A three degree-of-freedom (DOF) ultrasonic motor (USM) with a cylinder-shaped stator and a spherical rotor is introduced, which uses one first order longitudinal and two second order bending nature vibration modes of ...A three degree-of-freedom (DOF) ultrasonic motor (USM) with a cylinder-shaped stator and a spherical rotor is introduced, which uses one first order longitudinal and two second order bending nature vibration modes of the cylinder. Control strategies for the two DOF trajectory following are studied and applied to the prototype USM. Vibration amplitude control is employed for speed regulation. The first trajectory following strategy is a step-by-step interpolation. The second strategy is vector decomposition control. Three pulse width modulation (PWM) methods for the exciting voltage regulation are investigated. These methods are compared and verified by several experiments. The key is to keep the phase differences of the three vibration constants and small exciting voltage distortion while the exciting voltages are changed for simplifing the control process and obtaining good control performance. The vector control method has advantages of small trajectory following error, smooth moving and low noise.展开更多
The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was propo...The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.展开更多
This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophore...This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.展开更多
文摘A three degree-of-freedom (DOF) ultrasonic motor (USM) with a cylinder-shaped stator and a spherical rotor is introduced, which uses one first order longitudinal and two second order bending nature vibration modes of the cylinder. Control strategies for the two DOF trajectory following are studied and applied to the prototype USM. Vibration amplitude control is employed for speed regulation. The first trajectory following strategy is a step-by-step interpolation. The second strategy is vector decomposition control. Three pulse width modulation (PWM) methods for the exciting voltage regulation are investigated. These methods are compared and verified by several experiments. The key is to keep the phase differences of the three vibration constants and small exciting voltage distortion while the exciting voltages are changed for simplifing the control process and obtaining good control performance. The vector control method has advantages of small trajectory following error, smooth moving and low noise.
基金Project(70004782) supported by the Regional Strategic Technology Development Program of the Ministry of Knowledge Economy(MKE) of KoreaProject(2011-0017407) supported by the National Research Foundation of Korea (NRF) Funded by the Korea Government (MEST)
文摘The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.
基金supported by AcRF Tier 1(RG 8/16,RG 133/14 and RG 13/15)from MOE,SingaporeSTU Scientific Research Foundation for Talents(NTF15005)+1 种基金STU Youth Research Fund(YR15001)the Foundation for Young Talents in Higher Education of Guangdong(2015KQNCX042)
文摘This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.
