A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibratio...A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibration drilling based on the fuzzy least squares(FLS)-support vector machine(SVM) was developed, in which the fuzzy membership function was set by using linear distance, and its parameters, such as penalty factor and kernel parameter, were optimized by using adaptive genetic algorithm. And FLS-SVM identification on rock and soil parameters for vibration drilling was made by changing the input/output data from single freedom degree model of drilling bit-rock. The results of identification simulation and resonance column experiment show that relative error of natural frequency for some hard sand from identification simulation and resonance column experiment is 1.1% and the identification precision based on the fuzzy least squares-support vector machine is high.展开更多
A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then ...A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then it was simplified to a 2-DOF model with reasonable assumptions to design observer and optimal controllers.Then a simplified model was developed for steering system.The numerical simulations were carried out using vehicle parameters for standard maneuvers in dry and wet road conditions.Moreover,the hardware in the loop method was implemented to prove the controller ability in realistic conditions.Simulation results obviously show the effectiveness of NAOC on vehicle handling and reveal that the proposed controller can significantly improve vehicle handling during severe maneuvers.展开更多
A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a p...A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a predesigned selection metric to choose the optimal routing protocol. The routing evaluation and selection metric is derived by OPNET simulations. AODV and OLSR are used as the example to show the process of this mechanism with the moving speed varying. The routing protocol can be configured without central configuration and human management. Besides, the overhead of the mechanism is reasonable and doesnot affect the quality of service （QoS） of the traffic in the network. Results show that the optimal routing protocol can be configured adaptively according to the speed so that better performance than end-to-end delay and packet delivery ratio. a specific protocol can be obtained in terms of展开更多
In this paper, a planar five-freedom model of whole vehicle is set up and its corresponding sport differential equation is founded. The square root of the driver＇ s acceleration is selected as the estimate index by t...In this paper, a planar five-freedom model of whole vehicle is set up and its corresponding sport differential equation is founded. The square root of the driver＇ s acceleration is selected as the estimate index by the estimate way of vehicle＇ s comfort. The estimate index is minimized by optimization of fore-and-aft suspension＇ s stiffness and written with corresponding program. In the end, a model of comfort simulation by soitware of Simulink is found, and a temporal simulation for the upper example is applied to guessing the comfort of vehicle.展开更多
Herman constructed an autonomous system of two degrees of freedom which says that in non-convex situations, oscillations do happen and Aubry-Mather Theory cannot apply (see the results due to W. F. Chen in 1992). In t...Herman constructed an autonomous system of two degrees of freedom which says that in non-convex situations, oscillations do happen and Aubry-Mather Theory cannot apply (see the results due to W. F. Chen in 1992). In this paper, it is shown that although the orbits could visit a region far away from the initial point in phase space, they can only exist in some fixed regions in I = (I1 , I2 ) plane. Moreover, Aubry-Mather Theory can be applied outside the regions.展开更多
基金Project(2012BAK09B02-05) supported by the National Key Technology R&D Program of China during the Twelfth Five-year PeriodProject(51274250) supported by the National Natural Science Foundation of China
文摘A single freedom degree model of drilling bit-rock was established according to the vibration mechanism and its dynamic characteristics. Moreover, a novel identification method of rock and soil parameters for vibration drilling based on the fuzzy least squares(FLS)-support vector machine(SVM) was developed, in which the fuzzy membership function was set by using linear distance, and its parameters, such as penalty factor and kernel parameter, were optimized by using adaptive genetic algorithm. And FLS-SVM identification on rock and soil parameters for vibration drilling was made by changing the input/output data from single freedom degree model of drilling bit-rock. The results of identification simulation and resonance column experiment show that relative error of natural frequency for some hard sand from identification simulation and resonance column experiment is 1.1% and the identification precision based on the fuzzy least squares-support vector machine is high.
文摘A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then it was simplified to a 2-DOF model with reasonable assumptions to design observer and optimal controllers.Then a simplified model was developed for steering system.The numerical simulations were carried out using vehicle parameters for standard maneuvers in dry and wet road conditions.Moreover,the hardware in the loop method was implemented to prove the controller ability in realistic conditions.Simulation results obviously show the effectiveness of NAOC on vehicle handling and reveal that the proposed controller can significantly improve vehicle handling during severe maneuvers.
文摘A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a predesigned selection metric to choose the optimal routing protocol. The routing evaluation and selection metric is derived by OPNET simulations. AODV and OLSR are used as the example to show the process of this mechanism with the moving speed varying. The routing protocol can be configured without central configuration and human management. Besides, the overhead of the mechanism is reasonable and doesnot affect the quality of service （QoS） of the traffic in the network. Results show that the optimal routing protocol can be configured adaptively according to the speed so that better performance than end-to-end delay and packet delivery ratio. a specific protocol can be obtained in terms of
文摘In this paper, a planar five-freedom model of whole vehicle is set up and its corresponding sport differential equation is founded. The square root of the driver＇ s acceleration is selected as the estimate index by the estimate way of vehicle＇ s comfort. The estimate index is minimized by optimization of fore-and-aft suspension＇ s stiffness and written with corresponding program. In the end, a model of comfort simulation by soitware of Simulink is found, and a temporal simulation for the upper example is applied to guessing the comfort of vehicle.
基金Project Supported by the Graduate Student Research Fellowship of Jiangsu Province of China (No.CX10B_002Z)
文摘Herman constructed an autonomous system of two degrees of freedom which says that in non-convex situations, oscillations do happen and Aubry-Mather Theory cannot apply (see the results due to W. F. Chen in 1992). In this paper, it is shown that although the orbits could visit a region far away from the initial point in phase space, they can only exist in some fixed regions in I = (I1 , I2 ) plane. Moreover, Aubry-Mather Theory can be applied outside the regions.
