Research Of A New Type Of Micro Transient Variable Capacitance Detection System

Fuel gas pressure and the rule of changing verse time when an artillery gun fired is animportant parameter of interior ballistic performance. It determines not only the interiorballistics performance, but also play an important role for the design of artillery guns,projectiles, fuses, and propelling charge directly. So the P-T curve of chamber must bemeasured in design, acceptance inspection and finalization by the manufacture and researchunits. To understand the propellant feature of chamber combustion, provide the basis forsetting all parameters of the products. Therefore, the pressure measure measurementtechnology development is very important. The paper designs a transient variable capacitancedetection system via researching the shell and the capacitive pressure sensor integration.Reduced the volume of testing instruments, and the cost of the test equipment, Focusd onsolveing the problem of test data is not easy to analysis and processing.In this paper, on the basis of consulting a large number of data, through the analysis ofcomprehensive, calculation method of combining the simulation and experiment, carried outthe following researches.Through the analysis of the characteristics and application of the chamber pressure testerenvironment, as well as the dynamic change rule of shell capacitance under the influence ofchamber pressure. Design a micro transient variable capacitance detection circuit based onthe principle of the shell capacitor charge and discharge. The circuit mainly includes threeparts: the signal conditioning circuit and power management circuit, single chipmicrocomputer data acquisition and storage circuit. Through the theoretical analysis andcalculation, to determine all parameters of the circuit. Through the Multisim software to thesimulation of signal conditioning circuit, then observe the changeing process of the capacitorcharg and discharg. To design the hardware circuit, and analyzes the error of the acquisitionsignal through the experiment, points out the may sources of the error and put forward the improvement measures. Detailed analysis the processing of the collected data, Through thereasonable design of the circuit, makes the voltage signal collected and chamber pressurecaused by the capacitance changes have certain mathematical relationship, and make thecollected signals cover most of the range of capacitance oscillation frequency change.