Design and Implementation of Embedded Serial Communication Based on Finite State Machine

Jian Feng,Yuanyuan Ding 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.9

In order to solve problems of poor real-time capability, poor reliability and low fault tolerance for data transmission in embedded serial communication, a serial communication protocol based on finite state machine (FSM) was designed and implemented, and was applied in communications of network management. The packet format and the communication control mechanism of the serial communication protocol are described, and complete framework for the application is given. Process of receiving and transmitting FSM models in serial communication are abstracted, combined with the interrupt service routine. In practical application, the serial communication program can meet the functional and performance requirements of serial communication between embedded devices and network management system (NMS).

An Improved Strong Tracking UKF Based on Fading Factor

Jian Feng,Xiao-dong Su,Yu-ru Zhang,Hai-tao Jiang,Jun-ling Li 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.4

Experimental Measurement and Numerical Computation of Geogrid Tension in Centrifuge Modeling

Jianfeng Chen,Songbo Yu,Jianfeng Xue,Zhenming Shi 대한토목학회 2011 KSCE JOURNAL OF CIVIL ENGINEERING Vol.15 No.8

Tension measurement of geogrid is essential in reinforcement mechanisms studies. Geogrid is a nonlinear flexible material with large apertures, it is difficult to measure the tensions mobilized in geogrid, especially in scaled-down geogrid in centrifuge modeling. In this study, strain gauges were glued onto the surface of model geogrid with epoxy resin and were calibrated through multi-stage and continuous tensile tests. Generalized Kelvin model was used to fit the constitutive curves from the tensile tests. The model is capable to describe time-dependent and nonlinear behavior of the composite material of epoxy resin and model geogrid. Based on generalized Kelvin model, tensions in the model geogrid were measured in a centrifugal modeling of a reinforced embankment on soft clay. A finite element model was developed to simulate the centrifuge modeling and a comparison was carried out between the computed and measured tensions. The numerical results basically captured the measured reinforcements, indicating that the method of reinforcement measurement proposed in this study is appropriate and reasonable.

Failure Analyses of a Reinforced Embankment by Strength Reduction and Limit Equilibrium Methods Considering Hardening of Soft Clay

Jianfeng Chen,Junxiu Liu,Jianfeng Xue,Zhenming Shi 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.7

A 7.6 m high reinforced embankment-wall system was constructed in stages on very thick soft clay. The reinforced structure incurred a deep-seated global failure at the end of backfill loading. The Strength Reduction Method (SRM) and the Limit Equilibrium Method (LEM) were employed to analyze the stability of the structure. It was found that the SRM captured the deep-seated global failure of the structure through a coupled mechanical and hydraulic Finite Element (FE) modeling. The stability of the reinforced structure was much underestimated or overestimated by the LEM using unconsolidated-undrained or consolidated-undrained shear strength values. However, the stability of the structure could be still captured by the LEM with the increased shear strength values assigned to the consolidated zone directly beneath the reinforced structure and with the unconsolidated-undrained shear strength values assigned to the unconsolidated zone beyond the structure. In practice, both the SRM and the LEM are recommended for stability analyses of geosynthetic-reinforced structures on soft ground considering hardening of the soil so that the results from the two methods can be cross-examined.

Optimization and Control of Cable Tensions for Hyper-redundant Snake-arm Robots

Jianfeng Tao,Chengjin Qin,Zhilin Xiong,Xiang Gao,Chengliang Liu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11

Based on the feedback linearization of joints motion and the tension optimization of cables, a hyperredundant snake-arm robot control strategy is presented to solve the problems caused by the joint motion coupling and the cable drive redundancy. First, a hierarchical control system architecture of snake-arm robot is developed. Subsequently, the computed torque control method is utilized to decouple the motion in the joint space, and the tension distribution satisfying the constraint condition is obtained in the cable space by quadratic programming. Since it is hard and also expensive to feedback joint motion and cable tension by sensors, the cable tensions are obtained by the system dynamics equation and the position and speed of joints motion is calculated approximately from the driving electric motors’ position. Finally, the control performance under three typical conditions is studied by numerical simulation. The results demonstrate that the presented method can effectively limit the cable tensions within the range of the minimum preload tension and the maximum allowable tension.

