scholarly journals Characterisation and Control of a Woven Biomimetic Actuator for Wearable Neurorehabilitative Devices

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 37
Author(s):  
Vaughan Murphy ◽  
Brandon P. R. Edmonds ◽  
Ana Luisa Trejos
Keyword(s):  
Performance Metrics ◽  
Woven Fabric ◽  
Total Force ◽  
Control Methods ◽  
Soft Actuator ◽  
Sewing Thread ◽  
And Control ◽  
Fabric Mesh ◽  
Biomimetic Actuator ◽  
Multiple Units

Twisted coiled actuators (TCAs) are a type of soft actuator made from polymer fibres such as nylon sewing thread. As they provide motion in a compact, lightweight, and flexible package, they provide a solution to the actuation of wearable mechatronic devices for motion assistance. Their limitation is that they provide low total force, requiring them to actuate in parallel with multiple units. Previous literature has shown that the force and stroke production can be improved by incorporating them into fabric meshes. A fabric mesh could also improve the contraction efficiency, strain rate, and user comfort. Therefore, this study focused on measuring these performance metrics for a set of TCAs embedded into a woven fabric mesh. The experimental results show that the stroke of the actuators scaled linearly with the number of activated TCAs, achieving a maximum applied force of 11.28 N, a maximum stroke of 12.23%, and an efficiency of 1.8%. Additionally, two control methods were developed and evaluated, resulting in low overshoot and steady-state error. These results indicate that the designed actuators are viable for use in wearable mechatronic devices, since they can scale to meet different requirements, while being able to be accurately controlled with minimal additional components.

The study of sewing damage and defects in garments

2018 ◽  
Vol 22 (2) ◽  
pp. 109-125 ◽  
Author(s):  
Awadhesh Kumar Choudhary ◽  
Monica Puri Sikka ◽  
Payal Bansal
Keyword(s):  
Review Paper ◽  
Woven Fabric ◽  
Content Type ◽  
Sewing Thread ◽  
Fabric Structure ◽  
Optimum Selection ◽  
Fabric Construction ◽  
And Control ◽  
Selection Of

PurposeThe purpose of this review paper is to define the dominating factors (such as fiber, yarn, fabric structure, sewing thread, sewing needle and machine parameters) that affect the seam damages and causing defects. It also describes the various explanations of sewing defects in garment production and critically analyzes them for optimum selection of parameters and speeds for minimizing such faults. Hence, the knowledge of various factors which affect the sewing damages/defects will be helpful for garment manufacturers/researchers to know influence of the parameters and control the quality of producing seam.Design/methodology/approachThis section is not applicable for a review paper.FindingsSewing damages such as needle cut and other sewing damages/defects are studied mostly in woven fabric. There are very few studies conducted on knitted fabric sewing damages/defects. The sewing damage problems do not have single solution that is capable of removing these damages in fabric. All the determined and affecting parameters related to fiber, yarn, fabric construction, sewing thread and sewing machine must be examined to design appropriate remedial measurement related to machine design, fabric parameters and sewing thread. This could help in minimizing or eliminating the needle cut and other sewing damage problems.Originality/valueIt is an original review work and is helpful for garment manufacturers/researchers to reduce the defects and be able to produce good quality seam.

Cooperative ship formation system and control methods in the ship lock waterway

2021 ◽  
Vol 226 ◽  
pp. 108826
Author(s):  
Chenguang Liu ◽  
Junlin Qi ◽  
Xiumin Chu ◽  
Mao Zheng ◽  
Wei He
Keyword(s):  
Control Methods ◽  
And Control ◽  
Formation System ◽  
Ship Lock

scholarly journals Research on influence factors and control methods of backfill compactness

2021 ◽  
Vol 787 (1) ◽  
pp. 012027
Author(s):  
Yudian Li ◽  
Jiajie Dong ◽  
Kai Fei ◽  
Hao Song ◽  
Zeyi Li ◽  
...  
Keyword(s):  
Influence Factors ◽  
Control Methods ◽  
And Control

scholarly journals Resonance Instability of Photovoltaic E-Bike Charging Stations: Control Parameters Analysis, Modeling and Experiment

2019 ◽  
Vol 9 (2) ◽  
pp. 252 ◽  
Author(s):  
Ziqian Zhang ◽  
Cihan Gercek ◽  
Herwig Renner ◽  
Angèle Reinders ◽  
Lothar Fickert
Keyword(s):  
Major Effect ◽  
Current Control ◽  
Current Loop ◽  
Control Methods ◽  
Control Parameters ◽  
Charging System ◽  
Grid Connected Inverter ◽  
The Time Domain ◽  
Charging Stations ◽  
And Control

This article presents an in-situ comparative analysis and power quality tests of a newly developed photovoltaic charging system for e-bikes. The various control methods of the inverter are modeled and a single-phase grid-connected inverter is tested under different conditions. Models are constituted for two current control methods; the proportional resonance and the synchronous rotating frames. In order to determine the influence of the control parameters, the system is analyzed analytically in the time domain as well as in the frequency domain by simulation. The tests indicated the resonance instability of the photovoltaic inverter. The passivity impedance-based stability criterion is applied in order to analyze the phenomenon of resonance instability. In conclusion, the phase-locked loop (PLL) bandwidth and control parameters of the current loop have a major effect on the output admittance of the inverter, which should be adjusted to make the system stable.

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