A Time-Varying Lookahead Distance of ILOS Path Following for Unmanned Surface Vehicle

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.5

This paper is concerned with the path following control for an unmanned surface vessel subject to unknown dynamics and external disturbance. Firstly, an integral Line-of-Sight navigation strategy based on a fuzzy strategy to optimize lookahead distance to achieve faster convergence speed is proposed. Then a novel adaptive course control law based on trajectory linearization control technology is proposed, which is combined with the integral Line-of-Sight navigation strategy to form a complete unmanned surface vessel path following strategy. From the author’s point of view, this is the fi rst time that trajectory linearization control technology has been applied to the path following scheme by controlling the course. At the same time, in order to improve the robustness of the path following system, the unknown dynamics, external disturbance, and error in the system are compensated by neural network minimum learning parameter method with less computational complexity and a robust term, respectively. Furthermore, hyperbolic tangent function, Nussbaum function, and neural shunting model are introduced into the design of control law to solve the potential input saturation problem. Finally, the numerical simulation experiments of straight line and curve path following are given to prove the feasibility and universality of the whole set of path following scheme.

Preparation of porous cordierite ceramic with acid-leached coal gangue

Wang Xu-Dong,Xu Hai-Yan,Zhang Feng-Jun,Li Dong-Cai,Wang Ai-Guo,Sun Dao-Sheng,오원춘 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.4

The eff ect of impurities in coal gangue on the sintering and properties (porosity and compressive strength) of porous cordierite ceramics has been investigated by adjusting the amount of impurities by controlling the acid–gangue ratio during acid leaching. The sintering behavior and microstructure of the porous ceramics have been characterized via X-ray diff ractometry and scanning electron microscopy. The eff ects of both the acid–gangue ratio and sintering temperature on the porosity and compressive strength have been also investigated. The results indicated that both porosity and compressive strength of the porous cordierite ceramics prepared using acid-leached coal gangue were evidently improved. The content of the impurities in coal gangue was adjusted via acid leaching by controlling the acid–gangue ratio. The appropriate content of impurities in coal gangue facilitated the sintering process and improved the porosity and compressive strength of the obtained porous cordierite ceramics.

Design of Adaptive Neural Tracking Controller for Pod Propulsion Unmanned Vessel Subject to Unknown Dynamics

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from “explosion of complexity”, a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of “explosion of complexity”, and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.

Formation Control Strategy for Underactuated Unmanned Surface Vehicles Subject to Unknown Dynamics and External Disturbances with Input Saturation

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.11

This paper addresses the formation tracking control problem of multiple underactuated unmanned surface vehicles. Considering many actual situations, a practical formation control scheme, which is performed by using a leader-follower approach, minimum learning parameter technique, adaptive technology and so on. Firstly, a virtual unmanned surface vehicle is designed according to the location information of the leader unmanned surface vehicle to estimate the leader’s speed information while reducing the communication bandwidth. Secondly, a formationcontrol law is designed to make the follower underactuated unmanned surface vehicles track the leader. Unknown dynamics and external disturbances are regarded as a whole and compensated by the minimum learning parameter technique instead of multi-layer neural network and the neural shunt model can handle multiple derivation problems of virtual control laws. Meanwhile, the robustness of the controlled system is improved through adaptive technology. Besides, an auxiliary design system is employed to constrain the output range of the control law. Finally, numerical simulations are implemented to prove the feasibility of the formation tracking control strategy.

Tracking Control of Podded Propulsion Unmanned Surface Vehicle with Unknown Dynamics and Disturbance Under Input Saturation

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

This paper addresses two interrelated problems concerning the tracking control of podded propulsion unmanned surface vehicle (USV), namely, the modeling of podded propulsion USV, and trajectory tracking controller design. Based on the force analysis, the separation model of podded propulsion USV is established. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network minimum parameter learning method, neural shunting model and auxiliary dynamic system without the exact information of hydrodynamic damping structure and the sea disturbances. Using Lyapunov stability analysis theory, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of podded propulsion USV is demonstrated; then, neural shunting model and neural network minimum parameter learning method are introduced to cope with the problem of "explosion of complexity" and uncertainty factors, respectively; third, auxiliary dynamic system is introduced into controller design to reduce the risk of actuator saturation. Taking into account the above practical problems is helpful to engineering implementation in the marine practice. Finally, numerical simulation has been given to demonstrate the effectiveness of the proposed scheme.

