Because the general object of ship steering control system is singular, the state Of rudder force and the state of disturbance are separated, and the generalized yaw output disturhance is obtained. Furthermore, singul...Because the general object of ship steering control system is singular, the state Of rudder force and the state of disturbance are separated, and the generalized yaw output disturhance is obtained. Furthermore, singular system control problem of ship yaw and sway coupled system is transferred into nonsingular standard control problem. Then according to the linear fractional denoting algorithm of the rational function parameter perturbation system, the Linear Fractional Transform （LFT） model of yaw and sway coupled motion is solved, which is used to design the ship steering robust control system. For the ship steering system with the uncertain parameters, the robust control law is designed based on H^∞ μ-synthesis. And the robust performance of the system is analyzed and the simulation validation is made. Simulation results show that the designed control system has excellent control effect and robustness.展开更多
The distribution of front abutment pressure is closely related to the force,deformation and energy distribution of hard roof before periodic weighting. So it is necessary to carry out research on the relationship betw...The distribution of front abutment pressure is closely related to the force,deformation and energy distribution of hard roof before periodic weighting. So it is necessary to carry out research on the relationship between them. According to front abutment pressure distribution feature,using the location of peak front abutment pressure as the dividing point,coal seam is divided into two parts along the direction of mining: the yield zone that is the area between the faceline and the point where the maximum front abutment pressure occurs,and the elastic zone that is the part before the point of peak front abutment pressure. The proposed mechanical model of unit width hard roof at the panel center before periodic weighting consists of five parts including the yield zone. All parameters of the deflection equations for each of the five parts that satisfy the continuity conditions and natural boundary conditions are obtained by using the Matlab software. The continuous curves of front abutment pressure,deflection,bending moment and bending strain energy density distribution of hard roof are obtained by iterative approximation method,and the relationship between the yield zone width and the above curves are analyzed in detailed.展开更多
Aiming to improve the processes involved in the industrial beneficiation of the Brazilian nuts, this work used a new methodology based on concepts of computer vision and intelligent classification, with a focus on two...Aiming to improve the processes involved in the industrial beneficiation of the Brazilian nuts, this work used a new methodology based on concepts of computer vision and intelligent classification, with a focus on two of the various stages of the processing： classification according to the origin and selection. Using the proposed methodology for the selection of the nuts it was possible to distinguish between intact and broken nuts and between good and spoiled nuts with a very high percentage of correct identifications. Also to evaluate the efficiency of the proposed methodology, visual tests by human subjects were performed for the classification of the nuts, the results demonstrated that the intelligent techniques performed the same or better than the visual classification.展开更多
文摘Because the general object of ship steering control system is singular, the state Of rudder force and the state of disturbance are separated, and the generalized yaw output disturhance is obtained. Furthermore, singular system control problem of ship yaw and sway coupled system is transferred into nonsingular standard control problem. Then according to the linear fractional denoting algorithm of the rational function parameter perturbation system, the Linear Fractional Transform （LFT） model of yaw and sway coupled motion is solved, which is used to design the ship steering robust control system. For the ship steering system with the uncertain parameters, the robust control law is designed based on H^∞ μ-synthesis. And the robust performance of the system is analyzed and the simulation validation is made. Simulation results show that the designed control system has excellent control effect and robustness.
基金supported jointly by the National Basic Research Program of China (No.2015CB251603)the National Natural Science of China (No.51374197)the Independent Project of State Key Laboratory of Coal Resources and Safe Mining (CUMT) of China (No.SKLCRSM12X06)
文摘The distribution of front abutment pressure is closely related to the force,deformation and energy distribution of hard roof before periodic weighting. So it is necessary to carry out research on the relationship between them. According to front abutment pressure distribution feature,using the location of peak front abutment pressure as the dividing point,coal seam is divided into two parts along the direction of mining: the yield zone that is the area between the faceline and the point where the maximum front abutment pressure occurs,and the elastic zone that is the part before the point of peak front abutment pressure. The proposed mechanical model of unit width hard roof at the panel center before periodic weighting consists of five parts including the yield zone. All parameters of the deflection equations for each of the five parts that satisfy the continuity conditions and natural boundary conditions are obtained by using the Matlab software. The continuous curves of front abutment pressure,deflection,bending moment and bending strain energy density distribution of hard roof are obtained by iterative approximation method,and the relationship between the yield zone width and the above curves are analyzed in detailed.
文摘Aiming to improve the processes involved in the industrial beneficiation of the Brazilian nuts, this work used a new methodology based on concepts of computer vision and intelligent classification, with a focus on two of the various stages of the processing： classification according to the origin and selection. Using the proposed methodology for the selection of the nuts it was possible to distinguish between intact and broken nuts and between good and spoiled nuts with a very high percentage of correct identifications. Also to evaluate the efficiency of the proposed methodology, visual tests by human subjects were performed for the classification of the nuts, the results demonstrated that the intelligent techniques performed the same or better than the visual classification.
