• The Journal of Korea Robotics Society
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• v.16 no.2
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• pp.164-171
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• 2021

This paper proposes a continuum mechanism for manually controlled endoscopic surgical instruments. The wire-driven mechanism is typically adapted for endoscopic surgical tools because motors cannot be embedded to the joints due to the size limitation. However, the conventional wire-driven mechanism has inherent problems caused by redundancy, such as deflection and low precision. It does not have operating force and manipulability for surgery. Therefore, a method to increase the force of the continuum mechanism using a multi-wire with simple mechanical structure is proposed. Moreover, for intuitive operation, a hand-controller mechanism that can manipulate the length of the wire without complex process is proposed. Finally, we show that the proposed mechanism and methods are applicable to endoscopic surgical tools through simple experiments.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.139-147
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• 1996

PID control has been widely used for real control systems. Particularly, there are many researches on control schemes of tuning PID gains. However, to the best of our knowledge, there is no result for discrete-time systems with unknown time-delay and unknown system parameters. On the other hand, Generalized predictive control has been reported as a useful self-tuning control technique for systems with unknown time-delay. So, in this study, based on minimization of a GPC criterion, we present a self-tuning PID control algorithm for unknown papameters and unknown time-delay system. A numerical simulation was presented to illustrate the effectiveness of this method.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.77-83
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• 2018

A modular robot that memorizes motion can be easily created and operated because it expresses by hand. However, since there is not enough storage space in the module to store the user-created operation, it is impossible to reuse the created operation, and when the modular robot again memorizes the operation, it changes to another operation. There is no main controller capable of operating a plurality of modular robots at the same time, and thus there is a disadvantage that the user must input directly to the modular robot. To overcome these disadvantages, a remote controller has been proposed that can be operated in the surrounding smart devices by designing web server and component based software using wired and wireless network. In the proposed method, various types of structures are created by connecting to a modular robot, and the reconstructed operation is performed again after storing, and the usefulness is confirmed by regenerating the stored operation effectively. In addition, the reliability of the downloaded trajectory data is verified by analyzing the difference between the trajectory data and the actual trajectory. In the future, the trajectory stored in the remote controller will be standardized using the artificial intelligence technique, so that the operation of the modular robot will be easily implemented.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.15-29
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• 2021

The signal intersection is the most challenging space for autonomous vehicles. To promote the safe driving of autonomous vehicles on urban roads with traffic signals, autonomous vehicles need to receive traffic signal information from infrastructure through V2I communication. Thus, a protocol for providing traffic signal information was added to the standard traffic signal controller specification of the National Police Agency. On the other hand, there are technical limitations when applying this to digital traffic signal controllers because the protocols are defined mainly for analog traffic signal controllers. Therefore, this study proposes developing a signal information linkage module to provide traffic signal information from a digital traffic signal controller to an autonomous vehicle and an algorithm improvement method that can provide accurate traffic signal information at the time of traffic signal transition.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.487-495
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• 2012

In this paper, a Smart Home Service Robot, McBot II, which performs mess-cleanup function etc. in house, is designed much more optimally than other service robots. It is newly developed in much more practical system than McBot I which we had developed two years ago. One characteristic attribute of mobile platforms equipped with a set of dependent wheels is their omni- directionality and the ability to realize complex translational and rotational trajectories for agile navigation in door. An accurate coordination of steering angle and spinning rate of each wheel is necessary for a consistent motion. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A specialized anthropomorphic robot manipulator which can be attached to the housemaid robot McBot II, is developed in this paper. This built-in type manipulator consists of both arms with 4 DOF (Degree of Freedom) each and both hands with 3 DOF each. The robotic arm is optimally designed to satisfy both the minimum mechanical size and the maximum workspace. Minimum mass and length are required for the built-in cooperated-arms system. But that makes the workspace so small. This paper proposes optimal design method to overcome the problem by using neck joint to move the arms horizontally forward/backward and waist joint to move them vertically up/down. The robotic hand, which has two fingers and a thumb, is also optimally designed in task-based concept. Finally, the good performance of the developed McBot II is confirmed through live tests of the mess-cleanup task.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.760-766
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• 2014

