Most Down Articles

    Published in last 1 year | In last 2 years| In last 3 years| All| Most Downloaded in Recent Month| Most Downloaded in Recent Year|

    Most Downloaded in Recent Month
    Please wait a minute...
    For Selected: Toggle Thumbnails
    Physical Characterization of Ionic Liquid-Modified Polyvinyl Alcohol and Sodium Thiocyanate Polymer Electrolytes for Electrochemical Double-Layer Capacitor Application
    AZEMTSOP Manfo Theodore , MEHRA Ram Mohan , KUMAR Yogesh , GUPTA Meenal
    J Shanghai Jiaotong Univ Sci    2023, 28 (2): 161-171.   DOI: 10.1007/s12204-021-2397-y
    Abstract235)      PDF (1140KB)(94)      
    Novel gel polymer electrolytes (GPEs) composed of polyvinyl alcohol (PVA) and sodium thiocyanate were developed via a solution casting technique. An ionic liquid (IL), 1-ethyl-3-methyl-imidazolium tricyanomethanide ([EMIM][TCM]), was doped into a polymer–salt complex system (PVA + NaSCN) to further enhance the conductivity. IL-doped polymer electrolyte (ILDPE) films were characterized using X-ray diffraction (XRD), polarized optical microscopy (POM), Fourier-transform infrared (FTIR) spectroscopy, and conductivity measurements. XRD was performed to check the degree of crystallinity and amorphicity of the ILDPE films, and the amorphicity of GPEs increased with the increase of the IL content. POM was employed to evaluate the changes in the surface morphology due to the inclusion of salt and IL in the PVA. The compositional nature of the GPE films was examined via FTIR studies. The electrical and electrochemical properties were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The maximum conductivity for the GPE film was estimated to be 1.10 × 10-5 S/cm for 6% (mass fraction) of IL in the polymer–salt complex. The ionic transference number was approximately 0.97. An electrochemical double-layer capacitor (EDLC) was built from optimized GPE films and reduced graphene oxide-based electrodes. The specific capacitance calculated from the cyclic voltammograms of the EDLC cells was 3 F/g.
    Reference | Related Articles | Metrics
    Intelligent-Assist Algorithm for Remote Shared-Control Driving Based on Game Theory
    QIAO Bangjun∗ (乔邦峻), LI Huanghe (李黄河), WU Xiaodong (吴晓东)
    J Shanghai Jiaotong Univ Sci    2021, 26 (5): 615-625.   DOI: 10.1007/s12204-021-2351-z
    Abstract143)      PDF (759KB)(66)      
    Contemporary autonomous-driving technology relies on good environmental-perception systems and high-precision maps. For unknown environments or scenarios where perception fails, a human-in-the-loop remote-driving system can effectively complement common solutions, although safety remains an issue for its application. A haptic shared-control algorithm based on non-cooperative game theory is presented in this paper. The algorithm generates collision-free reference paths with model predictive control and predicts the driver’s path using a two-point preview model. Man-machine torque interaction is modeled as a Nash game, and the assist system’s degree of intervention is regulated in real time, according to assessments of collision risk and the driver’s concentration. Simulations of several representative scenarios demonstrate how the proposed method improves driving safety, while respecting driver decisions.
    Reference | Related Articles | Metrics
    Integrated Hydraulic-Driven Wearable Robot for Knee Assistance
    ZHAO Yafei (赵亚飞), HUANG Chaoyi (黄超逸), ZOU Yuging(邹玉莹), ZOUKehan(邹可涵), zoU Xiaogang(邹笑阳), XUE .Jiaqi(薛嘉琦), LI Xiaoting(李晓婷), KOH Keng Huat, WANG Xiaojun(王小军), LAI Wai Chiu King(赖伟超), HU Yong(胡勇), XI Ning(席宁), WANG Zheng(王峥)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 289-295.   DOI: 10.1007/s12204-023-2602-2
    Abstract60)      PDF (1156KB)(19)      
    Age-related diseases can lead to knee joint misfunction, making knee assistance necessary through the use of robotic wearable braces. However, existing wearable robots face challenges in force transmission and human motion adaptation, particularly among the elderly. Although soft actuators have been used in wearable robots, achieving rapid response and motion control while maintaining portability remains challenging. To address these issues, we propose a soft-robotic knee brace system integrated with multiple sensors and a direct-drive hydraulic actuation system. This approach allows for controlled and rapid force output on the portable hydraulic system. The multi-sensor feedback structure enables the robotic system to collaborate with the human body through human physiological signal and body motion information. The human user tests demonstrate that the knee robot provides assistive torques to the knee joint by being triggered by the electromyography signal and under human motion control.
    Reference | Related Articles | Metrics
    Control System of Two-Wheel Self-Balancing Vehicle
    REN Haoa∗ (任 淏), ZHOU Congb (周 聪)
    J Shanghai Jiaotong Univ Sci    2021, 26 (5): 713-721.   DOI: 10.1007/s12204-021-2361-x
    Abstract212)      PDF (351KB)(50)      
    This study mainly concerns a motion model and the main control algorithm of two-wheel self-balancing vehicle models. Details of the critical parameters fetching and output value of two-wheel self-balancing vehicle models are introduced, including those concerning balance control, speed control and direction control. An improved cascade coupling control scheme is proposed for two-wheel vehicles, based on a proportional-integral-derivative (PID) control algorithm. Moreover, a thorough comparison between a classic control system and the improved system is provided, and all aspects thereof are analyzed. It is determined that the control performance of the two-wheel self-balancing vehicle system based on the PID control algorithm is reliable, enabling the vehicle body to maintain balance while moving smoothly along a road at a fast average speed with better practical per-formance.
    Reference | Related Articles | Metrics
    D2EA: Depict the Epidemic Picture of COVID-19
    LIU Chenzhengyi (刘陈正轶), ZHAO Jingwei (赵经纬), LIU Guohang (刘国航), GAO Yuanning (高远宁), GAO Xiaofeng (高晓沨)
    J Shanghai Jiaotong Univ Sci    2020, 25 (2): 165-176.   DOI: 10.1007/s12204-020-2170-7
    Abstract429)      PDF (748KB)(332)      
    The outbreak of coronavirus disease 2019 (COVID-19) has aroused a global alert. To release social panic and guide future schedules, this article proposes a novel mathematical model, the Delay Differential Epidemic Analyzer (D2EA), to analyze the dynamics of epidemic and forecast its future trends. Based on the traditional Susceptible-Exposed-Infectious-Recovered (SEIR) model, the D2EA model innovatively introduces a set of quarantine states and applies both ordinary differential equations and delay differential equations to describe the transition between two states. Potential variations of practical factors are further considered to reveal the true epidemic picture. In the experiment part, we use the D2EA model to simulate the epidemic in Hubei Province. Fitting to the collected real data as non-linear optimization, the D2EA model forecasts that the accumulated confirmed infected cases in Hubei Province will reach the peak at the end of February and then steady down. We also evaluate the effectiveness of the quarantine measures and schedule the date to reopen Hubei Province.
