• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.421-426
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• 2013

Nowadays in building construction field, workers become aged and avoid dirty, difficult, and dangerous work. Above all, a person who is in charge of beam assembling work in high and narrow space just relies on safety belt. So these workers should be highly trained. This paper deals with a new locomotion robot that can take this in charge, which will be able to provide less labor costs, less time to build a building and safer environments for workers. The geometric features of steel structure in building construction were carefully analyzed and developed a locomotion mechanism optimized to it. The robot was designed to be rugged, strong, and fast rather than having excessive mobility. Feasibility of the developed robot was verified through experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.7
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• pp.688-694
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• 2010

This paper presents a gravity compensator for the manipulator of a service robot. The manipulator of a service robot is operated with low velocity for the safety reason in most cases. In this situation gravitational torques generated by the mass of links are often much greater than dynamic torques for motion. A gravity compensator can counterbalance the gravitational torques, thereby enabling to utilize relatively low power motors. In this paper the gravity compensation for the roll-pitch rotation is considered which is often used for the shoulder joints of the manipulator of a service robot or humanoid robot. A gimbals is implemented and two 1-dof gravity compensators are equipped at the base. One compensates the gravitational torque at the roll joint and another provides the compensational torque for the gimbals. Various analyses showed that the proposed compensator can counterbalance the gravitational torques of 87% at the pitch joint and 50% at the roll joint. It is verified from dynamic simulations that the proposed compensator effectively counterbalances the gravitational torques.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.45-54
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• 2018

The primary objective of this study is to develop a conceptual design of all-in-one attachment based steel pipe pile cutting robot that improves the conventional work in safety, quality, convenience and productivity. For this, the following research works are conducted sequentially; 1)literature review, 2)field investigation, 3)selection of element technology for conceptual design, 4)deduction of conceptual design and its work process, 5)technical feasibility analysis of the conceptual design and its work process. As a result, leveling laser and laser detector, plasma cutter, rotary grapple are selected as core technologies. Futhermore, a conceptual design and work process of an all-in-one attachment based steel pipe pile cutting robot are developed based on the core technologies. According to the technical feasibility analysis result, at least 76.8% of the respondents are selected positive answer about each device of the all-in-one attachment based steel pipe cutting robot. It is expected that the application range and impact on the construction industry will be enormous due to the increasing trend of the steel pipe pile market.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.37-44
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• 2019

The primary objective of this study is to develop a prototype of all-in-one attachment-based PHC pile head cutting robot that improves the conventional work in safety, productivity, and quality. For this, the following research works are conducted sequentially; 1)literature review, 2)development of an all-in-one attachment-based PHC pile head cutting robot prototype, 3)performance evaluation of each device, 4)economic analysis of an automated method. As a result, PHC pile cutting level sensing device, PHC pile cutting device, PHC pile handling device are developed. Futhermore, working process of an automated method is developed based on result of performance evaluation. According to the economic analysis result, the cost of the automated method was 21.37% less than that of the conventional method, and the economic efficiency was also superior(ROR 215.44%, Break-even Point 5.52month). It is expected that conclusions for future improvements are used in the development of the all-in-one attachment-based PHC pile head cutting robot to practical use.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1374-1381
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• 2022

Under the influence of nuclear radiation, the reliability of steam generators (SGs) is an important factor in the efficiency and safety of nuclear power plant (NPP) reactors. Motion planning that remotely manipulates an SG mobile tube-inspection robot to inspect SG heat transfer tubes is the mainstream trend of NPP robot development. To achieve motion planning, conditional traversal is usually used for base position optimization, and then the A^* algorithm is used for path planning. However, the proposed approach requires considerable processing time and has a single expansion during path planning and plan paths with many turns, which decreases the working speed of the robot. Therefore, to reduce the calculation time and improve the efficiency of motion planning, modifications such as the matrix method, improved parent node, turning cost, and improved expanded node were proposed in this study. We also present a comprehensive evaluation index to evaluate the performance of the improved algorithm. We validated the efficiency of the proposed method by planning on a tube sheet with square-type tube arrays and experimenting with Model SG.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.813-816
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• 1991

Direct-drive SCARA-type industrial robots are increasingly used in the assembly process of small mechanical parts as well as electronic components, which uses direct-drive (DD) motors instead of reduction gear-type conventional motors for the actuators of manipulator arms. There are many advantages in using DD motors for robots, such as no backlash, low friction, high mechanical stiffness capability for fast and precise arm control, and high repeatability of positioning. However, there exist a number of difficulties which must be overcome to ensure proper construction and operation; increasing effects of load veriation and nonlinear and coupling dynamics, severe vibration caused by resonance of the manipulator components and low mechanical damping, etc. In order to handle these difficulties, lots of efforts have been made such as reduction of the arm inertia and elimination of the resonance, Performance evaluation of a recently developed, domestic DD robot shows that it works excellently compared with conventional robots. It, however, requires proved reliability and price competitiveness against its foreign counterparts.

• Korean Journal of Bronchoesophagology
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• v.17 no.2
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• pp.83-88
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• 2011

Robotic thyroidectomy has been developed to minimize neck scarring, and several authors have described its feasibility and safety, and have reported surgical outcomes comparable with conventional open thyroidectomy. The da Vinci surgical system robot provides a three-dimensional $10-12{\times}$magnified view of the surgical area. It also provides hand-tremor filtration, fine motion scaling, and precise and multi-articulated hand-like motions. Recently, robotic technology has also been applied to lateral compartment neck dissection in thyroid cancer. We have developed a new novel selective neck dissection procedure by a gasless unilateral axillo-breast (GUAB) approach with a da Vinci Surgical System for well-differentiated thyroid carcinoma to avoid a long visible neck scar. Based on our early experience, robotic selective neck dissection by GUAB approach is a safe, feasible and cosmetically excellent procedure. It can be an alternative to conventional open surgery in the highly selected patients with well-differentiated thyroid carcinoma. The oncologic safety of robotic selective neck dissection should be verified with long-term follow-up data.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1077-1078
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• 2008

As power plant facilities are being deteriorated, their safety is getting more importance, and more routine surveillance is being required. For this purpose, this paper presents a field robot system which performs the surveillance of power plant facilities instead of human workers from the viewpoint of the workers' safety and work efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.417-423
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• 2012

In this paper, In order to make up for the weak point of driving structure that existing used single motor in motor design, as a method to make use of advantage for joint of hollow type, we propose implementation methods for high torque, high precision, backlash less, and design of secondary safety device, and application method through joint organization using multiple motors.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1559-1560
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• 2008

As power plant facilities are being deteriorated, their safety is getting more importance, and more routine surveillance is being required. For this purpose, this paper presents an indoor localization system for field robot system which performs the surveillance of power plant facilities instead of human workers from the viewpoint of the workers' safety and work efficiency.