This paper represents a portable robot for use in the welding process of the double hulls in shipbuilding yards. It has 5 degrees of freedom and 3kg of payload. Its body weight is 17.3 [kg] so that human workers can carry it by hand to the work place. Its body is mainly made of magnesium and aluminum alloys. Since the robot is placed about 25m apart from its controller, EtherCAT is adopted for reliable connection between the robot and controller through a single light cable. RTX real-time kernel and KPA EtherCAT master are used to control the robot on a Windows XP environment. The performance of the developed robot is satisfactory to the requirement in welding tasks of U-type cells in shipbuilding yards.

• KIISE Transactions on Computing Practices
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• v.23 no.1
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• pp.13-27
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• 2017

This paper presents a tool that automatically generates mobile web applications from user interface (UI) models which are based on PELUM (Pattern and Event based Logical User Interface Modeling). PELUM is a method for the effective development of UI-centered embedded systems via UI modeling. The proposed tool consists of a model editor and a code generator. The former provides an environment for modeling a Logical UI Model (LUM) and a Programming Interface Model (PIM) on the web. On the other hand, the code generator sets the screen configuration and events' behavior, according to the LUM, synthesizing a local database schema according to the PIM, and then generates an executable mobile web app. It also can produce mashup web apps by receiving an open API address via the PIM. The generated mobile web apps follow the Model-View-Controller (MVC) architecture in order for users to easily customize them. The proposed tool enables them to generate mobile web apps that can be executed on various devices by modeling logical UIs on the web.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1584-1590
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• 2017

This paper presents a implementation method of reliable speed limitation controller considering motor parameter variation in high speed operation. In spinning process of drum washing machine, speed increase has to be limited when unallowable imbalance mass is detected. Otherwise, severe noise and vibration can happen because noise and vibration are proportional to imbalance mass. To detect imbalance mass, d-axis current magnitude is used. However, we have to compensate for back-emf and power supply variation by means of detecting them because d-axis current is affected by both of them. On the other hand, we have to carefully estimate back-emf because back-emf is affected by stator resistance variation and inverter voltage error. Stator resistance variation can happen by manufacturing process for mass production or temperature variation in running. And there are inverter voltage errors between command voltage from micro-computer to inverter and real voltage from inverter to motor because of rising and falling time delay and turn-on resistance of power semiconductor switch. To solve this problem, we propose 2-step align current injection method which is to inject step-wise current right before starting. By this method, we can simply obtain stator resistance by ratio of voltage without inverter voltage error and current, and we can measure inverter voltage error. So we can obtain more exact model current, and then by simple calculation with compensation gain, we can estimate more accurate motor back-emf. We show that this method works well. It is verified through experiments.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.487-492
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• 2010

In this study, our system that the volume of collected human waste in the septic tank truck is measured accurately and the fee of disposing human waste can be calculated by using measured results has been developed. The level sensor and its circuits which can measure the height of the tank, the hand-held system that can be used by workers easily and simply with micro-controller have been developed. Also, this system has been built in the receipt printing function to charge for disposal fee. Even when working on a sloping field, this system can measure the accurate collected volume of human waste in the tank using the X-Y axis angle sensor. The results of this study expect that the popular complaints that generated from human waste can be reduced, the exportation possibility of our specialized systems can acquire foreign currency.

• Journal of Korea Game Society
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• v.13 no.2
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• pp.29-38
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• 2013

Recently there has been an increasing interest on tangible games in which human motions are recognized rather than the handling of keyboards and mouses. Such games require a motion controller for recognizing the motions of users. In this paper, we analyze the characteristics of values of accelerator sensors which are generated by a user who perform a tennis swing while holding a smartphone with his/her hand, and propose a method for motion recognition based on DWT(Discrete Wavelet Transform). The proposed method enables a smartphone to serve as a motion controller, so that a user can enjoy a tangible tennis game without eliminates a need for buying the device. We developed a tennis game prototype using the proposed method. To our experiment, our method showed a high recognition rate and the usefulness in the game.