    Reference | Related Articles | Metrics
    Review on Corrosion Characteristics of Porous Titanium Alloys Fabricated by Additive Manufacturing
    GAI Xin, (盖欣), BAI Yun (白芸), LI Shujun (李述军), WANG Liao (王燎), AI Songtao (艾松涛), HAO Yulin (郝玉琳), YANG Rui (杨锐), DAI Kerong (戴尅戎)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 416-430.   DOI: 10.1007/s12204-021-2314-4
    Abstract216)      PDF (1891KB)(79)      
    Porous titanium and its alloys have been considered as promising implants owing to their low elastic  modulus and capability to provide channels for bone growth. Currently, additive manufacturing (3D printing)  techniques have been successfully applied to produce porous titanium alloys owing to the advantages of controllable  and precise fabrication. Considering the safety aspect, an understanding of corrosion in porous titanium alloys  and the corresponding mechanisms is important for their long-term application in the human body. In this  paper, the recent progress in improving the corrosion properties of porous titanium alloys fabricated via 3D  printing techniques is reviewed. The effects of pore type, porosity, electrolyte, and modification of the material  on the corrosion properties of porous titanium alloys are introduced and discussed. In addition, the limitations of  traditional methods for measuring the corrosion performance of porous titanium alloys were analysed. Perspectives  for evaluating and improving the corrosion performance of porous titanium alloys using new methods are provided. 
    Reference | Related Articles | Metrics
    Ant Colony Algorithm Path Planning Based on Grid Feature Point Extraction
    LI Erchao∗ (李二超), QI Kuankuan (齐款款)
    J Shanghai Jiaotong Univ Sci    2023, 28 (1): 86-99.   DOI: 10.1007/s12204-023-2572-4
    Abstract134)      PDF (1196KB)(77)      
    Aimed at the problems of a traditional ant colony algorithm, such as the path search direction and field of view, an inability to find the shortest path, a propensity toward deadlock and an unsmooth path, an ant colony algorithm for use in a new environment is proposed. First, the feature points of an obstacle are extracted to preprocess the grid map environment, which can avoid entering a trap and solve the deadlock problem. Second, these feature points are used as pathfinding access nodes to reduce the node access, with more moving directions to be selected, and the locations of the feature points to be selected determine the range of the pathfinding field of view. Then, based on the feature points, an unequal distribution of pheromones and a two-way parallel path search are used to improve the construction efficiency of the solution, an improved heuristic function is used to enhance the guiding role of the path search, and the pheromone volatilization coefficient is dynamically adjusted to avoid a premature convergence of the algorithm. Third, a Bezier curve is used to smooth the shortest path obtained. Finally, using grid maps with a different complexity and different scales, a simulation comparing the results of the proposed algorithm with those of traditional and other improved ant colony algorithms verifies its feasibility and superiority.
    Reference | Related Articles | Metrics
    Synthesis and Characterization of Copper Doped Zinc Oxide Thin Films Deposited by RF/DC Sputtering Technique
    KHAN Mohibul, ALAM Md. Shabaz, AHMED Sk. Faruque∗
    J Shanghai Jiaotong Univ Sci    2023, 28 (2): 172-179.   DOI: 10.1007/s12204-022-2462-1
    Abstract120)      PDF (698KB)(39)      
    Undoped and copper (Cu) doped zinc oxide (Zn1-xCuxO, where x = 0—0.065) nano crystal thin films have been deposited on glass substrate via RF/DC reactive co-sputtering technique. The aim of this work is to investigate the crystal structure of ZnO and Cu doped ZnO thin films and also study the effect of Cu doping on optical band gap of ZnO thin films. The identification and confirmation of the crystallinity, film thickness and surface morphology of the nano range thin films are confirmed by using X-ray diffractometer (XRD), scanning electron microscope and atomic force microscope. The XRD peak at a diffractive angle of 34.44° and Miller indices at (002) confirms the ZnO thin films. Crystallite size of undoped ZnO thin films is 27 nm and decreases from 27 nm to 22 nm with increasing the atomic fraction of Cu (xCu) in the ZnO thin films from 0 to 6.5% respectively, which is calculated from XRD (002) peaks. The different bonding information of all deposited films was investigated by Fourier transform infrared spectrometer in the range of wave number between 400 cm-1 to 4 000 cm-1. Optical band gap energy of all deposited thin films was analyzed by ultraviolet visible spectrophotometer, which varies from 3.35 eV to 3.19 eV with the increase of xCu from 0 to 6.5% respectively. Urbach energy of the deposited thin films increases from 115 meV to 228 meV with the increase of xCu from 0 to 6.5% respectively.
    Reference | Related Articles | Metrics
    Strength-Toughness Improvement of 15-5PH Stainless Steel by Double Aging Treatment
    TE Rigele (特日格乐), ZHANG Yutuo, ∗ (张玉妥)
    J Shanghai Jiaotong Univ Sci    2023, 28 (2): 270-279.   DOI: 10.1007/s12204-021-2390-5
    Abstract149)      PDF (3166KB)(46)      
    To obtain better strength-toughness balance of 15-5PH stainless steel, a double aging treatment is proposed to investigate the mechanical properties and microstructure evolution. In this study, Cu precipitates and reversed austenite played a determining role to improve strength-toughness combination. The microstructure was observed using electron backscattered diffraction, transmission electron microscopy and scanning transmission electron microscopy. The volume fractions of Cu precipitates and reversed austenite were calculated with Thermo-Calc software and measured by X-ray diffraction. The results showed that the reversed austenite is formed at the martensitic lath boundaries and its volume fraction also increases with the increase of the aging temperature. At the same time, the size of the Cu precipitates gradually increases. Compared with the traditional single aging and double aging treatment, double aging treatment of 15-5PH stainless steel can increase the toughness while retaining the necessary strength. During double aging of 550 ℃ × 4 h + 580 ℃ × 1 h, 15-5PH stainless steel has the best strength and low-temperature (- 40 ℃) toughness match. Its yield strength, ultimate tensile strength and the Charpy impact energy are 1.037 GPa, 1.086 GPa and 179 J, respectively.
    Reference | Related Articles | Metrics
    Target Detection Algorithm Based On Human Judge Mechanism
    SHI Jichao1 (石继超), WANG Ziheng2 (王子恒), ZHAO Xianchao1 (赵现朝), ZHANG Zhinan1∗ (张执南)
    J Shanghai Jiaotong Univ Sci    2022, 27 (5): 660-670.   DOI: 10.1007/s12204-022-2450-5
    Abstract132)      PDF (1795KB)(26)      
    A D-G-YOLOV3 algorithm was proposed to identify and judge recyclables, which introduced a dense feature network to replace the feature pyramid network. The network closely connects and fits the feature maps and simulates human judgment mechanism. A three-stage judgment is made for judgment objects with lower confidence. Based on the judgment of the original image, the second-stage judgment is carried out after the channel contrast is increased. Finally, sampling is performed on the region of interest where the second-stage confidence score wins for the third stage of judgment, and then judgment result is sent to the gated recurrent unit network for final inference. The result shows that through experiments on the same recyclables data set, the algorithm reduces the missed detection rate by 15.54%, and the false detection rate by 0.97%, while improves the accuracy rate by 16.51%.
