Variable stiffness Mckibben muscles with hydraulic and pneumatic operating modes

Xiang, Chaoqun; Giannaccini, Maria Elena; Theodoridis, Theodoros; Hao, Lina; Nefti‐Meziani, Samia; Davis, Steve

doi:10.1080/01691864.2016.1154801

Cited by 41 publications

(28 citation statements)

References 23 publications

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“…When the valve is activated by a voltage, it allows the hydraulic fluid to flow from the pump to the muscle. The fluid entering the muscle causes it to retract and lift the load [3]. The components of the HAM model include directional control valve, cylinder, pump, pressure relief valve, and mechanical load, which is a spring-mass-damper system.…”

Section: Ham Modelmentioning

confidence: 99%

“…The components of the HAM model include directional control valve, cylinder, pump, pressure relief valve, and mechanical load, which is a spring-mass-damper system. The mass and the maximum stroke are set as 0.33 kg and 400 mm, respectively [3], while the main control parameter is the position of the muscle. The specifications of the hydraulic fluid used are shown in Table 1.…”

Section: Ham Modelmentioning

confidence: 99%

“…Therefore, a possible solution would be the use of combined PAM/HAM design, where the PAM interfaces the human and the HAM is used only when high power is needed. Xiang et al [3] found that seamless switching between the two modes is a challenge. They used PID controller for the pneumatic valve and P controller for the hydraulic valve, so as to achieve smooth switching between the two modes.…”

Section: Introductionmentioning

confidence: 99%

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Hybrid Pneumatic-Hydraulic Actuator with Adaptable Stiffness

O.*,

B.,

et al. 2020

IJRTE

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This work presents a method to control the stiffness of a hybrid actuator. The resulting stiffness is required to meet the conditions of real life applications, such as human prosthetics, human-robot interaction, and delicate robot interaction. The hybrid actuator is basically a pneumatic-hydraulic muscle, which can operate simultaneously in both pneumatic and hydraulic modes. The main challenge in this work is to manage the switching between pneumatic and hydraulic modes. In pneumatic mode when a load is applied to the actuator, air in the tank is allowed to compress resulting in muscle extension. While in hydraulic mode, the fluid is pressurized and the resultant system stiffness is higher. In both cases, the McKibben muscle is full with hydraulic fluid. It has been shown that the performance of the actuator is mostly the same in terms of response and bandwidth in both modes of operation. The use of different types of controllers to improve the system performance is investigated. It is found that the parallel configuration combined with PID controller is the best solution for achieving the required muscle performance.

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Section: Ham Modelmentioning

confidence: 99%

Section: Ham Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hybrid Pneumatic-Hydraulic Actuator with Adaptable Stiffness

O.*,

B.,

et al. 2020

IJRTE

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show abstract

“…If (16), (17) and 18are substituted into (15), then L1, L2 and L3 can be eliminated. So, it can be expressed as follows,…”

Section: Stiffness Model Of the Armmentioning

confidence: 99%

“…The authors of [13,15,16] chose to fill selected items with different solid particles to realize variable stiffness. In reference [17,18] , the authors used hydraulics to attain variable stiffness operations. However, high bulk modulus fluids have a disadvantage.…”

Section: Introductionmentioning

confidence: 99%

Design and control of a novel variable stiffness soft arm

et al. 2018

Self Cite

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Soft robot arms possess such characteristics as light weight, simple structure and good adaptability to the environment, among others. On the other hand, robust control of soft robot arms presents many difficulties. Based on these reasons, this paper presents a novel design and modelling of a fuzzy active disturbance rejection control (FADRC) controller for a soft PAM arm. The soft arm comprises three contractile and one extensor PAMs, which can vary its stiffness independently of its position in space. Force analysis for the soft arm is conducted, and stiffness model of the arm is established based on the relational model of contractile and extensor PAM. The accuracy of stiffness model for the soft arm was verified through experiments. Associated to this, a controller based on the fuzzy adaptive theory and ADRC, FADRC, has been designed to control the arm. The fuzzy adaptive theory is used to adjust the parameters of the ADRC, the control algorithm has the ability to control stiffness and position of the soft arm. In this paper, FADRC was further verified through comparative experiments on the soft arm. This paper reinforces the hypothesis that FADRC control, as an algorithm, indeed possesses good robustness and adaptive abilities.

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Hydration Programmable, Shape Memorable Artificial Muscles for Antagonistic Movements

Cui,

Lin,

Zhai

et al. 2024

Adv Funct Materials

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Shape memory polymers (SMPs) capable of generating various deformations from anisotropic temporary shapes to permanent shapes have been emerging as soft robots. However, traditional SMPs cannot imitate the antagonistic movement of human skeletal muscles due to their modulus limitations in shape programming and recovery process. Herein, hydration programmable shape memory polymer (HP‐SMP)‐based fibers that can undergo reversible actuation by assembling antagonistic pairs are reported, where the shape programming of the antagonist muscle relies on the contraction of agonist muscle. HP‐SMP fibers are composed of tunicate cellulose nanocrystals (TCNCs) reinforced semi‐interpenetrating polymer networks. Leveraging their distinctive structure and hydration programmability, the HP‐SMP fibers exhibit large actuation strain (−60%) and high work capacity (751 J kg−1), allowing for reversible actuation under constant stress. Most significantly, the continuous antagonistic movements of HP‐SMP fibers assembled into artificial limbs are demonstrated to realize humanoid motion. This work provides new possibilities for replicating a series of lifelike human movements through the biomimetic design of antagonistic pairs of artificial muscles, utilizing renewable and sustainable biosourced materials.

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Variable stiffness Mckibben muscles with hydraulic and pneumatic operating modes

Cited by 41 publications

References 23 publications

Hybrid Pneumatic-Hydraulic Actuator with Adaptable Stiffness

Hybrid Pneumatic-Hydraulic Actuator with Adaptable Stiffness

Design and control of a novel variable stiffness soft arm

Hydration Programmable, Shape Memorable Artificial Muscles for Antagonistic Movements

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