The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear...The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues, a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well, and all signals in the closed-loop system remain bounded. Moreover, a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers, this paper's robust controller based on backstepping recursive design method is easier to design, and is more suitable for implementation.展开更多
In this paper, graphical-user-interface （GUI） software for simulation and fuzzy-logic control of a remotely operated vehicle （ROV） using MATLABTM GUI Designing Environment is proposed. The proposed ROV＇s GUI plat...In this paper, graphical-user-interface （GUI） software for simulation and fuzzy-logic control of a remotely operated vehicle （ROV） using MATLABTM GUI Designing Environment is proposed. The proposed ROV＇s GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative （PID） and sliding-mode controller （SMC） systematically and interactively. External disturbance such as sea current can he added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance.展开更多
A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the contr...A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS.展开更多
Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues...Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues on biomechanics and hydrodynamic flow control offish swimming and(2) to summarize design and control methods for efficient and stable swimming in robotic fishes.Our review of state-of-the-art research and future-oriented new directions indicates that fish-inspired biology and engineering interact in mutually beneficial ways.This strong interaction offers an important insight into the design and control of novel fish-inspired robots that addresses the challenge of environmental uncertainty and competing objectives;in addition,it also facilitates refinement of biological knowledge and robotic strategies for effective and efficient swimming.展开更多
文摘The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues, a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well, and all signals in the closed-loop system remain bounded. Moreover, a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers, this paper's robust controller based on backstepping recursive design method is easier to design, and is more suitable for implementation.
基金Supported by the Newcastle University’s Project Account:C0570D2330
文摘In this paper, graphical-user-interface （GUI） software for simulation and fuzzy-logic control of a remotely operated vehicle （ROV） using MATLABTM GUI Designing Environment is proposed. The proposed ROV＇s GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative （PID） and sliding-mode controller （SMC） systematically and interactively. External disturbance such as sea current can he added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance.
基金Supported by the State Key Program of National Natural Science Foundation of China (No. 50835006)Science & Technology Support Planning Foundation of Tianjin (No. 09ZCKFGX03000)
文摘A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS.
基金supported by the National Natural Science Foundation of China(Grant Nos.61333016,61403012,61633004&61633020)the Beijing Natural Science Foundation(Grant Nos.4154077&4161002)
文摘Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues on biomechanics and hydrodynamic flow control offish swimming and(2) to summarize design and control methods for efficient and stable swimming in robotic fishes.Our review of state-of-the-art research and future-oriented new directions indicates that fish-inspired biology and engineering interact in mutually beneficial ways.This strong interaction offers an important insight into the design and control of novel fish-inspired robots that addresses the challenge of environmental uncertainty and competing objectives;in addition,it also facilitates refinement of biological knowledge and robotic strategies for effective and efficient swimming.