    Reference | Related Articles | Metrics
    Improvement of Physical Fitness Test Assessment Criteria Based on fNIRS Technology: Taking Pull-Up as an Example
    GONG Bin(巩斌), YU Xianghua(禹香华), FANG Yu (方宇), WANG Zheng (王正), YANG Hao (杨皓), CHEN Guodong (陈国栋), L Ü Na (吕娜)
    J Shanghai Jiaotong Univ Sci    2022, 27 (2): 219-225.   DOI: 10.1007/s12204-021-2367-4
    Abstract169)      PDF (1855KB)(74)      
    Pull-up, as an important physical fitness test event of the “National Student Physical Health Standard”, is known as a difficult physical fitness test event. To improve the assessment criteria of pull-ups, this paper uses the functional near-infrared spectroscopy (fNIRS) to monitor the changes and activation of oxyhemoglobin (HbO) signals in the brain motor cortex of people with different body mass indexes (BMIs) during the pullup assessment. Then the relationship between BMIs and evaluation criteria is discussed. After collecting and analyzing experimental data of 18 recruited college students, it is found that the number of pull-ups performed by people with different BMIs is different when they reach the peak state of brain activation. The results of the study indicate that different assessment criteria should be adopted for different BMI groups. It is suggested that the BMI should be introduced as one of the test indexes in the examination of pull-ups event in “National Student Physical Health Standard”.
    Reference | Related Articles | Metrics
    A Novel RRAM Based PUF for Anti-Machine Learning Attack and High Reliability
    DAI Lan *(戴澜), YAN Qiangqiang (闫强强), YI Shengyu (易盛禹), LIU Wenkai (刘文楷), QIAN He (钱鹤)
    Journal of Shanghai Jiao Tong University (Science)    2019, 24 (1): 101-106.   DOI: 10.1007/s12204-019-2043-0
    Abstract363)      PDF (2475KB)(108)      
    Due to the unique response mechanism, physical unclonable function (PUF) has been extensively studied as a hardware security primitive. And compared to other PUFs, the resistive random access memory (RRAM) based PUF has more flexibility with the change of conductive filaments. In this work, we propose an exclusive or (XOR) strong PUF based on the 1Kbit 1-transistor-1-resistor (1T1R) arrays, and unlike the traditional RRAM based strong PUF, the XOR PUF has a stronger anti-machine learning attack ability in our experiments. The reliability of XOR RRAM PUF is determined by the read instability, thermal dependence of RRAM resistance, and aging. We used a split current distribution scheme to make the reliability of XOR PUF significantly improved. After baking for 50 h at a high temperature of 150?C, the intra-chip Hamming distance (Intra-HD) only increased from 0 to 4.5%. The inter-chip Hamming distance (Inter-HD) and uniformity are close to 50% (ideally). And it is proven through the NIST test that XOR PUF has a high uniqueness.
    Reference | Related Articles | Metrics
    Biomechanical Analysis of Personalised 3D-Printed Clavicle Plates of Different Materials to Treat Midshaft Clavicle Fractures
    CHENG Rongshan, (程荣山), JIANG Ziang, (蒋子昂), DIMITRIOU Dimitris, GONG Weihua, (龚伟华), TSAI Tsung-Yuan, (蔡宗远)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 259-266.   DOI: 10.1007/s12204-021-2291-7
    Abstract310)      PDF (1656KB)(120)      
    This study was aimed at comparing the biomechanical performance of personalised 3D-printed clavicle  plates of different materials to treat midshaft clavicle fractures with the finite element (FE) method. The FE  model of a fractured clavicle with a personalised 3D-printed clavicle plate and screws was constructed. Three  types of materials were simulated, including stainless steel, titanium alloy, and magnesium alloy. Two loading  conditions (axial compression and inferior bending) were applied at the distal end of the clavicle to simulate arm  abduction. Plate stiffness, peak stress, and bone strain at the clavicle fracture site were measured and compared.  The stiffness of the stainless steel clavicle plate was significantly greater than that of the titanium alloy clavicle  plate. The stiffness of the magnesium alloy clavicle plate was similar to that of the intact clavicle; peak stress  of the magnesium alloy clavicle plate was the lowest; thus, it had less stress-shielding effects on bone formation.  The magnesium alloy clavicle plate was more likely to form bone by distributing proper strain at the clavicle  fracture site. According to the influence of different materials on the tensile strength, magnesium alloy clavicle  plates might be preferred owing to their bionic stiffness in the treatment of patients with a low risk of falling. For  patients who engage in contact sports, a titanium alloy clavicle plate might be more suitable.
    Reference | Related Articles | Metrics
    Simulation of Bimodal Fiber Distribution Effect on Transient Accumulation of Particles During Filtration
    AKAMPUMUZA Obed, WU Jiajun (吴佳骏), QUAN Zhenzhen (权震震), QIN Xiaohong (覃小红)
    J Shanghai Jiaotong Univ Sci    2021, 26 (2): 176-185.   DOI: 10.1007/s12204-020-2251-7
    Abstract231)      PDF (1849KB)(39)      
    Modeling has become phenomenal in developing new products. In the case of filters, one of the most applied procedures is via the construction of idealized physical computational models bearing close semblance to real filter media. It is upon these that multi-physics tools were applied to analyze the flow of fluid and the resulting typical performance parameters. In this work, two 3D filter membranes were constructed with MATLAB; one had a random distribution of unimodal nanofibers, and the other, a novel modification, formed a bimodal distribution; both of them had similar dimensions and solid volume fractions. A comparison of their performance in a dust-loading environment was made by using computational fluid dynamic-discrete element method (CFD-DEM) coupling technique in STAR-CCM+. It was found that the bimodal nanofiber membrane greatly improved the particle capture efficiency. Whereas this increased the pressure drop, the gain was not too significant. Thus, overall, the results of the figure of merit proved that adopting a bimodal formation improved the filter's quality.
    Reference | Related Articles | Metrics
    Development of Rehabilitation and Assistive Robots in China: Dilemmas and Solutions
    ZHAO Lingling1*(赵玲玲),GUO Yao2(郭遥)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 382-390.   DOI: 10.1007/s12204-023-2596-9
    Abstract27)      PDF (367KB)(8)      
    China is rapidly becoming an aging society, leading to a significant demand for chronic disease management and personalized healthcare. The development of rehabilitation and assistive robotics in China has gathered significant attention not only in research fields but also in industries. Such robots aim to either guide patients in completing therapeutic training or assist people with impaired functions in performing their daily activities. In the past decades, we have witnessed the advancement in rehabilitation and assistive robotics, with diverse mechanical designs, functionalities, and purposes. However, the construction of dedicated regulations and policies is relatively lagged compared with the flourishing development in research fields. Moreover, these kinds of robots are working or collaborating closely with human beings, bringing unprecedented considerations on ethical issues. This paper aims to provide an overview of major dilemmas in the development of rehabilitation and assistive robotics in China and propose several potential solutions.
