Teleostei: Salmonidae): behavioral modulation of a functional novelty

2001 ◽  
Vol 204 (22) ◽  
pp. 3905-3916
Author(s):  
Christopher P. J. Sanford
Keyword(s):  
Kinematic Analysis ◽  
Brook Trout ◽  
High Speed ◽  
Salvelinus Fontinalis ◽  
Univariate Analysis ◽  
Head Length ◽  
Power Stroke ◽  
Maximum Displacement ◽  
Open Mouth ◽  
Feeding Mechanism

SUMMARY The tongue-bite apparatus (TBA) of salmonids represents an impressive novel feeding mechanism. The TBA consists of a set of well-developed teeth on the dorsal surface of the anterior hyoid (basihyal) and an opposing set of teeth on the roof of the mouth (vomer). A kinematic analysis of behaviors associated with the TBA in the brook trout Salvelinus fontinalis was performed using high-speed video (250 frames s–1). Two distinct behaviors were identified, raking and open-mouth chewing. Univariate analysis demonstrated that these behaviors were significantly different from one another. The power stroke of raking is characterized by significantly greater neurocranial elevation (raking, 36°; open-mouth chewing, 16°) and retraction of the pectoral girdle (raking, 0.85 cm or 21 % of head length; open-mouth chewing, 0.41 cm or 10 % of head length). Open-mouth chewing is characterized predominantly by dorso-ventral excursions of the anterior hyoid (open-mouth chewing, 0.26 cm; raking, 0.14 cm). Raking is significantly shorter in duration (mean 49 ms) than open-mouth chewing (mean 77 ms). When presented with three different types of prey (crickets, fish or worms), Salvelinus fontinalis showed no variation in raking behavior, indicating that raking is highly stereotyped. In contrast, when feeding on worms, Salvelinus fontinalis modulated open-mouth chewing behavior with shorter durations to maximum displacement (at least 20 ms shorter than for either fish or cricket), although the magnitude of displacements did not vary. The reasons for the shorter duration of displacement variables while feeding on worms remains unclear. During post-capture processing behaviors in Salvelinus fontinalis, the magnitude of displacement variables is highly variable between individuals, but temporal patterns are not. This study characterizes two novel post-capture feeding behaviors and modulation of those behaviors in salmonids.

scholarly journals Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

2016 ◽  
Vol 113 (8) ◽  
pp. E950-E957 ◽  
Author(s):  
Kaushik Jayaram ◽  
Robert J. Full
Keyword(s):  
Body Weight ◽  
High Speed ◽  
Stride Length ◽  
Body Height ◽  
Legged Robot ◽  
Confined Space ◽  
Performance Limits ◽  
Biological Inspiration ◽  
Confined Spaces ◽  
Postural Changes

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

Rotordynamic Performance of a Shaft With Large Overhung Mass Supported by Foil Bearings

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Nguyen LaTray ◽  
Daejong Kim
Keyword(s):  
High Speed ◽  
Foil Bearings ◽  
Speed Test ◽  
Foil Bearing ◽  
Stable Conditions ◽  
Bending Mode ◽  
Mode Vibration ◽  
Lift Off ◽  
Compact Design ◽  
Bearing System

This work presents the theoretical and experimental rotordynamic evaluations of a rotor–air foil bearing (AFB) system supporting a large overhung mass for high-speed application. The proposed system highlights the compact design of a single shaft rotor configuration with turbomachine components arranged on one side of the bearing span. In this work, low-speed tests up to 45 krpm are performed to measure lift-off speed and to check bearing manufacturing quality. Rotordynamic performance at high speeds is evaluated both analytically and experimentally. In the analytical approach, simulated imbalance responses are studied using both rigid and flexible shaft models with bearing forces calculated from the transient Reynolds equation along with the rotor motion. The simulation predicts that the system experiences small synchronous rigid mode vibration at 20 krpm and bending mode at 200 krpm. A high-speed test rig is designed to experimentally evaluate the rotor–air foil bearing system. The high-speed tests are operated up to 160 krpm. The vibration spectrum indicates that the rotor–air foil bearing system operates under stable conditions. The experimental waterfall plots also show very small subsynchronous vibrations with frequency locked to the system natural frequency. Overall, this work demonstrates potential capability of the air foil bearings in supporting a shaft with a large overhung mass at high speed.

