Development of a novel compact hydraulic power unit for the exoskeleton robot

Ouyang, Xiaoping; Ding, Shuo; Fan, Boqian; Li, Perry Y.; Yang, Huayong

doi:10.1016/j.mechatronics.2016.06.003

Cited by 37 publications

(28 citation statements)

References 11 publications

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“…Here, using the model, we will predict the actuator performance for a range of operating conditions and report on the important differences between the open and closed cycle operations. The proposed actuator can be employed to charge an air tank that is intended to serve as a portable pneumatic energy source for a wide range of applications including exoskeleton [16], locomotion [17], and rehabilitation [18]. Our study will show that the proposed actuator offers a one order of magnitude higher energetic merit than the current portable power sources and actuation systems such as chemical batteries coupled with electric motors.…”

Section: Introductionmentioning

confidence: 93%

Evaluation of a Combustion-Based Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Burugupally¹

2019

Actuators

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A combustion-based mesoscale thermal actuator is proposed and its performance is studied in both open and closed cycle operations using a physics-based lumped-parameter model. The actuator design is unique as it implements a free-piston complaint architecture where the piston is free to move in a linear direction. Our objective is to study the actuator behavior in both the cycles to help identify the benefits and highlight the differences between the two cycles. The actuator is modeled as a spring-mass-damper system by taking an air standard cycle approach. Three observations are reported: (1) for nominal heat inputs (140 J/cycle), the actuator can produce large displacement strokes (16 cm) that is suitable for driving mesoscale robots; (2) the efficiency of the actuator depends on the heat input; and (3) for a specific heat input, both the open and closed cycles operate differently—with different stroke lengths, peak pressures, and thermal efficiencies. Our study reveals that the performance metrics of the actuator make it an ideal candidate for high speed, large force, and large displacement stroke related applications.

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Section: Introductionmentioning

confidence: 93%

Evaluation of a Combustion-Based Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Burugupally¹

2019

Actuators

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“…The charge and discharge efficiency of a battery usually falls into the range of 80% to 90%. Generally, a lithium ion battery has higher efficiency and power density, but it is significantly less compared with that of fossil fuels, of which the value is equal to about 1% [102][103][104]. Furthermore, safety and environmental protection are also major problems in the case that the battery is embedded into the energy harvesting system and attached to the human body all the time [105].…”

Section: Energy Storagementioning

confidence: 99%

Overview of Human Walking Induced Energy Harvesting Technologies and Its Possibility for Walking Robotics

2019

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This study is mainly to provide an overview of human walking induced energy harvest. Focusing on the proportion of all energy sources provided by daily activity, the available human walking induced energy is divided with respect to the generation principle. The extensive research on harvesting energy results from body vibration, inertial element, and foot press to convert into electricity is overviewed. Over the past decades, various smart materials have been employed to achieve energy conversion. Generators based on electromagnetic induction or the triboelectric effect were developed and integrated. Small captured power and low overall efficiency are criticized. The concept of human walking energy harvest is extended into the wearable walking robotics using other mediums, such as fluid, to transmit power instead of electricity. By comparison, it is indicated that less energy conversion links are involved in energy regeneration of such applications and expected to guarantee less loss and higher efficiency. Meanwhile, in order to overcome the shortage of relatively low power output, comments are made that the harvester should be capable of adaptation under the condition that the mechanical energy of lower limb and feet is subject to change in different gait phases so as to maximize the collected energy.

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“…To generate a pressure-volume diagram, the model Eqs. [7][8][9][10] is numerically integrated in the order 1→2→3→4→5→1 ( Fig. 2) starting with state 1: ∆V 1 , ∆P 1 , ∆T 1 , ∆˙V 1 = 0.…”

Section: Solving the Open Cycle Modelmentioning

confidence: 99%

Evaluation of a Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Burugupally

2019

Preprint

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Thermal-based actuators are known for generating large force and displacement strokes at mesoscale (millimeter) regime. In particular, two-phase thermal actuators are found to benefit from the scaling laws of physics at mesoscale to offer large force and displacement strokes; but they have low thermal efficiencies. As an alternative, a combustion-based thermal actuator is proposed and its performance is studied in both open and closed cycle operations. Through a physics-based lumped-parameter model, we investigate the behavior and performance of the actuator using a spring-mass-damper analogy and taking an air standard cycle approach. Three observations are reported: (1) the mesoscale actuator can generate peak forces of up to 400 N and displacement strokes of about 16 cm suitable for practical applications; (2) an increase in heat input to the actuator results in increasing the thermal efficiency of the actuator for both open and closed cycles; and (3) for a specific heat input, both the open and closed cycle operations respond differently \textemdash different stroke lengths, peak pressures, and thermal efficiencies.

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Development of a novel compact hydraulic power unit for the exoskeleton robot

Cited by 37 publications

References 11 publications

Evaluation of a Combustion-Based Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Evaluation of a Combustion-Based Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Overview of Human Walking Induced Energy Harvesting Technologies and Its Possibility for Walking Robotics

Evaluation of a Mesoscale Thermal Actuator in Open and Closed Operating Cycles

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