Development of a LabVIEW™-based pseudo real-time shaker controller. (3rd February 2009) - Aw, K.C.
This paper proposes a LabVIEW-based pseudo real-time shaker controller. The LabVIEW-based pseudo real-time shaker controller has been developed using National Instruments (NI) LabVIEW development environment. Two Sound Blaster sound cards are used for output of the excitation signal and acquisition of the feedback signal. The program uses a Frequency Domain Self Tuning (FDST) method in order to produce a random Gaussian noise that conforms to a predefined profile. A parallel bank of weighted Infinite Impulse Response (IIR) filters has been used to shape the profile of the random Gaussian noise. The weights are tuned using a Proportional Integral Differential (PID) control algorithm. A Fast Fourier transform-based spectrum estimator is used to determine the feedback profile for each of the discrete frequency bands. The performance of the LabVIEW-based controller is evaluated against a hardware-based controller. It has conclusively proven that a real-time hardware-based controller can be replaced with a software-based controller developed in LabVIEW. Even though the system is not a true real-time system, due to deterministic operation not being guaranteed using the LabVIEW and Windows XP alone, the program still produces comparable results and performance to that of hardware-based real-time controller.