Research On Data Acquisition System Of Multi-channel Wheel Load Weighing Instrument

In mechanical engineering area, vehicle wheel load measurement is the basis ofacquiring the parameters such as vehicle quality and centroid position. The existingmeasurement method is difficult to achieve the centroid position measurement ofmulti-axial vehicle. In order to acquire the centroid parameter of multi-axial vehicleon a tilting table, it is necessary to develop a wheel load weighing instrument whichcan be applied in horizontal and inclined state. The research on the data acquisitionsystem of multi-channel and integrated wheel load weighing instrument is conductedin this thesis.According to the actual working condition of wheel load weighing instrument,determine the requirements and precision index of data acquisition system. Analysisof structure decoupling and anti-partial load characteristics of wheel load weighinginstrument is made, and construct the integrated weighing platform with nine channelsensor signal output. In accordance with the measured signal characteristics and thepractical applications requirements, the signal conditioning, data acquisition andprocessing scheme of wheel load measurement system is determined.The designed wheel load measurement system works in a complicatedenvironment, it will be affected by factors like temperature, humidity, voltagefluctuation, electromagnetic fields. Anti-interference technologies such as isolation,filtering and grounding are applied in the hardware part, which enhance theanti-interference performance of system. The hardware design content containspower module selection, multi-channel signal switching, signal conditioning, analogto digital conversion, optical isolation, data display, temperature detecting,communication interface module. By choosing high precision and high performanceelectronic components, taking effective anti-interference measures, data acquisitionprecision of the electrical measurement system is improved.Electrical measurement system is composed of hardware and software. In this thesis, LabVIEW programming technology is used to develop the PC software. Themain body of software contains single channel acquisition module, multi-channelacquisition module, data management module, temperature detecting module. Bydesigning functional interface of each module, mainly achieving user rightsmanagement, multi-channel data switching and acquisition, data real-time displayand storage, waveform playback of off-line data, data fitting of measurement results,detecting and alarming of system working environment temperature. With the help ofPC’s powerful computing capability, The real-time acquisition and processing ofsystem data is accomplished in the PC interface.Data acquisition system of multi-channel wheel load instrument is set up, theloading experiment is done with standard weight. According to the distribution trendof experimental data, the calibration scheme of measurement system is determined,anti-partial load performance of system is also verified. By loading experiment inhorizontal and inclined state, relevant testing on calibration quality and workingperformance of system is accomplished. The experimental results show that thedesigned system is one of high measurement precision and stability.