The Research Of Dynamic Weighing Device

Produce, build, transport, trade, science and technology and daily life can not be imagined without weighing. With the progress of the industrial automation and modernization of management, the way of weighing has changed from traditional lever machinery type to digital intelligence weighing; especially the fast dynamic weighing has substaintally developed. Using the new technology and Digital Signal Processors, People have developped various kinds of automatic weighing system and device to improve the accuracy of the dynamic weighing device. In researching of both the structure and performance of the resistant strain gauge and theory and application of data collecting system, a kind of new-type dynamic weighing system has been introduced in this paper. Objects that the dynamic weighing device weighs are not in stable state, or in moving state, this requires the system adopts microprocessor that runs fast and has strong ability of data processing to guarantee dynamic measurement. The core-processing unit using TMS320C5402 DSP (Digital Signal Processing) and CPLD (Complex Programmable Logic Device) has been designed in the paper. The use of DSP makes the system improve a lot on data processing, measuring precision and measuring in real-time, meanwhile the use of CPLD makes the system flexible and reduces the design area of the circuit board. This system adopts switch capacitor filter and FIR digital filter in order to improve the system measuring accuracy; watching-dog software has been applied in software to ensure that the program can run stablely. Because of the non-linear of the sensor, the system adopts the law of neural network to correct non-linear of the sensor, and corrected experimental data were given in the paper. The system has offered several buttons to adjust to zero, change weighing units and stand-by etc. Wireless way is used to transmit on the spot data to computer, which avoids the drawback of the wire on the spot. PC adopts Windows operating system and facing target programming C++ Builder language and makes use of the MSComm controlling part in ActiveX offered by Microsoft. By revising MSComm attribute value and writing the incident driving codes communication can be achieved. Weight-time curve is shown on the screen window and the operators can monitor the dynamic electronic scale's working condition on the spot in real time. Compared with the traditional weighing system, this system weighing speed is quicker and accuracy precision is higher, installing and debugging is more convenient .It is also easier to realize the intelligent control. These advantages make it have wider market potentials.