Papers by Keyword: Data Acquisition (DAQ)

Abstract: The multiplexer act as the inputs of analog signals, enabling multi-channel analog signal acquisition; then filtered through a certain signal processing to ensure the most effective analog signals into the ADC; after conversion, the digital output is saved in the temporary buffer zone of the FPGA. The whole process is controlled by the FPGA. Finally, apply to the DAC-ADC joint debugging, in compare to the results, 14bit precision is guaranteed.

Abstract: An audio signal acquisition and analysis system with low-cost and high performance was developed, taking LabVIEW as the software development platform and the computer sound card as hardware platform. This system is capable of audio signal acquisition, real time dynamic display, analysis processing, storage and display of audio signal. Practical application shows that this system not only has those advantages such as high-precision, stability, reliable performance and being easy-operated, but also can achieve common data-acquisition within the designed frequency range of the sound card. The signal acquisition technology based on the sound card, especially the technology combining with virtual instruments has broad prospects in the field of engineering test measurement and teaching practice.

Abstract: Tire dynamic balance detection plays an important part in tire quality detection area. An accurate model structure and precise model parameters are the basis of the right test results. This paper builds a kinetic model based on engineering practice. To acquire parameters presents a method following identification theory. According to the need of actual production, a validation experiment is put forward. In the parameter identification process, data acquisition is completed by the PCI card. For data processing, this paper designs the fitting filter and then it also fetches the signal amplitude and phase with discrete Fourier transform. The results are proven to be right and practicable.

Abstract: Based on the analysis of the testing automatic transmission (AT), the AT’s solenoid valve control signals conditioning circuits and revolving speed F/V converter conditioning circuits are designed, and the data acquisition system is designed based on virtual instrument. The system is composed of the PCI-6024E data acquisition card, signal conditioning circuits and computer, and the acquisition procedure is programmed in graphical language LabVIEW. Finally, the data acquisition system has been verified on vehicle test bench which loads ZF-Ecomat 6HP500 AT. Controlling signals of switching solenoid valves, duty cycle signal of proportional solenoid valve, accelerator aperture signal, oil pressure signals and speed signals are collected, it turns out that the data acquisition system has good feasibility.

Abstract: Internet-enabled calibration, which is rapidly developing in recent years, combines the techniques of the Internet and metrology. So far, all the approaches realized for remote calibration of electrical instruments need to transfer high-accuracy units to the calibration site. This paper proposes a system using Virtual Instrument (VI) instead of traveling standard. The accuracy of data depends on the precision of data acquisition (DAQ) system and reliability of the Internet. Two basic architectures are given and several crucial techniques are discussed.

Abstract: As it is difficult to measure the temperature accurately under actually environment, this paper develops a virtual temperature measurement system based on LabVIEW. The system consists of AD590 temperature sensor and virtual instrument, and the properties and structure of AD590 is discussed in this paper. In addition, we do some research on the measurement method, and use soft filter and Normalized method to remove noise and improve the measurement accuracy. The structure and soft system of the virtual instruments system are designed and a high value measurement system is achieved using the resources of the virtual instruments. The experimental results have shown that the system can satisfy the accurate requirement in harsh condition.

Abstract: Telemetering power supply and distribution system is an important part of the telemetry system. Arming at a telemetering power supply and distribution system, this paper adopts digital multimeter and multiplex switch based on PXI bus to realize 32-channel power supply and distribution DC voltage signal acquisition, storage, real-time monitoring and analysis, and also automatic data interpretation. The system consists of PXI host, multiplex switch, digital multimeter, interface unit, a control software and so on, which has the advantages of high precision, high efficiency, easy to operate, and has been used successfully in the test of a telemetry system.

Abstract: In this paper, a flammable gas monitoring circuit is designed based on TGS813 that is a flammable gas sensor and has the characteristic of long life-pan, low prices. The principle and structure of TGS813 are introduced as well as applied in multi-channel data acquisition circuit.

Abstract: In Virtual instrument (VI) established for computer based automated test and control, the process with only single thread has limits when developed for acquiring high speed data, analyzing and displaying them the meaning while. Any interference from another task may block the whole running process and cause data missing. In order to increase the throughput, responding time and multi-task processing efficiency of VI, multi-thread programming with the platform LabWindows/CVI is introduced in this paper. Contents include the two strategies to establish multi-thread program, Thread pool and Asynchronous Timer, and how to protect data with multi-thread programming. Finally, a case study showed a multi-thread VI based on Asynchronous Timer method, with the comparison of performance between single thread and multi-thread program.

Abstract: This thesis offers a kind of multiple channels data acquisition device & system based on the sound card. The device converts input signals into frequency signals, and sound card collects the frequency signals. Then the frequency signals collected is restored into input signals by software. By doing so, it resolves the problem which the sound card can’t collect low frequency signals or dc signals. Meanwhile, using a piece of MCU controls the multi-channel analog switch, and the MCU also issues multi-path identification signals to the sound card. So the function of multiple signals collection is achieved.