Online Gait Generation Method Based on Neural Network for Humanoid Robot Fast Walking on Uneven Terrain

Haoran Zhong,Sicheng Xie,Xinyu Li,Shengyu Lu,Liang Gao 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.3

Advanced humanoid robots highlight the ability of fast walking and adaptability to uneven terrain. However, owing to the complexity in walking dynamics, disturbances introduced by terrain height variations can adversely affect the bipedal walking performance. Moreover, to generate periodic gaits, most methods require to solve the gait generation problem by using nonlinear optimization approaches, resulting in difficulties for online control. To solve this problem, this paper proposes an online gait generation method to find periodic gaits for fast walking on uneven terrain by using a pre-trained neural network. First, to enhance the terrain adaptability, this paper proposes an improved walking pattern that allows the robots to skip the last single support phase. Such improvement enlarges the feasible step region when stepping down. A compensation strategy is also proposed to reduce the velocity tracking error. Then the improved whale swarm algorithm (IWSA) is applied to generate various datasets that cover the ranges of target velocities and terrain height variations. A back-propagation (BP) network is employed to train these datasets offline to learn the gait dynamics, which is further used to generate the optimal trajectories. Simulation results suggest that, compared with the current methods, the proposed method can solve the walking return map in a short time, with improvements in both maximum walking speed and terrain adaptability.

Strongly Fluorescent Carbon Quantum Dots from Biomass Tar as Highly Selective and Sensitive Probe for Fe3+ Detection

Haoran Yuan,Xian Zhang,Denian Li,Yong Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.4

Nonhazardous and value-added utilization of biomass tar remains a great challenge in biomass gasification development. Herein, both model compounds and real biomass tar were for the first time tested as the carbon source for carbon quantum dots, where the resultants demonstrated excellent monodispersibility and strong fluorescence, quantum efficiency up to 53% and 43% were achieved. Moreover, the real tar-derived CQDs further revealed as a highly selective and sensitive probe for Fe3+, indicating its great potential ion sensing. It is expected that this work would open up a new strategy for biomass tar valorization.

Simultaneous out-of-plane and in-plane vibration mitigations of offshore monopile wind turbines by tuned mass dampers

Haoran Zuo,Kaiming Bi,Hong Hao 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.4

To effectively extract the vast wind resource, offshore wind turbines are designed with large rotor and slender tower, which makes them vulnerable to external vibration sources such as wind and wave loads. Substantial research efforts have been devoted to mitigate the unwanted vibrations of offshore wind turbines to ensure their serviceability and safety in the normal working condition. However, most previous studies investigated the vibration control of wind turbines in one direction only, i.e., either the out-of-plane or in-plane direction. In reality, wind turbines inevitably vibrate in both directions when they are subjected to the external excitations. The studies on both the in-plane and out-of-plane vibration control of wind turbines are, however, scarce. In the present study, the NREL 5 MW wind turbine is taken as an example, a detailed three-dimensional (3D) Finite Element (FE) model of the wind turbine is developed in ABAQUS. To simultaneously control the in-plane and out-of-plane vibrations induced by the combined wind and wave loads, another carefully designed (i.e., tuned) spring and dashpot are added to the perpendicular direction of each Tuned Mass Damper (TMD) system that is used to control the vibrations of the tower and blades in one particular direction. With this simple modification, a bi-directional TMD system is formed and the vibrations in both the out-of-plane and in-plane directions are simultaneously suppressed. To examine the control effectiveness, the responses of the wind turbine without control, with separate TMD system and the proposed bi-directional TMD system are calculated and compared. Numerical results show that the bi-directional TMD system can simultaneously control the out-of-plane and in-plane vibrations of the wind turbine without changing too much of the conventional design of the control system. The bi-directional control system therefore could be a cost-effective solution to mitigate the bi-directional vibrations of offshore wind turbines.

From a psychological point of view—Research on Interactive Art of Connecting Somatosensory Interactive Devices

HaoRan Wang,Hyung Gi Kim 중앙대학교 영상콘텐츠융합연구소 2020 TechArt :Journal of Arts and Imaging Science Vol.7 No.1

Impact of Delayed Control Message in AODV Protocol

( Haoran Miao ),( Ye-eun Lee ),( Ki-il Kim ) 한국정보처리학회 2022 한국정보처리학회 학술대회논문집 Vol.29 No.1

Ad-hoc On-demand Distance Vector (AODV), is one of well-designed routing protocols in mobile ad hoc networks. It supports the functionality of node mobility modules through multiple control messages to create and maintain paths for data transfer. Even though a number of studies have been conducted to achieve rapid discovery of paths across the network, but few have focused on impact of control messages. This paper proposes a method to adjust the transmission time of messages used in path recovery according to their individual characteristics. Simulation results show the improved performance of the proposed algorithm rather than traditional AODV routing protocol.

