介绍了一种基于自适应周期的快速频率采集的谐振式压力传感器的频率测试系统。该系统利用STM32输入捕获功能实现了快速高精度频率采集,响应时间小于20 ms,测量范围10 k Hz～150 k Hz,频率测量精度优于±0.05 Hz。采用频率自适应的...介绍了一种基于自适应周期的快速频率采集的谐振式压力传感器的频率测试系统。该系统利用STM32输入捕获功能实现了快速高精度频率采集,响应时间小于20 ms,测量范围10 k Hz～150 k Hz,频率测量精度优于±0.05 Hz。采用频率自适应的周期数迭代方法,明显提升了系统的频率测量范围和准确度,适用于传感器的频率变化过程。利用该系统进行传感器性能测试,20 ms采样条件下传感器输出波动小于±5 Pa;快速变温过程(5℃/min)传感器的输出与标准器的偏差小于±30 Pa,满足航空用压力传感器的频率测试要求。展开更多
Two different methods to model a point absorber wave energy converter （WEC） with direct drive linear power take-off （PTO） are proposed in the present study： the frequency domain （FD） method and the time domain ...Two different methods to model a point absorber wave energy converter （WEC） with direct drive linear power take-off （PTO） are proposed in the present study： the frequency domain （FD） method and the time domain （TD） method. In the FD analysis, the frequency response function （FRF） of the WEC device is obtained via the equation of motion, and the expressions of power capture width in regular and random waves are derived as well. In the TD modeling, based on a state space approximation of the convolution term in the motion equation, both regular wave and random wave simulations are carded out. The regular wave simulation results indicate that the state space approximation is sufficiently accurate and the capture width reaches the maximum in the vicinity of the natural frequency. In the random wave simulations, the effects of buoy size, the PTO damping and wave climate on the power capture width are discussed in detail, which leads to the conclusion that the capture widths are influenced by the natural frequency of the WEC device, peak frequency of the wave spectrum, the amplitude of FRF and PTO damping. Furthermore, the increase of the capture width is at the cost of a relatively large buoy size and PTO damping when control is not included.展开更多
文摘介绍了一种基于自适应周期的快速频率采集的谐振式压力传感器的频率测试系统。该系统利用STM32输入捕获功能实现了快速高精度频率采集,响应时间小于20 ms,测量范围10 k Hz～150 k Hz,频率测量精度优于±0.05 Hz。采用频率自适应的周期数迭代方法,明显提升了系统的频率测量范围和准确度,适用于传感器的频率变化过程。利用该系统进行传感器性能测试,20 ms采样条件下传感器输出波动小于±5 Pa;快速变温过程(5℃/min)传感器的输出与标准器的偏差小于±30 Pa,满足航空用压力传感器的频率测试要求。
基金supported by the State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University(Grant No.GKZD010023)
文摘Two different methods to model a point absorber wave energy converter （WEC） with direct drive linear power take-off （PTO） are proposed in the present study： the frequency domain （FD） method and the time domain （TD） method. In the FD analysis, the frequency response function （FRF） of the WEC device is obtained via the equation of motion, and the expressions of power capture width in regular and random waves are derived as well. In the TD modeling, based on a state space approximation of the convolution term in the motion equation, both regular wave and random wave simulations are carded out. The regular wave simulation results indicate that the state space approximation is sufficiently accurate and the capture width reaches the maximum in the vicinity of the natural frequency. In the random wave simulations, the effects of buoy size, the PTO damping and wave climate on the power capture width are discussed in detail, which leads to the conclusion that the capture widths are influenced by the natural frequency of the WEC device, peak frequency of the wave spectrum, the amplitude of FRF and PTO damping. Furthermore, the increase of the capture width is at the cost of a relatively large buoy size and PTO damping when control is not included.
