In this study, we present a numerical simulation approach for designing Fresnel zone plate (FZP) patterns. By optimizing surface phase parameters using desired merit functions in ray-tracing software, the obtained surface phase was converted into an FZP pattern through a 5-step procedure. A comparison between our numerical simulation approach and the traditional analytical method showed a negligible zone size difference of 0.606 nm and nearly absolute agreement of 17.549 μm in focal spot size. The FZP pattern was experimentally verified by an expected focal spot size of 18.55 μm. Our approach demonstrated design flexibility and has potential applications in simulating various functionalities in FZP patterns and refractive-diffractive hybrid lenses to address specific optical challenges. The surface phase can be freely modified based on optimization objectives that cannot be achieved using the analytical approach, ensuring high-precision design for accurate extraction.
Citations
Citations to this article as recorded by
Non-ablative transurethral laser treatment for collagen remodeling with functional recovery in an in vivo model of stress urinary incontinence Hwarang Shin, Minh Duc Ta, Myungji Kang, Yeachan Lee, Hyun Wook Kang Scientific Reports.2026;[Epub] CrossRef
High-Precision Metrology of Lens Mold Asphericity with High Dynamic Range Using Iterative Reverse Optimization in Radial Shearing Interferometry Huy Vu, Ba Son Nguyen, Tri Nguyen, Seunghoo Lee, Tiendung Vu, Doo Sun Choi, Jun Sae Han, Jeong Seok Oh, Young-Jea Choi, Joohyung Lee International Journal of Precision Engineering and Manufacturing.2026; 27(6): 2333. CrossRef
Impact of glass cap geometry on radial light emission Minh Duc Ta, Seonho Jung, Van Gia Truong, Hyun Wook Kang Optics and Lasers in Engineering.2026; 206: 110006. CrossRef
Mechanistic evaluations of radial fiber tip for circumferential laser ablation Minh Duc Ta, Jiho Lee, Seonho Jung, Van Gia Truong, Hyun Wook Kang Optics & Laser Technology.2025; 192: 113660. CrossRef
Quantitative investigations on light emission profiles for interstitial laser treatment Minh Duc Ta, Yeongeun Kim, Hwarang Shin, Van Gia Truong, Hyun Wook Kang Biomedical Optics Express.2024; 15(12): 6877. CrossRef
Silicon carbide (SiC) is chemically stable, highly heat-resistant, and resistant to thermal shock. SiC having excellent characteristics in a high temperature and high voltage environment is used in high-power semiconductors, highprecision mechanical devices, optical components, etc. As it is used in various industries, there is a growing demand for processing fine holes or grooves in silicon carbide. In this study, micro holes and grooves were machined on 4HSiC and sintered SiC using electrical discharge machining (EDM). Silicon carbide which has very high hardness can be easily processed by EDM as compared with mechanical processes. As a tool material, a polycrystalline diamond (PCD) which has high wear resistance was used and a micro tool of a diameter of 100 μm was fabricated by wire electrical discharge grinding (WEDG). In the EDM of SiC, the machining characteristics such as surface roughness, discharge gap, and tool wear were investigated.
