Measurement Of The Percussion Force Of Powder Grain To Projectile Base In Two-phase Fluid Interior Ballistics

The dissertation researched on detection technology of abnormal phenomenon in-born.The percussion force of powder grain to the projectile base in the launching environment wasdetected using missile-borne sensor to acquire state parameters, which are of significant toresearch and improve lauch security of gun.The mechanics of in-bore abnormal phenomenon was analyzed and the dectection projectof the percussion force of powder grain to the projectile base was put forward. The generalproject of abnormal phenomena dectection system was designed and key technology andresolution was elaborated.Solution was proposed in which PVDF piezoelectric film was used to detect thepercussion force of powder grain to the projectile base (for short in IT stress) in the launchingenvironment. IT stress sensor was made up and the structure design and execution technics ofthe IT stress sensor was presentated in detail. Becsuse IT stress sensor working in high transienttemperature enviorment, corresponding theorectics model was constructed and improvementtechnique was put forward. The factor benefit to the measurement precision was analysed andthe resolution was discussed.Temperature research was carried out in allowable temperature range of the PVDFpiezoelectric film and temperature characteric of IT stress sensor was acquired. Staticcharacteristic parameters of IT stress sensor were got through static calibration by pistonpressure gauge. Connection device was designed to connect the calibration equipment and thesensor in the course of static calibration, sealing component resove the leakage of the liquidmedium.Missile-borne condition circuit of the piezoelectric seneor and signal transmit systembased on PCM codes was designed and integrated. In order to overcome the measurement errorwhich was induced by the insensitive response in low-frequency band of the condition circuit ofpiezoelectric sensor, Digital filter method of dynamic real time compensation was put forward.Real time dynamic error adjustment based on digital filter was realized using CPLD device.Because missile-borne operator amplifer can not restared by handle, missile-borne micromationpower supply and power start-up module were designed, which were used to control the powdersupply to realize the restart of the operator amplifer, by this way, the error caused by the zeroshift of sensor was minished effectively. Experial research was carried on simulated gun with the application of the IT sensor andPCM signal hardwire transmission system. Realiable data was obtained and the result prove thatthe detection system was effective and flexible.Reaserch on the contrast calibration technique of the sensor which was of poor lowfrequency characteristic, complement sampling was used in deal with the experiment data, thisarithmetic resolve the spectrum leaking problem caused by the experiment data interception.