Adding and Subtracting Energy to Body Motion: Phase Oscillator

2014 ◽  
Author(s):  
Jason Kerestes ◽  
Thomas G. Sugar ◽  
Matthew Holgate
Keyword(s):  
Phase Angle ◽  
Metabolic Cost ◽  
Oscillatory Behavior ◽  
Body Motion ◽  
Phase Oscillator ◽  
Motion Energy

We are developing methods to add a bounded amount of energy to assist body motion. Energy is added based on the phase angle of the limb to create a “phase oscillator.” The energy is added assisting motion creating an oscillatory behavior. An anti-phase angle can be used to subtract energy from body motion as well. Using a “phase oscillator” controller, a powered hip exoskeleton assisted a runner and demonstrated a reduction in metabolic cost.

Shape Memory Polymers for Body Motion Energy Harvesting and Self-Powered Mechanosensing

2018 ◽  
Vol 30 (8) ◽  
pp. 1705195 ◽  
Author(s):  
Ruiyuan Liu ◽  
Xiao Kuang ◽  
Jianan Deng ◽  
Yi-Cheng Wang ◽  
Aurelia C. Wang ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Shape Memory ◽  
Shape Memory Polymers ◽  
Body Motion ◽  
Motion Energy ◽  
Self Powered

Robotic Hopper Using Phase Oscillator Controller

2014 ◽  
Author(s):  
Philip New ◽  
Chase Wheeler ◽  
Thomas G. Sugar
Keyword(s):  
Experimental Data ◽  
Phase Angle ◽  
Parametric Oscillator ◽  
Phase Oscillator ◽  
Forcing Function ◽  
Exceptional Stability

The work presented in this paper describes a robotic hopper that uses a bounded energy, phase oscillator controller. It exhibits exceptional stability when given disturbances. The controller uses a phase angle to regulate the forcing function, creating a parametric oscillator. In this paper we include simulated and experimental data for analysis of the hopper.

scholarly journals Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can reduce energy costs below normal

2015 ◽  
Vol 471 (2174) ◽  
pp. 20140662 ◽  
Author(s):  
Varun Joshi ◽  
Manoj Srinivasan
Keyword(s):  
Numerical Optimization ◽  
Energy Use ◽  
Metabolic Cost ◽  
Body Motion ◽  
Metabolic Energy ◽  
Upper Body ◽  
Biped Walking ◽  
Walking Motion ◽  
Mass Spring ◽  
Millennium Bridge

Understanding how humans walk on a surface that can move might provide insights into, for instance, whether walking humans prioritize energy use or stability. Here, motivated by the famous human-driven oscillations observed in the London Millennium Bridge, we introduce a minimal mathematical model of a biped, walking on a platform (bridge or treadmill) capable of lateral movement. This biped model consists of a point-mass upper body with legs that can exert force and perform mechanical work on the upper body. Using numerical optimization, we obtain energy-optimal walking motions for this biped, deriving the periodic body and platform motions that minimize a simple metabolic energy cost. When the platform has an externally imposed sinusoidal displacement of appropriate frequency and amplitude, we predict that body motion entrained to platform motion consumes less energy than walking on a fixed surface. When the platform has finite inertia, a mass- spring-damper with similar parameters to the Millennium Bridge, we show that the optimal biped walking motion sustains a large lateral platform oscillation when sufficiently many people walk on the bridge. Here, the biped model reduces walking metabolic cost by storing and recovering energy from the platform, demonstrating energy benefits for two features observed for walking on the Millennium Bridge: crowd synchrony and large lateral oscillations.

scholarly journals Core-Shell Fiber-Based 2D Woven Triboelectric Nanogenerator for Effective Motion Energy Harvesting

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Jinmei Liu ◽  
Long Gu ◽  
Nuanyang Cui ◽  
Suo Bai ◽  
Shuhai Liu ◽  
...  
Keyword(s):  
Electronic Devices ◽  
Human Movement ◽  
Development Trend ◽  
The Body ◽  
Body Motion ◽  
Triboelectric Nanogenerator ◽  
Core Shell ◽  
Output Current ◽  
Motion Energy ◽  
Textile Manufacture

