Having analyzed the drawbacks on the design of control system of hydraulic moment-adjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the bas...Having analyzed the drawbacks on the design of control system of hydraulic moment-adjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical ac-celeration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. ln the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hy-draulic brake at the beginning of deceleration, it will further improved reliability of conveyor sys-tem.展开更多
A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings,...A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings, a system control model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by dewatering and dynamic water levels during different working procedures being constraints, and the design parameter of pumping wells being the variable,so as to lower the jeopardizing of surrounding buildings, which provides a new method for active control over settlement during dewatering. Such a method of dewatering based on system control model should be of significance for similar projects involving dewatering.展开更多
This paper addresses the problem of synchronized path following of multiple homogenous underaetuated autonomous underwater vehicles （AUVs）. The dedicated control laws are categorized into two envelopes： One is stee...This paper addresses the problem of synchronized path following of multiple homogenous underaetuated autonomous underwater vehicles （AUVs）. The dedicated control laws are categorized into two envelopes： One is steering individual underwater vehicle to track along predefined path, and the other is ensuring tracked paths of multiple vehicles to be synchronized, by means of decentralized speed adaption under the constraints of multi-vehicle communication topology. With these two tasks formulation, geometric path following is built on Lyapunov theory and baekstepping techniques, while injecting helmsman behavior into classic individual path following control. Synchronization of path parameters are reached by using a mixture of tools from linear algebra, graph theory and nonlinear control theory. A simple but effective control design on direct inter-vehicle speed adaption with minimized communication variables, enables the multi-AUV systems to be synchronized and stabilized into an invariant manifold, and all speeds converge to desired assignments as a byproduct. Simulation results illustrate the performance of the synchronized path following control laws proposed.展开更多
The confinements of water can be divided into two main categories,namely,the confinements on surface or interface and the confinements in bulk water.By adding ions or applying electric field,the intensity and distribu...The confinements of water can be divided into two main categories,namely,the confinements on surface or interface and the confinements in bulk water.By adding ions or applying electric field,the intensity and distribution of the hydrogen bonds can be greatly affected.These are collectively known as confinement on water surface or interface,which has potential applications in life science and industries involving evaporation control.Confined bulk water could be found everywhere in nature,such as in granular and porous materials,macromolecules and gels,etc.The investigation of the physical properties and the transports of the confined bulk water will contribute to understanding certain types of life activities such as the water transport in plant and in new application of extracting the shale oil and water.展开更多
文摘Having analyzed the drawbacks on the design of control system of hydraulic moment-adjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical ac-celeration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. ln the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hy-draulic brake at the beginning of deceleration, it will further improved reliability of conveyor sys-tem.
基金National Science and Technology Support Program of China ( No. 2009BAG15B02) Key Pro-grams for Science and Technology Development of Chinese Transportation industry ( No. 2008-353-332-160) +2 种基金Jiangsu Province College Graduate Research and Innovation Program ( No. CX08B_123Z) 2009 Natural ScienceFoundation of Hohai University ( No. 2009424011)the Fundamental Research Funds for the Central Universi-ties ( No. 2009B11814)
文摘A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings, a system control model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by dewatering and dynamic water levels during different working procedures being constraints, and the design parameter of pumping wells being the variable,so as to lower the jeopardizing of surrounding buildings, which provides a new method for active control over settlement during dewatering. Such a method of dewatering based on system control model should be of significance for similar projects involving dewatering.
基金supported by the EU FP6 FreeSubNet project under Grant No.036186the National Science Foundation of China under Grant No.51079061+1 种基金the Key Laboratory of Education Ministry for Image Processing and Intelligent Control,Huazhong University of Science and Technology under Grant No. 200804supported by the European Marie Curie Fellowship
文摘This paper addresses the problem of synchronized path following of multiple homogenous underaetuated autonomous underwater vehicles （AUVs）. The dedicated control laws are categorized into two envelopes： One is steering individual underwater vehicle to track along predefined path, and the other is ensuring tracked paths of multiple vehicles to be synchronized, by means of decentralized speed adaption under the constraints of multi-vehicle communication topology. With these two tasks formulation, geometric path following is built on Lyapunov theory and baekstepping techniques, while injecting helmsman behavior into classic individual path following control. Synchronization of path parameters are reached by using a mixture of tools from linear algebra, graph theory and nonlinear control theory. A simple but effective control design on direct inter-vehicle speed adaption with minimized communication variables, enables the multi-AUV systems to be synchronized and stabilized into an invariant manifold, and all speeds converge to desired assignments as a byproduct. Simulation results illustrate the performance of the synchronized path following control laws proposed.
基金supported by the National Natural Science Foundation of China(Grant No.11290165)
文摘The confinements of water can be divided into two main categories,namely,the confinements on surface or interface and the confinements in bulk water.By adding ions or applying electric field,the intensity and distribution of the hydrogen bonds can be greatly affected.These are collectively known as confinement on water surface or interface,which has potential applications in life science and industries involving evaporation control.Confined bulk water could be found everywhere in nature,such as in granular and porous materials,macromolecules and gels,etc.The investigation of the physical properties and the transports of the confined bulk water will contribute to understanding certain types of life activities such as the water transport in plant and in new application of extracting the shale oil and water.
