• Smart Structures and Systems
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• v.14 no.5
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• pp.765-784
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• 2014

In comparison with conventional shape memory actuated structures, antagonistic shape memory alloy (SMA) actuators permits a fully reversible two-way response and higher response frequency. However, excessive internal stress could adversely reduce the stroke of the actuators under repeated use. The two-way shape memory effect might further decrease the range of the recovered strain under actuation of an antagonistic SMA actuator unless additional components (e.g., spring and stopper) are added to regain the overall actuation capability. In this paper, the performance of all four possible types of SMA actuation schemes is investigated in detail with emphasis on five key properties: recovered strain, cyclic degradation, response frequency, self-sensing control accuracy, and controllable maximum output. The testing parameters are chosen based on the maximization of recovered strain. Three types of these actuators are antagonistic SMA actuators, which drive with two active SMA wires in two directions. The antagonistic SMA actuator with an additional pair of springs exhibits wider displacement range, more stable performance under reuse, and faster response, although accurate control cannot be maintained under force interference. With two additional stoppers to prevent the over stretch of the spring, the results showed that the proposed structure could achieve significant improvement on all five properties. It can be concluded that, the last type actuator scheme with additional spring and stopper provide much better applicability than the other three in most conditions. The results of the performance analysis of all four SMA actuators could provide a solid basis for the practical design of SMA actuators.

• Fashion & Textile Research Journal
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• v.25 no.2
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• pp.248-254
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• 2023

This study aims to measure the skin rigidity of different facial areas among Koreans and propose guidelines for each area's skin rigidity that can be applied with a facial robot for testing respiratory protective devices. The facial skin rigidity of 40 participants, which included 20 men and 20 women, aged 20 to 50, was analyzed. The rigidity measurement was conducted in 13 facial areas, including six areas in contact with the mask and seven non-contact areas, by referring to the facial measurement guidelines of Size Korea. The facial rigidity was measured using the Durometer RX-1600-OO while in a supine position. The measurement procedure involved contacting the durometer vertically with the reference point, repeating the measurement of the same area five times, and using the average of three values whose variability was between 0.4 and 4.2 Shore OO. The rigidity data analysis used precision analysis, descriptive statistics analysis, and mixed-effect ANOVA. The analysis confirmed the rigidity of the 13 measurement areas, with the highest rigidity of the face being at the nose and forehead points, with values of 51.2 and 50.8, respectively, and the lowest rigidity being at the chin and center of the cheek points, with values of 19.2 and 20.7, respectively. Significant differences between gender groups were observed in four areas: the tip of the nose, the point below the chin, the area below the lower jaw, and the inner concha.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.60-69
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• 2022

To keep pace with Industry 4.0, it is imperative for companies to redesign their working environments by adopting robotic automation systems. Automation lines are facilitating the latest cutting-edge technologies, such as 3D vision and industrial robots, to outdo competitors by reducing costs. Considering the nature of the manufacturing industry, a time-saving workflow and smooth linkwork between processes is vital. At Dellics, without any additional new installation in the automation lines, only a few improvements to the working process could raise productivity. Three requirements are the development of gripping technology by utilizing a 3D vision system for the recognition of the material shape and location, research on lighting projectors to target long distances and high illumination, and testing of algorithms/software to improve measurement accuracy and identify products. With some of the functional requisites mentioned above, improved robotic automation systems should provide an improved working environment to maximize overall production efficiency. In this article, the ways in which such a system can become the groundwork for establishing an unmanned working infrastructure are discussed.

• Smart Structures and Systems
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• v.15 no.3
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• pp.593-608
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• 2015

In many of the industrialized countries an increasing amount of infrastructure is ageing. This has become specifically critical to bridges which are a major asset with respect to keeping an economy alive. Life of this infrastructure is scattering but often little quantifiable information is known with respect to its damage condition. This article describes how a damage tolerance approach used in aviation today may even be applied to civil infrastructure in the sense that operational life can be applied in the context of modern life cycle management. This can be applied for steel structures as a complete process where much of the damage accumulation behavior is known and may even be adopted to concrete structures in principle, where much of the missing knowledge in damage accumulation has to be substituted by enhanced inspection. This enhanced and continuous inspection can be achieved through robotic systems in a first approach as well as built in sensors in the sense of structural health monitoring (SHM).

