scholarly journals Biomechanical basis of wing and haltere coordination in flies

2015 ◽  
Vol 112 (5) ◽  
pp. 1481-1486 ◽  
Author(s):  
Tanvi Deora ◽  
Amit Kumar Singh ◽  
Sanjay P. Sane
Keyword(s):  
Flight Control ◽  
Motor System ◽  
Sensory Feedback ◽  
Phase Synchronization ◽  
Aerodynamic Forces ◽  
Precise Control ◽  
Wing Motion ◽  
Clutch System ◽  
Biomechanical Features ◽  
Ecological Habitats

The spectacular success and diversification of insects rests critically on two major evolutionary adaptations. First, the evolution of flight, which enhanced the ability of insects to colonize novel ecological habitats, evade predators, or hunt prey; and second, the miniaturization of their body size, which profoundly influenced all aspects of their biology from development to behavior. However, miniaturization imposes steep demands on the flight system because smaller insects must flap their wings at higher frequencies to generate sufficient aerodynamic forces to stay aloft; it also poses challenges to the sensorimotor system because precise control of wing kinematics and body trajectories requires fast sensory feedback. These tradeoffs are best studied in Dipteran flies in which rapid mechanosensory feedback to wing motor system is provided by halteres, reduced hind wings that evolved into gyroscopic sensors. Halteres oscillate at the same frequency as and precisely antiphase to the wings; they detect body rotations during flight, thus providing feedback that is essential for controlling wing motion during aerial maneuvers. Although tight phase synchrony between halteres and wings is essential for providing proper timing cues, the mechanisms underlying this coordination are not well understood. Here, we identify specific mechanical linkages within the thorax that passively mediate both wing–wing and wing–haltere phase synchronization. We demonstrate that the wing hinge must possess a clutch system that enables flies to independently engage or disengage each wing from the mechanically linked thorax. In concert with a previously described gearbox located within the wing hinge, the clutch system enables independent control of each wing. These biomechanical features are essential for flight control in flies.

scholarly journals A chordwise offset of the wing-pitch axis enhances rotational aerodynamic forces on insect wings: a numerical study

2019 ◽  
Vol 16 (155) ◽  
pp. 20190118 ◽  
Author(s):  
Wouter G. van Veen ◽  
Johan L. van Leeuwen ◽  
Florian T. Muijres
Keyword(s):  
Flight Control ◽  
Numerical Study ◽  
Force Production ◽  
Aerodynamic Forces ◽  
Rotational Force ◽  
Wing Motion ◽  
Forward Stroke ◽  
Insect Wings ◽  
Force Mechanism ◽  
Numerical Parametric Study

Most flying animals produce aerodynamic forces by flapping their wings back and forth with a complex wingbeat pattern. The fluid dynamics that underlies this motion has been divided into separate aerodynamic mechanisms of which rotational lift, that results from fast wing pitch rotations, is particularly important for flight control and manoeuvrability. This rotational force mechanism has been modelled using Kutta–Joukowski theory, which combines the forward stroke motion of the wing with the fast pitch motion to compute forces. Recent studies, however, suggest that hovering insects can produce rotational forces at stroke reversal, without a forward motion of the wing. We have conducted a broad numerical parametric study over a range of wing morphologies and wing kinematics to show that rotational force production depends on two mechanisms: (i) conventional Kutta–Joukowski-based rotational forces and (ii) a rotational force mechanism that enables insects with an offset of the pitch axis relative to the wing's chordwise symmetry axis to generate rotational forces in the absence of forward wing motion. Because flying animals produce control actions frequently near stroke reversal, this pitch-axis-offset dependent aerodynamic mechanism may be particularly important for understanding control and manoeuvrability in natural flyers.

