Instrument design of dynamic weighing system for bending plate

With the rapid development of highway transportation, the traditional dynamic truck scale has been unable to meet the current market demand. Traditional dynamic truck scale mainly has the following problems: because of the complex mechanical structure of the scale, it can not bear the high-speed impact of the vehicle, so it is not suitable for high-speed dynamic weighing; The complex mechanical structure of the weighing platform easily causes the damage of the sensor and the deformation and settlement of the weighing platform. Weighing table sealing is not good, resulting in water, sludge will affect the weighing accuracy. With the continuous improvement of dynamic weighing technology at home and abroad, in order to solve these problems, the bending plate dynamic truck scale came into being. With the advantages of integral weighing platform, good sealing, simple construction and free maintenance, the flexural plate dynamic weighing system can be applied to the dynamic weighing of vehicle wide speed range (0~200km/h). At present, the technology of this system is developing rapidly and becoming more and more mature, and has gradually become a new solution of highway weight toll system and highway overlimit detection system. Electronic weighing instrument (ECM) is the core unit of dynamic truck scale calculation and control. Its function and performance directly determine the technical level of dynamic weighing system. The instrument design scheme includes hardware design, software design and weighing algorithm design. The design ideas and main contents are as follows: 1) This paper discusses the background and significance of the research of dynamic truck scale and dynamic weighing instrument of bending plate, introduces the research status, development status and future development trend of relevant fields at home and abroad, and also details the application occasions and scope of dynamic truck scale of bending plate at home and abroad. 2) The structure of the flexural plate dynamic weighing system is discussed, including the flexural plate weighing sensor, vehicle separation device and instrument. Among them, the working principle of the flexion plate weighing sensor is mainly introduced. The working principle and flow chart of the bending plate weighing system are analyzed. 3) Based on the analysis of the design requirements of the flexural plate dynamic weighing instrument, the integral design of the instrument’s hardware and the modular electrical design are carried out. The design requirements, design process and design results of each hardware module are described in detail. 4) based on WIN32API using multi-threaded programming technology to develop the bending plate dynamic weighing instrument program. Each thread module and its main code of the main program are discussed in detail. 5) Analyze the high-speed weighing signal of the vehicle, and use the wavelet transform algorithm for digital signal processing of the weighing data according to the small data signal. In MATLAB environment, wavelet transform toolbox is used to reduce the noise of the original weighing signal, and good results have been obtained. Finally, the field experiment data is used to verify that this method has certain effect on improving the weighing accuracy and has practical application significance. 6) Summarize the design process of dynamic weighing system instrument for bending plate, analyze the insufficiency and look forward to the future. The main innovation points are as follows: 1) Since the system is suitable for high-speed dynamic weighing of vehicles, the weighing signal collected by the instrument when the vehicle passes at high speed is small data signal. In the aspect of digital signal processing, the small data signal analysis and processing, combined with the field experiment data, achieved a good effect of noise reduction and filtering. 2) The hardware design of the instrument uses the industrial computer as the core control unit. In the software design process, the multithreaded technology is used for programming, which improves the operation efficiency and performance of the instrument. The hardware and software program structure of the instrument designed in this paper has been applied in practical projects, and the operation is normal and stable in a number of county highway pre-inspection stations. The weighing algorithm based on wavelet transform can effectively filter out the noise signal for the small data of the weighing signal, and the error of the experimental results in the range of 0-50km /h can be controlled within 4%.

Post time: Aug-13-2021