Yan Xin Yu

Design of the Remote Liquid-Level Real-Time Monitoring System Based on Virtual Instrument

Real-time accurate level monitoring plays an important role in the field of industrial and agricultural production. In this paper, the remote real-time monitoring display system of liquid level was designed based on virtual instrument. The liquid-level data was obtained from ultrasonic sensor and data acquisition card, and then was transmitted to a remote client via ethernet without delay by the DataSocket technology. The real-time information of liquid level was displayed on the user interface of the client which was compiled based on LabVIEW. Test results show that this system can accurately monitor the remote real-time information of liquid level.

A New Method of Doppler frequency and DOA Estimation Based on Gradient-time-delay

This paper proposes that arrays of spatio-temporal data matrix was constructed by the arrays of the received signal delayed in time gradient, Meanwhile, applying the method of ESPIRT to get the twiddle factor of the received signal array element and the array element of the time and the space, finally get the final information of Doppler frequency and the information of arrival angle though applying least squares method.

A Method for Designing Low Peak to Average Power Cognitive Radar Waveform

In this paper, the basis function of TDCS system (Transform Domain Communication System) is used to design cognitive radar transmitter waveform. Based on the noise environment, the waveform can be adjusted adaptively. Then after clipping to reduce the PAPR (Peak to Average Power Ratio) of radar echo signal, the obtained signal is used as the next launch of the radar signal. The cognitive radar transmitter requires a nonlinear waveform to improve the efficiency of radar transmitter power amplifier, so reducing the PAPR of signal is essential. This paper presents the gray complementary sequence is applied to TDCS communication systems, and then it needs to reduce PAPR of signals by clipping. Proven, PAPR of the transmitted signal is maintained at about 3.25dB, and the signal has a low probability of intercept, high anti-interference ability and distant target detection range.

Test and Simulation System of Multi-Axis Controller

To realize the online error analysis and verification of control strategy, it is necessary to simulate the states of the motion mechanism, and accurately to obtain the motion relationship between multi-axis and between motors. So a test and simulation system of multi-axis controller was designed. The system consists of a unit of real-time acquisition and analysis, a simulation unit of motor loads, a motherboard and a computer. Motor driving signals for multi channels are synchronously sampled and analyzed by the unit of acquisition and analysis. Motherboard is used to link the various parts. The working states of motor divers under loads are simulated by simulating the motor loads. In the industrial computer, the control effects of multi-axis control system are displayed by 3D simulation. Test results show that the system is stable and reliable, and has a certain application value.

Improved Modeling and PID Control Algorithm for Three-Tank Liquid Level System

Three-tank liquid level system is a more typical non-linear and delay object with strong representation and background of industry. The part or whole of many objects can be abstracted into a mathematical model of three-tank liquid level system. Research on modeling and control of the system has important theoretical significance and practical value. This article describes how to use Simulink function to establish the mechanism of three-tank liquid level system model. And at the time, an improved PID control algorithm is proposed. The results show that it has more superior performance for three-tank liquid level system simulation control compared with the traditional PID control algorithm.

Design of SPR Spectrometer Automatic Sampling Control System

SPR detection technique is widely applied in biology, chemistry and other fields. Usually the unknown sample is liquid, so automatic sampling control system is an important part of SPR spectrometer. This paper introduces an automatic sampling control system design as the core of microcontroller and step motor, of which the main function is to control the volume and speed of trace liquid sample according to the parameters set by operators via user interface based on LabVIEW software. The test results show that the system has the advantages of convenient operation, high intelligence, high accuracy and so on, compared with the traditional instruments.