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Adaptive event-triggered control for quadrotor aircraft with output constraints

AEROSPACE SCIENCE AND TECHNOLOGY 2020年 105卷 105935-105935页

作者： Wang, Jie Wang, Ping Ma, Xiao Hebei Univ Technol Sch Artificial Intelligence Tianjin 300130 Peoples R China Hebei Engn Res Ctr Control Technol Tianjin 300130 Peoples R China Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300130 Peoples R China

This paper investigates the trajectory tracking problem of a quadrotor with six degrees of freedom (6-DOF) in the case of time-varying and asymmetric output constraints. To satisfy the output constraints, an Asymmetric Barrier Lyapunov Function (ABLF) is constructed and the control loop of the quadrotor is divided into position and attitude loop respectively. In the position loop, the adaptive controller is applied to estimate the upper bound of external interference online, and Dynamic Surface Control (DSC) technology is devoted to solve the 'explosion of complexity' problem of the traditional backstepping design process. Moreover, event-triggered control is implemented to the attitude loop controller design to reduce signal transmitting and communication burden in which the knowledge of the upper bounds of event-triggered thresholds is not required to be known in advance. Finally, the simulation results illustrate the effectiveness of the control method of this technology. (C) 2020 Elsevier Masson SAS. All rights reserved.

关键词： Quadrotor aircraft Asymmetric Barrier Lyapunov Function (ABLF) Sliding mode control Adaptive event-triggered control

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Unconstrained Detection of the Respiratory Motions of Chest and Abdomen in Different Lying Positions Using a Flexible Tactile Sensor Array

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IEEE SENSORS JOURNAL 2019年第21期19卷 10067-10076页

作者： Guo, Shijie Zhao, Xingli Matsuo, Kazuya Liu, Jinyue Mukai, Toshiharu Hebei Univ Technol Key Lab Reliabil & Intelligence Elect Equipment Tianjin 300130 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300130 Peoples R China Kyushu Inst Technol Fac Engn Kitakyushu Fukuoka 8048550 Japan Meijo Univ Fac Sci & Technol Nagoya Aichi 4688502 Japan

Respiratory Inductance Plethysmography (RIP) is commonly used to detect the respiratory motions of chest and abdomen during sleep. However, this method is not suitable for daily use due to its strong constraints. Many unconstrained methods have been developed, but they have a common problem with distinguishing the chest and abdominal motions, which are required for understanding the type of sleep apnea. In this paper, we proposed an unconstrained method to distinguish chest and abdominal motions by measuring the pressure fluctuations from the chest and abdomen acting on a mattress. We then investigated the feasibility of detecting respiratory motions by using a flexible tactile sensor array, which was laid on a bed like a bed sheet. Ten healthy subjects (five males and five females) were tested and the results were compared with those measured by the RIP band sensors. It was confirmed that the sensor array could measure the motions of the chest and abdomen and obtain the respiratory rate at a high accuracy. However, the phase of the pressure fluctuations measured by the sensor array might disagree with the outputs of the RIP band sensors, depending on the gender and lying position of the subject. The reason was discussed with a dynamic model, which showed that the disagreement might have been related to the coupling of the chest and abdomen. In addition, the influence of the stiffness of the mattress on the pressure fluctuations was investigated. The results showed that mattress stiffness had little effect on the measurement.

关键词： Abdomen Sensor arrays Sleep apnea Fluctuations Pressure measurement Monitoring Breath disorder flexible tactile sensor array pressure fluctuation respiratory motion respiratory Inductance plethysmography sleep apnea

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Low-dose CT image super resolution using a model-based framework with CNN prior 16

Low-dose CT image super resolution using a model-based frame...

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16th IEEE International Conference on Mechatronics and Automation (IEEE ICMA)

作者： Sun, Lei Guo, Shijie Tianjin Univ Technol Tianjin Key Lab Control Theory & Applicat Complic Tianjin 300384 Peoples R China Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300130 Peoples R China

ISBN: (纸本)9781728116976

Improve low-dose CT(LDCT) imaging quality is a hot research issue in the medical imaging field. However, current image post-processing method mainly focus on denoising, ignoring the limitations of image resolution. To this end, a new model-based LDCT image super resolution based on CNN prior is proposed in this paper. Meanwhile, the Half Quadratic Splitting (HQS) algorithm is selected to accelerate high resolution LDCT calculation process. The convolutional neural network(CNN) prior is pre-trained and integrated into the HQS algorithm to regularize the model-based LDCT SISR problem. Experimental results demonstrate that our method can improve the resolution of low-dose CT images effectively.

