Implementation of a high performance multirate control system using PC

In this paper, a high performance control system using personal computer (PC) is presented. This system uses a multifunction I/O card for control output and a 2 GHz digitizer for sampling system output to generate the feedback signal. Upon receiving few hundred points of data from the digitizer, the PC performs a simplified discrete Fourier transform (SDFT) for feedback control purpose. A proportional plus integral plus derivative (PID) feedback controller is implemented to control a commercial Spinstand, which has an add-on servo with a custom-made actuator. We tested the system under different operating systems, and achieved a feedback control sampling frequency of 10 kHz under the Linux operating system. The high performance and scalability of this system make it suitable for fast deployment of real time control applications that sample system variables of hundred mega Hertz and output control signal at about 10 kHz.