The Signals And Systems Toolbox: Comparing Theory, Simulation, And Implementation Using Matlab And Programmable Instruments

A software system to facilitate rapid comparison among theoretical models, simulations, and implementations of signals and systems can help engineering students develop physical intuition and an understanding of the capabilities and limitations of each. Using programmable instruments in laboratory experiments can improve the efficiency and accuracy of such comparisons. MATLAB and SIMULINK already provide students with easy methods to model and simulate systems and to specify arbitrary input functions. This paper describes a toolbox of MATLAB functions, called the “Signals and Systems Toolbox” that can automatically apply a specified input to a physical system using an arbitrary waveform generator and then use a programmable oscilloscope to measure the resulting output. A comparison of the simulated versus actual response of the system can then be performed. Other more specialized functions allow comparison between the frequency response of a model and that of an actual system by stepping through a desired range of frequencies and measuring the response. Basic functions allow easy generation and manipulation of complex signals. The toolbox is well suited to introductory laboratory courses since all students need to know is how to connect the input and output correctly. More advanced students can use a variety of software options to improve the accuracy or usefulness of the input/output comparison. The software system is designed to work with commonly available HP (Agilent) laboratory equipment, but it can be easily modified to use programmable instruments from other manufacturers. It is available for downloaded via the Web.