Citations
Citations to this article as recorded by
Experimental Study on the Formation of Discharge Crater Morphology in Micro EDM Jae Yeon Kim, Ui Seok Lee, Hee Jin Kong, Bo Hyun Kim Journal of the Korean Society for Precision Engineering.2026; 43(1): 61. CrossRef
Investigation of Crack Formation in Micro-groove Machining of Silicon Carbide Ju Hyeon Lee, Gyu Man Kim, Bo Hyun Kim International Journal of Precision Engineering and Manufacturing-Smart Technology.2026; 4(2): 199. CrossRef
Micro Hole Machining Characteristics of Glassy Carbon Using Electrical Discharge Machining (EDM) Jae Yeon Kim, Ji Hyo Lee, Bo Hyun Kim Journal of the Korean Society for Precision Engineering.2025; 42(4): 325. CrossRef
Prediction of Machining Conditions from EDMed Surface Using CNN Ji Hyo Lee, Jae Yeon Kim, Dae Bo Sim, Bo Hyun Kim Journal of the Korean Society for Precision Engineering.2024; 41(11): 865. CrossRef
Here in, a high-quality automotive camera lens was developed based on an ultra-precision diamond turning core and cyclic olefin polymer (COP) injection molding process. To improve surface roughness and achieve the accuracy of plastic injection molding lens, systematic mold core machining process was developed and demonstrated using the diamond turning machine. The cutting tool path was generated by using NanoCAM 2D, and it was partly revised to prevent interference between the cutting tool and the workpiece. After the initial machining using the generated tool path, the compensation-cutting process was conducted based on the measured surface profile of an initially machined surface. After two times of compensation machining, the fabricated core mold showed a shape error of 100 nm between peak to valley (PV) and Arithmetic mean roughness (Ra) of 3.9 nm. The performance of the fabricated core was evaluated using an injection molding test. Injection molded aspheric plastic lens showed contrasts that were higher than 55% at 0.0 F, 30% at 0.3 F, and 20% at 0.7 F without any moiré phenomenon that meets the specification for automotive vision module with 1MP and 140° field of view.
Citations
Citations to this article as recorded by
Research progress on grinding contact theory of axisymmetric aspheric optical elements Wenzhang Yang, Bing Chen, Bing Guo, Qingliang Zhao, Juchuan Dai, Guangye Qing Precision Engineering.2026; 97: 24. CrossRef
Non-uniform residual tool mark errors in diamond end-fly-cutting microstructures Jianpeng Wang, Zejia Zhao, Ling Ling Chen, Linhe Sun, Tengfei Yin, Suet To International Journal of Mechanical Sciences.2026; 311: 111148. CrossRef
Wafer‐Scale Vitreous Carbon Molds Enabling Precision Glass Molding of Aspherical Lenses Muzahir Ali, Yong Kyu Kim, Seongmin Lee, Tasadduq Hussain, Jung‐Ho Lee, Azfar Ali, Seok‐min Kim Journal of the American Ceramic Society.2026;[Epub] CrossRef
Performance enhancement of material removal using a surface-refinement model based on spatial frequency–response characteristics in magnetorheological finishing Minwoo Jeon, Seok-Kyeong Jeong, Woo-Jong Yeo, Hwan-Jin Choi, Mincheol Kim, Min-Gab Bog, Wonkyun Lee The International Journal of Advanced Manufacturing Technology.2024; 135(11-12): 5391. CrossRef
In order to monitor the machining status of a machine tool, it is necessary to measure the signal of the machine tool and establish the relationship between the machining status and the signal. One effective approach is to utilize an AIbased analysis model. To improve the accuracy and reliability of AI models, it is crucial to identify the features of the model through signal analysis. However, when dealing with time series data, it has been challenging to identify these features. Therefore, instead of directly applying time series data, a method was used to extract the best features by processing the data using techniques such as RMS and FFT. Recently, there have been numerous reported cases of designing AI models with high accuracy and reliability by directly applying time series data to find the best features, particularly in the case of AI models combining CNN and LSTM. In this paper, time series data obtained through a gap sensor are directly applied to an AI model that combines CNN, LSTM, and MLP (Multi-Layer Perceptron) to determine tool wear. The machine tool and tool status were monitored and evaluated through an AI model trained using time series data from the machining process.
