Patents by Inventor Bart J. Erickson

Bart J. Erickson 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: 5534876
    Abstract: A multilateration location system (12) includes a locatable unit (16) and any number of known-position locators (14). A time of arrival detector (22) determines instants in time when a location signal (20) transmitted by the locatable unit (16) arrives at various known-position locators (14). For each combination of two known-position locators (14) that receive the location signal (20), a pre-estimation process (32) determines whether the difference in arrival times is less than or equal to a maximum propagation duration for the locator pair. The maximum propagation duration is based upon the distance between the locators (14) in the locator pair. If the difference is greater than the maximum propagation duration, the difference is omitted from the data set processed by a multilateration calculation process (34). A post estimation filtering process (36) screens out location estimates that are too distant from a predicted position.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: July 9, 1996
    Assignee: Motorola, Inc.
    Inventors: Bart J. Erickson, Neal R. Anderson
  • Patent number: 5469409
    Abstract: Timing signals are transmitted from reference transmitters through antenna/receivers (antenna preamplifier nodes) to collector nodes (C-Nodes) and to a central computer. The times of arrival of the signals at the various C-Nodes are measured by the C-Nodes, relative to each C-Node's clock. The time of arrival signals at each C-Node must be based upon a common time reference to be useful for positioning. Therefore, the central computer determines the offsets of clocks relative to a selected reference C-Node clock. The time of arrival signals are then calibrated against one another and used to adjust the time of arrival signals so that all time-of-arrivals are relative to the same reference and can be used for position determination and the clocks of the collection nodes are effectively synchronized.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: November 21, 1995
    Assignee: Motorola, Inc.
    Inventors: Neal R. Anderson, Bart J. Erickson, Keith Leung