Gliotoxin is Antibacterial to Drug-resistant Piscine Pathogens

Haoran Feng,Sen Liu,SUMINGZHI,김은라,홍종기,정지형 한국생약학회 2018 Natural Product Sciences Vol.24 No.4

By activity-guided fractionation, gliotoxin was isolated as an antibacterial metabolite of the fungus Penicillium decumbens which was derived from the jellyfish Nemopilema nomurai. Gliotoxin was further evaluated for antibacterial activity against several piscine and human MDR (multidrug resistance) pathogens. Gliotoxin showed significant antibacterial activity against Gram-positive piscine pathogens such as Streptococcus iniae FP5228, Streptococcus iniae FP3187, Streptococcus parauberis FP3287, Streptococcus parauberis SPOF3K, S. parauberis KSP28, and Lactococcus garvieae FP5245. Gliotoxin showed strong activity especially against S. parauberis SPOF3K and S. iniae FP5228, which are resistant to oxytetracycline. It is noteworthy that gliotoxin effectively suppressed streptococci which are the major pathogens for piscine infection and mortality in aquaculture industry. Gliotoxin also showed strong antibacterial activity against multidrug- resistant human pathogens (MDR) including Enterococcus faecium 5270 and MRSA (methicillin-resistant Staphylococcus aureus) 3089.

Application of amine-loaded activated carbon fiber in CO2 capture and separation

Haoran Liu,Xinmei Lu,Liying Liu,Jian Wang,Pengyu Wang,Peng Gao,Tingsheng Ren,Guo Tian,Di Wang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.9

The CO2 emitted by coal-fired power plants is the main factor leading to global warming, and the captureof CO2 in the flue gas of power plants is still the main task at this stage. Many adsorbents have been developed to captureCO2 in high-temperature flue gas, but some materials are complicated to synthesize or the cost is too high. Here,we used low-cost raw materials activated carbon fiber and PEI, and used green synthesis to synthesize new adsorbentsin order to capture CO2 in high-temperature flue gas of a power plant. To improve the performance of highly porousactivated carbon fiber (ACF) in CO2 capture and separation, an organic polymer polyethylenimine (PEI) was loadedsuccessfully into the oxidized ACF. The modified adsorbent was tested by FT-IR, XRD and SEM, and the CO2 adsorptioncapacity and CO2/N2 selectivity were analyzed. The results showed that the as-synthesized PEI-modified adsorbenthas a CO2 adsorption capacity of 2.5mmol/g, which is 1.7 times better than that of the pristine ACF adsorbent(1.5mmol/g), at 1 bar and 333 K, and it has excellent CO2/N2 selectivity, as calculated by ideal adsorption solution theory(IAST). These data indicate that PEI was loaded successfully into the oxidized ACF. In addition, the dual site Langmuirisotherm equation and Langmuir isotherm equation can be in good agreement with the adsorption curves ofCO2 and N2. In comparison with other composite adsorbents, the preparation process of the present new adsorbent ishighly environmentally friendly, the synthesis method is simple and the cost is low, which demonstrates potential applicationsin the separation of CO2 from the flue gas of power plants.

Integrated expression and general optimisation method of bucket shape line of backhoe hydraulic excavator

Haoran Sun,Zhigui Ren,Junli Wang,Weifeng Wei,Yongyong Liang,Minghao Feng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

The bucket shape of a hydraulic excavator influences its excavating performance and is determined by its shape line. In this study, the inner surface line projected on the symmetrical plane of the bucket was adopted as the bucket shape line, and the value ranges of the main parameters for the shape line were investigated. By considering the centre of the arc at the bucket bottom as the origin, the Cartesian coordinate system was established, and the integrated equation of the bucket line was derived based on the geometric constraints related to the shape line. A general optimisation model of the bucket line was established using the integrated equation. The effects of four design variables on the optimisation goal were determined using the bucket of a 21 T excavator as an example, and the optimal shape line of the bucket was obtained using a genetic algorithm. The results indicated that the cutting angle decreased by 9.92 % in comparison with that before optimisation, which was beneficial in decreasing the digging resistance. Additionally, the aspect ratio decreased by 5.75 %, thereby reducing the bucket weight. Thus, the integrated expression and the optimisation of shape lines provide a general method and theoretical basis for optimising the bucket shape.

