Design of Control System for Hydraulically Vibrated Processing Tomato Fruit Seedling Separation Device

2014 ◽  
Vol 651-653 ◽  
pp. 693-696
Author(s):  
Li Hong Wang ◽  
Rong Qing Liang ◽  
Cheng Song Li ◽  
Za Kan ◽  
Jin Wei Qin

Eccentric style processing tomato fruit seeding separation device exist high machining and assembly precision or other issues. In order to solve this problem, the mode of vibration of hydraulic replaced the eccentric style to drive the fruit seedling separation roller to separate processing tomato effectively. To facilitate adjustment of the hydraulic system, a kind of control circuit PLC as the core was designed according to the actual production requirements. PLC and other elements were selected. The system control signal frequency was initially set up as 1~5 HZ, within the frequency range hydraulic simulation software was used to simulate and analyze the hydraulic vibration system. The result shows that the system rams steady when the input signal frequency range was 1~5HZ.

Author(s):  
Yong-gang Leng ◽  
Yan Guo

We develop and further explore the mechanism of re-scaling frequency stochastic resonance (RFSR) based on the Kramers rate. We find that when the input signal frequency for stochastic resonance (SR) exceeds the half the Kramers rate limit, a frequency-scale ratio of RFSR should be selected to re-scale the larger signal frequency to a small SR frequency. Within the SR frequency range, we compare the performance of two approaches of realizing SR, the method of adjusting system parameters and the method of frequency-scale ratio. We showed that the former makes the half the Kramers rate approaching the signal frequency, while the latter makes the signal frequency approaching the half the Kramers rate. An engineering example demonstrates excellent performance of the re-scaling frequency for SR in fault diagnosis.


2013 ◽  
Vol 22 (03) ◽  
pp. 1350008 ◽  
Author(s):  
GORAN JOVANOVIĆ ◽  
DARKO MITIĆ ◽  
MILE STOJČEV ◽  
DRAGAN ANTIĆ

One approach to design self-tuning gm-C biquad band-pass filter is considered in this paper. The phase control loop is introduced to force filter central frequency to be equal to input signal frequency what is achieved by adjusting the amplifier transconductance gm. Thanks to that, the filter is robust to parameter perturbations and it can be used as a selective amplifier. In the full tuning range, it has a constant maximum gain at central frequency as well as a constant bandwidth. The 0.25 μm SiGe BiCMOS technology was used during design and verification of the band-pass filter. The filter has 26 dB gain, quality factor Q = 20 and central frequency up to 150 MHz. Simulation results indicate that the total in-band noise is 59 μV rms , the output third intercept point OIP3 = 4.36 dB and the dynamic range is 35 dB. Maximal power consumption at 3 V power supply is 1.115 mW.


Geophysics ◽  
2010 ◽  
Vol 75 (6) ◽  
pp. F187-F197 ◽  
Author(s):  
Ben K. Sternberg

The variability of naturally occurring magnetic fields in the frequency range from [Formula: see text] over a period of one year was studied. Contour plots for the [Formula: see text], [Formula: see text], and [Formula: see text] components and for frequencies of 10, 100, 1000, 2000, and 8000 Hz were produced. Average, minimum, maximum, and the standard deviations of these fields were also calculated for 12 distinctive time intervals. In the 1– to 8–kHz frequency range, the noise levels are typically higher at night. In the 10- to 100-Hz frequency range, the noise levels are typically higher during the day. During mid- to late-summer, there is frequent thunderstorm activity, known in the southwest United States as the monsoon season. The magnetic field levels are often very high during this time period. These variability ranges can be used to estimate the lowest levels of noise that may be encountered during field surveys, which iswhat the authors are looking for when running controlled-source electrical method surveys. These variability ranges can also be used to estimate the highest levels that may be encountered, which is what the authors are looking for when running natural-source electrical methods surveys, such as audio frequency magnetotelluric (AMT) surveys. These measurements of magnetic field strength variability show that better data for controlled-source electrical measurements can be obtained using the minimum noise level measurements, as opposed to using signal integration or signal averaging with all of the data. The minimum noise level is found by using frequency bins adjacent to the signal-frequency bin. Likewise, if one is interested in measuring the naturally occurring magnetic field data, using the maximum values during each time interval makes AMT measurements possible when the natural signal level is very low, particularly in the AMT dead zone around [Formula: see text].


Author(s):  
E. A. Romaniuk ◽  
V. Yu. Rumiantsev ◽  
Yu. V. Rumiantsev ◽  
A. A. Dziaruhina

Digital filters made with the use of discrete Fourier Transform are applied in most microprocessor protections produced both in the home country and abroad. When the input signal frequency deviates from the value to which these filters are configured, a signal is generated at their output with oscillation amplitude that is proportional to the deviation of the signal frequency from the specified one. The article proposes an algorithm for compensating the oscillations of orthogonal components of the output signals of digital filters implemented on the basis of a discrete Fourier transform, when the input signal frequency deviates from the nominal one. A mathematical model of the proposed digital filter with an algorithm for compensating the oscillations of its orthogonal components, as well as a signal model for reproducing input effects, is implemented in the MatLab-Simulink dynamic modeling environment. The digital filter model is provided with two channels, viz. a current channel and a voltage channel, which makes it possible to simulate their operation in relation to protections that use one or two input values, for example, for current and remote protection. Verification of the functioning of the digital filter model with compensation for fluctuations in its output signal was carried out with the use of two types of test effects, viz. a sinusoidal signal with a frequency of 48–51 Hz (idealized effect), and the effects that are close to the real secondary signals of measuring current transformers and voltage transformers in case of short circuits accompanied by a decrease in frequency. The conducted computational experiments with deviation of frequency from the nominal one, revealed the presence of undamped oscillations at the output of standard digital Fourier filters and their almost complete absence in the proposed digital filters. This makes us possible to recommend digital filters based on a discrete Fourier transform supplemented by an algorithm for compensation of fluctuations in the amplitudes of the output signals for the use in microprocessor protection.