    Reference | Related Articles | Metrics
    Exergy Analysis of Direct-Expansion Solar-Assisted Heat Pump Based on Experimental Data
    KONG Xiangqiang (孔祥强), CUI Fulin (崔福林), LI Jianbo (李见波), ZHANG Maoyuan (张茂远)
    J Shanghai Jiaotong Univ Sci    2021, 26 (2): 138-145.   DOI: 10.1007/s12204-020-2228-6
    Abstract249)      PDF (948KB)(71)      
    The purpose of this research is to reveal the exergy variation of each component in a direct-expansion solar-assisted heat pump (DX-SAHP) system. Exergy analysis of the DX-SAHP system with R134a is conducted,and the performance evaluation is done. The proposed system is mainly composed of a bare plate solar collector/evaporator, a hermetic variable-frequency rotary-type compressor, a micro-channel condenser and an electronic expansion valve. The experimental data include the exergy loss rates, irreversibility rates and exergy loss ratios of all components and the influences of ambient temperature on these parameters. The analysis results show that the average irreversibility rate of the compressor is 204.8 W at an ambient temperature of 16 °C, and 149.9 W at an ambient temperature of 27 °C. The highest irreversibility rate occurs in the compression process, followed by the throttling process, the evaporation process and the condensation process.

    Reference | Related Articles | Metrics
    Two Generative Design Methods of Hospital Operating Department Layouts Based on Healthcare Systematic Layout Planning and Generative Adversarial Network
    ZHAO Chaowang (赵朝望), YANG Jian (杨健), XIONG Wuyue (熊吴越), LI Jiatong (李佳潼)
    J Shanghai Jiaotong Univ Sci    2021, 26 (1): 103-115.   DOI: 10.1007/s12204-021-2265-9
    Abstract420)      PDF (1551KB)(121)      
    With the increasing demands of health care, the design of hospital buildings has become increasingly demanding and complicated. However, the traditional layout design method for hospital is labor intensive, time consuming and prone to errors. With the development of artificial intelligence (AI), the intelligent design method has become possible and is considered to be suitable for the layout design of hospital buildings. Two intelligent design processes based on healthcare systematic layout planning (HSLP) and generative adversarial network (GAN) are proposed in this paper, which aim to solve the generation problem of the plane functional layout of the operating departments (ODs) of general hospitals. The first design method that is more like a mathematical model with traditional optimization algorithm concerns the following two steps: developing the HSLP model based on the conventional systematic layout planning (SLP) theory, identifying the relationship and flows amongst various departments/units, and arriving at the preliminary plane layout design; establishing mathematical model to optimize the building layout by using the genetic algorithm (GA) to obtain the optimized scheme. The specific process of the second intelligent design based on more than 100 sets of collected OD drawings includes: labelling the corresponding functional layouts of each OD plan; building image-to-image translation with conditional adversarial network (pix2pix) for training OD plane layouts, which is one of the most representative GAN models. Finally, the functions and features of the results generated by the two methods are analyzed and compared from an architectural and algorithmic perspective. Comparison of the two design methods shows that the HSLP and GAN models can autonomously generate new OD plane functional layouts. The HSLP layouts have clear functional area adjacencies and optimization goals, but the layouts are relatively rigid and not specific enough. The GAN outputs are the most innovative layouts with strong applicability, but the dataset has strict constraints. The goal of this paper is to help release the heavy load of architects in the early design stage and present the effectiveness of these intelligent design methods in the field of medical architecture.

    Reference | Related Articles | Metrics
    Game Theory Based Sensor Management in Reducing Target Threat Level Assessment Risk
    PANG Ce∗ (庞策), SHAN Ganlin (单甘霖)
    J Shanghai Jiaotong Univ Sci    2022, 27 (5): 649-659.   DOI: 10.1007/s12204-021-2372-7
    Abstract138)      PDF (822KB)(28)      
    Sensor management schemes are calculated to reduce target threat level assessment risk in this paper. Hidden Markov model and risk theory are combined to build the target threat level model firstly. Then the target threat level estimation risk is defined. And the sensor management schemes are optimized with the smallest target threat level assessment risk. What’s more, the game theory is applied to calculate the optimal sensor management scheme. Some simulations are conducted to prove that the proposed sensor management method is effective.
    Reference | Related Articles | Metrics
    Shape Sensing for Single-Port Continuum Surgical Robot Using Few Multicore Fiber Bragg Grating Sensors
    LI Dingjia1,2,3,4(黎定佳),WANG Chongang1,2,3(王重阳),GUO Wei5(郭伟),WANG Zhidong6(王志东),ZHANG Zhongtao5(张忠涛),LIU Hao1,2,3*(刘浩)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 312-322.   DOI: 10.1007/s12204-023-2579-x
    Abstract42)      PDF (2606KB)(7)      
    We proposed a method for shape sensing using a few multicore fiber Bragg grating (FBG) sensors in a single-port continuum surgical robot (CSR). The traditional method of utilizing a forward kinematic model to calculate the shape of a single-port CSR is limited by the accuracy of the model. If FBG sensors are used for shape sensing, their accuracy will be affected by their number, especially in long and flexible CSRs. A fusion method based on an extended Kalman filter (EKF) was proposed to solve this problem. Shape reconstruction was performed using the CSR forward kinematic model and FBG sensors, and the two results were fused using an EKF. The CSR reconstruction method adopted the incremental form of the forward kinematic model, while the FBG sensor method adopted the discrete arc-segment assumption method. The fusion method can eliminate the inaccuracy of the kinematic model and obtain more accurate shape reconstruction results using only a small number of FBG sensors. We validated our algorithm through experiments on multiple bending shapes under different load conditions. The results show that our method significantly outperformed the traditional methods in terms of robustness and effectiveness.
    Reference | Related Articles | Metrics
    Camera-Radar Fusion Sensing System Based on Multi-Layer Perceptron
    YAO Tong (姚 彤), WANG Chunxiang(王春香), QIAN Yeqiang(钱烨强)
    J Shanghai Jiaotong Univ Sci    2021, 26 (5): 561-568.   DOI: 10.1007/s12204-021-2345-x
    Abstract288)      PDF (1189KB)(182)      
    Environmental perception is a key technology for autonomous driving. Owing to the limitations of a single sensor, multiple sensors are often used in practical applications. However, multi-sensor fusion faces some problems, such as the choice of sensors and fusion methods. To solve these issues, we proposed a machine learning-based fusion sensing system that uses a camera and radar, and that can be used in intelligent vehicles. First, the object detection algorithm is used to detect the image obtained by the camera; in sequence, the radar data is preprocessed, coordinate transformation is performed, and a multi-layer perceptron model for correlating the camera detection results with the radar data is proposed. The proposed fusion sensing system was verified by comparative experiments in a real-world environment. The experimental results show that the system can effectively integrate camera and radar data results, and obtain accurate and comprehensive object information in front of intelligent vehicles.
