Patents by Inventor Weng K. Ho

Weng K. Ho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method and apparatus for determining the ultimate gain and ultimate period of a controlled process
    Patent number: 5587899
    Abstract: A method and apparatus determine the ultimate frequency and ultimate gain of a controlled process. The apparatus comprises a process gain and phase lag calculation module, a ultimate gain (K.sub.U) and ultimate period (T.sub.U) calculation module, and a tuning sequence control module. The tuning sequence control module initiates a tuning sequence and the process gain and phase lag calculation module samples the process input signal and the process output signal, and isolates from the process input signal and the process output signal at least one input sample signal and at least one corresponding output sample signal by bandpass filtering the process input signal and the process output signal at at least one observation frequency. The process gain and phase lag calculation module then calculates a phase lag of each output sample signal with respect to a corresponding input sample signal and a signal gain of each output sample signal with respect to a corresponding input sample signal.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: December 24, 1996
    Assignee: Fisher-Rosemount Systems, Inc.
    Inventors: Weng K. Ho, Chang C. Hang, Wilhelm K. Wojsznis