2013 ◽  
Vol 310 ◽  
pp. 518-523
Author(s):  
Zhi Qiang Chao ◽  
Xin Ze Li ◽  
Ai Hong Meng

In recent years, hydraulic simulation has become an important means to research hydraulic system, in order to enable the single degree platform vibration curve with better traceability and reach the requirement of the test, this paper represent single degree system platform stimulated by simulation software AMESim, taking the Single degree freedom vibration hydraulic system as an example, MATlab/simulink is applied to the design of the vibration platform system fuzzy PID controller. Through the comparison between the simulation test and traditional PID controller, the designed self-tuning fuzzy controller can control the platform better, with smaller overshoot, faster response, shorter adjusting time, as well as fulfill the permissible accuracy.


Author(s):  
John S. Morse

Abstract A graphical method is proposed for removing the “drudge work” of looking up property values and solving the conservation equations and second law in an Applied Thermodynamics course. The vehicle used is VisSim simulation software. The method requires the student to perform the thermodynamic analysis and set up the equations, but the computer finds the property values and solves the equations. This concept allows the student to explore various aspects of the topics covered in such a course, including power and refrigeration cycles, mixtures and psychrometrics, and combustion and equilibrium. Substantial design type problems can be solved easily, as can complicated analyses that are too difficult and time consuming for traditional solution methods.


Author(s):  
Ying Liu ◽  
Qimin Wang ◽  
Xiaoxiao Li ◽  
Liming Wang

In this paper, the transformation of steam turbine regulating system from mechanical hydraulic regulation to electro-hydraulic regulation is realized. And the internal leakage mechanism of the hydraulic control switch valve and the electro-hydraulic proportional valve in the system is analyzed. With the use of hydraulic simulation software AMESim, the mathematical model of the electro-hydraulic control system after transforming is established. The parameters of the hydraulic control switch valve and the electro-hydraulic proportional valve in the hydraulic control system of steam turbine inlet valve are studied under different internal leakage locations and different leakage degree, such as piston regulating time, steady position of piston, oil pressure and leakage flow flux. The fault characteristic table of internal leakage is obtained. An experimental platform for simulating internal leakage is built. The experimental curves of several physical quantities under different internal leakage conditions are obtained. The experimental results prove that the internal leakage has a great impact on the performance of the electro-hydraulic control system. The results of internal leakage experiment are consistent with those of internal leakage simulation.


2012 ◽  
Vol 201-202 ◽  
pp. 202-207
Author(s):  
Zhi Hua Li ◽  
Hong Guang Yang ◽  
Jun Yu ◽  
You Ping Gong

There is still lack of effective modeling and simulation method for complex electromechanical coupling system. Modelica is a multi-domain unified modeling language to solve the modeling and simulation problems of the complex and heterogeneous physical systems. Dymola is a Modelica-based modeling and simulation platform for the complex physical systems. In this paper, the dynamics model of the permanent magnet synchronous motor (PMSM)-precision reducer system is established using Lagrange-Maxwell equation. The simulation model of this system is set up with Modelica language. The simulation of the system is realized in Dymola. Results show that the system can respond to good static and dynamic characteristics under a given speed for different loads. The dynamics model of the PMSM-precision reducer system can be further used in system control and optimization. The proposed modeling and simulation method based on Modelica may be commonly applied to other complex electromechanical systems.


2012 ◽  
Vol 229-231 ◽  
pp. 941-944
Author(s):  
Fei Yan ◽  
Zhong Cai Yuan ◽  
Yong Wang ◽  
Shi Lian Gong ◽  
Zheng Li

This paper presents numerical results in the form of graphs of the power reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with two layers of inhomogeneous plasma slabs. The plasma electron density varies only in the direction perpendicular to the plane. Parameters considered in the computation cover a relatively wide range and the functional dependence of the power reflection coefficients on these parameters is studied. The results indicate that in a rather broad frequency range, the electromagnetic attenuations by the double slabs obviously excel the sum of attenuations resulted from two plasma layers when each layer exits respectively. The structure presented is easy to set up, which is instructive for plasma stealth.


2010 ◽  
Vol 168-170 ◽  
pp. 2315-2320
Author(s):  
Mei Yang ◽  
Qing Shen Zeng ◽  
Hong Yu Wang ◽  
Wei Xing Zhang

Resin transfer molding (RTM) is a very important category of low cost fibre reinforcement composite material manufacturing technique. But void which mainly formed at the process of filling and infiltration is able to reduce the performance of products. This paper first introduced how harmful the void is, and then formation theory, finally focus on the technical feature and resent evolution. Numerical simulation is always a mature and efficient research method for this field of investigation. Formerly, scientists also attribute their effort to such investigation, but, at that time, their simulation was 1D or 2D which can not represent the process accurately enough. Therefore the results are not so significant. Recently most studies pay attention to 3D simulation and how factors (such as injection pressure, structure of preform and so on) work. With the development of mathematic theory and simulation software some new numerical simulation methods present itself. Researchers may copy the course of resin’s filling in RTM more integrity to make their relation close to reality. Based on their achievement, the technique of RTM also improved to eliminate void’s emergence. However the real flow of resin is more than complex, more work should be done to avoid it and then set up a controllable industrial production system.


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