Design of Adaptive Neural Tracking Controller for Pod Propulsion Unmanned Vessel Subject to Unknown Dynamics

Mu, Dong-Dong,Wang, Guo-Feng,Fan, Yun-Sheng The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from "explosion of complexity", a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of "explosion of complexity", and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.

Application of Intraoperative Ultrasonography for Guiding Microneurosurgical Resection of Small Subcortical Lesions

Jia Wang,Yun You Duan,Xi Liu,Yu Wang,Guo Dong Gao,Huai Zhou Qin,Liang Wang 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.5

Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions. Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions.

The Computer Control On Laser Pulse Energy In Precise Laser Machinings

Xiao Dong Wang,Kun Sun,Zhong Ming Piao,Guo Liang Yuan,De Seng Xin,Hui Dong 대한전자공학회 1991 International Conference on Electronics, Informati Vol.1 No.1

No Association Between the USP7 Gene Polymorphisms and Colorectal Cancer in the Chinese Han Population

Li, Xin,Wang, Yang,Li, Xing-Wang,Liu, Bao-Cheng,Zhao, Qing-Zhu,Li, Wei-Dong,Chen, Shi-Qing,Huang, Xiao-Ye,Yang, Feng-Ping,Wang, Quan,Wang, Jin-Fen,Xiao, Yan-Zeng,Xu, Yi-Feng,Feng, Guo-Yin,Peng, Zhi-Ha Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Colorectal cancer (CRC), now the third most common cancer across the world, is known to aggregate in families. USP7 is a very important protein with an important role in regulating the p53 pathway, which is critical for genomic stability and tumor suppression. We here genotyped eight SNPs within the USP7 gene and conducted a case-control study in 312 CRC patients and 270 healthy subjects in the Chinese Han population. No significant associations were found for any single SNP and CRC risk. Our data eliminate USP7 as a potential candidate gene towards for CRC in the Han Chinese population.

Galectin-9 Acts as a Prognostic Factor with Antimetastatic Potential in Hepatocellular Carcinoma

Zhang, Zhao-Yang,Dong, Jia-Hong,Chen, Yong-Wei,Wang, Xian-Qiang,Li, Chong-Hui,Wang, Jian,Wang, Guo-Qiang,Li, Hai-Lin,Wang, Xue-Dong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Considerable research has been conducted concerning galectin-9 and carcinomas, but little information is available about any relation with the hepatocellular carcinoma. In this study, we employed a small interfering RNA (siRNA) targeting galectin-9 to down-regulate the expression in HepG2 cells. As a result, after galectin-9 expression was reduced, cell aggregation was suppressed, while other behaviour such as the proliferation, adhesion and invasion to ECM, cell-endothelial adhesion and transendothelial invasion of the cells were markedly enhanced. When tumors of 200 patients with hepatocellular carcinoma were tested for galectin-9 expression by immunohistochemistry, binding levels demonstrated intimate correlations with the histopathologic grade, lymph node metastasis, vascular invasion and intrahepatic metastasis (P<0.05). Moreover, survival analysis indicated that patients with galectin-9 expression had much longer survival time than those with negative lesions, and the Log-rank test indicated that this difference was statistical significant (P<0.0001). The Cox proportional hazards model suggested that negative galectin-9 expression in hepatocellular carcinoma represented a significant risk factor for patient survival. We propose that galectin-9 might be a new prognostic factor with antimetastatic potential in patients with hepatocellular carcinoma.