Lift and power requirements of hovering flight inDrosophila virilis

2002 ◽  
Vol 205 (16) ◽  
pp. 2413-2427 ◽  
Author(s):  
Mao Sun ◽  
Jian Tang
Keyword(s):  
Flight Control ◽  
Stokes Equations ◽  
Fruit Fly ◽  
The Body ◽  
Drosophila Virilis ◽  
Specific Power ◽  
Aerodynamic Forces ◽  
Hovering Flight ◽  
Power Expenditure ◽  
The Mean

SUMMARYThe lift and power requirements for hovering flight in Drosophila virilis were studied using the method of computational fluid dynamics. The Navier-Stokes equations were solved numerically. The solution provided the flow velocity and pressure fields, from which the unsteady aerodynamic forces and moments were obtained. The inertial torques due to the acceleration of the wing mass were computed analytically. On the basis of the aerodynamic forces and moments and the inertial torques, the lift and power requirements for hovering flight were obtained.For the fruit fly Drosophila virilis in hovering flight (with symmetrical rotation), a midstroke angle of attack of approximately 37°was needed for the mean lift to balance the insect weight, which agreed with observations. The mean drag on the wings over an up- or downstroke was approximately 1.27 times the mean lift or insect weight (i.e. the wings of this tiny insect must overcome a drag that is approximately 27 % larger than its weight to produce a lift equal to its weight). The body-mass-specific power was 28.7 W kg-1, the muscle-mass-specific power was 95.7 W kg-1 and the muscle efficiency was 17 %.With advanced rotation, larger lift was produced than with symmetrical rotation, but it was more energy-demanding, i.e. the power required per unit lift was much larger. With delayed rotation, much less lift was produced than with symmetrical rotation at almost the same power expenditure; again, the power required per unit lift was much larger. On the basis of the calculated results for power expenditure, symmetrical rotation should be used for balanced, long-duration flight and advanced rotation and delayed rotation should be used for flight control and manoeuvring. This agrees with observations.

Switched Reluctance Motor for Electric Submersible Pump

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Adams ◽  
Jinjiang Xiao ◽  
Michael Cross ◽  
Max Deffenbaugh
Keyword(s):  
State Space ◽  
Performance Feedback ◽  
Motor System ◽  
Reverse Direction ◽  
Submersible Pump ◽  
Pump System ◽  
Switched Reluctance ◽  
Precise Control ◽  
And Control ◽  
Electric Submersible Pump

Switched reluctance motors may be advantageous when used as the primary motor for an electric submersible pump system.  They are less susceptible to jamming failures due to their high starting torque and ability to reverse direction.  Driving these motors requires well-timed pulse waveforms and precise control of the motor based on its rotational position.  In general, voltage-based sensing and control systems at the surface see highly unpredictable waveforms with excessive ringing behaviour due to the impedance characteristics of the long cabling between the surface controller and the downhole motor system.  In this work, a system is detailed which monitors the current waveforms on the motor coil excitation conductors at the surface as a source of motor performance feedback and control.  State-space modelling of the system shows stable current waveforms at the surface controller for both short and long interconnect cable systems.  A laboratory demonstration of the surface controller, interconnect cabling, and motor system is shows excellent agreement with the current and voltage waveforms predicted by the state-space system model.

scholarly journals State-dependent sensorimotor gating in a rhythmic motor system

2017 ◽  
Vol 118 (5) ◽  
pp. 2806-2818 ◽  
Author(s):  
Rachel S. White ◽  
Robert M. Spencer ◽  
Michael P. Nusbaum ◽  
Dawn M. Blitz
Keyword(s):  
Motor Activity ◽  
Motor System ◽  
Sensory Feedback ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Projection Neuron ◽  
Projection Neurons ◽  
Gastric Mill ◽  
Sensory Regulation ◽  
Motor Circuits

