Patents by Inventor Douglas B. Engum

Douglas B. Engum 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).

  • Patent number: 4089494
    Abstract: In a hydraulic actuator such as those used in multiple degree freedom motion bases for aircraft simulators, a secondary force sensitive hydraulic servo loop is added in parallel to the primary position feedback servo loop with the secondary loop having a servo valve possessing substantially greater band pass and less capacity than the main valve used in the first servo loop. Force feedback from the control actuator is applied degeneratively to the smaller servo valve, thereby reducing noise and jitter caused by responses of the system outside the response of the primary servo loop. The response of the main servo loop which control the position of the actuator is low pass and restricts response to the full desired band pass of operational frequencies. The secondary loop is high pass and is shaped to prevent degeneration of operational frequencies while providing optimum gain and phase for the degeneration of the unwanted high frequency portion of the band wherein noise and jitter reside.
    Type: Grant
    Filed: December 16, 1976
    Date of Patent: May 16, 1978
    Assignee: McDonnell Douglas Corporation
    Inventors: Alvin M. Anderson, William Comley, Douglas B. Engum