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Adaptive Reflection Detection and Control Strategy of Pointer Meters Based on YOLOv5s

SENSORS 2023年第5期23卷 2562页

作者： Liu, Deyuan Deng, Changgen Zhang, Haodong Li, Jinrong Shi, Baojun Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equipm Tianjin 300401 Peoples R China Hebei Key Lab Robot Sensing & Human Robot Integrat Tianjin 300401 Peoples R China Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China

Reflective phenomena often occur in the detecting process of pointer meters by inspection robots in complex environments, which can cause the failure of pointer meter readings. In this paper, an improved k-means clustering method for adaptive detection of pointer meter reflective areas and a robot pose control strategy to remove reflective areas are proposed based on deep learning. It mainly includes three steps: (1) YOLOv5s (You Only Look Once v5-small) deep learning network is used for real-time detection of pointer meters. The detected reflective pointer meters are preprocessed by using a perspective transformation. Then, the detection results and deep learning algorithm are combined with the perspective transformation. (2) Based on YUV (luminance-bandwidth-chrominance) color spatial information of collected pointer meter images, the fitting curve of the brightness component histogram and its peak and valley information is obtained. Then, the k-means algorithm is improved based on this information to adaptively determine its optimal clustering number and its initial clustering center. In addition, the reflection detection of pointer meter images is carried out based on the improved k-means clustering algorithm. (3) The robot pose control strategy, including its moving direction and distance, can be determined to eliminate the reflective areas. Finally, an inspection robot detection platform is built for experimental study on the performance of the proposed detection method. Experimental results show that the proposed method not only has good detection accuracy that achieves 0.809 but also has the shortest detection time, which is only 0.6392 s compared with other methods available in the literature. The main contribution of this paper is to provide a theoretical and technical reference to avoid circumferential reflection for inspection robots. It can adaptively and accurately detect reflective areas of pointer meters and can quickly remove them by controlling the

关键词： inspection robot YOLOv5s k-means clustering algorithm reflection detection pose transformation

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The Analysis of Muscle-Synergy Similarity between Walking and Pedaling Based on Variational Mode Decomposition and Non-Negative Matrix Factorization 30

The Analysis of Muscle-Synergy Similarity between Walking an...

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30th IEEE International Conference on Engineering, Technology, and Innovation

作者： Ge, Wangyang She, Jinhua Guo, Shijie Wang, Feng Zhao, Juan Kawata, Seiichi China Univ Geosci Sch Automat Wuhan 430074 Peoples R China Hubei Key Lab Adv Control & Intelligent Automat C Wuhan 430074 Peoples R China Minist Educ Engn Res Ctr Intelligent Technol Geoexplorat Wuhan 430074 Peoples R China Tokyo Univ Technol Sch Engn Hachioji Tokyo 1920982 Japan Minist Educ Intelligent Rehabil Equipment & Detec Hebei Key Lab Robot Sensing & Human Robot Interac Engn Res Ctr Tianjin 300401 Peoples R China Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China

ISBN: (纸本)9798350362442;9798350362435

Pedaling lower-limb rehabilitation robots are widely used in various stages of lower-limb rehabilitation because of their high safety and low requirements for patients' lower-limb strength. Researchers found that the activation sequence of the surface electromyographic (sEMG) signals of the muscles of the lower limb during pedaling is very similar to that of walking, which makes it possible to simulate the muscle force generation during walking by changing the pedal load during pedaling training. However, most pedaling lower-limb rehabilitation robots use constant loads, and it is of great importance to study the relationship between load and muscle synergy and to design load phase angle trajectories with higher muscle synergy consistency in the walking-pedaling motion to optimize the training effect of pedal-type rehabilitation robots. In this paper, we used variational mode decomposition (VMD) and non-negative matrix factorization (NMF) to extract the muscle synergy features in each band of sEMG during walking and pedaling and to study the similarity of pedaling and walking and the influence of pedal load on muscle synergy consistency.

关键词： muscle-synergy similarity sEMG signal variational mode decomposition non-negative matrix factorization

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Microfluidics Temperature Compensating and Monitoring Based on Liquid Metal Heat Transfer

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MICROMACHINES 2022年第5期13卷 792-792页

作者： Meng, Jiyu Yu, Chengzhuang Li, Shanshan Wei, Chunyang Dai, Shijie Li, Hui Li, Junwei Hebei Univ Technol Sch Mech Engn Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300130 Peoples R China Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300401 Peoples R China Hebei Univ Technol Sch Hlth Sci & Biomed Engn Tianjin 300401 Peoples R China

