Ultra-wideband location systems and methods

A real-time location method comprising:

• sending and receiving ultra-wideband frames using an exchange protocol based on an ultra-wideband frame format, wherein the exchange protocol defines a location rate frame format comprising:
• a beacon section comprising a series of time slots associated to at least one frame of interleaved pairs of beacon frames,
• wherein a first beacon frame and a second beacon frame of each pair are separated in time by a master time delay, and
• wherein, between time slots assigned to the beacon frames of an opening pair comprising an initial one of the beacon frames within the beacon section, an array of time slots is respectively assigned to the first beacon frames of the remaining pairs;
• and
• a tag response section comprising a sequence of time slots associated to tag response frames.

A real-time location system comprising:

• a master beacon device comprising:
• a beacon transmission unit configured to transmit two successive beacon frames including a first beacon frame transmitted at a first beacon transmission time point and a second beacon frame transmitted at a second beacon transmission time point,
• a master clock defining a master time, and
• a master storage unit configured to store a master time delay data,
• wherein the two successive beacon frames are transmitted with a master time delay that corresponds to the master time delay data;
• a plurality of tag devices, each tag device comprising:
• a tag clock defining a tag time that is specific for the respective tag device;
• a reception unit configured to:
• receive the two successive beacon frames sent from the master beacon device,
• determine a first tag beacon time point and a second tag beacon time point for the receiving of the two successive beacon frames at the respective tag device, and
• generate a tag-specific reception time delay data from the first tag beacon time point and the second tag beacon time point;
• a tag data storage unit configured to store the master time delay data, a reference time point associated with receiving of one of the beacon frames being used as a reference beacon frame, and a tag-specific emission time delay data associated to the respective tag device and the reference time point;
• a calibration and calculation unit configured to calibrate the tag clock with respect to the master time by comparing the tag-specific reception time delay data and the master time delay data;
• and
• a tag response emission unit configured to:
• derive a tag-specific emission time delay from the tag-specific emission time delay data for the calibrated tag clock and the reference time point, and
• emit a tag response frame after waiting for the tag-specific emission time delay upon the reference time point;
• a plurality of tag response receptor units, each comprising:
• a receptor clock defining a respective receptor time, wherein each tag response receptor unit is configured to
• receive a plurality of the tag response frames sent from the plurality of the tag devices, and
• determine a plurality of receptor response time points for arrival times of the tag response frames at the respective response receptor unit, wherein each receptor response time point is specific for the respective tag response receptor unit and the respective tag device due to the tag-specific emission time delay;
• and
• a distance determination unit comprising:
• a data storage unit configured to store the tag-specific emission time delay data and a plurality of installation position data representing the positions of each of the plurality of tag response receptor units and the beacon transmission unit of the master beacon device, and
• a calculation unit configured to, for a selected tag device, determine distance values associated to the position of the selected tag device using the first transmission time point or the second beacon transmission time point, the receptor response time points, and the tag-specific emission time delay data of the selected tag device and optionally the master time delay data and the plurality of installation position data.

A method for providing distance values between a tag device and a plurality of tag response receptor units of a real-time location system, the method comprising:

• operating a master beacon device or a beacon repeater device to transmit successive beacon frames, wherein set a master time delay is arranged between two neighboring of the successive beacon frames;
• operating the tag device and the tag response receptor units to receive the successive beacon frames and to calibrate clocks of the tag device and the tag response receptor units using the master time delay;
• operating the tag device to emit a tag response frame at a preset tag-specific emission time delay with respect to a reference time point associated with the receiving of a reference beacon frame, the reference beacon frame being one of the successive beacon frames;
• operating the tag response receptor units to receive the tag response frame and to determine receptor response time points for arrival times of the tag response frame at the respective response receptor units, wherein each receptor response time point is specific for the respective tag response receptor unit and the tag device due to the tag-specific emission time delay;
• and
• determining the distance values associated to the position of the tag device from the receptor response time points and installation position data representing the position of each of the plurality of tag response receptor units and the master beacon device.