EXTENSIBLE OBJECT LOCATION SYSTEM AND METHOD USING MULTIPLE REFERENCES
First Claim
1. A zone-based object location system to determine a position of an object in one of multiple zones, the object being associated with an object tag that transmits an RF object signal, the system comprising:
- respective groups of receivers, each group of receivers including multiple receivers and defining a corresponding zone, wherein at least one receiver is common to at least two zones and wherein each receiver includes a timing circuit to detect an arrival time of an RF signal;
a clock source to lock phase relations of the timing circuits relative to each other;
a reference tag associated with each zone is configured to transmit an RF reference signal from a known location within the zone; and
a processing hub configured to obtain time-of-arrival information indicative of arrival times of the RF object signal transmitted by the object tag and the RF reference signal transmitted by the reference tag at receivers of a group of receivers to determine the position of the object within one of the multiple zones.
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0 Petitions
Accused Products
Abstract
An ultra wideband (UWB) or short-pulse RF system is disclosed that can be used to precisely locate or track objects (such as personnel, equipment, assets, etc.) in real-time in an arbitrarily large, physically connected or disconnected, multipath and/or noisy environment. A system implementation includes multiple zones or groups of receivers that receives RF signals transmitted by one or more timing reference tags and one or more objects having associated object tags. Each zone or group may share a common receiver. By combining a multiple reference tag system with a virtual group of receivers, i.e., a zoning technique or system, a cost-effective system can be provided that offers scalability and flexibility to monitor a significantly expanded coverage area.
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Citations
20 Claims
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1. A zone-based object location system to determine a position of an object in one of multiple zones, the object being associated with an object tag that transmits an RF object signal, the system comprising:
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respective groups of receivers, each group of receivers including multiple receivers and defining a corresponding zone, wherein at least one receiver is common to at least two zones and wherein each receiver includes a timing circuit to detect an arrival time of an RF signal; a clock source to lock phase relations of the timing circuits relative to each other; a reference tag associated with each zone is configured to transmit an RF reference signal from a known location within the zone; and a processing hub configured to obtain time-of-arrival information indicative of arrival times of the RF object signal transmitted by the object tag and the RF reference signal transmitted by the reference tag at receivers of a group of receivers to determine the position of the object within one of the multiple zones. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A zone-based object location system to determine a position of an object in one of multiple zones of a region, each object being associated with an object tag, the system comprising:
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respective groups of receivers, each group of receivers configured to include multiple receivers and define a corresponding zone, wherein at least one receiver is common to at least two zones and wherein each receiver includes a free-running digital counter to measure an arrival time of an ultra-wideband signal; a clock common to the multiple zones configured to lock the free-running digital counters in relative phase relationship via a daisy-chained cable; a reference tag associated with each zone is configured to transmit an ultra-wideband signal from a known location within the zone to provide a timing reference; and a processing hub configured to obtain digital representations of time-of-arrival information indicative of the timing reference and arrival times of the ultra-wideband signal transmitted by the reference tag at receivers of a group of receivers to determine the position of the object. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A zone-based object location method to determine a position of an object in a region, the method comprising:
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defining zones by respective groups of receiver in a monitored region in which to detect the object, wherein at least one receiver is common to at least two zones; receiving an RF reference signal transmitted from a reference tag at two or more receivers from a known location within a zone; receiving an RF object signal transmitted from an object tag associated with the object at the two or more receivers within the zone; recording, by timing circuits, arrival times of the received RF reference signal and the received RF object signal at the two or more receivers; and acquiring, by a processing hub, time-of-arrival information indicative of the arrival times to determine the position of the object in one of the zones within the region. - View Dependent Claims (17, 18, 19, 20)
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Specification