Microfluidic devices offer excellent heat transfer, enabling the biochemical reactions to be more efficient. However, the precision of temperature sensing and control of microfluids is limited by the size effect. Here in this work, the relationship between the microfluids and the glass substrate of a typical microfluidic device is investigated. With an intelligent structure design and liquid metal, we demonstrated that a millimeter-scale industrial temperature sensor could be utilized for temperature sensing of micro-scale fluids. We proposed a heat transfer model based on this design, where the local correlations between the macro-scale temperature sensor and the micro-scale fluids were investigated. As a demonstration, a set of temperature-sensitive nucleic acid amplification tests were taken to show the precision of temperature control for micro-scale reagents. Comparations of theoretical and experimental data further verify the effectiveness of our heat transfer model. With the presented compensation approach, the slight fluorescent intensity changes caused by isothermal amplification polymerase chain reaction (PCR) temperature could be distinguished. For instance, the probability distribution plots of fluorescent intensity are significant from each other, even if the amplification temperature has a difference of 1 degrees C. Thus, this method may serve as a universal approach for micro-macro interface sensing and is helpful beyond microfluidic applications.

关键词： heat transfer microfluidics liquid metal measurement temperature monitoring PCR

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Vibration Characteristics Analysis of Planetary Gears with a Multi-Clearance Coupling in Space Mechanism

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ENERGIES 2018年第10期11卷 2687-2687页

作者： Zhang, Huibo Qi, Chaoqun Fan, Jizhuang Dai, Shijie You, Bindi Hebei Univ Technol Sch Mech Engn Tianjin 300130 Peoples R China Hebei Key Lab Robot Percept & Human Robot Interac Tianjin 300130 Peoples R China Harbin Inst Technol State Key Lab Robot & Syst Harbin 150080 Heilongjiang Peoples R China Harbin Inst Technol Weihai Sch Naval Architecture & Ocean Engn Weihai 264209 Peoples R China

Multi-clearance is the main cause for the performance and reliability decline of complicated mechanical systems. The increased clearance could induce contacts and impacts in joints, and consequently affect control accuracy. A nonlinear dynamic model of planetary gears with multi-clearance coupling is proposed in the current study to investigate the mechanism of influence of clearance on the dynamic performance. In addition, the coupling relationship between radial clearance and backlash is integrated into the multi-body system dynamics. The vibration characteristics of planetary gears with the changes of rotational velocity, clearance size and inertia load are explored. The numerical simulation results show that there are complex coupling relations in planetary gear systems, due to the multi-clearance coupling. The phenomenon of system resonance may occur with the changes of rotational velocities and clearances' sizes. Multi-clearance coupling can significantly increase the resonant response of planetary gear systems in empty-load or light-load states.

关键词： space mechanism multi-clearance nonlinear dynamic model planetary gears vibration characteristics

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A Cost-Effective Nucleic Acid Detection System Using a Portable Microscopic Device

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MICROMACHINES 2022年第6期13卷 869-869页

作者： Yu, Chengzhuang Li, Shanshan Wei, Chunyang Dai, Shijie Liang, Xinyi Li, Junwei Hebei Univ Technol Sch Mech Engn Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300130 Peoples R China Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300130 Peoples R China Hebei Univ Technol Inst Biophys Sch Hlth Sci & Biomed Engn Tianjin Peoples R China

A fluorescence microscope is one of the most important tools for biomedical research and laboratory diagnosis. However, its high cost and bulky size hinder the application of laboratory microscopes in space-limited and low-resource applications. Here, in this work, we proposed a portable and cost-effective fluorescence microscope. Assembled from a set of 3D print components and a webcam, it consists of a three-degree-of-freedom sliding platform and a microscopic imaging system. The microscope is capable of bright-field and fluorescence imaging with micron-level resolution. The resolution and field of view of the microscope were evaluated. Compared with a laboratory-grade inverted fluorescence microscope, the portable microscope shows satisfactory performance, both in the bright-field and fluorescence mode. From the configurations of local resources, the microscope costs around USD 100 to assemble. To demonstrate the capability of the portable fluorescence microscope, we proposed a quantitative polymerase chain reaction experiment for meat product authenticating applications. The portable and low-cost microscope platform demonstrates the benefits in space-constrained environments and shows high potential in telemedicine, point-of-care testing, and more.

