Design Of Dynamic Railroad Track Scale And Development Of Monitoring Software

With the rapid development of economy, the demand of cargo weighing becoming higher and higher, it has the requirement of real-time and accuracy. In such circumstances, dynamic railroad scales have come into being. Dynamic railroad scale can weigh the good without stopping the train and achieve a fast and high efficiency precision measurement. Nowadays, technology of dynamic railroad scale is relatively mature after decades of development; however, some dynamic railroad scales still have deficiencies.To compensate for the deficiencies of the existing dynamic railroad scales and improve the accuracy and speed of the dynamic weighing, this thesis makes the design of dynamic track scale and the development of monitoring software. The development history and the research background of the dynamic railroad scales are introduced at the beginning of this thesis, and then a detailed description of the hardware system and the implementation of functions of the dynamic railroad scales are given in the thesis, finally the development environment and function components of the entire monitoring software are presented. The hardware system includes the weighing channel, LCD display module,microprocessor and the Ethernet communication interface. Column sensors are used to collect the weight signals of the measured train, the signals are then filtered and amplified by amplifying and filtering circuit, at last the analog signals are converted into digital signals by the16bit high accuracy AD converter, and then the digital signals are processed by the DSP chip, finally, the signals are sent to host computer through the Ethernet communication interface. In the software system, the host computer module and the slave computer module are introduced separately. In the slave computer module the functions and design of this module are analyzed respectively. In the host computer module, the design and interface introduction of this part and the implementation of all functions are analyzed in detail. The host computer software is written in the object-oriented language C#, establishing a friendly interface which carries out the functions of storage, print, searching and statistics.The innovation of this thesis is summed up as follows:(1)Pre-process of the weighing signals:The comprehensive simulation identification is used to identify the train. The method is simple and quick, what’s more, it’s convenient to search out the malfunction of sensors.(2)On the aspect of data transmission, Ethernet communication mode based on the UDP protocol is proposed, which makes the performance of real time better. The reliability mechanisms which ensure a secure and reliable data transmission is established to solve the problem of packet loss in the process of transmission. Considering the transmission data quantity is so large in practical that the buffer cache is insufficient, under this condition the scheme of interleaving is put forward to avoid packet loss. The interleaving means reordering the data packets and then sending staggered packets to the host computer.(3)To ensure the measurement precision of the entire system, this thesis uses wavelet transform algorithm to filter the dynamic data on the basis of the characteristics of the dynamic weighing signals. The characteristic of time domain localization of wavelet transform and the flexible choice of wavelet-base can make up for the deficiency of traditional denoising method.(4)Dynamic weighing algorithm:dynamic weighing algorithm based on the recursive least squares method is put forward. The final stable weight data can be analyzed according to the data of transient waveform.The experiment and the simulation shows that hardware circuit function is perfect; the comprehensive simulation identification of train is feasible and accurate; the reliability mechanisms restrain the loss of packets effectively; the signals processed by the wavelet algorithm can reflect the weight of track quickly and accurately. The system has good anti-interference ability, higher accuracy and better performance of real time.