Citations
Citations to this article as recorded by
A Study on the Prediction of Tool Wear Using Multi-sensor and SVR in the Turning Process Seok Jin Kim, Roh Won Kim, Young Soo Kim, Sang Jik Lee Journal of the Korean Society for Precision Engineering.2026; 43(5): 449. CrossRef
Development of AI-based Bearing Machining Process Defect Monitoring System Dae-Youn Kim, Dongwoo Go, Seunghoon Lee Journal of Society of Korea Industrial and Systems Engineering.2025; 48(3): 112. CrossRef
A Review of Intelligent Machining Process in CNC Machine Tool Systems Joo Sung Yoon, Il-ha Park, Dong Yoon Lee International Journal of Precision Engineering and Manufacturing.2025; 26(9): 2243. CrossRef
Gearboxes used in the drivetrain of intelligent robots are key mechanical components that play a significant role in determining the performance of modern robotic systems. Gearboxes employing the planetary gear mechanism, known to achieve a wide range of reduction ratios while remaining relatively cost-effective, have recently been adopted in robot drivetrains. In this paper, we utilize domestic technology to fabricate a gearbox using a compound planetary gear mechanism and conduct an evaluation of eight performance aspects of the developed gearbox through the fabrication of a dynamometer and a jig. The dynamometer comprised of the gearbox, input motor, input-output torque sensors, and a powder brake. By driving the input motor and applying braking force with the powder brake, we compare input torque sensor values with output torque sensor values to derive results. A test jig is created, consisting of an input motor, gearbox, and encoder sensor, for the measurement of inverse operation characteristics and backlash. By conducting a performance evaluation of the developed high-strength, high-reduction-ratio compact planetary gearbox, we validate the potential of the testing system and extend the scope of domestic gearbox technology development.
Citations
Citations to this article as recorded by
Development of an Actuator and Controller for Robotic Joints Integrating a Frameless BLDC Motor and a Stepped Planetary Gear Reducer Sangsin Park Journal of the Korean Society for Precision Engineering.2026; 43(2): 183. CrossRef
Performance Test for 1-stage Shifting Planetary Gear Reducer for Hydraulic Motors Jin-Gyeong Kang, Young-Rak Yoo, Kyu-Tae Park, Sung-Ki Lyu Journal of the Korean Society of Manufacturing Process Engineers.2026; 25(5): 127. CrossRef
Three-dimensional reconstruction of gearbox from multi-view point clouds with surface feature parfameter measurement method Jian Chen, Zhijia Zhang, Guanghui Liu, Dejian Li, Qiushuang Li Engineering Research Express.2025; 7(4): 045253. CrossRef
The fourth industrial revolution led to advanced servo systems, enhancing productivity across industries. However, designing these systems remains challenging due to the performance-stability trade-off. This paper presents a model-based motion control of a linear motor motion stage in frequency domain. A user-code for the PowerPMAC commercial controller was developed to excite motion control system so that we could get a frequency response. The theoretical frequency response of the servo algorithm was compared with the experimental frequency response. Based on this, a tuning graphical user interface (GUI) was developed to predict performance when the servo loop gain is changed. Especially, to compensate for residual vibrations caused by high acceleration and deceleration and to improve tracking error, DOB (Disturbance Observer) and ILC (Iterative Learning Control) control techniques were applied in the frequency domain. Through the design of the frequency domain motion controller, the control performance of the linear motor motion stage could be predicted with over 96% accuracy, resulting in a 54.32% improvement in tracking error and a 93.56% improvement in settling time, 85.29% in RMS error.
Citations
Citations to this article as recorded by
Disturbance Rejection and Robust Tracking Using a Compound Control Approach for RFC Linear Motor Motion Stage Kyung Ho Yang, Hyeong-Joon Ahn International Journal of Precision Engineering and Manufacturing.2026;[Epub] CrossRef
Fuzzy Neural Network Control for a Reaction Force Compensation Linear Motor Motion Stage Kyung Ho Yang, Hyeong-Joon Ahn International Journal of Precision Engineering and Manufacturing-Smart Technology.2024; 2(2): 109. CrossRef
Customized Current Control of a Linear Motor Motion Stage Kyung Ho Yang, Hyeong-Joon Ahn Journal of the Korean Society for Precision Engineering.2024; 41(11): 875. CrossRef
Glassy carbon (GC) has superior properties such as high corrosion resistance, heat resistance, and low adhesion to glass materials in a glass molding process (GMP). In addition, the demand for GC molds is increasing in various industries that require high precision of glass parts. However, GC is a difficult-to-machine material with high hardness and brittleness. Electrical discharge machining (EDM) can machine GC regardless of its strength or hardness. In this study, tungsten carbide (WC-Co) electrode was fabricated by wire electrical discharge grinding (WEDG). Characteristics of EDM of micro holes on GC were then analyzed. As capacitance and voltage increased, material removal rate (MRR) increased while machining time tended to decrease. However, at low voltages, short circuit and secondary discharge occurred, which increased the electrode wear rate (EWR). As a result, a D-shaped electrode that could prevent short circuit and debris accumulation was fabricated and a micro hole array was machined.