    Reference | Related Articles | Metrics
    Using a Patient-Specific 3D-Printed Surgical Guide for High Tibial Osteotomy: A Technical Note
    JIANG Xu, (江旭), XIE Kai (谢凯), LI Bo (李波), HU Xumin (胡旭民), WU Haishan (吴海山), GAO Liangbin (高梁斌), WANG Liao (王燎), YAN Mengning (严孟宁)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 339-345.   DOI: 10.1007/s12204-021-2302-8
    Abstract258)      PDF (1004KB)(95)      
    Patient-specific instrumentation (PSI) enables a more accurate alignment of the lower limbs in a high  tibial osteotomy (HTO) than in traditional surgery; however, the current design of commercial PSIs is not perfect.  Therefore, we designed a new patient-specific surgical guide to improve the accuracy of the osteotomy and verified  its reliability through a clinical operation. Here, we describe a patient with isolated medial-compartment bilateral  knee osteoarthritis, accompanied by a varus deformity of the proximal tibia. The patient was treated with HTO  using a patient-specific 3D-printed surgical guide. We concluded that the patient-specific 3D-printed surgical  guide improved the accuracy of the osteotomy and the alignment of the lower limb. 
    Reference | Related Articles | Metrics
    Spatial Temporal Correlation 3D Vehicle Detection and Tracking System with Multiple Surveillance Cameras
    XUE Weipeng (薛炜彭), WU Minghu (吴明虎), WANG Lin∗ (王 琳)
    J Shanghai Jiaotong Univ Sci    2023, 28 (1): 52-60.   DOI: 10.1007/s12204-023-2567-1
    Abstract88)      PDF (1375KB)(29)      
    Compared to 3D object detection using a single camera, multiple cameras can overcome some limitations on field-of-view, occlusion, and low detection confidence. This study employs multiple surveillance cameras and develops a cooperative 3D object detection and tracking framework by incorporating temporal and spatial information. The framework consists of a 3D vehicle detection model, cooperatively spatial-temporal relation scheme, and heuristic camera constellation method. Specifically, the proposed cross-camera association scheme combines the geometric relationship between multiple cameras and objects in corresponding detections. The spatial-temporal method is designed to associate vehicles between different points of view at a single timestamp and fulfill vehicle tracking in the time aspect. The proposed framework is evaluated based on a synthetic cooperative dataset and shows high reliability, where the cooperative perception can recall more than 66% of the trajectory instead of 11% for single-point sensing. This could contribute to full-range surveillance for intelligent transportation systems.
    Reference | Related Articles | Metrics
    Wavelet Transform-Based High-Definition Map Construction From a Panoramic Camera
    ZHUANG Hanyang (庄瀚洋), ZHOU Xuejun (周学军), WANG Chunxiang (王春香), QIAN Yuhan (钱宇晗)
    J Shanghai Jiaotong Univ Sci    2021, 26 (5): 569-576.   DOI: 10.1007/s12204-021-2346-9
    Abstract222)      PDF (1242KB)(82)      
    High-definition (HD) maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems. A complete ground orthophoto is usually used as the base image to construct the HD map. The ground orthophoto is obtained through inverse perspective transformation and image mosaicing. During the image mosaicing, multiple consecutive orthophotos are stitched together using pose information and image registration. In this study, wavelet transform is introduced to the image mosaicing process to alleviate the information loss caused by image overlapping. In the orthophoto wavelet transform, high-frequency and low-frequency components are fused using different strategies to form a complete base image with clearer local details. Experimental results show that the accuracy of the orthophotos generated using this method is improved.
    Reference | Related Articles | Metrics
    Novel Data Placement Algorithm for Distributed Storage System  Based on Fault-Tolerant Domain
    SHI Lianxing (石连星), WANG Zhiheng (王志恒), LI Xiaoyong (李小勇)
    J Shanghai Jiaotong Univ Sci    2021, 26 (4): 463-470.   DOI: 10.1007/s12204-020-2253-5
    Abstract222)      PDF (1240KB)(70)      
    The 3-replica redundancy strategy is widely used to solve the problem of data reliability in large-scale distributed storage systems. However, its storage capacity utilization is only 33%. In this paper, a data placement algorithm based on fault-tolerant domain (FTD) is proposed. Owing to the fine-grained design of the FTD, the data reliability of systems using two replicas is comparable to that of current mainstream systems using three replicas, and the capacity utilization is increased to 50%. Moreover, the proposed FTD provides a new concept for the design of distributed storage systems. Distributed storage systems can take FTDs as the units for data placement, data migration, data repair and so on. In addition, fault detection can be performed independently and concurrently within the FTDs.

    Reference | Related Articles | Metrics
    Binary-Sequence Frequency Hopping Communication Method Based on Pseudo-Random Linear Frequency Modulation
    TANG Zhiqiang (唐志强), QUAN Houde (全厚德), SUN Huixian (孙慧贤), CUI Peizhang (崔佩璋)
    J Shanghai Jiaotong Univ Sci    2021, 26 (4): 534-542.   DOI: 10.1007/s12204-020-2250-8
    Abstract241)      PDF (949KB)(48)      
    To improve the signal detection performance of binary-sequence frequency hopping communication when the complementary channel is jammed, a binary-sequence frequency hopping communication system based on pseudo-random liner frequency modulation (LFM) is proposed. The transmitting end uses the chirp signal to carry out the in-band spread spectrum of the binary-sequence frequency hopping signal, and then sends it out through the radio frequency front end. At the receiving end, the received signal is dehopped and processed by fractional Fourier transform. The source information is obtained by sampling decision. Firstly, a binarysequence frequency hopping system model based on pseudo-random LFM is constructed. Secondly, the bit error rate expression of anti-partial band jamming and follower jamming under the Rice channel is derived. The results show that this method has at least 5 dB performance gain than binary sequence frequency hopping for different parameter settings under partial band jamming and follower jamming, and the anti-jamming performance is significantly better than the conventional frequency hopping communication.

