采用板的一阶剪切变形理论,对含有压电材料层的复合材料层合板,从机电耦合的变分方程及 Hamilton 原理出发,建立起求解其动态响应的有限元方程。同时也给出了压电材料层作为传感元件时的传感方程及作为作动元件时的作动方程。并采用速...采用板的一阶剪切变形理论,对含有压电材料层的复合材料层合板,从机电耦合的变分方程及 Hamilton 原理出发,建立起求解其动态响应的有限元方程。同时也给出了压电材料层作为传感元件时的传感方程及作为作动元件时的作动方程。并采用速度反馈控制实现了层合板的主动振动控制。最后给出了计算实例。展开更多
针对星上微振动主动隔离/抑制的要求,以VCM(voice coil motor)作动器Stewart平台为控制装置,通过对其动力学模型解耦将控制转化为SISO(single input single output)问题;分析了Skyhook控制方法的隔振效果及其对抑振的局限性,在控制系统...针对星上微振动主动隔离/抑制的要求,以VCM(voice coil motor)作动器Stewart平台为控制装置,通过对其动力学模型解耦将控制转化为SISO(single input single output)问题;分析了Skyhook控制方法的隔振效果及其对抑振的局限性,在控制系统中加入了PFF(positive force feedback)控制回路,并引入加速度反馈环节以提高系统的鲁棒稳定性,形成一种振动主动隔离/抑制控制方法;利用Stewart平台的单杆开展了基础扫频激励和负载单频直接干扰共同作用下的S-DOF(single degree of freedom)微振动主动隔离/抑振控制实验,建立了Stewart平台刚/柔混合动力学模型并通过仿真研究了6-DOF振动主动隔离/抑振控制效果。实验和仿真结果表明:该方法可实现良好的振动主动隔离/抑制效果且性能稳定。展开更多
PWM变流器应用LCL型滤波结构来获得高的滤波性能。无源元件之间相互作用导致的谐振现象需使用无源阻尼或有源阻尼来抑制。相对于无源阻尼来说使用有源阻尼,采用合适的控制策略,能在保证滤波器性能的同时能耗也有所减少。提出了用有源阻...PWM变流器应用LCL型滤波结构来获得高的滤波性能。无源元件之间相互作用导致的谐振现象需使用无源阻尼或有源阻尼来抑制。相对于无源阻尼来说使用有源阻尼,采用合适的控制策略,能在保证滤波器性能的同时能耗也有所减少。提出了用有源阻尼控制策略去抑制两线间的振荡。该有源阻尼控制策略依据状态反馈的极点配置方法达到抑制共振的目的,并使用加权导纳函数来分析和选择合适的有源阻尼增益来抑制PWM变流器的低次谐波。给出了容量为10 k VA PWM变流器原型机的实验结果,实验结果验证了有源阻尼方法的有效性和设置阻尼增益方法的正确性。展开更多
Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recover...Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recovery outcome of motor dysfunction patients after stroke.Rehabilitation robots mainly have been developed along this direction to satisfy requirements of recovery therapy,or focused on one or more of the above three points.Therefore,rehabilitation robot based on neuro-machine interaction has been proposed for the paralyzed limb training of post-stroke patient,which utilizes motor related EEG,UCSDI(Ultrasound Current Source Density Imaging),EMG for the robot control and feeds back the multi-sensory interaction information such as visual,auditory,force,haptic sensation to the patient simultaneously.This neuro-controlled and perceptual rehabilitation robot will bring great benefits to post-stroke patients.In order to develop such a kind of rehabilitation robot,some key technologies,such as non-invasive precise measurement and decoding of neural signals,realistic sensation feedback,coordinated control for both the rehabilitation robot and the patient,need to be solved.In this paper,some fundamental problems in developing and optimizing such a kind of rehabilitation robot based on neuro-machine interaction are proposed and discussed.展开更多
文摘针对星上微振动主动隔离/抑制的要求,以VCM(voice coil motor)作动器Stewart平台为控制装置,通过对其动力学模型解耦将控制转化为SISO(single input single output)问题;分析了Skyhook控制方法的隔振效果及其对抑振的局限性,在控制系统中加入了PFF(positive force feedback)控制回路,并引入加速度反馈环节以提高系统的鲁棒稳定性,形成一种振动主动隔离/抑制控制方法;利用Stewart平台的单杆开展了基础扫频激励和负载单频直接干扰共同作用下的S-DOF(single degree of freedom)微振动主动隔离/抑振控制实验,建立了Stewart平台刚/柔混合动力学模型并通过仿真研究了6-DOF振动主动隔离/抑振控制效果。实验和仿真结果表明:该方法可实现良好的振动主动隔离/抑制效果且性能稳定。
文摘PWM变流器应用LCL型滤波结构来获得高的滤波性能。无源元件之间相互作用导致的谐振现象需使用无源阻尼或有源阻尼来抑制。相对于无源阻尼来说使用有源阻尼,采用合适的控制策略,能在保证滤波器性能的同时能耗也有所减少。提出了用有源阻尼控制策略去抑制两线间的振荡。该有源阻尼控制策略依据状态反馈的极点配置方法达到抑制共振的目的,并使用加权导纳函数来分析和选择合适的有源阻尼增益来抑制PWM变流器的低次谐波。给出了容量为10 k VA PWM变流器原型机的实验结果,实验结果验证了有源阻尼方法的有效性和设置阻尼增益方法的正确性。
基金supported by the National Natural Science Foundation of China ( Grant no. 61272379, 61325018)the Technique Support Project of Jiangsu Province ( Grantno. BE2014132)
文摘Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recovery outcome of motor dysfunction patients after stroke.Rehabilitation robots mainly have been developed along this direction to satisfy requirements of recovery therapy,or focused on one or more of the above three points.Therefore,rehabilitation robot based on neuro-machine interaction has been proposed for the paralyzed limb training of post-stroke patient,which utilizes motor related EEG,UCSDI(Ultrasound Current Source Density Imaging),EMG for the robot control and feeds back the multi-sensory interaction information such as visual,auditory,force,haptic sensation to the patient simultaneously.This neuro-controlled and perceptual rehabilitation robot will bring great benefits to post-stroke patients.In order to develop such a kind of rehabilitation robot,some key technologies,such as non-invasive precise measurement and decoding of neural signals,realistic sensation feedback,coordinated control for both the rehabilitation robot and the patient,need to be solved.In this paper,some fundamental problems in developing and optimizing such a kind of rehabilitation robot based on neuro-machine interaction are proposed and discussed.