Abstract Personal electronic devices have a general development trend of miniaturization, functionality, and wearability. Their wireless, sustainable, and independent operation is critically important, which requests new power technologies that can harvest the ambient environmental energy. Here, we report a new kind of 2D woven wearable triboelectric nanogenerator (2DW-WTNG) composed of core-shell fibers via the twisting process and weaving process in the textile manufacture. The 2DW-WTNG can convert the body motion energy into electricity with an output current of 575 nA and an output voltage of 6.35 V. At an external load of 50 MΩ, it generated a maximum power density of 2.33 mW/m2. Electricity can be produced from the 2DW-WTNG driven in arbitrary in-plane directions. A tiny displacement of 0.4 mm can drive the 2DW-WTNG, which verified its capability to harvest energy from small human movement. The robust 2DW-WTNG can work continuously for 12 h without obvious performance degradation.

scholarly journals Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting

Sensors ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 524 ◽  
Author(s):  
Antonino Proto ◽  
Marek Penhaker ◽  
Daniele Bibbo ◽  
David Vala ◽  
Silvia Conforto ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Wearable Sensors ◽  
Body Motion ◽  
Motion Energy

Nonlinear, Phase-Based Oscillator to Generate and Assist Periodic Motions

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Juan De la Fuente ◽  
Thomas G. Sugar ◽  
Sangram Redkar
Keyword(s):  
Limit Cycle ◽  
Phase Angle ◽  
Trajectory Planning ◽  
Nonlinear Oscillator ◽  
Oscillatory Behavior ◽  
Periodic Motions ◽  
Nonlinear Phase ◽  
Forcing Function ◽  
Line Trajectory ◽  
Bendixson Criterion

Oscillatory behavior is important for tasks, such as walking and running. We are developing methods for wearable robotics to add energy to enhance or vary the oscillatory behavior based on the system's phase angle. We define a nonlinear oscillator using a forcing function based on the sine and cosine of the system's phase angle that can modulate the amplitude and frequency of oscillation. This method is based on the state of the system and does not use off-line trajectory planning. The behavior of a limit cycle is shown using the Poincaré–Bendixson criterion. Linear and rotational models are simulated using our phase controller. The method is implemented and tested to control a pendulum.

Limit Cycles to Enhance Human Performance Based on Phase Oscillators

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Thomas G. Sugar ◽  
Andrew Bates ◽  
Matthew Holgate ◽  
Jason Kerestes ◽  
Marc Mignolet ◽  
...  
Keyword(s):  
Human Performance ◽  
Initial Conditions ◽  
Metabolic Cost ◽  
Phase Oscillator ◽  
Phase Oscillators ◽  
Resonant Energy ◽  
Energy Pumping ◽  
Wearable Robots ◽  
At Resonance ◽  
Tiny Amount

Wearable robots including exoskeletons, powered prosthetics, and powered orthotics must add energy to the person at an appropriate time to enhance, augment, or supplement human performance. This “energy pumping” at resonance can reduce the metabolic cost of performing cyclic tasks. Many human tasks such as walking, running, and hopping are repeating or cyclic tasks where assistance is needed at a repeating rate at the correct time. By utilizing resonant energy pumping, a tiny amount of energy is added at an appropriate time that results in an amplified response. However, when the system dynamics is varying or uncertain, resonant boundaries are not clearly defined. We have developed a method to add energy at resonance so the system attains the limit cycle based on a phase oscillator. The oscillator is robust to disturbances and initial conditions and allows our robots to enhance running, reduce metabolic cost, and increase hop height. These methods are general and can be used in other areas such as energy harvesting.

Harvesting Body Motion Energy

2016 ◽  
pp. 207-236
Author(s):  
Zhong Lin Wang ◽  
Long Lin ◽  
Jun Chen ◽  
Simiao Niu ◽  
Yunlong Zi
Keyword(s):  
Body Motion ◽  
Motion Energy
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