Development On The Testing Instrument Of The Missile Cable Connected And Insulated Resistance

The test of connected and insulated resistance of missile cable and its control attachment's cable is the key test content of missile control system. Missile cable is made of multi-wire, and often used under the hard environment, etc. These increase the chance of cable error. Testing the connected and insulated resistance of missile cable can find error in advance, guarantee the success of testing job, and improve the stability of missile. However, the contemporary test instruments of connected and insulated resistance of missile cable are relatively simple. They couldn't meet the fast and universal testing demands. After analyzing the previous research achievements, and connecting the features of insulated resistance of missile cable's more test points and low test voltage, this thesis proposed a technical plan of testing instrument. The test instrument was made of upper computer, lower computer and cable interface adaptor.The upper computer included hardware interface module, man-machine interaction module, data process module, status display module and database module. The hardware interface module connects with lower computer by serial port under the RS-232 bus protocol, and sent the sample data signals of lower computer to the upper computer. Data process module analyzed data with fixed algorithm, optimized the testing data, then saved these data into database, and displayed the test result on the screen with status display module. Man-machine module included cable information entering, cable information searching, test result examining and saving, etc. The other function was managing database. Database module included cable information and students'information. By installing the upper computer brings a lot of advantages to maintain and manage testing instrument.Lower computer was made of single-chip system and signal switch system. Single-chip system includes CPU board, I/O extension circuit board, and control circuit board, on/off power switch circuit board, master matrix relay board, slave matrix relay board, sample circuit board and digital transistor drive board. Single-chip connected different pin by master matrix relay and slave matrix relay, then signal sample circuit sampled the analog signal, and then sent it to the upper computer, after processing with the fixed algorithm, saved the result to the database. The procedure improves the process speed by using single-chip.Cable interface adaptor was part of lower computer; its function was to match the different kind of missile cable interface and realized the goal of testing connected and insulated resistance of multi-type missile cable. It improves the testing instrument commonality.By contrast with the traditional test method through experiment, this testing instrument has the advantage of faster test speed and universal to existing missile type. Its main functions meet the demands of project development. Basically, it gets over the project.