Projects

In the context of this project, which focuses on estimating the relative positions between human body segments, such estimation can be derived from the relative orientation between segments and the position vectors from each segment to the joint center. While these position vectors are typically treated as constants in existing studies, human body segments are not perfectly rigid bodies—deformations occur due to soft tissue such as skin and muscle. As a result, variability in these vectors caused by soft tissue deformation becomes a major factor that degrades the accuracy of relative position estimation. In addition to this, various other factors contribute to the current limitations of inertial sensor–based position estimation, which still lacks sufficient accuracy for commercial application.

This project aims to develop a method that improves the accuracy of estimating relative positions between body segments using inertial sensor signals.

This project aims to develop a battalion-level K-201 training simulator to be used within the operational environment of the Multiple Integrated Laser Engagement System (MILES), which is employed by the military for tactical training.

The objective is to develop a high-precision K-201 mock launcher capable of long-range one-to-one communication (2.4 GHz) without relying on base stations, suitable for field training environments. To ensure training effectiveness, the system will incorporate an Attitude and Heading Reference System (AHRS) that is robust against magnetic disturbances.

This project aims to improve the manufacturing process of valve seats, a core component in multipoint fuel injection (MPI) engine injectors. Instead of traditional blasting-based deburring, the process introduces dry ice deburring to simultaneously achieve both high burr removal efficiency and superior surface roughness—two typically conflicting requirements.

As the demand for MPI injectors continues to rise, enhancing product quality becomes essential. In particular, improving the deburring quality in the final stage of the process is expected to significantly boost manufacturing yield.

This project aims to develop valve seats and a dedicated processing machine as core components for 350-bar GDI (Gasoline Direct Injection) engine injectors.

Due to the nature of this manufacturing-focused project, both the structural design that can fundamentally prevent machining defects and the precision of the final machining process are critical success factors—yet remain significant technical challenges. As a result of these difficulties, all 350-bar injectors are currently imported, and even domestically produced 250-bar injectors suffer from high defect rates. This project seeks to address and resolve these issues.

The lower limb exoskeleton system is a physical assistive device designed to support leg muscle strength. While various exoskeleton robots have been actively studied, most are powered systems. In contrast, the target of this proposed study is an unpowered exoskeleton system, which assists walking passively without using external energy, operating solely through the wearer’s motion. However, if the system is not well-matched to the user or walking conditions, wearing the exoskeleton can result in increased physical burden rather than assistance.

This project aims to: (i) develop an unpowered exoskeleton system in which spring stiffness and clutch timing can be independently adjusted to enable optimization, and (ii) study human-in-the-loop (HITL) optimization techniques that determine optimal spring–clutch parameters (i.e., stiffness and timing) based on IMU signals—a wearable sensor system unaffected by location constraints. By integrating these two elements, the project seeks to overcome the limitations of existing unpowered exoskeletons and ensure walking efficiency across a variety of gait conditions.

In cryogenic vacuum-insulated piping, liquefied gas flowing through the bellows-type inner pipe often collides with the corrugations of the bellows, generating turbulence, which leads to pressure loss and flow disturbances. Over extended use, this can result in damage and deformation of the bellows. Existing solutions, such as installing guides on the outside of the corrugated section, have proven ineffective in resolving these issues.

This project proposes a novel approach by installing a tube-type guide inside the bellows, aiming to mitigate the aforementioned problems and thereby improve the quality and performance of the system. In addition, compared to conventional designs, this method reduces the number of welded joints and improves the weldability of the piping system by incorporating an adapter that facilitates more efficient welding processes.

This project aims to develop a novel liquid nitrogen supply system capable of anytime, immediate delivery of low-pressure cryogenic liquid nitrogen without standby time. The system incorporates automated vapor-liquid separation and state control within the storage unit.

To achieve this, the project includes: (i) stress analysis and feedback control of the supply system through custom software, (ii) development of a controller for solenoid valve operation based on sensor data, and (iii) implementation of a real-time monitoring program to track system status.

In response to environmental pollution and rising fuel costs, the government is promoting the Electric Fishing Vessel Deployment Project. Aligned with this initiative, this project aims to enhance the safety and efficiency of electric vessels through the development of a smart VDR-BMU (Voyage Data Recorder–Boat Management Unit) system.

This project builds upon the outcomes of the first-year R&D project, titled "Development of a Smart VDR-Integrated Control System for Electric Vessels to Enhance Navigational Safety." The current study focuses on further R&D efforts to address limitations identified during the first-year development phase, as well as essential advancements required for mass production readiness.

An axial flux type motor differs from conventional radial type motors, in which the rotor and stator are arranged in the radial direction around the shaft. In axial flux motors, by contrast, the rotor and stator face each other along the axis of rotation, resulting in a magnetic flux that flows in the axial direction. This structure enables compact and lightweight designs, offering potential cost savings through reduced volume and mass, depending on the application. Notably, its slim profile makes it especially suitable for use in elevator traction machines, where ease of installation is a key advantage.

While 3D rolling lamination offers the potential for very high manufacturing productivity, mass production methods for this technique have not yet been fully realized. The objective of this research project is to improve the manufacturability of axial cores using rolling lamination techniques.

A tip dresser is a device used in spot welding to grind off adhered base material or deformed electrode tips on the welding gun electrode.

Through this project, the goal is to improve machinability by increasing the cutting torque (to 28.7 N·m) and rotational speed (to 276 r/min), while reducing the gear ratio. Additionally, the project aims to achieve a dressing time of less than 1.1 seconds and realize a 10% reduction in gearbox size and weight, targeting a total weight of 17 kg or less.

In a 9-axis IMU, the magnetometer is commonly used to estimate the yaw component of 3D orientation. However, despite its widespread use, it is also a major source of error in orientation estimation accuracy. This study fundamentally addresses this issue by eliminating the need for a magnetometer, thereby removing the primary factor that degrades estimation accuracy.

Ultimately, this approach enhances the accuracy and reliability of wearable inertial motion capture systems. Notably, even the highest-performing existing orientation estimation systems demonstrate their accuracy under uniform magnetic field conditions; under real-world magnetic disturbances, yaw errors exceeding 20 degrees are frequently observed. By excluding the magnetometer, this research enables robust and accurate 3D orientation estimation, regardless of the surrounding magnetic environment.

In response to environmental pollution and rising fuel prices, and in line with the government’s Electric Fishing Vessel Deployment Initiative, this research aims to enhance the safety and efficiency of electric ships through the development of a dedicated control system.

By integrating a smart Voyage Data Recorder (VDR)—capable of analyzing the ship’s dynamic behavior—with the electric ship’s controller, the system is designed to ensure navigational safety during operation.

Falls are a leading cause of serious injuries such as fractures and traumatic brain injuries, and represent a major contributor to mortality among the elderly. Therefore, early detection of abnormal movement patterns during daily life can help prevent fall-related accidents or minimize injury through timely intervention in the event of a fall.

The goal of this study is to develop a fall detection system that can be used in everyday life without spatial or temporal limitations, using wearable sensors—such as compact inertial sensors—that can be worn with minimal discomfort. In particular, the system aims to detect falls prior to ground impact, enabling effective preemptive response.