关键词： portable fluorescence microscope meat products authenticating

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Mercaptosilane Engineered Interface with Surface-Preferred Crystal Plane for High-Performance Zn Anode

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BATTERIES & SUPERCAPS 2024年第3期7卷

作者： Li, Guo-Xian Zhao, Zhen Yu, Wei Meng, Chui-Zhou Guo, Shi-Jie Hebei Univ Technol Sch Mech Engn State Key Lab Reliabil & Intelligence Elect Equipm Hebei Key Lab Smart Sensing & Human Res Ctr Robot 5340Xiping Rd Tianjin 300401 Peoples R China

Zn-ion battery (ZIB) has drawn huge attentions as a prospective energy storage system for the next generation, but dendrite and side reaction issues related to Zn have limited their potential applications. Here, a combined approach involving the modification of surface texture and the implementation of a passivation layer is proposed to tackle the problem. A zinc-silane composite layer is coated on (002)-preferred Zn (ZSi@Zn) by selective acid etching, concomitant with the hydrolysis of Mercaptosilane. The preferred (002) crystal plane, in conjunction with the zinc-silane composite layer, leads in integrated interfacial transport and deposition control. As a result, the ZSi@Zn electrode has dramatically increased stability and uniform Zn deposition behavior. Remarkably, it exhibits a Coulombic efficiency of approximately 99.4 %, a long lifespan of around 3000 hours at the current density of 1 mA cm-2 with a capacity of 0.5 mAh cm-2. The excellent reversibility of zinc persists with current densities of 2, 5, and 10 mA cm-2. Furthermore, Zn-MnO2 battery constructed with ZSi@Zn also delivers excellent performance, manifesting a capacity retention of 88.4 % after 4000 cycles. A zinc anode modification method combining surface texture regulation and passive layer coating is proposed to overcome the dendrites and side reaction issues. The synergy between the preferred (002) crystalline surface and the zinc-silane composite layer achieves suppression of water-induced side reactions and guiding the preferred orientation deposition, resulting in high electrochemical performance for zinc ion ***

关键词： Zn metal anodes Interface stability crystal plane dendrite-free Zinc ion batteries

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Fluid mixing in droplet-based microfluidics with T junction and convergent-divergent sinusoidal microchannels

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ELECTROPHORESIS 2018年第3期39卷 512-520页

作者： Yang, Li Li, Shanshan Liu, Jixiao Cheng, Jingmeng Hebei Key Lab Smart Sensing & Human Robot Intera Tianjin Peoples R China Hebei Univ Technol Sch Mech Engn Tianjin Peoples R China

To explore and utilize the advantages of droplet-based microfluidics, hydrodynamics, and mixing process within droplets traveling though the T junction channel and convergent-divergent sinusoidal microchannels are studied by numerical simulations and experiments, respectively. In the T junction channel, the mixing efficiency is significantly influenced by the twirling effect, which controls the initial distributions of the mixture during the droplet formation stage. Therefore, the internal recirculating flow can create a convection mechanism, thus improving mixing. The twirling effect is noticeably influenced by the velocityof thecontinuous phase;in the sinusoidal channel, the Dean vortices and droplet deformation are induced by centrifugal force and alternative velocity gradient, thus enhancing the mixing efficiency. The best mixing occurred when the droplet size is comparable with the channel width. Finally, we propose a unique optimized structure, which includes a T junction inlet joined to a sinusoidal channel. In this structure, the mixing of fluids in the droplets follows two routes: One is the twirling effect and symmetric recirculation flow in the straight channel. The other is the asymmetric recirculation and droplet deformation in the winding and variable cross-section. Among the three structures, the optimized structure has the best mixing efficiency at the shortest mixing time (0.25 ms). The combination of the twirling effect, variable cross-section effect, and Dean vortices greatly intensifies the chaotic flow. This study provides the insight of the mixing process and may benefit the design and operations of droplet-based microfluidics.

关键词： Dean vortices Microdroplet Mixing Twirling effect

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Bioinspired flexible, breathable, waterproof and self-cleaning iontronic tactile sensors for special underwater sensing applications

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NANO ENERGY 2023年 110卷

作者： Sun, Guifen Wang, Peng Jiang, Yongxiang Sun, Hongchang Liu, Teng Li, Guoxian Yu, Wei Meng, Chuizhou Guo, Shijie Tianjin Univ Technol & Educ Sch Mech Engn Inst Robot & Intelligent Equipment Tianjin 300222 Peoples R China Hebei Univ Technol Sch Mech Engn State Key Lab Reliabil & Intelligence Elect Equipm Hebei Key Lab Smart Sensing & Human Robot Interact Tianjin 300401 Peoples R China

Flexible tactile sensors are under high pursuit for wearable healthcare devices. However, challenges still exist in achieving both wearing comfortability through air permeability and hydrophobicity to resist water splash or even to be used in the special underwater circumstance. Inspired by the smart bio-structure of lotus leaf, we develop a flexible, breathable, waterproof and self-cleaning tactile sensor by sandwiching one ionogel electrolyte between two polydopamine (PDA)/MXene/stearic acid (STA) fabric electrodes. The micro-channels in the fabric and the through-holes in the gel endow the sensor with a high air breathability of 723.5 mm s-1 and the STA micro-sheets decorated on the outside surface of the sensor provide hydrophobicity with a large water droplet contact angle of 140.7 degrees for the unique properties of self-cleaning and washability. By taking advantage of the supercapacitive sensing mechanism, the microstructures of MXene nanosheets on microfibers and the using of an interlayer with an internal aperture to initially separate electrodes and electrolyte, an extremely high sensitivity of up to 1677.79 kPa(-1) is achieved. Practical sensing applications of the developed flexible sensors worn on different parts of human body for physiological signal monitoring, motion detection and silent information communication through Morse code in the special underwater circumstance are demonstrated.