    Reference | Related Articles | Metrics
    Enhancement of Pinching Grasping Robustness Using a Multi-Structure Soft Gripper
    LI Linlin (李林霖), GAO Feiyang (高飞扬), ZHENG Xiongfei(郑雄飞), ZHANG Liming(张黎明), LI Shijie (李世杰), WANG Heran(王赫然)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 307-311.   DOI: 10.1007/s12204-022-2508-4
    Abstract46)      PDF (2071KB)(6)      
    Recently, soft grippers have garnered considerable interest in various fields, such as medical rehabilitation, due to their high compliance. However, the traditional PneuNet only reliably grasps medium and large objects via enveloping grasping (EG), and cannot realize pinching grasping (PG) to stably grasp small and thin objects as EG requires a large bending angle whereas PG requires a much smaller one. Therefore, we proposed a multi-structure soft gripper (MSSG) with only one vent per finger which combines the PneuNet in the proximal segment with the normal soft pneumatic actuator (NSPA) in the distal segment, allowing PG to be realized without a loss in EG and enhancing the robustness of PG due to the height difference between the distal and proximal segments. Grasping was characterized on the basis of the stability (finger bending angle describes) and robustness (pull-out force describes), and the bending angle and pull-out force of MSSG were analyzed using the finite element method. Furthermore, the grasping performance was validated using experiments, and the results demonstrated that the MSSG with one vent per finger was able to realize PG without a loss in EG and effectively enhance the PG robustness.
    Reference | Related Articles | Metrics
    Application of 3D Printing and WebGL-Based 3D Visualisation Technology in Imaging Teaching of Ankle Joints
    LI Xiaomin (李小敏), DAI Xiaoqing(戴晓庆), GUO Jiuhong (郭久红), QU Yang (曲扬), WU Bing (吴兵), LIU Siyu (柳思宇), WAN Daqian (万大千), AI Songtao(艾松涛)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 319-324.   DOI: 10.1007/s12204-021-2299-z
    Abstract286)      PDF (344KB)(59)      
     With the rapid development of medical technology, 3D printing technology with realistic representation  can perfectly display static human anatomy, while 3D visualisation technology based on Web Graphics Library  (WebGL) can promote the rigid replication characteristics of traditional teaching models and express the dynamic  spatial relationship between different anatomical structures. Medical students traditionally have less cognition of  ankle ligament sprains. In this study, computed tomography (CT) and magnetic resonance imaging (MRI) data of  the ankle joints of volunteers were used to print models of the ankle bone, tendon, and ligament using 3D printing  technology, and a real-time interactive 3D digital model of the functional ankle joint was designed using 3D  visualisation based on WebGL and 2D image real-time rendering technology for interactive teaching. The utility  of the 3D printing model combined with the WebGL-based 3D digital teaching model was evaluated in comparison  with traditional teaching methods in 24 medical students. The results showed that the total score of students  in the experimental group (mean ± SD, 79.48 ± 12.93) was significantly better than that of the control group  (61.00±14.94) with P <0.05. The practical test scores of the experimental group (18.00±2.70) were significantly  higher than those of the control group (13.67 ± 4.96) with P < 0.05. In the satisfaction survey, the feedback  questionnaire showed that the interactive teaching model of 3D printing technology combined with WebGL-based  3D visualisation technology was recognised by students in terms of quality and overall satisfaction. In addition,  female students who used 3D printing combined with WebGL-based 3D visualisation technology as learning aids  had a greater difference in practical test scores from the control group than male students. This study has  demonstrated that the interactive teaching mode of 3D printing combined with WebGL-based 3D visualisation  technology is beneficial to the teaching of medical imaging, enriching the learning experience of students, and  increasing the interaction between teachers and students.
    Reference | Related Articles | Metrics
    Prediction of COVID-19 Outbreak in China and Optimal Return Date for University Students Based on Propagation Dynamics
    HUANG Ganyu (黄甘雨), PAN Qiaoyi (潘荍仪), ZHAO Shuangying (赵双楹), GAO Yucen (高宇岑), GAO Xiaofeng (高晓沨)
    J Shanghai Jiaotong Univ Sci    2020, 25 (2): 140-146.   DOI: 10.1007/s12204-020-2167-2
    Abstract546)      PDF (550KB)(328)      
    On 12 December 2019, a novel coronavirus disease, named COVID-19, began to spread around the world from Wuhan, China. It is useful and urgent to consider the future trend of this outbreak. We establish the 4+1 penta-group model to predict the development of the COVID-19 outbreak. In this model, we use the collected data to calibrate the parameters, and let the recovery rate and mortality change according to the actual situation. Furthermore, we propose the BAT model, which is composed of three parts: simulation of the return rush (Back), analytic hierarchy process (AHP) method, and technique for order preference by similarity to an ideal solution (TOPSIS) method, to figure out the best return date for university students. We also discuss the impacts of some factors that may occur in the future, such as secondary infection, emergence of effective drugs, and population flow from Korea to China.
    Reference | Related Articles | Metrics
    Fabrication and Performance Investigation of Karma Alloy Thin Film Strain Gauge
    LEI Peng (雷鹏), ZHANG Congchun (张丛春), PANG Yawen (庞雅文), YANG Shenyong (杨伸勇), ZHANG Meiju (张梅菊)
    J Shanghai Jiaotong Univ Sci    2021, 26 (4): 454-462.   DOI: 10.1007/s12204-021-2315-3
    Abstract267)      PDF (1164KB)(72)      
    Karma alloy thin film strain gauges were fabricated on alumina substrates by magnetron sputtering. The electrical properties of strain gauges annealed at different temperatures were then tested. The surface morphology and phase structure of the Karma alloy thin films were analyzed using X-ray diffraction and scanning electron microscopy. The effect of the annealing temperature on the performance of the Karma alloy thin film strain gauge was also investigated. As the annealing temperature increased, it was found that the resistivity of the thin films decreased, whereas the temperature coefficient of resistance (TCR) of the thin films increased. A Karma alloy thin film strain gauge was annealed at 200 °C, thereby obtaining a gauge factor of 1.7 and a corresponding TCR of 64.8 × 10-6 K-1. The prepared Karma alloy thin film strain gauge had a lower TCR than other strain gauges at room temperature. This result can provide a reference for the preparation and application of Karma alloy thin film strain gauges in specific scenarios.
    Reference | Related Articles | Metrics
    Progress in Force-Sensing Techniques for Surgical Robots
    GAO Hongyan1,2(高红岩),AI Xiaojie1,2(艾孝杰),SUN Zhenglong3(孙正隆),CHEN Weidong1,2(陈卫东),GAO Anzhu1,2*(高安柱)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 370-381.   DOI: 10.1007/s12204-023-2607-x
    Abstract26)      PDF (1017KB)(6)      
    Force sensing is vital for situational awareness and safe interaction during minimally invasive surgery. Consequently, surgical robots with integrated force-sensing techniques ensure precise and safe operations. Over the past few decades, there has been considerable progress in force-sensing techniques for surgical robots. This review summarizes the existing electrically- and optically-based force sensors for surgical robots, including piezoresistive, piezoelectric, capacitive, intensity/phase-modulated, and fiber Bragg gratings. Their principles, applications, advantages, and limitations are also discussed. Finally, we summarize our conclusions regarding state-of-the-art force-sensing technologies for surgical robotics.
