Exploratory Research On Testing System Of Projectile Bottom Pressure Based On The Arm And Calibration Techniques

With the continuous development of artillery, the muzzle velocity of artillery andchamber pressure is continuously increased, the phenomenon that the classic ballistic theory isdifficult to make a satisfactory explanation is more and more, and the malfunction in chamberis more and more serious. Testing of projectile bottom pressure is essential for resolving theseissues, the designing of projectile, barrel and fuse in modern artillery and the research oninterior ballistics. In addition, whether there is difference between the projectile bottompressure and chamber pressure and what kind of relationship existing between the two, whichrequires accurate projectile bottom pressure data to analyze and compare the two. Thus thereis an urgent need for developing the projectile bottom pressure test system, and continuouslyimproving the performance of the test system.For the harsh environment of high temperature, high pressure, high impact, this subjectdeveloped a projectile bottom pressure test system based on ARM with micro-volume, lowpower consumption, high sampling frequency. The test system selected the chip of LPC1768which kernel is Cortex-M3 as the main controller, using the two-channel AD integrated in thechip to acquire the signals of projectile bottom pressure and the projectile acceleration duringlaunch respectively, and stored the data to the on-chip FLASH memory. In addition, in orderto filter out the effect of acceleration in the projectile bottom pressure test, proposed acalibration method of the pressure sensor acceleration effect, which solved the systematicerrors caused by acceleration effect.This article focuses on the following three aspects:Firstly, described the overall program design of the projectile bottom pressure test systemwhich chose ARM with Cortex-M3 as the main controller. Focused on explaining the keytechniques of the projectile bottom pressure test system such as collection methods, storage methods, low-power design and so on.Secondly, Elaborated on the hardware debugging environment, the hardware circuitdesign, software application development environment and the software design process of theprojectile bottom pressure test system. And introduced programmed interface using VCsoftware for reading data and erasing the FLASH. Confirmed that the correctness of the testsystem program applying of signal generator.Finally, established acceleration effect calibration model of the pressure sensor based onthe structure of the piezoelectric pressure sensor. Using ANSYS simulation verified theexistence of the pressure sensor acceleration effect, and analysed the systematic error broughtabout by the acceleration effect, and illustrated the need for calibration. Proposed a calibrationmethod of the pressure sensor acceleration effect, and obtained acceleration sensitivity curveunder a standard atmospheric pressure through the experimental data.