关键词： Low-dose CT CNN super resolution deep learning

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Touch position identification based on a flexible array-less supercapacitive tactile sensor

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AIP ADVANCES 2019年第1期9卷

作者： Liu, Jixiao Liu, Na Hashimoto, Kazunobu Meng, Chuizhou Guo, Shijie Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Hebei Univ Technol Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300132 Peoples R China Fudan Univ Acad Engn & Technol Shanghai 200433 Peoples R China

Flexible tactile sensors with simple structures, minimal peripheral electric connections and straightforward data processing will benefit the human-machine interactions in which the contact information is crucial. However, it is still hard to balance the easy fabrication, full flexibility, large measurement area and minimal electric connection in existed tactile sensing systems. This study introduces an innovative positioning method based on a flexible supercapacitive tactile sensor. A 100 mmx100 mm prototype sensor, which contains two layers of flexible electrodes and a layer of ionic gel membrane in the middle to construct electrostatic double-layer capacitors (EDLCs), is developed to study the underlying physical principles. Following the established method, minimized electric connections are needed to achieve the mm-scale touch position/movement trace identification. Under the touch pressure, the formation of supercapacitors around the touch area leads to re-distribution of electric potential within the sensor. The electrical voltage variation is gauged at four points, and the data are calculated to estimate the touch positions following a two-step protocol. The developed method demonstrates high accuracy of position identification (around 5% in the 100 mmx100 mm flexible sensor), superior anti-disturbance capability (more than similar to 10(4) variation of capacitance) and fast response (similar to ms level). At the same time, it has no dependency on complex fabrication, redundant electric circuit or sensing unit arrays. These promising characteristics can benefit various application fields, such as intelligent robotics, biomedical devices and wearable equipment. (C) 2019 Author(s).

关键词： Capacitance

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Pre-Degassed Microfluidic Chamber-Based Digital PCR Device for Meat Authentication Applications

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MICROMACHINES 2021年第6期12卷 694-694页

作者： Hu, Hezhi Cheng, Jingmeng Wei, Chunyang Li, Shanshan Yu, Chengzhuang Meng, Xiaoshuai Li, Junwei Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300132 Peoples R China Hebei Univ Technol Dept Elect & Informat Engn Langfang 065000 Peoples R China Sch Mech Engn Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300130 Peoples R China Jiangsu Key Lab Adv Food Mfg Equipment & Technol Wuxi 214122 Jiangsu Peoples R China Hebei Univ Technol Sch Sci Inst Biophys Tianjin 300401 Peoples R China

Droplet digital polymerase chain reaction (ddPCR) suffers from the need for specific equipment and skilled personnel;thus, we here present a chamber-based digital PCR microfluidic device that is compatible with fluorescence image read-out systems and removes bubbles by a pre-degassed microfluidic device that consists of a pilot channel and micro chamber arrays. Digitalized PCR reagents are introduced into micro chambers, and thermocycles are taken to perform a DNA amplification process. Then, fluorescence images of a micro chamber array are read out and analyzed to obtain the total number of positive chambers. Thereby, the copy numbers of target DNA are calculated for quantitative detections. As a validation, this device is evaluated by the application of meat authentication. We performed dPCR tests using DNA templates extracted from a pure mutton DNA template with different dilutions. Then, the dPCR chip was used to identify the meat authentication using mutton-chicken mixtures with different mass ratios, showing its performance in real biotechnical applications.

关键词： microfluidics digital polymerase chain reaction degas meat authentication

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Fully stretchable, porous MXene-graphene foam nanocomposites for energy harvesting and self-powered sensing

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NANO ENERGY 2022年第PartA期103卷

作者： Yang, Li Liu, Chaosai Yuan, Wenjing Meng, Chuizhou Dutta, Ankan Chen, Xue Guo, Langang Niu, Guangyu Cheng, Huanyu Hebei Univ Technol Sch Hlth Sci & Biomed Engn State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300130 Peoples R China Hebei Univ Technol Tianjin Key Lab Mat Laminating Fabricat & Interfa Sch Mat Sci & Engn Tianjin 300130 Peoples R China Hebei Univ Technol Sch Mech Engn State Key Lab Reliabil & Intelligence Elect Equip Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300401 Peoples R China Penn State Univ Dept Engn Sci & Mech University Pk PA 16802 USA Hebei Univ Technol Sch Elect Engn State Key Lab Reliabil & Intelligence Elect Equip Key Lab Bioelectromagnet & Neuroengn Hebei Prov Tianjin 300130 Peoples R China Hebei Univ Technol Sch Architecture & Art Tianjin 300130 Peoples R China

