The Reaserch Of The USB-based Mould Filling Testing System Of Anti-gravity Casting

In recent years, with the increasing demand in the aerospace, defense andautomotive industry and other industries of large, precision, thin walled, complex, highquality increases, the demand for high strength aluminum alloy castings， anti-gravitycasting as to meet the need of the production of advanced casting molding process,increasingly attracting attention of casting, widely applied in the countries all over theworld. In the process of counter gravity casting, the filling process of molten metalhave a critical impact on the quality of the castings. So the casting mould fillingprocess of modern testing methods, improve the production process, to prevent thecasting defects, access to quality thin wall casting is of great significance. This paperuse the USB serial bus to realize the PC and data acquisition system of communication,and using FPGA as controller always put forward a kind of based on USB2.0anti-gravity casting filling the design of data acquisition and processing of the test.The combination of FPGA technology and USB interface technology to achieveanti-gravity casting casting filling in test data acquisition and processing, both theflexibility of FPGA design and USB transmission speed, easy to use, the advantages of51single-chip microcomputer and can be solved using standard serial interface (RS-232) for filling test data processing ability is weak, the problems of slow speed and realtime capability is not strong, and relatively are cheaper to using professionalequipment to test. This system has high data acquisition speed, accuracy, testmulti-channel, high transmission rate, real-time strong, has a good application prospectin the field of casting test.This article first briefly introduces the principle of anti-gravity casting processand casting filling test method adopted in the design of thermocouple temperaturemeasurement method. Then from two aspects of hardware and software of the castingfilling test system is studied. Hardware design emphatically the USB data acquisitionmodule, the module adopts integrated with the USB interface of the microprocessorchip CY7C68013A to complete the test collection system and data transmissionbetween the PC, and adopts a high integration of the FPGA chip as control core of theentire data acquisition and transmission, and gives the specific hardware designscheme of modules. Software part mainly includes the firmware and USB devicedrivers and host application. The CY7C68013A firmware framework, on the basis of the firmware program for the development of adopted Slave FIFO interface mode andautomatic transmission mode, to improve the transmission rate; In driver programmingsection, introduced the WDM driver development model, and introduces the WDMdriver of USB architecture and USB device driver development process; Hostapplication with vc++6.0platform design has realized the USB communication, datastorage, real-time display test point temperature change and fluctuation pressure tank.Finally, to summarize current work and testing system, puts forward improvement forthe next step research reference.