High frequency signal acquisition and control system based on DSP+FPGA

2017 ◽  
Author(s):  
YaDong Yin ◽  
DaZhi Zhang ◽  
XiaoQi Liu
Keyword(s):  
Control System ◽  
High Frequency ◽  
Signal Acquisition ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
And Control

scholarly journals A Facile Strategy for Visualizing and Modulating Droplet-Based Microfluidics

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 291 ◽  
Author(s):  
Zehang Gao ◽  
Huo Peng ◽  
Minjie Zhu ◽  
Lei Wu ◽  
Chunping Jia ◽  
...  
Keyword(s):  
High Throughput ◽  
High Frequency ◽  
Imaging System ◽  
Low Cost ◽  
Low Frequency ◽  
Microfluidic Chips ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Additional Signal ◽  
And Control

In droplet-based microfluidics, visualizing and modulating of droplets is often prerequisite. In this paper, we report a facile strategy for visualizing and modulating high-throughput droplets in microfluidics. In the strategy, by modulating the sampling frequency of a flash light with the droplet frequency, we are able to map a real high frequency signal to a low frequency signal, which facilitates visualizing and feedback controlling. Meanwhile, because of not needing synchronization signals, the strategy can be directly implemented on any droplet-based microfluidic chips. The only cost of the strategy is an additional signal generator. Moreover, the strategy can catch droplets with frequency up to several kilohertz, which covers the range of most high-throughput droplet-based microfluidics. In this paper, the principle, setup and procedure were introduced. Finally, as a demonstration, the strategy was also implemented in a miniaturized picoinjector in order to monitor and control the injection dosage to droplets. We expect that this facile strategy supplies a low-cost yet effective imaging system that can be easily implemented in miniaturized microfluidic systems or general laboratories.

Variable Multi-Channel High Frequency Signal Acquisition System

2013 ◽  
Vol 798-799 ◽  
pp. 515-519
Author(s):  
Yan Jun Zhang ◽  
Li Xia Di ◽  
Jing Cui ◽  
Jing Yang
Keyword(s):  
Real Time ◽  
High Frequency ◽  
Computer Software ◽  
Digital Signal ◽  
Storage Device ◽  
Signal Acquisition ◽  
Control Logic ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Flexible System

A flexible system to multi-channel high frequency signal acquisition and transmission was designed. The system took FPGA as the center control logic unit. It could realize real-time acquisition, conditioning, modulus conversion to multi-channel high frequency signal and sent the converted digital signal to the storage device through FIFO. The system could also realize the real-time monitoring, data unpacking and analysis to storaged data by using computer software. FPGA software design adopted VHDL language. The experiment results show that this data acquisition and transmission system is stable and accurate.

Dither in a rolling airframe flight vehicle with a two-position actuator: An amplitude distribution approach

2016 ◽  
Vol 39 (8) ◽  
pp. 1205-1215 ◽  
Author(s):  
Bahram Mohammadi ◽  
Mohammad Reza Arvan ◽  
Yousof Koohmaskan
Keyword(s):  
High Frequency ◽  
Degrees Of Freedom ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Amplitude Distribution ◽  
Feedback System ◽  
Flight Vehicle ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Minimal Error

Rolling airframe manoeuvring is a type of manoeuvre in which the missile provides continuous roll during flight. Cross-coupling between the angle of attack and sideslip in rolling airframe missiles (RAMs) yields a coning motion around the flight path. As the pitch and yaw cross-coupling effect decreases, the radius of this coning motion decreases and the accuracy of the control system increases. Two-position (on–off) actuators are used in most RAMs. The presence of a two-position actuator in a feedback system makes its characteristics non-linear. A high-frequency signal so-called dither is applied to compensate for the non-linearity effect of the actuator characteristic in the feedback system and to stabilize the coning motion. The amplitude distribution function (ADF) method in dither analysis shows that the smoothed non-linearity characteristic can be computed as the convolution of the original non-linearity and the ADF of the dither signal. According to the four-degrees-of-freedom (4-DOF) equations of RAMs in a non-rolling frame and regarding various dither signals through the ADF approach on a two-position actuator, an analytical condition for dither amplitude in coning motion stability of RAMs is derived. It was shown that the triangular signal with specified amplitude and high enough frequency led to a smoother response of two-position actuators. Finally, by applying beam-riding guidance to a RAM, the performance of dithers for decreasing the distance of the missile from the centre of the beam is validated through simulations. It is illustrated that applying the triangular dither resulted in minimal error.

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