# US 2019/0170516 A1 · Magnetic beacon and inertial sensor localization technology > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170516 A1 - Document ID: US20190170516A1 - Status: Published application - Kind: A1 - Application number: 16/092,677 - Filed: 2017-04-10 - Published: 2019-06-06 - Earliest claimed: 2016-04-11 - Assignees: The Regents of the University of Michigan - Applicants: The Regents of The University of Michigan - Inventors: Mark B. MOLDWIN; Lauro V. OJEDA - Web page: https://patentgrep.com/patent/US20190170516A1 ## CPC - G01C 21/1654: {with electromagnetic compass} - G01R 33/02: Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) - G01S 1/68: Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information - H04W 64/00: Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A magnetic beacon and inertial sensor system for precise indoor localization is provided using active magnetic beacons, magnetometers and inertial measurement units. The system is designed to work in environments that are not conducive to radio frequency (RF) (such as GPS, cell, Wi-Fi, or Bluetooth) or optical techniques (CCTV, IR), such as inside heavy industrial plant settings, underground or underwater. ## Claims ### Claim 1 A magnetic beacon and inertial sensor system comprising: a plurality of magnetic beacons each outputting a discrete signal, each of the plurality of magnetic beacons being positioned in a predetermined position within a map; a portable integrated magnetometer and inertial measurement unit (PIMIMU) device, the PIMIMU device determining its location and outputting a location signal; and a controller or computing device is configured to determine the location of the PIMIMU device within the map based on information from the plurality of magnetic beacons, the controller further configured to determine the location of the PIMIMU device based on the information from the plurality of magnetic beacons and the location signal and outputting a location of the PIMIMU device. ### Claim 2 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the PIMIMU device is configured to output attitude information and the controller is configured to determine the location of the PIMIMU device based on only one of the plurality of magnetic beacons in conjunction with the attitude information from the PIMIMU device. ### Claim 3 (depends on 2) The magnetic beacon and inertial sensor system according to claim 2 wherein the controller is configured to calculate a step length of an individual based on the attitude information. ### Claim 4 (depends on 3) The magnetic beacon and inertial sensor system according to claim 3 wherein the controller is configured to calculate relative location from a previously known location of the individual based on the attitude information and the step length. ### Claim 5 (depends on 2) The magnetic beacon and inertial sensor system according to claim 2 wherein the controller is configured to calculate relative location from a previously known location of the individual based on the attitude information. ### Claim 6 (depends on 2) The magnetic beacon and inertial sensor system according to claim 2 wherein the controller is configured to calculate a step length of an individual based on the location signal of the PIMIMU device. ### Claim 7 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the controller is configured to determine the location of the PIMIMU device based on triangulation of the information from the plurality of magnetic beacons and output the location signal in response thereto. ### Claim 8 (depends on 7) The magnetic beacon and inertial sensor system according to claim 7 wherein the PIMIMU device is configured to calculate a step length of an individual based on at least one of attitude information and the location signal, the controller is configured to determine the location of the PIMIMU device based on the plurality of magnetic beacons in conjunction with the attitude information from the PIMIMU device. ### Claim 9 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the controller is configured to determine the location of the PIMIMU device based on only two of the plurality of magnetic beacons and output the location signal in response thereto. ### Claim 10 (depends on 9) The magnetic beacon and inertial sensor system according to claim 9 wherein the PIMIMU device is configured to calculate a step length of an individual based on at least one of attitude information and the location signal, the controller is configured to determine the location of the PIMIMU device based on the plurality of magnetic beacons in conjunction with the attitude information from the PIMIMU device. ### Claim 11 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the controller is configured to determine at least one of the location and the orientation of the PIMIMU device based on only one of the plurality of magnetic beacons and output the location signal in response thereto. ### Claim 12 (depends on 11) The magnetic beacon and inertial sensor system according to claim 11 wherein the PIMIMU device is configured to calculate a step length of an individual based on at least one of attitude information and the location signal, the controller is configured to determine the location of the PIMIMU device based on the plurality of magnetic beacons in conjunction with the attitude information from the PIMIMU device. ### Claim 13 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1, wherein each of the plurality of magnetic beacons outputs the discrete signal at a low frequency in the range of about 1 Hz to 10,000 Hz. ### Claim 14 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the PIMIMU device is configured to output attitude information. ### Claim 15 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the location signal comprises magnetic strength and direction information. ### Claim 16 (depends on 1) The magnetic beacon and inertial sensor system according to claim 1 wherein the location signal comprises acceleration and rate of rotation information.