The growing demand for intelligent wearable electronic devices has spurred the rapid developments of high-performance deformable power supplies such as triboelectric nanogenerators (TENGs) with high output performance. However, the intrinsically stretchable TENGs especially those prepared with low-cost manufacturing approaches still suffer from poor performance. To address the challenge, this paper presents a fully stretchable TENG consisting of an intrinsically stretchable MXene/silicone elastomer and silver nanowires (Ag NWs)graphene foam nanocomposite. The intrinsically stretchable TENG exhibits high output performance (voltage, current, and power of 73.6 V, 7.75 mu A, and 2.76 W m(-2)), long-term reliability, and stable electrical output under various extreme deformation conditions. In addition to the application on the human skin and clothing for human motion monitoring and detecting the strength training postures, the intrinsically stretchable TENG can also harvest the intermittent mechanical energy from human bodies to charge various energy storage units such as commercial capacitors for driving wearable electronic devices. The resulting systems have been demonstrated in applications from home anti-theft to water resources early warning systems, which provide the proof-of-the-concept demonstrations for the next-generation standalone device platforms.

关键词： Triboelectric nanogenerator (TENG) MXene-graphene foam nanocomposites Ag NWs/LIG composites Fully stretchable Energy harvesting and self-powered sensing

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Lower limb motor function assessment based on TensorFlow convolutional neural network and kernel entropy component analysis-local tangent space alignment

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ADVANCES IN MECHANICAL ENGINEERING 2020年第7期12卷

作者： Zhang, Yan Li, SiNing Zhou, Ying Liu, Jian Hebei Univ Technol Sch Artificial Intelligence Tianjin 300310 Peoples R China Hebei Univ Technol Engn Res Ctr Intelligent Rehabil Minist Educ Tianjin Peoples R China Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin Peoples R China

Motor function assessment of patients and the elderly is crucial to gait assessment and gait rehabilitation. Accuracy of the assessment is affected by clinician's experience. To solve the problem, this article proposes motor function assessment index to assess the motor function of patients. VICON system collects video of subjects when they are walking. And the original gait videos are pre-processed by the pixel-based adaptive segmenter and extracted by the convolutional neural network. The kernel entropy component analysis and local tangent space alignment reduced the dimensions of extracted features, and motor function assessment index is obtained. The Pearson correlation analysis shows that the motor function assessment index and modified gait abnormality rating scale are significantly correlated, and Pearson correlation coefficient is 0.92. These effectiveness results demonstrate that the proposed method has the considerable potential to promote the future design of automatic motor function assessment for clinical rehabilitation research.

关键词： Convolutional neural network lower limb motor function assessment transfer learning kernel entropy component analysis local tangent space alignment

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A Microfluidic Concentration Gradient Maker with Tunable Concentration Profiles by Changing Feed Flow Rate Ratios

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MICROMACHINES 2020年第3期11卷 284-284页

作者： Zhang, Tao Meng, Jiyu Li, Shanshan Yu, Chengzhuang Li, Junwei Wei, Chunyang Dai, Shijie Hebei Univ Technol Hebei Key Lab Robot Sensing & Human Robot Interac Sch Mech Engn Tianjin 300132 Peoples R China Hebei Univ Technol Natl Key Lab Reliabil & Elect Equipment Tianjin 300130 Peoples R China Hebei Univ Technol Dept Comp Sci & Elect Engn Langfang 065000 Peoples R China Hebei Univ Technol Inst Biophys Sch Sci Tianjin 300401 Peoples R China

Microfluidic chips-in which chemical or biological fluid samples are mixed into linear or nonlinear concentration distribution profiles-have generated enormous enthusiasm of their ability to develop patterns for drug release and their potential toxicology applications. These microfluidic devices have untapped potential for varying concentration patterns by the use of one single device or by easy-to-operate procedures. To address this challenge, we developed a soft-lithography-fabricated microfluidic platform that enabled one single device to be used as a concentration maker, which could generate linear, bell-type, or even S-type concentration profiles by tuning the feed flow rate ratios of each independent inlet. Here, we present an FFRR (feed flow rate ratio) adjustment approach to generate tens of types of concentration gradient profiles with one single device. To demonstrate the advantages of this approach, we used a Christmas-tree-like microfluidic chip as the demo. Its performance was analyzed using numerical simulation models and experimental investigations, and it showed an excellent time response (similar to 10 s). With on-demand flow rate ratios, the FFRR microfluidic device could be used for many lab-on-a-chip applications where flexible concentration profiles are required for analysis.