Development of Admittance Control Method with Parameter Self-optimization for Hydraulic Series Elastic Actuator

Haoran Zhong,Xinyu Li,Liang Gao,Haozhen Dong 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

Series elastic actuators (SEAs) have emerged as promising devices to enhance the safety of human-robot interactions in the manufacturing industry. However, the control of a hydraulic SEA under disturbance remains an unexplored issue. To address this problem, an admittance control method with parameter self-optimization is developed in this study. The hydraulic SEA and its dynamic model are first developed, and then, an admittance controller that combines a passive disturbance observer (DOB) and a feedback compensator is developed based on load movement dynamics. The control law of the framework is made independent of the hydraulic dynamics by considering the uncertainty and tracking error as disturbances. This simplifies the controller computation, enhances system robustness, and facilitates practical application. Next, the control performance is further improved by optimizing the control parameters using an improved crowding-based dynamic population size differential evolution (crowdingbased dynNP-DE) algorithm. Benchmark and optimization experiments are performed to verify the superiority of the modified algorithm and obtain the control parameters. Finally, the optimized parameters are applied to practical experiments to validate the improved performance of the proposed admittance control scheme. The results show that the proposed method effectively reduces the SEA stiffness tracking error, with respect to the external contact force.

기업 로고 리디자인이 브랜드 이미지에 미치는 영향 연구 - 자동차 브랜드를 중심으로

HaoRan Wang 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.10

세계 경제통합이 추진됨에 따라, 자동차업체들은 시장경쟁에 대응하고 소비자 수요에 부응하기 위해 적극적인 경영전략을 전개하고 있다. 본 연구는 선행 연구를 토대로 브랜드 디자인 요소를 발굴하고 브랜드의 소비 기억을 통해 로고 리디자인의 변화와 발전 및 로고 리디자인이 브랜드에 미치는 혁신과 영향에 대해 분석하고자 한다. 연구 결과, 자동차 브랜드 로고의 리디자인에서 점의 요소는 더 이상 사용되지 않고 있으며, 가장 많이 사용되는 것은 곡선형 선과 면임을 알 수 있었다. 그리고 로고에 가장 많이 사용되는 색상은 검정색과 흰색이고, 스타일링도 가장 기본적인 그래픽을 꾸준히 사용하고 있으며, 갈수록 단순해지고 있는 것으로 나타났다. 현재 자동자 브랜드 로고 리다자인에 가장 인기 있는 플랫 디자인과 단일 색상 디자인을 채택하여 미니멀한 스타일로 모두에게 선보이고 있으며, 이는 주요 브랜드 LOGO의 발전추세이다. 이로써 글로벌 자동차 기업의 디자인은 플랫디자인, 단순하고 임팩트 있는 디자인 추세임을 알 수 있으며, 이러한 변화는 로고 스타일의 변화 뿐만 아니라 전체 업계의 발전상을 나타낸 것으로 현시대 디자인 흐름에 부응하기 위한 것이기도 하다. With the globalization of the global economy, automobile companies are actively promoting their business strategies to cope with market competition and meet consumer demands. This study aims to investigate and summarize the elements of brand design through literature research and case studies, analyzing the changes and developments in brand consumer memory. Additionally, the study also aims to analyze the innovation and impact of logo redesign on brands. The research results show that in the redesign of automobile brand logos, point elements are basically no longer used, and curves and surfaces are the most commonly employed. The most frequently used colors for logos are black and white, and the shapes adhere to the most basic graphics, becoming increasingly simple. The trend for major brand logos is towards popular flat and monochromatic designs, presenting a simplistic style. It can be seen that the adoption of platform design, simplicity, and impactful design by global automobile companies is not only a sign of stylistic change but also an indication of the development of the entire industry. Moreover, in order to better adapt to the development of modern society, this trend also provides new design directions for future logo development. Additionally, an increasing number of new logos completely abandon their previous design styles and embrace the currently popular trend of flat design.