    Reference | Related Articles | Metrics
    High-Performance Single-Side Fabricated (111)-Silicon Dual-Cantilever Accelerometer with Squeeze-Film Air Damping Modulation
    JIAO Ding (焦 鼎), NI Zao (倪 藻), WANG Jiachou (王家畴), LI Xinxin∗ (李昕欣)
    J Shanghai Jiaotong Univ Sci    2023, 28 (2): 197-206.   DOI: 10.1007/s12204-021-2288-2
    Abstract77)      PDF (1510KB)(27)      
    This study proposes a novel design and micromachining process for a dual-cantilever accelerometer. Comb and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping, thus effectively optimizing the response frequency bandwidth. Owing to the high stress concentration on the dual-cantilever integrated with a fully sensitive piezoresistive Wheatstone bridge, a high sensitivity to acceleration is achieved. In addition, the dual-cantilever accelerometer is fabricated using a specifically developed low-cost and high-yield (111)-silicon single-side bulk-micromachining process. The test results show that the proposed dualcantilever accelerometer exhibits a sensitivity of 0.086—0.088 mV/g/3.3 V and a nonlinearity of ±(0.09%—0.23%) FS (full-scale). Based on dynamic characterization, an adequate frequency bandwidth of 2.64 kHz is verified. Furthermore, a resonant frequency of 4.388 kHz is measured, and a low quality factor (Q) of 7.62 is obtained, which agrees well with the design for air-damping modulation. The achieved high performance renders the proposed dual-cantilever accelerometer promising in applications such as automotive and consumer electronics.
    Reference | Related Articles | Metrics
    Eye Robotic System for Vitreoretinal Surgery
    DAI Qianlin (代倩琳), XU Mengqiao (徐梦乔), SUN Xiaodong (孙晓东), XIE Le∗ (谢叻)
    J Shanghai Jiaotong Univ Sci    2022, 27 (1): 1-6.   DOI: 10.1007/s12204-021-2369-2
    Abstract420)      PDF (1040KB)(247)      
    Micro incision vitrectomy system (MIVS) is considered to be one of the most difficult tasks of eye surgery, due to its requirements of high accuracy and delicate operation under blurred vision environment. Therefore, robot-assisted ophthalmic surgery is a potential and efficient solution. Based on that consideration, a novel master-slave system for vitreoretinal surgery is realized. A 4-DOF remote center of motion (RCM) mechanism with a novel linear stage and end-effector is designed and the master-slave control system is implemented. The forward and inverse kinematics are analyzed for the controller implementation. Then, algorithms with motion scaling are also integrated into the control architecture for the purpose to enhance the surgeon’s operation accuracy. Finally, experiments on an eye model are conducted. The results show that the eye robotic system can fulfill surgeon’s motion following and simulate operation of vitrectomy, demonstrating the feasibility of this system.
    Reference | Related Articles | Metrics
    Velocity-Varying Target Tracking of Mobile Sensor Network Based on Flocking Control
    ZHANG Lulu (章露露), DONG Xiangxiang (董祥祥), YAO Lixiu (姚莉秀), CAI Yunze (蔡云泽)
    J Shanghai Jiaotong Univ Sci    2021, 26 (4): 446-453.   DOI: 10.1007/s12204-021-2283-7
    Abstract298)      PDF (481KB)(83)      
    Existing coupled distributed estimation and motion control strategies of mobile sensor networks present limitations in velocity-varying target tracking. Therefore, a velocity-varying target tracking algorithm based on flocking control is proposed herein. The Kalman-consensus filter is utilized to estimate the position, velocity and acceleration of a target. The flocking control algorithm with a velocity-varying virtual leader enables the position of the center of the mobile sensor network to converge to that of the target. By applying an effective cascading Lyapunov method, stability analysis is performed. Simulation results are provided to validate the feasibility of the proposed algorithm.

    Reference | Related Articles | Metrics
    Travel Intention of Electric Vehicle Sharing based on Theory of Multiple Motivations
    BAO Lewen (鲍乐雯), MIAO Rui, ∗ (苗 瑞), CHEN Zhihua (陈志华), ZHANG Bo (张 博), GUO Peng (郭 鹏), MA Yuze (马宇泽)
    J Shanghai Jiaotong Univ Sci    2023, 28 (1): 1-9.   DOI: 10.1007/s12204-023-2563-5
    Abstract268)      PDF (467KB)(107)      
    Determining the travel intention of residents with shared electric vehicles (EVs) is significant for promoting the development of low-carbon transportation, considering that common problems such as high idle rate and lack of attractiveness still exist. To this end, a structural equation model (SEM) based on the theory of multiple motivations is proposed in this paper. First, the influencing motivations for EV sharing are divided into three categories: consumer-driven, program-driven, and enterprise-driven motivations. Then, the intentions of residents in Shanghai to travel with shared EVs are obtained through a survey questionnaire. Finally, an SEM is constructed to analyze quantitatively the impact of different motivations on the travel intention. The results show that consumer-driven motivations with impact weights from 0.14 to 0.63 have the overwhelming impact on travel intention, compared to program-driven motivations with impact weights from ?0.14 to 0.15 and enterprise-driven motivations with impact weights from 0.02 to 0.06. In terms of consumer-driven motivations, the weight of green travel awareness is the highest. The implications of these results on the policy to enable large-scale implementation of shared EVs are discussed from the perspectives of the resident, enterprise, and government.
    Reference | Related Articles | Metrics
    Collision-Free Path Planning with Kinematic Constraints in Urban Scenarios
    WANG Liang (王 亮), WANG Bing (王 冰), WANG Chunxiang∗ (王春香)
    J Shanghai Jiaotong Univ Sci    2021, 26 (5): 731-738.   DOI: 10.1007/s12204-021-2363-8
    Abstract247)      PDF (2199KB)(99)      
    In urban driving scenarios, owing to the presence of multiple static obstacles such as parked cars and roadblocks, planning a collision-free and smooth path remains a challenging problem. In addition, the path-planning problem is mostly non-convex, and contains multiple local minima. Therefore, a method for combining a sampling-based method and an optimization-based method is proposed in this paper to generate a collision-free path with kinematic constraints for urban scenarios. The sampling-based method constructs a search graph to search for a seeding path for exploring a safe driving corridor, and the optimization-based method constructs a quadratic programming problem considering the desired state constraints, continuity constraints, driving corridor constraints, and kinematic constraints to perform path optimization. The experimental results show that the proposed method is able to plan a collision-free and smooth path in real time when managing typical urban scenarios.
    Reference | Related Articles | Metrics
    Total Talar Replacement Using a Novel 3D-Printed Prosthesis for Recurrent Giant Cell Tumour of the Talus
    GAN Yaokai (干耀恺), DAI Kerong (戴尅戎), LI Jianying (李健瑛), SHI Dingwei (史定伟), SHEN Lu (沈陆), JIANG Wenbo (姜闻博)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 391-397.   DOI: 10.1007/s12204-021-2310-8
    Abstract317)      PDF (1816KB)(34)      
    In our case, 3D printing was used to fabricate a custom-made titanium alloy total talar prosthesis as  a mirror image of the contralateral healthy talus for a 16-year-old girl who underwent right talar resection for a  recurrent giant cell tumour (GCT) of the talus. A porous surface was used over the neck and tail of the talus  prosthesis to promote soft tissue attachment and improve the stability of the prosthesis. Pre-drilled medial and  lateral holes were prepared for ligament repair and attachment. Eighteen months after the operation, there was  no tumour recurrence, and the patient walked without symptoms. The Musculoskeletal Tumour Society score was  22/30, the American Orthopaedic Foot and Ankle Society score was 88/100, and the prosthesis was well positioned  on radiographs. The short- and medium-term outcomes indicated that 3D-printed modular talar prostheses could  be an effective treatment option. 