An Efficient Algorithm for the Tensor Product Model Transformation

Jianfeng Cui,Ke Zhang,Tiehua Ma 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.5

The tensor-product (TP) model transformation was proposed recently as a numerical and automaticallyexecutable method which is capable of transforming linear parameter varying (LPV) state-space models into thehigher order singular value decomposition (HOSVD) based canonical form of polytopic models. The crucial disadvantageof the TP model transformation is that its computational load explodes with the density of discretization andthe dimensionality of the parameter vector of the parameter-varying state-space model. In this paper we propose anew algorithm that leads to considerable reduction of the computation in the TP model transformation. The mainidea behind the modified algorithm is to minimize the number of discretized points to acquire as much informationas possible. The modified TP model transformation can readily be executed on a regular computer efficiently andconcisely, especially in higher dimensional cases when the original TP model transformation fails. The paper alsopresents numerical examples to show the effectiveness of the new algorithm.

WSN Missing Data Imputing Based on Multiple Time Granularity

Jianfeng Xu,Yu Li,Yuanjian Zhang,Azhar Mahmood 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.6

Missing data is a common phenomenon in the data collection process of wireless sensor network (WSN), and the missing data imputing is an important issue of WSN stream data mining. Currently WSN missing data imputing method has little considered about the dynamic characteristics of internal data time structure during the data collection process, which makes data imputing difficult to reflect the real monitoring change objectively. In order to analyze the internal structure and dynamics of WSN time sequence data systematically, with the equivalence relation of the monitored object the time domain can be regarded as a series of integral time granule (ie atomic time point set), a wireless sensor network timing information system (WTIS) is established. The system can reason logically at different time granularity, and a multiple optimal time granularity strategy of WTIS based on hierarchical successive approximation approach is proposed. Finally, based on the research, a multiple optimal time granularity WSN missing data clustering imputing algorithm is proposed. Compared with traditional fixed time granularity missing data imputing algorithm, experiments show that the algorithm can lower error rate when imputing WSN missing data.

Numerical investigation on the dynamic behaviors of turbine valve disc–seat impact at low velocity

Jianfeng Mao,Wei Zhe Wang,Junhui Zhang,Ying Zheng Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

In this study, the dynamic behaviors on a valve seat subjected to the impact of the valve disc at low velocities were investigated by usingnumerical analysis with finite element method. The impact damage of the valve disc against seat was evaluated through a threedimensionaldynamic explicit calculation. The parameters considered in the simulations were impact velocity, disc obliquity, aspect ratio,and contact area ratio. The model for impact calculation was implemented in the code ABAQUS, which is based on the constitutiveequation and fracture strain equation of Johnson and Cook, as well as on continuum damage mechanics. The distribution of damagecaused by the impact was computed and discussed. The impact damage of the valve disc was minimized when the disc obliquity wasapproximately 40°. The effects of variation of selected design parameters on dynamic behaviors were discussed. The best design parameterswere proposed, which served as a guide for future valve design.

Novel spherical TiO2 supported PdNi alloy catalyst for methanol electroxidation

Jianfeng Ju,Donghui Wu,Xi Chen,Yujun Shi,Ping Hua 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

A novel PdNi/TiO2 electrocatalyst for methanol oxidation is fabricated using spherical TiO2 nanoparticles as support. The structural and electrochemical properties of the PdNi/TiO2 catalyst are characterized by XRD, TEM and electrochemical analysis. The cyclic voltammograms of PdNi/TiO2 catalyst show that there is a large methanol oxidation peak in about 0.882 V that is much bigger than that of the commercial PtRu/C catalyst in 0.7 V. The composite TiO2 material has high catalytic activity without UV light illumination. The electrocatalytic activity and anti-poisoning capability of the PdNi/TiO2 catalyst are promising, which may become a potential candidate for direct methanol fuel cell.

Characteristics and mechanism of Pb(II) adsorption/desorption on GO/ r-GO under sulfide-reducing conditions

Jianfeng Zhang,Xiaodan Xie,Cheng Liang,Weihuang Zhu,Xiaoguang Meng 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.73 No.-

Compared with graphene oxide (GO), r-GO (the reduced form) has a lower adsorption capacity for heavymetal ions and, therefore, generates concern over the release of adsorbed contaminants when GOadsorbent is discharged into a reducing environment. This study reveals that the maximum adsorptioncapacity of Pb(II) on GO and r-GO was 937.65 and 92.99 mg g 1 respectively. GO was reduced to r-GO bysulfide, causing 2.59–6.46% of the adsorbed Pb(II) to be released and was stably dispersed as a Pb(II)-oxidative debris (OD) complex. Our results provide valuable information about heavy metaltransportation in environments containing GO under different redox conditions.