According to the test requirements of a missile rudder controller component and its components, an automatic test system based on virtual instrument technology is designed. The hardware part is composed of industrial computer, power supply, measuring instrument and regulating circuit. The industrial computer is used to collect and analyze data and control the measuring instrument through GPIB interface. The power supply provides the working environment for the product under test; the measuring instrument is used to collect the parameters of the product under test; and the regulating circuit provides the work for the product under test. The required signal.
The testing software is implemented by LabVIEW software development platform, which has mature development process and high reliability. Virtual instrument technology is the product of the combination of instrument technology and computer technology. It replaces the data analysis and processing and real-time functions realized by hardware in the traditional test system with computer, configures the I/O interface equipment with the main purpose of acquiring conditioning signals, and realizes the software of different measurement functions to analyze and process the collected signal data, display it in real time and record it into documents. The controller is an important part of a missile rudder. Through testing, defects of steering gear controller and its components can be exposed, problems can be found and eliminated as soon as possible, and performance verification, fault location, commissioning and production, quality control and acceptance of delivery have been completed. [2] Based on Labview virtual instrument technology, an automatic test system with expansibility and high reliability is designed for the static and performance characteristics of the steering gear controller, which solves the problems of long development time, low test efficiency and difficult management of test data. The normal temperature test equipment of steering gear controller is mainly composed of power supply unit, signal conditioning unit and acquisition unit, signal generation and communication unit, static parameter test unit, voltage judgment circuit test unit of steering gear battery, unlocking circuit and unlocking judgment circuit test unit, measurement and control computer system and time-sharing measurement and control unit. Form. The system block diagram is shown in Figure 1.
The unit includes PXI controller, thermostatic element multi-function acquisition card, communication interface card and PXI chassis. The measurement and control unit has the hardware and software interface connecting the optical fiber network and receives the test instructions issued by MES system, and can upload the equipment status and test data; the ANDON system with display equipment status has the ability to cooperate with the temperature box; it can control and manage the testing equipment as a general instrument and its components, and collect and test data. Test data, with data analysis, report generation, data record storage and upload functions. This unit includes host computer and communication interface unit, realizes RS422 communication function, outputs control signal, power on self-test, battery activation and servo unlocking commands needed for control controller test. The unit uses high-speed multi-function data acquisition unit and signal conditioning circuit to test the voltage information needed to be monitored and recorded, and complete the test of four PWM signals and four direction signals. According to the characteristics of position feedback signal, it is necessary to filter and adjust the collected position feedback signal in the data acquisition and processing module. Because LabVIEW provides a variety of software modules for signal filtering and conditioning, so the signal filtering and conditioning in the system are implemented by software. The unit completes the performance test of the battery voltage detection circuit and the automatic test of the battery voltage flip threshold. According to the output voltage of 90V power supply when the circuit is turned over in hardware test, it is tested twice.
For the first time, the 90V power supply is controlled to output a voltage value slightly less than the flip voltage, and then the battery voltage self-check instructions are sent every 12 ms through RS-422 communication, three times in total, and the “normal signal of battery voltage” is collected to judge the circuit Flip status. The second control 90V power supply outputs a voltage value greater than the flip voltage. The same method is used to test and determine whether the circuit is normal flip.
The unit simulates the unlocking of the steering gear and completes the test of the unlocking circuit. The unlock control signal is sent out by RS422 bus, and the ignition signal is generated by the controller through a 0.5_resistor analog load, which is collected by analog acquisition channel and sent to the measurement and control computer for judgment. After the unlocking is completed, the equipment outputs the unlocking status signal, and collects the unlocking normal signal through RS-422, which completes the judgment of the self-check signal of unlocking. The power supply unit consists of 90V power supply, 28.
5V signal power supply, LEM voltage sensor, LEM current sensor, multi-function board and GPIB communication part. The 90V power supply consists of two high-power power supply in series. The measurement and control computer sets parameters and controls output through GPIB communication bus. The static parameter testing unit is programmed by LabVIEW, and the Keithley 2700 digital multimeter and switch array module 7702 are operated by PXI controller through RS232 serial port.
According to the communication protocol between the two sides, the corresponding software is programmed to complete the data communication of the automatic testing system.
In terms of software, the organic combination of general computer software and instrument software constitutes the basic software framework of the automatic test system for controllers. The software interface design is divided into five parts: test menu bar, test item selection bar, test status bar, test curve window, test result display panel and display control panel. When displaying the curve, the software takes the curve of oscilloscope as the design blueprint, and provides the function of local amplification. In order to improve the efficiency of testing and facilitate the management of subsequent test data, the system automatically generates test reports by software during the process, and the template format of test reports keeps consistent with the process document test record card to meet user requirements.
The automatic test system of rudder controller based on virtual instrument can well complete the automatic test of a certain type of rudder controller and its components. Based on virtual instrument and Labview software as development platform, the system completes the communication between computer and data acquisition equipment through GPIB bus, completes data acquisition, display, storage, processing and so on. The system has high reliability and stability, and has a high degree of automation.
It has practical application. Use value. The comprehensive parameters of the controller are tested by the automatic test system. The test results verify the effectiveness of the system.