Sensory feedback influences motor circuits and/or their projection neuron inputs to adjust ongoing motor activity, but its efficacy varies. Currently, less is known about regulation of sensory feedback onto projection neurons that control downstream motor circuits than about sensory regulation of the motor circuit neurons themselves. In this study, we tested whether sensory feedback onto projection neurons is sensitive only to activation of a motor system, or also to the modulatory state underlying that activation, using the crab Cancer borealis stomatogastric nervous system. We examined how proprioceptor neurons (gastropyloric receptors, GPRs) influence the gastric mill (chewing) circuit neurons and the projection neurons (MCN1, CPN2) that drive the gastric mill rhythm. During gastric mill rhythms triggered by the mechanosensory ventral cardiac neurons (VCNs), GPR was shown previously to influence gastric mill circuit neurons, but its excitation of MCN1/CPN2 was absent. In this study, we tested whether GPR effects on MCN1/CPN2 are also absent during gastric mill rhythms triggered by the peptidergic postoesophageal commissure (POC) neurons. The VCN and POC pathways both trigger lasting MCN1/CPN2 activation, but their distinct influence on circuit feedback to these neurons produces different gastric mill motor patterns. We show that GPR excites MCN1 and CPN2 during the POC-gastric mill rhythm, altering their firing rates and activity patterns. This action changes both phases of the POC-gastric mill rhythm, whereas GPR only alters one phase of the VCN-gastric mill rhythm. Thus sensory feedback to projection neurons can be gated as a function of the modulatory state of an active motor system, not simply switched on/off with the onset of motor activity. NEW & NOTEWORTHY Sensory feedback influences motor systems (i.e., motor circuits and their projection neuron inputs). However, whether regulation of sensory feedback to these projection neurons is consistent across different versions of the same motor pattern driven by the same motor system was not known. We found that gating of sensory feedback to projection neurons is determined by the modulatory state of the motor system, and not simply by whether the system is active or inactive.

scholarly journals The biophysics of bird flight: functional relationships integrate aerodynamics, morphology, kinematics, muscles, and sensors

2015 ◽  
Vol 93 (12) ◽  
pp. 961-975 ◽  
Author(s):  
Douglas L. Altshuler ◽  
Joseph W. Bahlman ◽  
Roslyn Dakin ◽  
Andrea H. Gaede ◽  
Benjamin Goller ◽  
...  
Keyword(s):  
Flight Control ◽  
Sensory Information ◽  
Polar Regions ◽  
Bird Flight ◽  
Avian Flight ◽  
Functional Relationships ◽  
Wing Motion ◽  
Extant Species ◽  
Terrestrial Habitats ◽  
High Elevations

Bird flight is a remarkable adaptation that has allowed the approximately 10 000 extant species to colonize all terrestrial habitats on earth including high elevations, polar regions, distant islands, arid deserts, and many others. Birds exhibit numerous physiological and biomechanical adaptations for flight. Although bird flight is often studied at the level of aerodynamics, morphology, wingbeat kinematics, muscle activity, or sensory guidance independently, in reality these systems are naturally integrated. There has been an abundance of new studies in these mechanistic aspects of avian biology but comparatively less recent work on the physiological ecology of avian flight. Here we review research at the interface of the systems used in flight control and discuss several common themes. Modulation of aerodynamic forces to respond to different challenges is driven by three primary mechanisms: wing velocity about the shoulder, shape within the wing, and angle of attack. For birds that flap, the distinction between velocity and shape modulation synthesizes diverse studies in morphology, wing motion, and motor control. Recently developed tools for studying bird flight are influencing multiple areas of investigation, and in particular the role of sensory systems in flight control. How sensory information is transformed into motor commands in the avian brain remains, however, a largely unexplored frontier.

scholarly journals Modeling the Role of Sensory Feedback in Speech Motor Control and Learning

2019 ◽  
Vol 62 (8S) ◽  
pp. 2963-2985 ◽  
Author(s):  
Benjamin Parrell ◽  
John Houde
Keyword(s):  
Motor Control ◽  
Motor System ◽  
Sensory Feedback ◽  
Computational Models ◽  
State Feedback Control ◽  
Speech Motor Control ◽  
Control Feedback ◽  
Motor Production ◽  
Speech Motor

