Analysis and Detection of Transmission Lines Based on Twin Reality

Dong Yang,Bolin Du,Yan Lu,Suxin Zhang,Chengjun Xu,Jian Zhang 한국멀티미디어학회 2023 The journal of multimedia information system Vol.10 No.1

Now life has been transformed and upgraded to the direction of intelligence, digitalization and informatization along with the advancement of scientific and technological information. The traditional detection of transmission lines is completed by the professional maintenance per-sonnel of the power grid through manual detection of lines. This method is inefficient and has a certain threat to the life safety of detection personnel. The development of deep learning and computational vision supplies a fresh idea for detection of transmission lines. Therefore, this paper analyzes the traditional Faster R-CNN based on twin reality scene modeling technology. Then aiming at the shortcomings of traditional algorithms, the Cascade R-CNN algorithm is proposed to complete the detection of transmission lines based on twin reality system. It com-pares the accuracy and other indicators of Cascade R-CNN and Faster R-CNN algorithms. The effectiveness of two algorithms for analysis and detection of transmission lines is verified through experiments. Finally, the results indicates that the system using Cascade R-CNN has higher prediction accuracy, and has better practicability for analysis and detection of transmission lines.

A rule-based classifier ensemble for fault diagnosis of rotating machinery

Dongyang Dou,Jian Jiang,Yuling Wang,Yong Zhang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6

To predict potential problems and avoid an unexpected breakdown of rotating machinery, a rule-based classifier ensemble approach is presented. Feature reduction was first implemented on a fault decision table using discernibility matrices and the genetic algorithm. The generated rules of the reducts were used to build the candidate base classifiers. Then, several base classifiers were selected according to their diversity and scale. The weights of the selected base classifiers were also calculated based on the support rate measurements. A classifier ensemble was constructed through an integration of the base classifiers using an improved weighted voting technique. Finally, the proposed classifier ensemble was verified based on the vibration data of bearing types SKF6203 and NU205. The accuracy for the SKF6203 bearing type reached 88.75 %, which is at least 5 % higher than that of the three base classifiers for this type of bearing. In addition, the recognition rate for the latter bearing type was 90 %. The reasoning process was much easier to comprehend owing to the semantic descriptions of the rules. The results show that this is a promising and transparent approach for diagnosing typical faults of rotating machinery.

Vibration Suppression Method Based on PI Fuzzy Controller Containing Disturbance Observe for Dual-flexible Manipulator with an Axially Translating Arm

Dongyang Shang,Xiaopeng Li,Fanjie Li,Meng Yin 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.5

A dual-flexible manipulator with an axially translating arm is composed of a motor, a flexible joint, and a flexible load that can be telescopic. The friction torque at the motor, the time-varying characteristics of load parameters, as well as the flexibility of joints and loads will cause the vibration of the manipulator. Transverse vibration will affect the movement accuracy of the end-effector. In this paper, a fuzzy adaptive PI control strategy containing disturbance observers (DOB) is used to reduce the fluctuation of the servo system’s output speed, thereby suppressing the vibration of the manipulator. Firstly, the dynamical model of the dual-flexible manipulator considering the friction torque is established. Then, the low-pass filter in the DOB is designed, and the PI controller parameters are adjusted in real-time by the fuzzy adaptive control strategy. Finally, the numerical simulation analysis and experiments of the dual-flexible manipulator are carried out. The simulation and experimental results show that; 1) The DOB can effectively eliminate the influence of friction torque; 2) The control strategy can reduce the output speed error. Therefore, the control strategy proposed in this paper can effectively reduce the vibration of the dual-flexible manipulator with an axially translating arm to improve the movement accuracy of the end-effector.

Prefabrication of Axially Vascularized Bone by Combining β-Tricalciumphosphate, Arteriovenous Loop, and Cell Sheet Technique

Dongyang Ma,Liling Ren,Zhen Cao,Jianxue Li,Jian Cao,Wenyan Tian,Hong Yao 한국조직공학과 재생의학회 2016 조직공학과 재생의학 Vol.13 No.5

The repair of bone defects poses a great challenge for reconstructive surgeons. Although the development of tissue engineering has exhibited promise in replacing damaged bone, the fabrication of large constructs with functional blood vessels remains an obstacle. From the orthopedic surgeon’s point of view, the generation of axially vascularized bone, which can anastomose with the recipient vessel, might be a solution to this medical problem. In this study, we aimed to prefabricate an axially vascularized bone by combining a β-TCP scaffold, arteriovenous loop (AVL), and cell sheet in a bioreactor in vivo. Twelve rabbits were randomly allocated into two groups: the experimental group (presence of AVL) and the control group (absence of AVL). The constructs were explanted at 8 weeks postoperatively. The histomorphometric results showed 42.8±5.9% of the bone area in the AVL group and 26.6±3.5% in the control group. Similarly, vessel analysis revealed the average vessel density in the AVL group (12.5±3.3) was significantly more than that in the control group (6.1±1.5, p<0.05). Our research indicated that the combination of a β-TCP scaffold, AVL and cell sheet might engineer vascularized bone. This prefabrication strategy might facilitate clinical translation of bone tissue engineering in reconstructing large bone defects.

