An improved OPCL method is developed and applied to both small swing and giant rotation synchronization of a two-link mechanism. Transition processes of the two kinds of synchronization are discussed. Comparisons of d...An improved OPCL method is developed and applied to both small swing and giant rotation synchronization of a two-link mechanism. Transition processes of the two kinds of synchronization are discussed. Comparisons of different motion characteristics of the two-link synchronization and the effects of different control parameters on synchronous processes are investigated with numerical simulations.展开更多
主动快门式3D技术的关键在于左右眼帧序的同步,尤其在无线及多人观看的条件下,帧序同步仍存在着很多问题。提出了一种在DLP Link 3D投影显示平台上利用红外光通信实现统一帧序同步的解决方案,旨在进一步提高DLP Link主动快门3D技术的易...主动快门式3D技术的关键在于左右眼帧序的同步,尤其在无线及多人观看的条件下,帧序同步仍存在着很多问题。提出了一种在DLP Link 3D投影显示平台上利用红外光通信实现统一帧序同步的解决方案,旨在进一步提高DLP Link主动快门3D技术的易用性和灵活性。展开更多
A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensa...A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensation link is classified as both a real pole compensator(RPC) and a complex pole compensator(CPC) according to the pole position. Given a model for the VCI power output, the design process for the second-order compensation link, which is equipped with an RPC and a CPC, is detailed. Moreover, the frequency-domain compensation effects of the RPC and CPC are analyzed using the root locus and Bode diagrams of the system before and after compensation. Finally, the compensation effects of the two types of second-order compensators are compared with the commonly used high-pass filter using MATLAB/Simulink, which verifies the RPC and CPC strategies. Simulation results show that the two types of compensators designed in this study can effectively increase the system cutting frequency and improve the phase margin in the frequency domain while accelerating the power synchronization process, simultaneously making it smoother and reducing overshoot in the time domain. The RPC has better gain robustness, whereas the CPC has better time constant robustness. By implementing an RPC or a CPC, the dynamic time of the power synchronization compensation strategy is reduced within 0.5 s, and the overshoot is reduced within 10% in the experiments with two inverters.展开更多
在纺织布匹疵点检测系统中,获取平稳清晰图像对后续布匹图像疵点的精确检测和类别正确识别至关重要。由于布匹疵点检测系统外部事件的不可预测性,如何控制线阵CCD以获取平稳清晰的图像。针对这一问题提出了一种线阵CCD相机外同步控制方...在纺织布匹疵点检测系统中,获取平稳清晰图像对后续布匹图像疵点的精确检测和类别正确识别至关重要。由于布匹疵点检测系统外部事件的不可预测性,如何控制线阵CCD以获取平稳清晰的图像。针对这一问题提出了一种线阵CCD相机外同步控制方法。该方法采用VHDL语言在Xilinx公司Virtex-II PRO FPGA架构上设计实现。重点介绍了相机自适应的外同步控制设计方案和实现方法,通过ModelSim仿真和布匹疵点检测系统的在线测试,验证了该方法的有效性和可行性。展开更多
A flux linkage compensation field oriented control (FOC) method was proposed to suppress the speed and torque ripples of a brushless wound-field synchronous motor in its starting process. The starting process was anal...A flux linkage compensation field oriented control (FOC) method was proposed to suppress the speed and torque ripples of a brushless wound-field synchronous motor in its starting process. The starting process was analyzed and the model of wound-field synchronous electric machine was established. The change of field current of the electric machine was described mathematically for simplified exciter and rotate rectifier. Based on the traditional field control, the flux linkage compensation was introduced in d-axis current to counteract the flux ripple. Some simulation and preliminary experiments were implemented. The results show that the proposed method is feasible and effective.展开更多
Study of chaotic synchronization as a fundamental phenomenon in the nonlinear dynamical systems theory has been recently raised many interests in science, engineering, and technology. In this paper, we develop a new m...Study of chaotic synchronization as a fundamental phenomenon in the nonlinear dynamical systems theory has been recently raised many interests in science, engineering, and technology. In this paper, we develop a new mathematical framework in study of chaotic synchronization of discrete-time dynamical systems. In the novel drive-response discrete-time dynamical system which has been coupled using convex link function, we introduce a synchronization threshold which passes that makes the drive-response system lose complete coupling and synchronized behaviors. We provide the application of this type of coupling in synchronized cycles of well-known Ricker model. This model displays a rich cascade of complex dynamics from stable fixed point and cascade of period-doubling bifurcation to chaos. We also numerically verify the effectiveness of the proposed scheme and demonstrate how this type of coupling makes this chaotic system and its corresponding coupled system starting from different initial conditions, quickly get synchronized.展开更多
基金supported by the Key Project of Science and Technology Research of Ministry of Educationof China (No. 108037)the National Natural Science Foundation of China (No. 10402008 and50535010)
文摘An improved OPCL method is developed and applied to both small swing and giant rotation synchronization of a two-link mechanism. Transition processes of the two kinds of synchronization are discussed. Comparisons of different motion characteristics of the two-link synchronization and the effects of different control parameters on synchronous processes are investigated with numerical simulations.
