Design Of Data Acquisition System Of Intelligent Truck Scale

Truck scale is known as weighbridge, which is the main weighing equipment for the vehicle load. Truck scale is widely applied to many fields such as industry, agriculture, storage, commerce, trade, transport and scientific research, which is positive social significance and great economic value on the national economy. In the traditional truck scales, the outputs of all load cells are accumulated with serial or parallel in connection box, the eccentric and nonlinearity error compensation is realized by repeatedly regulating the potentiometer in junction box to adjust gain of each channel with load cell, which is fussy, lower efficiency and accuracy. Moreover, the effects of temperature and creep error is the main factors on accuracy of truck scale which is formed by load cells. Inconsistent with the compensation effect on cells will be a greater weighting error.Under the supports of Ministry of Commerce of PRC Optimizing Composition of Importing and Exporting Electromechanical Device and High Technological Produce Foundation (Project [2007]301, "Intelligent truck scale based on multisensor Information fusion"), the data acquisition system of multi-sensor for intelligent truck scale is designed, and the method for multi-sensor information fusion based on RBF neural network is used to determine the gain of each load cell. The system can simplify installation and commissioning requirements of truck scales, compensate effectively the effect on weighting results by some factors, such as nonlinearity, eccentric, temperature and creep, and improve the accuracies of weighing results.This thesis consisted of six chapters:The first chapter briefly introduced the current situation and development course of truck scale technology, analysed the current signal combinations of the multi-load cells, investigated the current shortage of truck scale weighing method, and pointed out the main tasks of this paper.The second chapter introduced the method for multi-sensor information fusion based on RBF neural network, including of weighing fusion and output fusion of truck scale, which can effective remedy the technical defects of all load cells in serial or parallel, and achieve truck scale weighing accuracy.The third chapter described the composition, function, performance index and multi-sensor of the data acquisition system, based on the structure and working principle of intelligent truck scale are introduced.The fourth chapter gave a detailed discussion on the hardware structure, principles and functions with the main circuit elements of the data acquisition system, and briefly introduced the design of time, reset, power supply.The fifth chapter introduced the software development platform of system, explained the modular design method for system software, and gave a detailed description on software design about weighing data acquisition module which includes program flow and data preprocessing.The sixth chapter is the reliability design on the data acquisition system and field verification.Finally, the working of this thesis was summarized, and the improvement methods were proposed.Intelligent truck scale prototype had been verificated and calibrated by the Testing Institute of Measurement Technology in Liuzhou. All results of field verification show that the performances of intelligent truck scale with this data acquisition system of multi-sensor is far better than that of class III scales defined by Chinese national standard of "JJG539-97 Digital-Indicating Scale".