关键词： microfluidics concentration gradient nonlinear feed flow rate ratios mixing

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A single-step DNAzyme sensor for ultra-sensitive and rapid detection of Pb²⁺ ions

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ELECTROCHIMICA ACTA 2021年 368卷 137551-137551页

作者： Meng, Jiyu Huang, Jiamei Oueslati, Rania Jiang, Yu Chen, Jiangang Li, Shanshan Dai, Shijie He, Qiang Wu, Jayne Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300132 Peoples R China Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA Univ Tennessee Dept Publ Hlth Knoxville TN 37996 USA Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300130 Peoples R China Univ Tennessee Dept Civil & Environm Engn Knoxville TN 37996 USA

Effective protection from Pb2+ contamination calls for its rapid detection in environmental and biological samples, including water sources. This work demonstrates a rapid, highly sensitive and specific DNAzyme-based Pb2+ biosensor, which is also the first reported label free bioelectronic sensor for catalytic hydrolysis. The sensors are prepared from gold-plated interdigitated electrodes (IDEs), functionalized with oligonucleotide substrate strands and subsequent hybridization with DNAzyme strands. After sample fluid is applied onto a sensor for detection, the sensor's serial capacitance is continuously interrogated by an optimized alternating current (AC) signal for 15 s. If Pb2+ is present, the DNAzyme catalyzes a cleavage reaction of the substrate, releasing the DNAzyme and substrate fragments into the solution. The reaction leaves partial substrate strand at the sensor surface, causing a change in the IDEs' interfacial capacitance. Another novelty here is that capacitance measurement simultaneously induce a fluidic enrichment effect, AC electrothermal effect, thus concentrating and measuring Pb2+ in a single step. The AC signal is carefully optimized to minimize non-specific collection of macromolecules, including released DNAzyme and substrate fragments. In this work, Pb2+ level can be quantified in 15 s with a detection limit of 1.26 fM and a linear dynamic range from 1 fM to 1 pM in analytical buffer. To demonstrate the sensor's specificity, non-target metal ions are tested, all giving negligible responses. Testing of tap water samples collected under different conditions also yields reasonable results, validating the robustness of this sensor. This rapid and sensitive sensor holds high promise for on-site detection of Pb2+ in practical samples. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Heavy metal ion detection Affinity sensor Capacitive sensing AC electrokinetics Interdigitated microelectrodes

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Sensitivity Analysis and Interval Multi Objective Optimization for an Occupant Restraint System Considering Craniocerebral Injury

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JOURNAL OF MECHANICAL DESIGN 2020年第2期142卷 p1-11页

作者： Liu, Qiming Wu, Xingfu Han, Xu Liu, Jie Zhang, Zheyi Guo, Shijie Hebei Univ Technol Sch Elect Engn State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300401 Peoples R China Hunan Univ Coll Mech & Vehicle Engn State Key Lab Adv Design & Mfg Vehicle Body Changsha 410082 Peoples R China Hebei Univ Technol Sch Mech Engn State Key Lab Reliabil & Intelligence Elect Equip Hebei Key Lab Robot Sensing & Human Robot Interac Tianjin 300401 Peoples R China

In vehicle collision accidents, an occupant restraint system (ORS) is crucial to protect the human body from injury, and it commonly involves a large number of design parameters. However, it is very difficult to quantify the importance of design parameters and determine them in the ORS design process. Therefore, an approach of the combination of the proposed approximate sensitivity analysis (SA) method and the interval multi-objective optimization design is presented to reduce craniocerebral injury and improve ORS protection performance. First, to simulate the vehicle collision process and obtain the craniocerebral injury responses, the integrated finite element model of vehicle -occupant (IFEM-VO) is established by integrating the vehicle, dummy, seatbelt, airbag, etc. Then, the proposed approximate SA method is used to quantify the importance ranking of design parameters and ignore the effects of some nonessential parameters. In the SA process, the Kriging meta model characterizing the relationships between design parameters and injury responses is fitted to overcome the time-consuming disadvantage of IFEM-VO. Finally, according to the results of SA, considering the influence of uncertainty, an interval multiobjective optimization design is implemented by treating the brain injury criteria (BRIC, BrIC) as the objectives and regarding the head injury criterion (HIC) and the rotational injury criterion (RIC) as the constraints. Comparison of the results before and after optimization indicates that the maximum values of the translational and rotational accelerations are greatly reduced, and the ORS protection performance is significantly improved. This study provides an effective way to improve the protection performance of vehicle ORS under uncertainty.

关键词： occupant restraint system craniocerebral injury sensitivity analysis interval multi-objective optimization design Kriging metamodel Monte Carlo method uncertainty analysis

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