THE QNDE USING IMAGE PROCESSING OF THE MAGNETIC CAMERA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4625-4630 ◽  
Author(s):  
JINYI LEE ◽  
JISEONG HWANG ◽  
SEHO CHOI
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Magnetic Hysteresis ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Second Derivatives ◽  
Crack Volume ◽  
Lift Off ◽  
Magnetic Camera ◽  
Derivatives Of

A scan type magnetic camera was proposed to satisfy the following demands: to obtain high speed quantitative magnetic flux leakage (MFL) distribution with homogeneous lift-off by using 2-dimensionally arrayed high sensitivity magnetic sensors; to concentrate the MFL; and to ignore the residual magnetization and magnetic hysteresis by using a magnetic fluid lens. The magnetic field distribution (MFD) image obtained by using the scan type magnetic camera is inclined to the scanning direction (x-direction) because of the poles of the magnetizer. Also, the image shows a homogeneous trend relative to the x-direction, but there are small waves in the distribution in the sensor arraying direction (y-direction). The crack information in the MFD image can be extracted using image processing. The first and second derivatives of both x and y are used in this processing. These are "1st derivative of x, ∂B/∂x", "1st derivative of y, ∂B/∂y", "2nd derivative of x, ∂2B/∂x2", "2nd derivative of y, ∂2B/∂y2", and "2nd derivative of x and y, ∂2B/∂x∂y". The ∂B/∂x distribution shows the existence of the crack. Also, the crack volume can be evaluated quantitatively, regardless of the crack direction, by using ∂B/∂x and a cross type magnetic coil.

Gyroscope-Free Link Parameter Measurement Using Accelerometers and Magnetometer

2014 ◽  
Author(s):  
Vishesh Vikas ◽  
Carl D. Crane
Keyword(s):  
Angular Velocity ◽  
Joint Angle ◽  
Inertial Sensors ◽  
Angular Acceleration ◽  
Parameter Measurement ◽  
Joint Angles ◽  
Symmetry Constraint ◽  
Estimation Techniques ◽  
Angular Velocities ◽  
Joint Parameters

Knowledge of joint angles, angular velocities is essential for control of link mechanisms and robots. The estimation of joint angles and angular velocity is performed using combination of inertial sensors (accelerometers and gyroscopes) which are contactless and flexible at point of application. Different estimation techniques are used to fuse data from different inertial sensors. Bio-inspired sensors using symmetrically placed multiple inertial sensors are capable of instantaneously measuring joint parameters (joint angle, angular velocities and angular acceleration) without use of any estimation techniques. Calibration of inertial sensors is easier and more reliable for accelerometers as compared to gyroscopes. The research presents gyroscope-less, multiple accelerometer and magnetometer based sensors capable of measuring (not estimating) joint parameters. The contribution of the improved sensor are four-fold. Firstly, the inertial sensors are devoid of symmetry constraint unlike the previously researched bio-inspired sensors. However, the accelerometer are non-coplanarly placed. Secondly, the accelerometer-magnetometer combination sensor allows for calculation of a unique rotation matrix between two link joined by any kind of joint. Thirdly, the sensors are easier to calibrate as they consist only of accelerometers. Finally, the sensors allow for calculation of angular velocity and angular acceleration without use of gyroscopes.

Invariant Manifolds in Human Joint Angle Analysis During Walking Gait

2021 ◽  
Author(s):  
Sandesh Bhat ◽  
Sangram Redkar ◽  
Thomas G. Sugar
Keyword(s):  
Invariant Manifolds ◽  
Joint Angle ◽  
Walking Gait ◽  
Human Joint
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