The Automatic Recognition of Large Ball Valve Sealing Bolt Based on Digital Image

Qingjun Song,Xingming Xiao,Haiyan Jiang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

In this paper, we put forward an effective algorithm for edge detection based on combination of multi-shape/scale Mathematical morphology and wavelet transformation. Firstly, the bimodal method and multi-threshold method were combined for the image segmentation. Then, the image edge was detected by the algorithm. Finally, the angle between the bolt and manipulator was calculated using the rotation conversion matrix. With the systematic error and correlation coefficient, the calculated angle was verified. Experimental results show that the method can protect the edge integrity of the nut image, with fast processing speed and strong anti-noise ability. The work in this paper provides a theoretical basis for the automatic recognition in the large ball valve sealing bolt system.

A new multi-class classification method based on minimum enclosing balls

QingJun Song,XingMing Xiao,HaiYan Jiang,XieGuang Zhao 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8

With respect to classification problems, the Minimum enclosing ball (MEB) method was recently studied by some scholars as a newsupport vector machine. As a nascent technology, however, MEB reports poor adaptability for different types of samples, especiallymulti-class samples. In this paper, we propose a new multi-class classification method based on MEB. This method is derived from eachclass sample center and radius with the Gaussian kernel width factor parameter σ, which is labelled as σ-MEB. σ is a variable parameteraccording to the different sample characteristics. When this parameter is considered, the multi-class classifier is easy to adapt and is robustin diverse datasets. The quadratic programming problem was transformed into its dual form with Lagrange multipliers using thismethod. Finally, we applied sequential minimal optimization method and Karush—Kuhn—Tucker conditions to accelerate the trainingprocess. Numerical experiment results indicate that given different types of samples, the proposed method is more accurate than themethods with which it is compared. Moreover, the proposed method reports values in the upper quantile with respect to adaptation performance.

Dynamic behavior of lifting pipe with equivalent model under mining vessel heave motion

QingHui Song,HaiYan Jiang,QingJun Song,Linjing Xiao,FangPing Yan 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

The lifting pipe is a key component of deep sea mining whose dynamic response directly affects the safety of the lift-ing operation. The objective of this paper was to investigate the effects of heave motion and sailing velocity of mining vessel and the buffer mass on the dynamic response of lifting pipe. First, an equivalent model of the lifting pipe was established, and the natural frequency and dynamic response of the lifting pipe equivalent model were determined with consideration of the wave action by the method of separated variables. Secondly, the reliability of the equivalent model was verified by simulating a 5000 m stepped pipe with OrcaFlex software. Then the dynamic displacement, axial tension, axial stress of the lifting pipe under different sea conditions and sailing velocities were studied, and the main factors affecting the dynamic response of the pipe described. By comparing the simulation results of actual and equivalent models, the equivalent model can be used to analyze the longitudinal vibration characteristics of the lifting pipe. The sailing velocity of the mining vessel has little effect on the dynamic response of the lifting pipe, but the surface wave has a significant effect.

Sliding Mode Robust Control of Hydraulic Drive Unit of Hydraulic Quadruped Robot

Rui Zhu,Qingjun Yang,Yudong Liu,Rizhi Dong,Chunli Jiang,Jiaxing Song 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.4

This paper focuses on the position control of the quadruped robot hydraulic drive unit (HDU). The proposed control strategy has the advantages of excellent output tracking performance, strong robustness, no chattering and low computational complexity. HDU has the characteristics of nonlinearity and parameter uncertainty, coupled with unpredictable external interference, which makes it difficult to achieve precise position control. In this paper, we first establish the mathematical model of the HDU based on the actual parameters and obtain the state space of the system. Through the pole placement, the simplified system can easily achieve the expected control goal. Then, the state equation of the error system is constructed, and the nonlinearity, parameter uncertainty and external interference of the HDU are summarized as the matched and unmatched uncertainties of the system. The integral sliding mode control (ISMC) is used to derive the control law, and the response characteristics of the system when pole placement and state feedback H∞ control are used for the nominal control are compared. It can be concluded that the system with state feedback H∞ control for nominal control has stronger robustness and can resist the unmatched uncertainties. Finally, the control law of the simplified system is used as feedforward and combined with the ISMC of the error system, the output tracking control framework of the HDU is proposed. Simulations and experiments show that the proposed control method has excellent tracking performance and strong robustness.

Research and Improvement on Active Compliance Control of Hydraulic Quadruped Robot

Rui Zhu,Qingjun Yang,Jiaxing Song,Shangru Yang,Yudong Liu,Qi Mao 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.5

This paper focuses on active compliance control of hydraulic quadruped robot, especially the analysis of the inner-loop of the coupled system. Current researches on active compliance control regard the bandwidth of the inner loop of the system as infinite, while ignoring that the extra-load will cause the inner-loop response characteristics to deteriorate when the leg is in the stance phase. In this work, we first briefly introduced the structure of the robot, and its kinematics and dynamics are analyzed. Next, the robot’s active compliance control framework is established, and the inner-loop two-cylinder coupling system is analyzed in depth. It can be concluded that the existence of low frequency poles in the system is the main reason for the poor response characteristics. Then through the analysis of the state equation and transfer function matrix of the multi-input multi-output system, we show that the equivalent hydraulic spring stiffness (EHSS) is the main factor affecting the zero-pole distribution. Furthermore, we optimize the structure to increase the EHSS to improve the response characteristics of the system. Finally, the co-simulation platform and single-leg experiment bench are introduced. The simulation and experimental results show that the response speed of the inner-loop control is significantly improved after optimization, and the robot with active compliance control strategies can significantly reduce the impact of the foot.

Indole-3-acetic acid ameliorates dextran sulfate sodium-induced colitis via the ERK signaling pathway

Xinyan Qu,Yingying Song,Qingjun Li,Qi Xu,Yanru Li,Huimin Zhang,Xuemei Cheng,Charles R. Mackay,Quanbo Wang,Wei Liu 대한약학회 2024 Archives of Pharmacal Research Vol.47 No.3

Microbiota-derived catabolism of nutrients is closely related to ulcerative colitis (UC). The level of indole-3-acetic acid(IAA), a microbiota-dependent metabolite of tryptophan, was decreased signifi cantly in the feces of UC patients. Thus supplementationwith IAA could be a potential therapeutic method for ameliorating colitis. In this work, the protective eff ect ofsupplementation with IAA on dextran sulfate sodium (DSS)-induced colitis was evaluated, and the underlying mechanismwas elucidated. The results indicated that the administration of IAA signifi cantly relieved DSS-induced weight loss, reducedthe disease activity index (DAI), restored colon length, alleviated intestinal injury, and improved the intestinal tight junctionbarrier. Furthermore, IAA inhibited intestinal infl ammation by reducing the expression of proinfl ammatory cytokines andpromoting the production of IL-10 and TGF-β1. In addition, the ERK signaling pathway is an important mediator of variousphysiological processes including infl ammatory responses and is closely associated with the expression of IL-10. Notably,IAA treatment induced the activation of extracellular signal-regulated kinase (ERK), which is involved in the progressionof colitis, while the ERK inhibitor U0126 attenuated the benefi cial eff ects of IAA. In summary, IAA could attenuate theclinical symptoms of colitis, and the ERK signaling pathway was involved in the underlying mechanism. Supplementationwith IAA could be a potential option for preventing or ameliorating UC.