Industrial Instrumentation and Control Systems II

文章题目 页数

作者: Yan Jun Zhang, Wen Sheng Qiao, Jin Ling Wang
摘要: In the background of requirement which apply in aerospace remote measurement electronic equipment, a new requirement for the universal degree to the remote measurement system is proposed. This paper design communicating solutions of the multi-interface device, hardware circuit,FPGA as the core logic controller, coordinating RS-422 interface chip, Ethernet controller W5300,USB-FIFO,FT245 interface chip and other functional modules. The communication equipment has a variety of interfaces; achieve the reliability of transmission of high data rate. This has been applied for engineering practice and improves the efficiency of the design of the remote measurement equipment and maintenance.
作者: Xi Qin, Chang Qing Feng, De Liang Zhang, Lei Zhao, Shu Bin Liu, Qi An
摘要: Theoretical analysis and performance of multi-time averaging TDCs are presented in this paper. The TDCs are implemented in an Actel flash-based FPGA A3PE1500 using delay lines for time interpolating and utilizing CMOS buffers as the delay elements. Wave-union and Multi parallel delay chains method are employed for multi-time averaging to improve timing performance. The 17 times Wave-union TDC can achieve a best resolution of 32 ps RMS, while the 20 times Multi delay chains TDC can achieve a minimum resolution of 23 ps RMS. Without the multi-time scheme, the TDC resolution is 127 ps RMS and 427 ps averaged bin size.
作者: Bai Fen Liu, Ying Gao
摘要: Digital control algorithm common neural networks, fuzzy control, digital PID digital PID technology used widely and mature, the digital PID proportional, integral, derivative control the abbreviation. These advantages: simple in principle, applicability; little within the small range of the controlled object parameter changes on the performance indicators, a great guarantee the validity of the regulation. PID is the most successful control strategy in the analog control technology, digitized; people naturally will this control strategy is grafted onto the digital control technology. The system is digital PID.Used to implement a digital control chip has many, e.g., microcontroller, field programmable gate arrays (FPGAs), digital signal processor (DSP) and the microcontroller (ARM). SCM is the first large-scale application of the controller, but due to the speed of operation and the median can not meet the growing industrial control requirements. .
作者: Hong Xu, Yong Jun Zhang, Ping Zhang
摘要: This paper describes a portable food can be several key techniques in the design of electronic balance. First introduced the electronic balance control planning and power in the hardware design. Then analysis system software development process, and gives the software method to reduce system power consumption, and improve the system operation speed by adjusting the position of software code. The scheme of the embedded network communication system, for consumers and food operators to provide a friendly interface, service, humanity has the advantages of simple operation, low power consumption, good portability, meets the requirements of food traceability and food supervision.
作者: Wu Zhu, Jia Min Zhang, Yuan Zhang, Juan Juan Yu, Shi Bing Wu
摘要: With the improvement of output frequency of electric fast transients (EFT) burst generator, amplitude attenuation of pulse train appeared in the high frequency. Therefore, the method of pulse width programmed digitally ,and realized by Field Programmable Gate Array (FPGA) device was put forward to overcome burst amplitude attenuation. The technology of direct digital frequency synthesis was used to adjust the output signal frequency changes. The linear array memory with one bit was adopted to store square-wave waveform, the output signal duty cycle is digital adjustable, which is achieved by changing the waveform data in the linear array memory. Brust generator is designed by using VHDL languages in the QUARTUS II 6.0 simulation platform. The simulation and experiment results show that when the frequency of the output signal reaches 1 MHz, frequency resolution arrives at 6Hz, error of pulse width is less than 10 ns.
作者: Xing Zhe Piao, Hai Yin Piao, Song Yang
摘要: The design principles of conversion circuit for intellect vortex flow-meter with MSP430 microcontroller used as the core was described in detail. The implementation plan of system development was confirmed based on the analyzing of the key technology of vortex flow-meter, which collected and processed the pulse signal from the pre-amplified circuit and sent to the module of D/A conversion converted into standard 4 ~ 40 mA output. The key of the design of hardware circuit and implementation of software was stated. The result tested and approved by the site shows that the technology index has met the design requirement with the character of reliability, which solves the problem of the large wastage of power and low stability. Its performance can be comparable with that of the same import products and its cost is much lower. It has a broad market prospect.
作者: Xin Yue Kan, Li Feng Wen, Hui Ling Zhou, Shu Yun Wang
摘要: To improve energy harvesting performance, a magnet-coupled piezoelectric vibration energy harvester (MCPEH) for low-level and low-frequency vibration was presented and investigated experimentally. The MCPEH consisted mainly of a piezo-cantilever with a permanent magnet at its free-end and another excitation magnet fixed on vibration structure. The magnets are used to produce magnetic attractive force to enhance energy generation. A MCPEH was fabricated with a piezo-cantilever measured 60x10x0.5mm3 and two magnets sized ø12x3mm3. The testing results show that the magnetic force, denoted by the initial separated distance between the magnetic dipoles (SDMD), exerts great influence on all of the generated voltage, optimal frequency, and effective bandwidth. With the SDMD reducing from 40mm to 15mm, the optimal frequency decrease from 32.75Hz to 30.5Hz, the effective bandwidth for the MCPEH to generated voltage of 15V rises from 2.5Hz to 7.5Hz, and the generated voltage rises from 30.4V to 44.4V.
作者: Xian Guang Fan, Xin Wang, Ying Jie Xu, Zhen Bang Hu, Zhen Wang
摘要: Online viscosity and density estimation of ternary solution with sucrose and sodium chloride means a lot in osmotic dehydration of food. The authors proposed a novel B-spline method using recursive least squares to estimate viscosity and density using concentrations of the two solutes and temperature. A 4-D B-spline is established to estimate viscosity with the inputs of sucrose concentration, sodium chloride concentration and temperature. And a 3-D B-spline is also established to estimate density in a fixed temperature. The maximum relative errors of viscosity and density estimation are 0.0062% and 1.33×10-5% respectively which show that the method is of high accuracy and suitable for practical application.
作者: Zhi Wei Cao, Yi Ming Zhang, Xu Zhang
摘要: The Forward Switch mode power supply is good selection for power supplies of Unmanned Aerial Vehicle (UAV). Compared with the conventional forward converter, there is one auxiliary switch in the active clamp forward converter to recycle the energy stored in the transformer leakage in order to minimize the voltage stress of the main switch. The power system is designed and the operation characteristics of the active switching power supply are revealed by analysis a typical second-order system in this paper. Active Clamp Forward Converter reduce the generation of EMI, the EMC of UAV equipment is greatly improved. The results of the analysis are verified by SPICE simulation.