Citations
Citations to this article as recorded by
Experimental Study on the Formation of Discharge Crater Morphology in Micro EDM Jae Yeon Kim, Ui Seok Lee, Hee Jin Kong, Bo Hyun Kim Journal of the Korean Society for Precision Engineering.2026; 43(1): 61. CrossRef
Investigation of Crack Formation in Micro-groove Machining of Silicon Carbide Ju Hyeon Lee, Gyu Man Kim, Bo Hyun Kim International Journal of Precision Engineering and Manufacturing-Smart Technology.2026; 4(2): 199. CrossRef
In this paper, a deburring tool with 3-axis compliance is presented for deburring using a robot manipulator. Compliance is provided with beam structures instead of pneumatic pressure, which enables integrated 3-axis force sensing and variable stiffness. Two radial compliances were achieved using 4-PSS (Prismatic-Spherical-Spherical) legs, with P joints composed of cantilever beams. The one axial compliance was configured with two ball bushings and a linear spring. Strain gauges were attached to cantilever beams and a load cell was mounted between the linear spring and the universal joint to perform force sensing. The stability of vibrations and force sensing were verified through deburring experiments using the proposed deburring tool. Additionally, experiments on automatic offset for applying a constant force during deburring were conducted and results were validated by comparing the workpiece before and after the deburring process.
Citations
Citations to this article as recorded by
Stress Analysis of a Robot End-Effector Knife for the Deburring Process Jeong-Jin Park, Jeong-Hyun Sohn, Kyung-Chang Lee Journal of the Korean Society of Manufacturing Process Engineers.2025; 24(6): 42. CrossRef
Stress Analysis of a Robot End-Effector Knife for the Deburring Process Jeong-Jin Park, Jeong-Hyun Sohn, Kyung-Chang Lee Journal of the Korean Society of Manufacturing Process Engineers.2025; 24(6): 42. CrossRef
In this study, we developed and evaluated a simple device for removing ionic impurities that affect the performance of a polymer electrolyte membrane fuel cell (PEMFC) in a marine environment. In such environments, PEMFCs may experience performance degradation due to the presence of Na+ and Cl- in the air. To address this issue, the decontamination device was designed with both heating and cooling components. This device was positioned between a humidifier containing NaCl solution and a humidifier containing deionized water, both connected on the cathode side. The decontamination device effectively removed impurities (Na+ and Cl-) during experiments. As a result, the electrochemical performance of the fuel cell with the decontamination device improved compared to that of the fuel cell without it. Notably, the activation resistance and electrochemical surface area were significantly enhanced, and the ohmic resistance also improved when compared to the fuel cell without the decontamination device.
Citations
Citations to this article as recorded by
Effects of NaCl Solution on Proton Exchange Membrane Fuel Cell with Serpentine Flow Channel of Different Depths Dong Kun Song, Ho Jun Yoo, Jung Soo Kim, Ki Won Hong, Do Young Jung, George Ilhwan Park, Gu Young Cho Journal of the Korean Society for Precision Engineering.2025; 42(5): 399. CrossRef
Fuel Cell–Battery Hybrid Power System for Autonomous Agricultural Vehicles YERIM KWON, GUYOUNG CHO, SEUNGJIN YU, SANGHO LEE Transactions of the Korean Hydrogen and New Energy Society.2025; 36(6): 748. CrossRef
This paper proposes an algorithm to improve path planning and tracking performance for autonomous robots using a Four- Wheel Steering (4WS) system in constrained environments. Traditional Ackermann steering systems face limitations in narrow spaces, which the 4WS system aims to address. By extending the Hybrid A* algorithm to adapt to the unique characteristics of the 4WS system, and integrating it with Model Predictive Control, the study achieves efficient path planning and precise tracking in complex environments. A distinctive aspect of the proposed approach is its adaptive control strategy, dynamically switching between three modes—Normal driving, Pivot, and Parallel movement—based on the vehicle's motion state, thus enhancing both flexibility and efficiency. The algorithm's performance was validated through MATLAB simulations in a logistics warehouse setting, showing high path tracking accuracy in confined spaces. The study effectively demonstrates the feasibility of the proposed method in a simulated environment.
