US Patent 10444323 Expandable, decentralized position tracking systems and methods

Systems and methods for position tracking include at least three spatially separated radio-frequency (RF) sources of radio signals. Each RF source is disposed in an area at a location known to that RF source. Each RF source includes an RF transmitter configured to transmit radio signals that carry a unique identifier and the known location of that RF source. The position tracking system and method include at least one tag. Each tag is coupled to a different mobile object and includes a radio module with an RF receiver for receiving the radio signals transmitted by the at least three spatially separated RF sources. Each tag further includes memory and a processor that executes executable code stored in the memory to compute a range from that tag to each of the at least three RF sources and to compute a position of that tag based on at least three computed ranges.