Web based control system design and analysis

The World Wide Web has provided an opportunity for design and analysis of control systems through the Internet. An increasing number of Web-based software packages have been developed to enhance the teaching and design of control systems. A Web-based interactive control design and analysis system (WCDAS) based on Ch (which is a C/C++ interpreter) and Ch control systems toolkit is developed. Most functions in the system support both continuous-time and discrete-time linear time-invariant systems modeled in state space, transfer functions, or zero-pole-gain representation. Users can select a design and analysis method and specify system model type, system type and system parameters in the Web browser. These data are transferred to the server for numerical computation, and the simulation results are sent back to the client through the common gateway interface (CGI) using the Ch interpretative environment. Because both CGI scripts and simulation programs are written in Ch, data exchange between client and server is easily achieved. The system is available for use through the Web without any software installation, system configuration, or programming. This Web-based system is ideal for teaching as well as for solving practical problems in control systems design and analysis. The software packages Ch, CCST and WCDAS are available for downloading on the Web. The design, implementation and salient features of WCDAS are described in this article.