# US 12,001,223 B2 · Plurality of autonomous mobile robots and controlling method for the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,223 B2 - Document ID: US12001223B2 - Status: Granted - Kind: B2 - Application number: 17/498,985 - Filed: 2021-10-12 - Published: 2022-01-27 - Granted: 2024-06-04 - Earliest claimed: 2018-05-04 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Donghoon Kwak; Jaehwan Ko; Hyukdo Kweon - Web page: https://patentgrep.com/patent/US12001223B2 ## CPC - G05D 1/0295: {by at least one leading vehicle of the fleet} - G01S 5/0284: {Relative positioning} - G01S 5/14: Determining absolute distances from a plurality of spaced points of known location - G01S 13/74: Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems - G05D 1/0242: {using non-visible light signals, e.g. IR or UV signals} - G05D 1/028: {using a RF signal} - G05D 1/0282: {generated in a local control room} - G05D 1/247: using signals provided by artificial sources external to the vehicle, e.g. navigation beacons - G05D 1/695: for maintaining a fixed relative position of the vehicles, e.g. for convoy travelling or formation flight - G06K 7/10306: {ultra wide band} - A47L 2201/04: Automatic control of the travelling movement; Automatic obstacle detection - F24F 2221/42: Mobile autonomous air conditioner, e.g. robots - G01S 2205/02: Indoor - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - 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 - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08) - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) ## Abstract A plurality of autonomous mobile robots includes a first mobile robot having a first module for transmitting and receiving an Ultra-Wideband (UWB) signal, and a second mobile robot having a second module for transmitting and receiving the UWB signal. The second mobile robot follows the first mobile robot using the UWB signal. ## Claims ### Claim 1 A plurality of autonomous mobile robots, comprising: a first mobile robot including a first module for transmitting and receiving an Ultra-Wideband (UWB) signal; and a second mobile robot including a second module for transmitting and receiving the UWB signal, wherein the second mobile robot is configured to follow the first mobile robot using the UWB signal, wherein the second module included in the second mobile robot comprises two antennas, wherein the two antennas are disposed at outermost portions of a main body of the second mobile robot to have a maximum spaced distance between the two antennas on the main body, wherein the two antennas include a first antenna disposed on a front of the main body, and a second antenna disposed on a rear of the main body, wherein the main body of the second mobile robot attenuates intensities of the UWB signal, and wherein a control unit of the second mobile robot is configured to determine a relative position of the first mobile robot based on the intensities of the UWB signal received through the two antennas. ### Claim 2 (depends on 1) The robots of claim 1, wherein the second module included in the second mobile robot includes a plurality of antennas, and wherein the control unit of the second mobile robot is configured to determine the relative position of the first mobile robot based on the UWB signal received from the first mobile robot through the plurality of antennas. ### Claim 3 (depends on 1) The robots of claim 1, wherein the two antennas are arranged on a same line. ### Claim 4 (depends on 1) The robots of claim 1, wherein the two antennas comprise: the first antenna; and the second antenna located at a rear of the first antenna relative to a direction of movement of the second mobile robot, wherein the first antenna and the second antenna are disposed with a blocking member for blocking the UWB signal interposed between the first antenna and the second antenna. ### Claim 5 (depends on 1) The robots of claim 1, wherein: the second module is a UWB anchor, the first mobile robot is provided with one UWB tag, and the second mobile robot is provided with two UWB anchors. ### Claim 6 (depends on 5) The robots of claim 5, wherein the second mobile robot comprises a first UWB anchor and a second UWB anchor, and the first UWB anchor comprises: the first antenna; the second antenna located at a rear of the first antenna relative to a direction of movement of the second mobile robot; and a blocking member interposed between the first antenna and the second antenna to block the UWB signal. ### Claim 7 (depends on 6) The robots of claim 6, wherein the control unit of the second mobile robot is configured to determine the relative position of the first mobile robot, based on the UWB signal received through the first and second UWB anchors and an antenna receiving the UWB signal of the first and second antennas. ### Claim 8 (depends on 1) The robots of claim 1, wherein the control unit of the second mobile robot is configured to control the second module to output the UWB signal, and wherein a control unit of the first mobile robot is configured to output the UWB signal through the first module, in response to reception of the UWB signal from the second module. ### Claim 9 (depends on 1) The robots of claim 1, wherein the second mobile robot comprises a first UWB anchor and a second UWB anchor included in a plurality of second modules and located at different positions, wherein the first module included in the first mobile robot includes a UWB tag, and wherein the control unit of the second mobile robot is configured to calculate a first distance between the first UWB anchor and the UWB tag and a second distance between the second UWB anchor and the UWB tag, in response to the UWB signal output from the UWB tag being received through the first and second UWB anchors. ### Claim 10 (depends on 9) The robots of claim 9, wherein the control unit of the second mobile robot is further configured to determine two intersections between a first circle formed with a center located at the first UWB anchor and having a radius equal to the first distance, and a second circle formed with a center located at the second UWB anchor and having a radius equal to the second distance. ### Claim 11 (depends on 1) The robots of claim 1, wherein: the second mobile robot comprises a first UWB anchor and a second UWB anchor corresponding to a plurality of second modules, the first UWB anchor comprises the first antenna, the second antenna and a blocking member, the blocking member is interposed between the first antenna and the second antenna to block the UWB signal, and the control unit of the second mobile robot is configured to determine one of two positions determined by the plurality of second modules as the relative position of the first mobile robot, based on whether the UWB signal has been received through the first antenna of the first UWB anchor or through the second antenna of the first UWB anchor. ### Claim 12 (depends on 11) The robots of claim 11, wherein the control unit of the second mobile robot is further configured to: determine a position located at a front of the second mobile robot relative to a direction of travel of the second mobile robot as the relative position of the first mobile robot when the UWB signal has been received through the one of the first antenna and the second antenna that is located at a front of the blocking member, and determine a position located at a rear of the second mobile robot as the relative position of the first mobile robot when the UWB signal has been received through the one of the first antenna and the second antenna that is located at a rear of the blocking member. ### Claim 13 (depends on 1) The robots of claim 1, wherein the second module included in the second mobile robot comprises three antennas. ### Claim 14 (depends on 13) The robots of claim 13, wherein the three antennas are arranged in a triangular configuration. ### Claim 15 (depends on 1) The robots of claim 1, wherein: the second mobile robot comprises a first UWB anchor and a second UWB anchor included in a plurality of second modules and located at different positions, the first module comprises one UWB tag, and the control unit of the second mobile robot is configured to determine a direction in which the first mobile robot is located with respect to a front of the second mobile robot based on a phase difference between respective signals that are output from the one UWB tag and received through the first UWB anchor and output from the one UWB tag and received through the second UWB anchor. ### Claim 16 (depends on 15) The robots of claim 15, wherein the control unit of the second mobile robot is further configured to: determine an angle at which the first mobile robot is located with respect to the front of the second mobile robot based on the phase difference between the respective signals received through the first UWB anchor and the second UWB anchor, and determine the direction in which the first mobile robot is located with respect to the front of the second mobile robot based on the determined angle information. ### Claim 17 (depends on 16) The robots of claim 16, wherein the control unit of the second mobile robot is further configured to: determine a distance from the second mobile robot to the first mobile robot based on a time between when a signal is transmitted and received between the first module and one of the plurality of second modules, and determine the relative position of the first mobile robot based on the determined distance and direction.