Abstract: An apparatus and method for diagnosing rotating equipment commonly used in the factory and process control industry are provided. The apparatus and method are intended for use in assisting a maintenance engineer in the diagnosis of turbines, compressors, fans, blowers and pumps. The preferred embodiments are an apparatus and method for diagnosing pumps, with a focus on centrifugal pumps. The apparatus and method are based on the comparison of the current pump signature curves resulting from the acquisition of process variables from sensors monitoring the current condition of the pump and the original or previous pump performance curve from prior monitoring or knowledge of the pump geometry, installation effects and properties of the pumped process liquid. The diagnostic apparatus and method can be applied to any rotating machine, but the apparatus and method for pumps are described herein.

Abstract: An apparatus and method for diagnosing rotating equipment commonly used in the factory and process control industry are provided. The apparatus and method are intended for use in assisting a maintenance engineer in the diagnosis of turbines, compressors, fans, blowers and pumps. The preferred embodiments are an apparatus and method for diagnosing pumps, with a focus on centrifugal pumps. The apparatus and method are based on the comparison of the current pump signature curves resulting from the acquisition of process variables from sensors monitoring the current condition of the pump and the original or previous pump performance curve from prior monitoring or knowledge of the pump geometry, installation effects and properties of the pumped process liquid. The diagnostic apparatus and method can be applied to any rotating machine, but the apparatus and method for pumps are described herein.

Abstract: A process controller controls an integrating-type process based on a measured process variable and a set point. The process controller includes an error generating circuit, a non-integrating control circuit and an adaptive bias circuit. The error generating circuit generates an error signal based on a difference between the set point and the measured process variable. The control circuit generates a control signal as a function of the error signal. The adaptive bias circuit adds a bias value to the control signal, the measured process variable or the set point. The bias value is selectively updated as a function of the error signal to force the error signal toward zero.

Abstract: A process control system controls a process through a control output signal based on a set point and a measured process variable. The process control system includes a control circuit having a set point input, a process variable input and a control output. The control circuit generates the control output signal on the control output as a function of the set point received on the set point input and the measured process variable received on the process variable input. An auto-tuning circuit excites the process, estimates a process model based on a rising dead time, a rising rate-of-change, a falling dead time and a falling rate-of-change in the measured process variable and then tunes the control function to the process based on the process model. The auto-tuning circuit obtains robust results, but is computationally simple such that the circuit can be implemented with hardware or software in low-power and low-memory applications, such as in such in field-mounted control units.