For motor controller designers, building a simulation environment is not a difficult process. After verifying the controller by simulation, it is common to select 20kHz for the current control loop, 1kHz for the speed loop, and 100Hz for the position loop when implementing the actual HW embedded system. This is because maximized cycles (20kHz) for each control loop are unnecessary in control theory and are a waste of cost and HW resources. However, in a simulation environment, each loop will often have the same control cycle (20kHz maximum). This is because we think it is unnecessary to reflect this part in the simulation. In this paper, it is shown that the difference in the sampling time of each control loop makes a big difference in the simulation result, and as a solution, it is proposed to apply LPF to the position loop output stage. In the process, the reasons for the differences were analyzed, and the effect of LPF, the reason for application, and the feasibility of implementation were proved by actual software coding.

본 연구는 지카바이러스, 메르스, coronavirus disease-19 (COVID-19) 등의 감염병 방역 및 의료현장에서 사용할 수 있는 의료용 공기정화호흡기(powered air purifying respirators, PAPR)의 항균성 보호복의 후드와 필터를 개발하였다. PAPR은 전동팬 본체 및 필터, 배터리팩, 후드로 구성되며 보호복의 후드 소재는 뛰어난 흡습성, 풍압, 외부충격을 견딜 수 있는 폴리프로필렌 슐폰레이스(spunlace) 부직포 직물(SFS)을 사용하였다. 사용자의 감염위험을 낮추기 위해 후드의 외피에는 피톤치드계 물질을 사용하여 99.9%의 안티-박테리얼(antibacterial) 효과를 얻었으며 내피에는 친수가공을 하여 흡수성을 25% 향상시켰다. 의료용 보호복 후드에 필요한 인공혈액 침투저항성, 건조미생물 침투저항성, 습식세균 침투저항성, 그리고 박테 리오파아지 침투저항성을 평가한 결과 2~6 단계의 합격평가를 받았다. 한편, 항균 처리된 슐폰레이스(spunlace filter, SF) 헤 파 필터(high efficiency particulate air, HEPA)의 성능을 평가한 결과 우수한 항균성, 분진제거율, 차압 효과를 확인하였다.

본 논문에서는 다중 시그마포인트 세트(MSP)를 사용하는 분산점 칼만필터(UKF)인 UKF-MSP를 소개한다. 비선형 동적시스템을 표현하기 위해 널리 알려진 Bouc-Wen 모델을 사용하였고, 비선형성 고려가 가능한 칼만필터 중 UKF를 선정하였다. 그런데 UKF는 두 가지 인공오차와 시그마포인트의 분포를 결정하는 스케일링 파라미터의 값을 튜닝(Tuning)하는 과정을 통해 적절히 설정해야만 대상 동적시스템의 추정하고자 하는 상태(State)를 정확히 추정할 수가 있다. 본 논문에서는 후자의 스케일링 파라미터 설정 문제를 완화하고자 하였으며, MSP를 사용함으로써 기존 UKF에 비해 칼만필터 튜닝 과정에 덜 민감한 UKF-MSP를 제안하였다. 지진으로 인한 급격한 구조손상 시나리오에 대해 UKF-MSP의 안정성을 검증하였다. 제안된 방법은 튜닝과정을 완화함과 동시에 다른 칼만필 터 파라미터인 인공오차에 대해서도 덜 민감한 거동을 보임을 확인하였다.

Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.

We have observed a phenomenon where the internal X capacitors of the input EMI filter experienced damage during operation. To solve the problem, we have analyzed the malfunction by identifying the characteristics and operating principles of EMI filter. Based on this analysis, we have derived improvement strategies and validated them through experiments. This paper help some people prevent the similar problem when developing the similar equipment and solve the similar problem of the similar equipment.

In this study, we present an algorithm for indoor robot position estimation. Estimating the position of an indoor robot using a fixed imaging device obviates the need for complex sensors or hardware, enabling easy estimation of absolute position through marker recognition. However, location estimation becomes impossible when the device moves away from the surrounding obstacles or the screen, presenting a significant drawback. To solve this problem, we propose an algorithm that improves the precision of robot indoor location estimation using a Gaussian Mixture Model(GMM) and a Kalman filter estimation model. We conducted an actual robot operation experiment and confirmed accurate position estimation, even when the robot was out of the image.

Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.