关键词： Iontronic tactile sensor Flexible electronics Breathable Waterproof Self-cleaning Underwater sensing application

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Standing Air Bubble-Based Micro-Hydraulic Capacitors for Flow Stabilization in Syringe Pump-Driven Systems

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MICROMACHINES 2020年第4期11卷 396-396页

作者： Zhou, Yidi Liu, Jixiao Yan, Junjia Zhu, Tong Guo, Shijie Li, Songjing Li, Tiejun Hebei Univ Technol Sch Mech Engn Tianjin 300132 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Percept & Human Robot Interac Tianjin 300401 Peoples R China Univ Calif Berkeley Dept Bioengn Berkeley CA 94720 USA Harbin Inst Technol Sch Mechatron Harbin 150001 Peoples R China

Unstable liquid flow in syringe pump-driven systems due to the low-speed vibration of the step motor is commonly observed as an unfavorable phenomenon, especially when the flow rate is relatively small. Upon the design of a convenient and cost-efficient microfluidic standing air bubble system, this paper studies the physical principles behind the flow stabilization phenomenon of the bubble-based hydraulic capacitors. A bubble-based hydraulic capacitor consists of three parts: tunable microfluidic standing air bubbles in specially designed crevices on the fluidic channel wall, a proximal pneumatic channel, and porous barriers between them. Micro-bubbles formed in the crevices during liquid flow and the volume of the bubble can be actively controlled by the pneumatic pressure changing in the proximal channel. When there is a flowrate fluctuation from the upstream, the flexible air-liquid interface would deform under the pressure variation, which is analogous to the capacitive charging/discharging process. The theoretical model based on Euler law and the microfluidic equivalent circuit was developed to understand the multiphysical phenomenon. Experimental data characterize the liquid flow stabilization performance of the flow stabilizer with multiple key parameters, such as the number and the size of microbubbles. The developed bubble-based hydraulic capacitor could minimize the flow pulses from syringe pumping by 75.3%. Furthermore, a portable system is demonstrated and compared with a commercial pressure-driven flow system. This study can enhance the understanding of the bubble-based hydraulic capacitors that would be beneficial in microfluidic systems where the precise and stable liquid flow is required.

关键词： fluidic capacitors bubble-based flow regulation theoretical model experimental studies

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Thorax Dynamic Modeling and Biomechanical Analysis of Chest Breathing in Supine Lying Position

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JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME 2022年第10期144卷 101004-101004页

作者： Zhao, Xingli Guo, Shijie Xiao, Sen Song, Yao Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip 81 Dingzigu Rd Tianjin 300131 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac 81 Dingzigu Rd Tianjin 300131 Peoples R China Hebei Univ Technol Sch Mech Engn 81 Dingzigu Rd Tianjin 300131 Peoples R China

During respiration, the expansion and contraction of the chest and abdomen are coupled with each other, presenting a complex torso movement pattern. A finite element (FE) model of chest breathing based on the HUMOS2 human body model was developed. One-dimensional muscle units with active contraction functions were incorporated into the model based on Hill's active muscle model so as to generate muscle contraction forces that can change over time. The model was validated by comparing it to the surface displacement of the chest and abdomen during respiration. Then, the mechanism of the coupled motion of the chest and abdomen was analyzed. The analyses revealed that since the abdominal wall muscles are connected to the lower edge of the rib cage through tendons, the movement of the rib cage may cause the abdominal wall muscles to be stretched in both horizontal and vertical in a supine position. The anteroposterior and the right-left diameters of the chest will increase at inspiration, while the right-left diameter of the abdomen will decrease even though the anteroposterior diameter of the abdomen increases. The external intercostal muscles at different regions had different effects on the motion of the ribs during respiration. In particular, the external intercostal muscles at the lateral region had a larger effect on pump handle movement than bucket handle movement, and the external intercostal muscles at the dorsal region had a greater influence on bucket handle movement than pump handle movement.

关键词： respiratory biomechanics surface displacement active muscle model rib cage motion

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