A 3-DOF ultrasonic motor with a cylinder-shaped stator and a spherical rotor is developed. The motor provides 3-DOF rotation around x, y, and z-axes implemented by two second order bending modes with orthogonality an...A 3-DOF ultrasonic motor with a cylinder-shaped stator and a spherical rotor is developed. The motor provides 3-DOF rotation around x, y, and z-axes implemented by two second order bending modes with orthogonality and one first order longitudinal mode of the stator. The three modes must satisfy some conditions. In our previous research, in order to satisfy these conditions, a parameter fitting design method is used. However, it is an experiential design method with low efficiency and costs much time, sometimes it even cannot find a desired solution. This paper puts forward an optimal design method for the stator. Based on the method, an optimization program is developed in MATLAB environment. Using the program, a new prototype of 3-DOF ultrasonic motor is designed. Its stator has diameter of 20 mm, height of 67 mm, and mass of 157 g. Experimental results show that the measured stators′ modal frequencies and modal shapes are in good consistent agreement with the results obtained by the optimal design program.展开更多
The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiab...The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.展开更多
The aim of this study was to design three-phase induction motors with aluminum and copper cage, in the range 0.75 ÷22 kW, to fulfill the 1E3 efficiency level according to typical performance and standard constrai...The aim of this study was to design three-phase induction motors with aluminum and copper cage, in the range 0.75 ÷22 kW, to fulfill the 1E3 efficiency level according to typical performance and standard constraints. The proposed study has concerned TEFC （ totally Enclosed Fan-Cooled ）, 400 V, 50 Hz, SI duty three phase squirrel-cage induction motors only. The motors＇ designs, with AI and Cu cage, have been optimized in order to reach the minimum efficiency level IE3 at lowest active material costs and satisfy the physical and performance constraints of the designs, which are the motor specifications. A suitable optimization procedure has been used which allowed to find the ＂best design＂ by chancing the geometric dimensions of the stator, rotor shape, the stator winding and the stack length. In order to guarantee the goodness and feasibility of the optimized designs, several constrains have been imposed.展开更多
In this letter, an improved three-step search algorithm is presented, which uses both gray and chromatic information to boost the performance with random optimization and converge the motion vectors to global optima. ...In this letter, an improved three-step search algorithm is presented, which uses both gray and chromatic information to boost the performance with random optimization and converge the motion vectors to global optima. Experimental results show that this algorithm can efficiently improve the PSNR after motion compensation.展开更多
文摘A 3-DOF ultrasonic motor with a cylinder-shaped stator and a spherical rotor is developed. The motor provides 3-DOF rotation around x, y, and z-axes implemented by two second order bending modes with orthogonality and one first order longitudinal mode of the stator. The three modes must satisfy some conditions. In our previous research, in order to satisfy these conditions, a parameter fitting design method is used. However, it is an experiential design method with low efficiency and costs much time, sometimes it even cannot find a desired solution. This paper puts forward an optimal design method for the stator. Based on the method, an optimization program is developed in MATLAB environment. Using the program, a new prototype of 3-DOF ultrasonic motor is designed. Its stator has diameter of 20 mm, height of 67 mm, and mass of 157 g. Experimental results show that the measured stators′ modal frequencies and modal shapes are in good consistent agreement with the results obtained by the optimal design program.
文摘The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.
文摘The aim of this study was to design three-phase induction motors with aluminum and copper cage, in the range 0.75 ÷22 kW, to fulfill the 1E3 efficiency level according to typical performance and standard constraints. The proposed study has concerned TEFC （ totally Enclosed Fan-Cooled ）, 400 V, 50 Hz, SI duty three phase squirrel-cage induction motors only. The motors＇ designs, with AI and Cu cage, have been optimized in order to reach the minimum efficiency level IE3 at lowest active material costs and satisfy the physical and performance constraints of the designs, which are the motor specifications. A suitable optimization procedure has been used which allowed to find the ＂best design＂ by chancing the geometric dimensions of the stator, rotor shape, the stator winding and the stack length. In order to guarantee the goodness and feasibility of the optimized designs, several constrains have been imposed.
文摘In this letter, an improved three-step search algorithm is presented, which uses both gray and chromatic information to boost the performance with random optimization and converge the motion vectors to global optima. Experimental results show that this algorithm can efficiently improve the PSNR after motion compensation.