Citations
Citations to this article as recorded by
Research on path planning for four-wheel steering robots based on improved TEB algorithm Ming Huang, Ting Lan, Ze Liu, Haoyu Zhang Engineering Research Express.2026; 8(11): 115214. CrossRef
Adaptive Multi-Mode Path Planning for Four-Wheel Independent Steering Vehicles Jiawu Zhu, Gang Li, Ning Li, Dong Zhang World Electric Vehicle Journal.2026; 17(7): 335. CrossRef
CNN is one of the deep learning technologies useful for image-based pattern recognition and classification. For machining processes, this technique can be used to predict machining parameters and surface roughness. In electrical discharge machining (EDM), the machined surface is covered with many craters, the shape of which depends on the workpiece material and pulse parameters. In this study, CNN was applied to predict EDM parameters including capacitor, workpiece material, and surface roughness. After machining three metals (brass, stainless steel, and cemented carbide) with different discharge energies, images of machined surfaces were collected using a scanning electron microscope (SEM) and a digital microscope. Surface roughness of each surface was then measured. The CNN model was used to predict machining parameters and surface roughness.
Citations
Citations to this article as recorded by
Experimental Study on the Formation of Discharge Crater Morphology in Micro EDM Jae Yeon Kim, Ui Seok Lee, Hee Jin Kong, Bo Hyun Kim Journal of the Korean Society for Precision Engineering.2026; 43(1): 61. CrossRef
Investigation of Crack Formation in Micro-groove Machining of Silicon Carbide Ju Hyeon Lee, Gyu Man Kim, Bo Hyun Kim International Journal of Precision Engineering and Manufacturing-Smart Technology.2026; 4(2): 199. CrossRef
Manned water-powered aerial vehicles have been implemented into specialized missions around water bodies, such as firefighting and rescue. However, the dual requirement of vehicle motion control and performing tasks challenges operators. Moreover, in the presence of a low visibility, dense smoke, and extreme temperature, they always face potential risks. Motivated by these difficulties, this paper proposed an unmanned water-powered aerial vehicle using a nozzle rotation mechanism. This mechanism allows the vehicle to have a wide range of forces and torques in multiple directions under constant mass flowrate condition. A simple controller was designed to investigate the fundamental flight motions and verify dynamic properties of the vehicle in practical testing. To come up with the control law, the following steps were taken. Firstly, a mathematical model was derived to reflect the vehicle’s dynamic characteristics. Secondly, a well-known proportional-derivative-integral controller incorporating gravity compensation was deployed to regulate the 3-degree-of-freedom motion system. Thirdly, experiments were conducted to confirm the flight ability of the proposed vehicle. Results demonstrated that the control system preserved stability and the vehicle could fly following the desired altitude.
