Abstract: A method for determining vibration amplitude limits of a mechanical device. The method comprises identifying a mechanical device and a frequency range for a spectrum to be analyzed, retrieving vibration spectra comprising individual spectrum for the mechanical device and the frequency range, calculating frequency for the individual spectrum, and identifying the individual spectrum with the smallest number of frequency lines. In addition, the method comprises calculating noise bandwidths and a largest noise bandwidth, removing outlier data, calculating conditional kernel density, and calculating vibration amplitude limits to detect faults in the mechanical device.

Abstract: A pattern recognition adaptive controller configured to dynamically adjust proportional gain and integral time control parameters based upon patterns that characterize the closed-loop response. The pattern recognition adaptive controller receives a sampled signal representative of the controlled variable, and determines a smoothed signal based on the sampled signal. The controller determines an estimated noise level of the sampled signal and determines if the control output and process output are oscillating quickly based on predefined criteria. The controller adjusts the gain used by the controller if the control output and process output are oscillating quickly. If the control output and process are not oscillating quickly, the controller determines whether there has been a significant load disturbance, whether there is an insignificant pattern, and/or whether the control output is saturated.

Abstract: The present invention relates to a diagnostic system for use in a network control system. The diagnostic system is preferably utilized to analyze HVAC system or VAV box performance in an environmental control system such as a network facilities management system. The diagnostic system advantageously records temperature, air flow, and actuator position data in the controller associated with the VAV box and calculates an exponentially weighted moving average value. The exponentially weighted moving average value may be related to error values, process output values, change in actuator position, actuator position, duty cycle of the actuator, or starts, stops and reversals of the actuator. Such a system allows a person to analyze VAV boxes and controller performance over a particular timely period and the lifetime of the system. Box and damper warnings may be provided by the diagnostic system when the EWMA values are over or under particular threshold values.