Model reduction of a multibody system including a very flexible beam element

Dongyang Sun,Guo-Ping Chen,Rujie Sun 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.8

An optimum method to reduce the system size of a multibody system including a very flexible beam element is presented. In this paper,the absolute nodal coordinate formulation (ANCF) is used to describe the motion of the flexible beam in this system. Based on continuummechanics approach, the bending stiffness matrix of the system is assumed to be a constant matrix when the axial strain is small. Thus, free-interface method, in which modal coordinate vector is free from the boundary region, is used to reduce the degrees of freedomof a flexible beam with sliding joints. Finally, two numerical examples are presented to verify the efficiency and accuracy of this method. The results show that the present method can reduce the computing time with precision. Meanwhile, a deformation energy criterion ofmode truncation is established.

Three-Phase Static Var Generator Based on Z-Source Network

Yang Dongyang,Li Wenjuan,Cheng Jingsi 보안공학연구지원센터 2013 International Journal of Control and Automation Vol.6 No.6

[서평] 인간지장론ㆍ도시건축

양동양(Yang Dongyang) 대한건축학회 2004 建築 Vol.48 No.7

An Adaptive Trust Sampling Method for P2P Traffic Inspection

Hongwei Chen,Dongyang Yu,Chunzhi Wang,Shuping Wang 보안공학연구지원센터(IJGDC) 2013 International Journal of Grid and Distributed Comp Vol.6 No.6

Modeling and control strategy of flexible joint servo system in humanoid manipulator driven by tendon-sheath

Meng Yin,Dongyang Shang,Binhua Huang,Xinyu Wu,Wei Feng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

The control effect of rotational speed in joints directly affects the motion accuracy of a humanoid manipulator driven by tendon-sheath. The dynamic parameters of the joint have time-varying characteristics due to the posture change of the manipulator. The joint driven by tendon-sheath has a specific torsional stiffness, so flexibility should be considered in the humanoid manipulator’s servo system. The time-varying of the parameters in the servo system and the joint flexibility can cause fluctuation of the output speed. To improve the motion accuracy of the humanoid manipulator, a fuzzy-tuned PI control strategy is used to suppress the instability of the output speed. First, the change law of the inertia on the motor side of the flexible joint is calculated by the dynamics equation of the humanoid manipulator. Next, a mathematical model of the joint is established, and the transfer function from the load speed to the electromagnetic torque is obtained. Furthermore, according to the pole-placement strategy, the fuzzy-tuned PI controller parameters are selected appropriately for the manipulator in different postures. Finally, the effectiveness of the proposed method is verified by numerical simulations and control experiments of the manipulator. The results show that the fuzzy-tuned PI control strategy can significantly reduce the tracking errors and improve the control performance of the manipulator.

Behaviour of lightweight aggregate concrete-filled steel tube under horizontal cyclic load

Zhongqiu Fu,Bohai Ji,Dongyang Wu,Zhenpeng Yu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.6

A horizontal cyclic test was carried out to study the seismic performance of lightweight aggregate concrete filled steel tube (LACFST). The constitutive and hysteretic model of core lightweight aggregate concrete (LAC) was proposed for finite element simulation. The stress and strain changes of the steel tube and concrete filled inside were measured in the experiment, and the failure mode, hysteresis curve, skeleton curve, and strain curve of the test specimens were obtained. The influence of axial compression ratio, diameter-thickness ratio and material strength were analysed based on finite element model. The results show that the hysteresis curve of LACFST indicated favourable ductility, energy dissipation, and seismic performance. The LACFST failed when the concrete in the bottom first crushed and the steel tube then bulged, thus axial force imposed by prestressing was proved to be feasible. The proposed constitutive model and hysteretic model of LAC under the constraint of its steel tube was reliable. The bearing capacity and ductility of the specimen increase significantly with increasing thickness of the steel tube. The bearing capacity of the member improves while the ductility and energy dissipation performance slightly decreased with the increasing strength of the steel and concrete.