scholarly journals Hawkmoths use wingstroke-to-wingstroke frequency modulation for aerial recovery to vortex ring perturbations

2020 ◽  
Author(s):  
Jeff Gau ◽  
Ryan Gemilere ◽  
James Lynch ◽  
Nick Gravish ◽  
Simon Sponberg ◽  
...  
Keyword(s):  
Frequency Modulation ◽  
High Speed ◽  
Insect Flight ◽  
Control Strategies ◽  
Flapping Wing ◽  
Wingbeat Frequency ◽  
Mechanical Constraints ◽  
Power And Control ◽  
Long Time ◽  
And Control

AbstractCentimeter-scale fliers that combine wings with springy elements must contend with the high power requirements and mechanical constraints of flapping wing flight. Insects utilize elastic energy exchange to reduce the inertial costs of flapping wing flight and potentially match wingbeat frequencies to a mechanical resonance. Flying at resonance may be energetically favorable under steady conditions, but it is difficult to modulate the frequency of a resonant system. Evidence suggests that insects utilize frequency modulation over long time scales to adjust aerodynamic forces, but it remains an open question the extent to which insects can modulate frequency on the wingstroke-to-wingstroke timescale. If wingbeat frequencies deviate from resonance, the musculature must work against the elastic flight system, thereby potentially increasing energetic costs. To assess how insects address the simultaneous needs for power and control, we tested the capacity for wingstroke-to-wingstroke wingbeat frequency modulation by perturbing free hovering Manduca sexta with vortex rings while recording high-speed video at 2000 fps. Because hawkmoth flight muscles are synchronous, there is at least the potential for the nervous system to modulate frequency on each wingstroke. We observed ± 16% wingbeat frequency modulation in just a few wing strokes. Via instantaneous phase analysis of wing kinematics, we found that over 85% of perturbation responses required active changes in motor input frequency. Unlike their robotic counterparts that explicitly abdicate frequency modulation in favor of energy efficiency, we find that wingstroke-to-wingstroke frequency modulation is an underappreciated control strategies that complements other strategies for maneuverability and stability in insect flight.

A Review of Switched Inertance Hydraulic Converter Technology1

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Chenggang Yuan ◽  
Min Pan ◽  
Andrew Plummer
Keyword(s):  
Energy Efficient ◽  
High Speed ◽  
Control Strategies ◽  
New Technology ◽  
High Energy ◽  
Hydraulic Power ◽  
Controlled Systems ◽  
Hydraulic Machines ◽  
And Control ◽  
High Speed Switching

Abstract Digital hydraulics is a new technology providing an alternative to conventional proportional or servovalve-controlled systems in the area of fluid power. Digital hydraulic applications, such as digital pumps, digital valves and actuators, switched inertance hydraulic converters (SIHCs), and digital hydraulic power management systems, promise high-energy efficiency and less contamination sensitivity. Research on digital hydraulics is driven by the need for highly energy efficient hydraulic machines but is relatively immature compared to other energy-saving technologies. This review introduces the development of SIHCs particularly focusing on the work being undertaken in the last 15 years and evaluates the device configurations, performance, and control strategies that are found in the current SIHC research. Various designs for high-speed switching valves are presented, and their advantages and limitations are compared and discussed. The current limitations of SIHCs are discussed and suggestions for the future development of SIHCs are made.

Modeling and Control of Pantograph and Contact Wire for High Speed Train

2000 ◽  
Author(s):  
Marco Muenchhof ◽  
Timothy Hindle ◽  
Tarunraj Singh
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
Control Strategies ◽  
Optimization Techniques ◽  
High Speed Train ◽  
Modeling And Control ◽  
Contact Wire ◽  
Closed Form Solutions ◽  
Mass Damper ◽  
And Control

Abstract The paper focuses on the modeling and control of a catenary-pantograph system. For the catenary system, only the contact wire is considered. Initially, the case of a constant force traveling at a constant velocity along the wire is investigated and closed form solutions are derived. Next, the pantograph dynamics are considered using a simple spring-mass-damper model, where the force is no longer assumed to be constant. The need for control in this case is apparent and motivates two different control strategies. The first control strategy utilizes a feed-forward Fourier series control profile. For the second control strategy, a proportional force feed-back control is added. All control parameters are obtained using constrained optimization techniques. Stability and sensitivity issues are addressed.

Power and Control Autonomy for High-Speed Locomotion With an Insect-Scale Legged Robot

2018 ◽  
Vol 3 (2) ◽  
pp. 987-993 ◽  
Author(s):  
Benjamin Goldberg ◽  
Raphael Zufferey ◽  
Neel Doshi ◽  
Elizabeth Farrell Helbling ◽  
Griffin Whittredge ◽  
...  
Keyword(s):  
High Speed ◽  
Legged Robot ◽  
Power And Control ◽  
And Control

Automatic In-Process Chatter Avoidance in the High-Speed Milling Process

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
N. J. M. van Dijk ◽  
E. J. J. Doppenberg ◽  
R. P. H. Faassen ◽  
N. van de Wouw ◽  
J. A. J. Oosterling ◽  
...  
Keyword(s):  
High Speed ◽  
Control Strategies ◽  
Detection Algorithm ◽  
Milling Process ◽  
Process Conditions ◽  
High Speed Milling ◽  
Milling Operations ◽  
Milling Operation ◽  
Automatic Adaptation ◽  
And Control