Purpose While the speech motor system is sensitive to feedback perturbations, sensory feedback does not seem to be critical to speech motor production. How the speech motor system is able to be so flexible in its use of sensory feedback remains an open question. Method We draw on evidence from a variety of disciplines to summarize current understanding of the sensory systems' role in speech motor control, including both online control and motor learning. We focus particularly on computational models of speech motor control that incorporate sensory feedback, as these models provide clear encapsulations of different theories of sensory systems' function in speech production. These computational models include the well-established directions into velocities of articulators model and computational models that we have been developing in our labs based on the domain-general theory of state feedback control (feedback aware control of tasks in speech model). Results After establishing the architecture of the models, we show that both the directions into velocities of articulators and state feedback control/feedback aware control of tasks models can replicate key behaviors related to sensory feedback in the speech motor system. Although the models agree on many points, the underlying architecture of the 2 models differs in a few key ways, leading to different predictions in certain areas. We cover key disagreements between the models to show the limits of our current understanding and point toward areas where future experimental studies can resolve these questions. Conclusions Understanding the role of sensory information in the speech motor system is critical to understanding speech motor production and sensorimotor learning in healthy speakers as well as in disordered populations. Computational models, with their concrete implementations and testable predictions, are an important tool to understand this process. Comparison of different models can highlight areas of agreement and disagreement in the field and point toward future experiments to resolve important outstanding questions about the speech motor control system.

Design of a Bio-Inspired Spherical Four-Bar Mechanism for Flapping-Wing Micro Air-Vehicle Applications

2008 ◽  
Author(s):  
Matt McDonald ◽  
Sunil K. Agrawal
Keyword(s):  
Three Dimensional ◽  
Micro Air Vehicles ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Aerodynamic Forces ◽  
Flapping Motion ◽  
Wing Motion ◽  
Air Vehicle ◽  
Flapping Mechanism

Design of flapping-wing micro air-vehicles presents many engineering challenges. As observed by biologists, insects and birds exhibit complex three-dimensional wing motions. It is believed that these unique patterns of wing motion create favorable aerodynamic forces that enable these species to fly forward, hover, and execute complex motions. From the perspective of micro air-vehicle applications, extremely lightweight designs that accomplish these motions of the wing, using just a single, or a few actuators, are preferable. This paper presents a method to design a spherical four-bar flapping mechanism that approximates a given spatial flapping motion of a wing, considered to have favorable aerodynamics. A spherical flapping mechanism was then constructed and its aerodynamic performance was compared to the original spatially moving wing using an instrumented robotic flapper with force sensors.

Sensory Feedback Does Not Cause Selective Adaptation of Human “Command Neurons”

1977 ◽  
Vol 44 (2) ◽  
pp. 447-451 ◽  
Author(s):  
David A. Rosenbaum ◽  
Michael Radford
Keyword(s):  
Present Experiment ◽  
Motor System ◽  
Sensory Feedback ◽  
Negative Transfer ◽  
Human Subjects ◽  
Selective Adaptation ◽  
Positive Transfer ◽  
Command Neurons ◽  
Body Movements ◽  
Human Motor

It has been proposed that body movements are partly controlled by a neural hierarchy, with cells at successively higher levels controlling increasing numbers of muscles engaged in functionally equivalent responses. In addition to physiological support for the hypothesis, obtained from infrahuman species, evidence from human subjects has been obtained in the form of negative transfer between successive similar responses. This negative transfer has been attributed to selective adaptation of “command neurons” in the human motor system. The present experiment found no evidence for negative (or positive) transfer between passive and active movements, suggesting that selective adaptation of human command neurons is caused by efference rather than afference.

wUbi-Pen: Sensory Feedback Stylus Interacting with Graphical User Interface

2012 ◽  
Vol 21 (2) ◽  
pp. 142-155 ◽  
Author(s):  
Ki-Uk Kyung ◽  
Jun-Young Lee ◽  
Junseok Park ◽  
Mandayam A. Srinivasan
Keyword(s):  
User Interface ◽  
Graphical User Interface ◽  
Sensory Feedback ◽  
Haptic Feedback ◽  
Touch Screen ◽  
Precise Control ◽  
Communication Module ◽  
Interaction Scheme ◽  
Touch Screen Devices ◽  
Haptic Cues

In this work, we designed an interactive stylus interface for touch-screen devices, the wUbi-Pen haptic stylus. The stylus has functions of providing both vibration and impact with a single actuator, and it is a stand-alone system including its own battery and communication module. We present a new interaction scheme on the graphical user interface (GUI) based on sensory feedback events for clicking, drag-and-drop, moving, sliding, highlighting, and drawing. Experiments evaluating stylus performance indicated that the haptic cues improved precise control of GUI elements. A simple interactive digital sketchbook was also implemented, which provided a variety of haptic feedback while drawing and touching objects.

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