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.881-891
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• 2020

In recent years robotics has become an important resource in engineering. Adoption of Robotics and Autonomous Systems (RAS) in activities related to ship inspections has obvious potential advantages, but also arises particular challenges, both from technical and legal viewpoints. The ROBINS project (ROBotics technology for INspection of Ships) is a collaborative project co-funded within the H2020 EU Research and Innovation programme call, aimed at filling the gap between current ship inspections approach and available robotic technology, both from technological and regulatory point of view. Main goal of the present work is to highlight how ship inspections are currently carried out by humans, how they could be improved using RAS, even if not completely autonomous for the time being, at least in selected operational scenarios and how the performances of RAS platforms can be tested to assess their effectiveness in carrying out surveys onboard. In such a framework, a testing facility aimed at assessing RAS' capabilities as well as providing suitable environment for their development has been built and it is still under development along with dedicated testing protocols, able to assess the equivalence between human and RAS inspection of ship and marine structures. The features of a testing facility where RAS can be tested and the testing protocols are presented, showing how technological and regulatory gaps are filled.

• The Journal of Korea Robotics Society
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• v.19 no.1
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• pp.71-78
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• 2024

The paper presents a hardware-in-the-loop (HIL) system designed for satellite movement testing in the microgravity environment on the ground with two industrial robots. Especially, the paper deals with the contact between satellites during rendezvous and docking simulations of satellites using a robotic HILS system. For this purpose, the admittance control method plays a core role in preventing damage to the satellite or robot from contact force between satellites. The coordinate frames are transformed into the mass center of the satellite and the admittance control at the level of exponential coordinates is adopted to actively use the properties of Lie groups related to tracking errors. These methods effectively mitigate the risk of robot damage during inter-satellite contact and ensure efficient tracking performance of satellite movements.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.121-129
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• 2000

The robotic automation in NonDestructive Testing(NDT) is a promising field of research and it helps to expand the applications of NDT enormously. Especially, in the case of pipelines which are widely used in various industrial facilities, it is required to secure adequate ways of inspection in the usual maintenance activitites. In this paper, we present a robot system for inpipe inspection of underground urban gas pipelines. The robot is configured as an articulated structure like a snake with a tether cable. Two active driving vehicles are located in front and rear of the system, respectively and passive modules such as a NonDestructive Testing module and a control module are chained between the active vehicles. The proposed system has outstanding mobility by employing a new steering mechanism called Double Active Universal Joint, which makes it possible to cope with complicated configurations of underground pipelines. Characteristic features of the system are described and the construction of the system is briefly outlined.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.657-664
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• 2007

URC robot offers necessary service anytime and anywhere by using a network to the robot, expanding the applicable service, keeping all the functions in itself, it undertakes functions for the causing problems through the network. URC software components are composed of HRI(Human Robot Interaction), robot action technology and others. We analyze the quality models based on ISO/IEC 9126, define URC components evaluation specification consists of 4 parts such as generic rule, instance rule, evaluation value and test method. And we define the quality process and test case design for URC, and show a testing and evaluation process for URC components.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.181-189
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• 2000

This paper presents the optimal redundant actuation of parallel manipulators for complicated robotic applications such as cutting grinding drilling and digging that require a high degree of operational stiffness as well as the balance between force applicability and dexterity. First by taking into account the distribution(number and location) of active joints the statics and the operational stiffness of a redundant parallel manipulator are formulated and the effects of actuation redundancy are analyzed, Second for given task requirements including joint torque limit task force maximum allowable disturbance and maximum allowable deflection the task execution conditions of a redundant parallel manipulator are derived and the efficient testing formulas are provided. Third to achieve high operational stiffness while maintaining moderate dexterity the redundant actuation of a parallel manipulator is optimized which determines the optimal distribution of active joints and the optimal internal joint torque, Finally the simulation results for the optimal redundant actuation of a planar parallel manipulator are given.

• Smart Structures and Systems
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• v.11 no.2
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• pp.135-161
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• 2013

This work presents a test platform for the assessment and benchmarking of modern actuators which have been specifically developed for the new field and service robotics applications. This versatile platform has been designed for the comparative analysis of actuators of dissimilar technology and operating conditions. It combines a modular design to adapt to linear and rotational actuators of different sizes, shapes and functions, as well as those with different load capacities, power and displacement. This test platform emulates the kinematics of robotic joints while an adaptive antagonist-load actuator allows reproducing the variable dynamic loads that actuators used in real robotics applications will be subjected to. A data acquisition system is used for monitoring and analyzing test actuator performance. The test platform combines hardware and software in the loop to allow actuator performance characterization. The use of the proposed test platform is demonstrated through the characterization and benchmarking of three controllable impedance actuators recently being incorporated into modern robotics.