| The levitation control system is the peculiar kernel subsystem of the Maglev. Aiming at its test and maintenance, a set of off-line simulation test platform is designed. Not only can the platform realize the automatic test of the hardware system, but also it can evaluate the software's performance by imitation, simulation and other means. After the test requirements have been analyzed, the platform is constructed primarily, and the test ways and the test schemes to the whole levitation system are shown. Facing on the levitation control arithmetic test of the whole schemes, the platform is designed in detail and accomplished finally.The platform consists of three parts: the Upper PC, the data acquisition cards and the corresponding software. Thereinto, the Upper PC is used to calculate the electromagnet model and to display the test results, etc; the data acquisition cards, as the interface between the Upper PC and the levitation controller, transmit the upward and downward simulation data. The real levitation controller and the platform, which can be regarded as a virtual electromagnet, form a closed HIL (Hardware In the Loop) simulation system together. The levitation arithmetic can be tested With the HIL system under various practical situations. Around the accomplishment of the platform, the paper researches mainly on three aspects, as shown below:①The research of dynamic modeling of the single electromagnet, which is a non-linear and unstable system. Firstly, the familiar mechanism model is shown, and the numerical calculation method is presented for the digital system simulation. Because of the big error of the mechanism model, the paper focuses on the online identification of the suspending system under closed-loop control, which belongs to one of the experimental modeling methods. Considering the identifiability of the closed-loop system, two identification schemes are given: One is the irrelative noise inspired method and the other is high-order controller method. For the two schemes, one two-order controller and one three-order controller are designed, and the recursive least-squares method which is fit for on-line identification is studied. Finally, a simulation test of the shemes is carried out, and the model parameters of the electromagnet are identified accurately.②The hardware development and the software exploration for the HIL simulation platform based on the industrial computer. According to the requirement of interface, a PWM (Pulse-Width Modulation) signal measurement card is developed. The card, based on the ISA (Industry Standard Architecture) Bus and CPLD, can capture the control information of the levitation controller accurately through measuring the impulse width of the PWM signal (Def. up-transmit data). With a ready-made D/A card, the platform outputs the state information of the virtual electromagnet (Def. down-transmit data). For the real-time simulation, the software of the platform is explored based on the RTX, which consists of one RTSS process and one Win32 process. The RTSS process is used for real-time data acquisition, real-time model calculation and real-time data output, while the Win32 process is used to control the simulation and to display the crucial data, etc. ③Experimental studies on the functional modules of the platform. The studies include: the D/A card tests, the PWM measurement card tests, the software's real-time ability tests, and the platform's closed-loop function tests. These tests show that the platform satisfies the interface of the hardware and the real-time requirement of the software. Finally, the test ability of the platform is shown for the levitation control arithmetic test.The platform, which aims at the software test of the levitation controller of the Maglev, can also be used for the levitation arithmetic study and debugging and has a broad application perspective. |
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