基金supported by the National Key R&D Program Funding Projects (No.2018YFB1503001)the Science and Technology Plan Project of the Shanghai Science and Technology Commission (No.21DZ1207300)the Industrial Strengthening Program Projects from the Shanghai Municipal Commission of Economy and Informatization (No.GYQJ-2022-1-14)。
文摘A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensation link is classified as both a real pole compensator(RPC) and a complex pole compensator(CPC) according to the pole position. Given a model for the VCI power output, the design process for the second-order compensation link, which is equipped with an RPC and a CPC, is detailed. Moreover, the frequency-domain compensation effects of the RPC and CPC are analyzed using the root locus and Bode diagrams of the system before and after compensation. Finally, the compensation effects of the two types of second-order compensators are compared with the commonly used high-pass filter using MATLAB/Simulink, which verifies the RPC and CPC strategies. Simulation results show that the two types of compensators designed in this study can effectively increase the system cutting frequency and improve the phase margin in the frequency domain while accelerating the power synchronization process, simultaneously making it smoother and reducing overshoot in the time domain. The RPC has better gain robustness, whereas the CPC has better time constant robustness. By implementing an RPC or a CPC, the dynamic time of the power synchronization compensation strategy is reduced within 0.5 s, and the overshoot is reduced within 10% in the experiments with two inverters.
文摘在纺织布匹疵点检测系统中,获取平稳清晰图像对后续布匹图像疵点的精确检测和类别正确识别至关重要。由于布匹疵点检测系统外部事件的不可预测性,如何控制线阵CCD以获取平稳清晰的图像。针对这一问题提出了一种线阵CCD相机外同步控制方法。该方法采用VHDL语言在Xilinx公司Virtex-II PRO FPGA架构上设计实现。重点介绍了相机自适应的外同步控制设计方案和实现方法,通过ModelSim仿真和布匹疵点检测系统的在线测试,验证了该方法的有效性和可行性。
基金Sponsored by the NSFC General Project (51177135)the Key Project of Natural Science Foundation of Shaanxi Province (2011GZ013)
文摘A flux linkage compensation field oriented control (FOC) method was proposed to suppress the speed and torque ripples of a brushless wound-field synchronous motor in its starting process. The starting process was analyzed and the model of wound-field synchronous electric machine was established. The change of field current of the electric machine was described mathematically for simplified exciter and rotate rectifier. Based on the traditional field control, the flux linkage compensation was introduced in d-axis current to counteract the flux ripple. Some simulation and preliminary experiments were implemented. The results show that the proposed method is feasible and effective.
文摘Study of chaotic synchronization as a fundamental phenomenon in the nonlinear dynamical systems theory has been recently raised many interests in science, engineering, and technology. In this paper, we develop a new mathematical framework in study of chaotic synchronization of discrete-time dynamical systems. In the novel drive-response discrete-time dynamical system which has been coupled using convex link function, we introduce a synchronization threshold which passes that makes the drive-response system lose complete coupling and synchronized behaviors. We provide the application of this type of coupling in synchronized cycles of well-known Ricker model. This model displays a rich cascade of complex dynamics from stable fixed point and cascade of period-doubling bifurcation to chaos. We also numerically verify the effectiveness of the proposed scheme and demonstrate how this type of coupling makes this chaotic system and its corresponding coupled system starting from different initial conditions, quickly get synchronized.
