The Research And Implementation Of Digital Strain Sensor Module With ID Number

At present, the common method of plane structure strength test is that Wheatstone bridge circuit takes advantage of strain gages on the surface of the plane to convert strength into voltage, which transports analog signal to the measuring processing equipment in control room where makes AD sample, process, compensate, and get the measurement data of aircraft strength finally. This method in the process of plane strength test(especially the machine strength test), has some disadvantages, such as the difficulty of identifying large nodes, the large wiring scale, the long time of test preparation and so on. The digital strain sensor module with ID number is proposed to improve the common method of plane structure strength test.The ID number of the digital strain sensor module is allocated by the built-in way. In the process of plane structure strength test, modules communicate with digital strain sensor subsystem and bus driver/controller with ID number which is according to the bus extension agreement and obtain power by two wire bus. Modules convert strain into voltage through the four arms differential bridge circuit, and use differential amplifier circuit to enlarge the weak signal, and then use the internal 16-bit ADC of the microcontroller to convert, compensate and store the data. Modules periodically receive the precise time which bus driver/controller sends broadcast, and compare the inner time with the precise time to decide whether update the internal time, which can ensure real-time measurement data. Modules have application online upgrade function, which enhance the module's application adaptability. From the viewpoint of the engineering application, The miniaturization of mechanical structure design of the modules can reduce the interference which the module itself may lead to the strength test. From the perspective of feasibility validation module, in the process of test, the test system simulates the complete test system through the study of the cycle test of 10 modules.The digital strain sensor module with ID number can avoid adding power transmission conductor by the two wire bus that integrates communication and power supply, which can reduce the wiring scale. The module with the exclusive ID number can avoid marking the nodes in the preparation process of plane structure strength test. Measurement data with the clock synchronization between modules can guarantee the data consistency of the measurement system. The module obtains the function of the application online upgrade. The module which integrates the ADC sampling compensation and other parts of the processing equipment will be placed on the test object.