    Reference | Supplementary Material | Related Articles | Metrics
    Novel Concentric Tube Robot Based on Double-Threaded Helical Gear Tube
    CHEN Weichi(陈韦池), LIU Haocheng(刘浩城), LI Zijian(李子建), GUO Jing, (郭靖), ZHAI Zhenkun(翟振坤), MENG Wei(孟伟)
    J Shanghai Jiaotong Univ Sci    2023, 28 (3): 296-306.   DOI: 10.1007/s12204-023-2595-x
    Abstract53)      PDF (2087KB)(6)      
    Nasopharyngeal carcinoma is a malignant tumor originating from the nasal mucosa. It is a malignant tumor of the head and neck. Concentric tube robot (CTR), as it can form a complicated shape and access hardto-reach lesions, is often used in minimally invasive surgeries. However, some CTRs are bulky because of their transmission design. In this paper, a light CTR based on double-threaded helical gear tube is proposed. Such a CTR is less cumbersome than the traditional CTR as its actuation unit is compact and miniaturized. The mapping relationship between the gear tube attitude and motor output angle is obtained by kinematic analysis. The precision, stability, and repeatability of the driving mechanism are tested. The experimental results show that the positioning error in the translation test is less than 0.3 mm, the rolling angle error in the stability test is less than 0.6?, and the error in the translation repeatability test is less than 0.005 mm. Finally, a tip-targeting test is performed using the new CTR, which verifies the feasibility of the CTR for surgeries.
    Reference | Related Articles | Metrics
    Numerical Simulation on the Effect of Conveyor Velocity of the Roller Table on Stress Distribution and Evolution in Large Aluminum Alloy Thick Plates
    ZHU Kai, (祝 楷), XIONG Baiqing, ∗ (熊柏青), YAN Hongwei, (闫宏伟), ZHANG Yongan, (张永安), LI Zhihui, (李志辉), LI Xiwu, (李锡武), LIU Hongwei, (刘红伟), WEN Kai, (温 凯), YAN Lizhen, (闫丽珍)
    J Shanghai Jiaotong Univ Sci    2023, 28 (2): 255-263.   DOI: 10.1007/s12204-021-2389-y
    Abstract90)      PDF (1596KB)(23)      
    Solution heat treatment combined with a rapid quenching operation, which can effectively suppress the decomposition of the supersaturated solid solution in the matrix, is a vital process step for producing large precipitation-hardenable aluminum alloy thick plates with desired properties. However, large thermal gradients that result from the non-uniform cooling rates during quenching usually give rise to severely heterogeneous distributions of residual stress in thick plates. The presence of roller-hearth furnaces makes it possible to achieve continuous and integral solution-quenching treatment for large aluminum alloy thick plates. The conveyor velocity of the roller table in the roller-hearth furnace is a key parameter but its influence is less addressed in literature. Thus, in the present work, finite element thermal-mechanical simulations taking into account different conveyor velocities of the roller table were employed to predict the temperature variations and residual stress distributions in large aluminum alloy thick plates during quenching process. Four different velocities were utilized in the simulations. The modeling results showed that the temperature evolutions as well as the distributions of the induced internal stresses in those large thick plates during quenching treatments were indeed affected by the conveyor velocities. Slower velocities were demonstrated to be favorable for gaining thick plates being with relatively homogeneous residual stress distributions in the plates.
    Reference | Related Articles | Metrics
    UAV Task Allocation for Hierarchical Multiobjective Optimization in Complex Conditions Using Modified NSGA-III with Segmented Encoding
    JIN Yudong (靳宇栋), FENG Jiabo (冯家波), ZHANG Weijun (张伟军)
    J Shanghai Jiaotong Univ Sci    2021, 26 (4): 431-445.   DOI: 10.1007/s12204-021-2269-5
    Abstract348)      PDF (2668KB)(292)      
    With the recent boom in unmanned aerial vehicle (UAV) technology, many UAV applications involving complex and risky tasks in military and civilian fields have emerged, such as military strikes and disaster monitoring. Task allocation for UAVs is the process of planning the division of work among UAVs, controlled from ground stations by human operators. This study formulates the UAV task-allocation problem as an extended traveling salesman problem and presents a novel UAV task-allocation model for complex air concentration monitoring tasks. Then, an optimized non-dominated sorting genetic algorithm III (NSGA-III) based on a twin-exclusion mechanism, hierarchical objective-domination operator, and segmented gene encoding (i.e., NSGA-III-TEHOD) is developed to solve complex task-allocation problems involving multiple UAVs, hierarchical objectives, obstacles, and ambient wind. The algorithm is tested in several simulations, and the results demonstrate that the new algorithm outperforms NSGA-III, non-dominated sorting genetic algorithm II (NSGA-II), and genetic algorithm (GA) in terms of efficiency of global convergence and early maturation prevention and is available for the hierarchical objective-optimization problems.

    Reference | Related Articles | Metrics
    Safety Protection Method of Rehabilitation Robot Based on fNIRS and RGB-D Information Fusion
    LI Dong (李栋), FAN Yulin (樊钰琳), L v Na (吕娜), CHEN Guodong∗ (陈国栋), WANG Zheng (王正), CHI Wenzheng (迟文政)
    J Shanghai Jiaotong Univ Sci    2022, 27 (1): 45-54.   DOI: 10.1007/s12204-021-2365-6
    Abstract233)      PDF (2503KB)(82)      
    In order to improve the safety protection performance of the rehabilitation robot, an active safety protection method is proposed in the rehabilitation scene. The oxyhemoglobin concentration information and RGB-D information are combined in this method, which aims to realize the comprehensive monitoring of the invasion target, the patient’s brain function movement state, and the joint angle in the rehabilitation scene. The main focus is to study the fusion method of the oxyhemoglobin concentration information and RGB-D information in the rehabilitation scene. Frequency analysis of brain functional connectivity coefficient was used to distinguish the basic motion states. The human skeleton recognition algorithm was used to realize the angle monitoring of the upper limb joint combined with the depth information. Compared with speed and separation monitoring, the protection method of multi-information fusion is safer and more comprehensive for stroke patients. By building the active safety protection platform of the upper limb rehabilitation robot, the performance of the system in different safety states is tested, and the safety protection performance of the method in the upper limb rehabilitation scene is verified.
    Reference | Related Articles | Metrics