Citations
Citations to this article as recorded by
Intelligent Robust Motion Control of Aerial Robot Cao-Tri Dinh, Thien-Dinh Nguyen, Young-Bok Kim, Thinh Huynh, Jung-Suk Park Actuators.2025; 14(4): 197. CrossRef
A Hybrid Flying Robot Utilizing Water Thrust and Aerial Propellers: Modeling and Motion Control System Design Thien-Dinh Nguyen, Cao-Tri Dinh, Tan-Ngoc Nguyen, Jung-Suk Park, Thinh Huynh, Young-Bok Kim Actuators.2025; 14(7): 350. CrossRef
In recent years, significant progress has been made in functional soft materials, alongside advances in nano/micromanufacturing techniques, driving the evolution of soft grippers to the forefront of robotics innovation. Compared to their traditional rigid counterparts, soft grippers offer unparalleled adaptability, effortlessly conforming to objects of varying sizes and shapes. This comprehensive review explores the latest trends shaping the landscape of soft robotic grippers, providing insights into their diverse functionalities and applications. The exploration begins with an examination of the various actuation mechanisms utilized by soft grippers, including cable or tendon-driven, pneumatic, electroactive, and thermoactive systems. Additionally, the review delves into the intricacies of grasping and manipulating mechanisms, spanning from multi-finger configurations to innovative approaches, such as jamming, suction, and adhesion grasping. Notably, hybrid grippers, which integrate multiple actuation and grasping mechanisms, are of particular interest, thereby enhancing the range of functionalities offered by these grippers. Finally, the review briefly addresses current limitations and future directions in the field.
Citations
Citations to this article as recorded by
Soft autonomous mobile manipulators in agricultural automation – a review Tahsin Khan, Mervin Joe Thomas Industrial Robot: the international journal of robotics research and application.2026; 53(2): 376. CrossRef
A Study on Automated Box Incasing Processes in Dried Seaweed Packaging Chang Hee Lee, Van Tung Ha, Hyeonwoo Tak, Myeongsu Jeong, Jaeyoul Lee Journal of the Korean Society for Precision Engineering.2026; 43(5): 457. CrossRef
A magnetic levitation system (MLS) controls the position of a steel ball with the magnetic force of the electromagnetic actuator. A disturbance observer (DOB) could improve the disturbance rejection and command tracking performance of the voltage-controlled MLS. This paper studied control boost of MLS using current and position DOB. The current-controlled MLS had a higher control performance than the voltage-controlled MLS. The combination of PID position and PI current controls provided stable levitation and a wide operation range of MLS. When DOB was applied to PI current control, it could compensate for inductance change according to the position of the steel ball. In addition, when another DOB was introduced to the PID position control, it improved the disturbance removal performance. Finally, we discussed the effectiveness and limitations of the DOB-based current and position control by measuring closed-loop frequency responses.
Citations
Citations to this article as recorded by
Uncertainty-aware RBF-enhanced Sliding Mode Control for Magnetic Levitation System Seseung Namgung, Hyeong-Joon Ahn International Journal of Precision Engineering and Manufacturing-Smart Technology.2026; 4(2): 67. CrossRef
Improvement of the Transient Levitation Response of a Magnetic Levitation System Using Hybrid Fuzzy and Artificial Neural Network Control Yupeng Zheng, Hyeong-Joon Ahn International Journal of Precision Engineering and Manufacturing.2025; 26(5): 1159. CrossRef
In recent years, research on machine learning techniques that can be integrated with existing suspension control algorithms for enhanced control effects has advanced considerably. Machine learning, especially involving neural networks, often requires many samples, which makes maintaining robust performance in diverse, changing environments challenging. The present study applied reinforcement learning, which can generalize complex situations not previously encountered, to overcome this obstacle and is crucial for suspension control under varying road conditions. The effectiveness of the proposed control method was evaluated on different road conditions using the quarter-vehicle model. The impact of training data was assessed by comparing models trained under two distinct road conditions. In addition, a validation exercise on the performance of the control method that utilizes reinforcement learning demonstrated its potential for enhancing the adaptability and efficiency of suspension systems under various road conditions.
Citations
Citations to this article as recorded by
Control Characteristics of Active Suspension in Vehicles using Adaptive Control Algorithm Jeong Seo Jang, Jung Woo Sohn Transactions of the Korean Society for Noise and Vibration Engineering.2024; 34(5): 568. CrossRef
Suspension Mechanism Design of a Low-platform Target Robot for Evaluating Autonomous Vehicle Active Safety Jae Sang Yoo, Do Hyeon Kim, Jayil Jeong Journal of the Korean Society for Precision Engineering.2024; 41(5): 375. CrossRef
First
Prev
