Research On System Identification Machine Based On USB2.0

Nowadays, USB2.0 provides a new choice for the bus of virtual instruments. Meanwhile, developments in science and technology bring about more and more extensive requirements for system identification. Against such a background, this paper proposes and implements a kind of system identification machine based on USB2.0 virtual instrument using a novel approach, extending the application of USB2.0 to the areas of virtual instrument and automatic test.Aiming at the universality and flexibility of the system, this paper first establishes a USB2.0-based universal interface platform consisting of a set of universal hardware, firmware, device drivers and interface library, which provides a set of powerful and convenient development utilities. Based on these utilities, this paper then designs two USB2.0-based virtual instruments, namely, a signal generator and a data acquisition device, and resolves the issue of the synchronization between the two devices according to the requirement of system identification. The linear difference equation model and the algorithm of LS, GLS and ELS are selected for the system and the influence of noise and configuration to the system is considered. Finally, this paper develops the application software of the system identification machine making full use of the PC's powerful functions in computing, displaying and human interfacing.Finishing the hardware and software of the system identification machine, this paper conducts mathematical simulations and physical experiments of the process of identification using the developed system identification machine. The results show that the system identification machine works effectively on linear systems and is expected to become a practical testing instrument.