High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control strategies are presented that guarantee a chatter-free high-speed milling operation by automatic adaptation of spindle speed and feed. Moreover, the proposed strategies are robust for changing process conditions (e.g., due to heating of the spindle or tool wear). An important part of the control strategy is the detection of chatter. A novel chatter detection algorithm is presented that automatically detects chatter in an online fashion and in a premature phase such that no visible marks on the workpiece are present. Experiments on a state-of-the-art high-speed milling machine underline the effectiveness of the proposed detection and control strategies.

scholarly journals Active and passive stabilization of body pitch in insect flight

2013 ◽  
Vol 10 (85) ◽  
pp. 20130237 ◽  
Author(s):  
Leif Ristroph ◽  
Gunnar Ristroph ◽  
Svetlana Morozova ◽  
Attila J. Bergou ◽  
Song Chang ◽  
...  
Keyword(s):  
Active Control ◽  
Insect Flight ◽  
Control Strategies ◽  
Fruit Flies ◽  
Flapping Wing ◽  
Passive Stability ◽  
Flying Insects ◽  
Body Drag ◽  
Instability Growth ◽  
Passive Stabilization

Flying insects have evolved sophisticated sensory–motor systems, and here we argue that such systems are used to keep upright against intrinsic flight instabilities. We describe a theory that predicts the instability growth rate in body pitch from flapping-wing aerodynamics and reveals two ways of achieving balanced flight: active control with sufficiently rapid reactions and passive stabilization with high body drag. By glueing magnets to fruit flies and perturbing their flight using magnetic impulses, we show that these insects employ active control that is indeed fast relative to the instability. Moreover, we find that fruit flies with their control sensors disabled can keep upright if high-drag fibres are also attached to their bodies, an observation consistent with our prediction for the passive stability condition. Finally, we extend this framework to unify the control strategies used by hovering animals and also furnish criteria for achieving pitch stability in flapping-wing robots.

Discussion of “A Review of Propulsion, Power, and Control Architectures for Insect-Scale Flapping Wing Vehicles” by E. F. Helbling and R. J. Wood (Helbling, E. F., and Wood, R. J., 2018, ASME Appl. Mech. Rev., 70(1), p. 010801)

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Satyandra K. Gupta
Keyword(s):  
Flapping Wing ◽  
Point Of View ◽  
Small Scale ◽  
Flying Insects ◽  
Power And Control ◽  
Significant Interest ◽  
Challenges And Opportunities ◽  
And Control ◽  
Propulsion Power ◽  
Remarkable Progress

Flying insects exhibit truly remarkable capabilities. There has been significant interest in developing small-scale flying robots by taking inspiration from flying insects. The paper by Helbling and Wood reports remarkable progress made by the research community in realizing insect-scale flapping wing vehicles and identifies research challenges and opportunities. This discussion builds upon their paper and examines the potential of insect-scale flapping wing flight from an application point of view. It summarizes requirements and mention implications of these requirements on propulsion, power, and control architecture.

Learning and Conditioning

2018 ◽  
Author(s):  
George R. Mastroianni
Keyword(s):  
Situational Factors ◽  
Impact Behavior ◽  
Middle Ground ◽  
Historical Factors ◽  
Power And Control ◽  
Long Time ◽  
The Media ◽  
And Behavior ◽  
Short Time ◽  
And Control

Chapter 6 argues that when considering potential causative factors for the development of genocidal behavior, there is a middle ground between cultural and historical factors that operate over a very long time-scale and situational factors that impact behavior in a very short time. This middle ground is inhabited by basic mechanisms of learning and conditioning, such as nonassociative learning, classical and operant conditioning, and observational learning. These mechanisms are constant but subtle forces shaping our thinking and behavior. The Nazi regime used its coercive power and control over the media and education to manipulate and shape the attitudes and behavior of the population, effects that were mediated through basic mechanisms of learning and conditioning.

scholarly journals A Review of Propulsion, Power, and Control Architectures for Insect-Scale Flapping-Wing Vehicles

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
E. Farrell Helbling ◽  
Robert J. Wood
Keyword(s):  
Integrated Circuit ◽  
Micro Air Vehicles ◽  
High Energy ◽  
Flapping Wing ◽  
High Energy Density ◽  
Small Scale ◽  
Flying Insects ◽  
Power And Control ◽  
Recent Developments ◽  
And Control

Flying insects are able to navigate complex and highly dynamic environments, can rapidly change their flight speeds and directions, are robust to environmental disturbances, and are capable of long migratory flights. However, flying robots at similar scales have not yet demonstrated these characteristics autonomously. Recent advances in mesoscale manufacturing, novel actuation, control, and custom integrated circuit (IC) design have enabled the design of insect-scale flapping wing micro air vehicles (MAVs). However, there remain numerous constraints to component technologies—for example, scalable high-energy density power storage—that limit their functionality. This paper highlights the recent developments in the design of small-scale flapping wing MAVs, specifically discussing the various power and actuation technologies selected at various vehicle scales as well as the control architecture and avionics onboard the vehicle. We also outline the challenges associated with creating an integrated insect-scale flapping wing MAV.

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