# US 12,411,495 B2 · Mobile robot and control method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,411,495 B2 - Document ID: US12411495B2 - Status: Granted - Kind: B2 - Application number: 17/785,544 - Filed: 2020-12-14 - Published: 2023-10-26 - Granted: 2025-09-09 - Earliest claimed: 2019-12-20 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Sanggyu Han - Web page: https://patentgrep.com/patent/US12411495B2 ## CPC - G05D 1/0234: {using optical markers or beacons (optical beacons per se G01S1/70)} - A47L 11/4011: {Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor} - G05D 1/0214: {in accordance with safety or protection criteria, e.g. avoiding hazardous areas (monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13)} - G05D 1/0246: {using a video camera in combination with image processing means} - G05D 1/0289: {with means for avoiding collisions between vehicles (vehicle fittings for automatically controlling speed including means for detecting potential obstacles B60K31/0008; avoiding obstacles by action on the steering system B62D; radar, sonar, lidar systems designed for anti-collision purposes G01S13/93, G01S15/93, G01S17/93)} - G05D 1/243: Means capturing signals occurring naturally from the environment, e.g. ambient optical, acoustic, gravitational or magnetic signals (using passive navigation aids external to the vehicle G05D1/244; using signals from positioning sensors located off-board the vehicle G05D1/249) - G05D 1/244: using passive navigation aids external to the vehicle, e.g. markers, reflectors or magnetic means - G05D 1/648: Performing a task within a working area or space, e.g. cleaning - G05D 1/695: for maintaining a fixed relative position of the vehicles, e.g. for convoy travelling or formation flight - G05D 1/6985: {using a lead vehicle, e.g. primary-secondary arrangements} - A47L 2201/04: Automatic control of the travelling movement; Automatic obstacle detection - G05B 2219/39146: Swarm, multiagent, distributed multitask fusion, cooperation multi robots - G05B 2219/45098: Vacuum cleaning robot - G05D 2105/10: for cleaning, vacuuming or polishing - G05D 2107/40: Indoor domestic environment - G05D 2109/10: Land vehicles - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - 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) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract In a mobile robot and a control method therefor according to the present disclosure, a plurality of mobile robots located in an area confirm the positions of other mobile robots and operate in cooperation with each other to cooperatively clean then area. One mobile robot moves to follow the position of another mobile robot, so that the mobile robots with different cleaning types cooperate to clean the area. Accordingly, the plurality of mobile robots can cooperatively perform cleaning without colliding within one area, and by combining or changing a plurality of position detection methods as needed, the position of another mobile robot can be easily calculated and the cleaning efficiency is greatly improved. ## Claims ### Claim 1 A mobile robot comprising: a main body that travels in an area; an image acquisition processor configured to acquire an image; a communication processor configured to receive a position signal transmitted from a first mobile robot that the main body is configured to follow; a control processor configured to determine a position of the first mobile robot from an image acquired by the image acquisition processor or the position signal, and configured to set a travel route with the position of the first mobile robot as a target point; and a driving processor configured to move the main body, such that the main body follows the first mobile robot along the travel route, wherein the control processor changes a position calculation method based on a distance to the first mobile robot, and wherein the control processor determines the position of the first mobile robot from the acquired image when the distance to the first mobile robot is greater than or equal to a set distance, and when the distance to the first mobile robot is less than the set distance, the control processor receives the position signal of the first mobile robot and determines the position of the first mobile robot; and wherein the control processor extracts a marker from the acquired image, calculates the position of the marker in the area, and based on the calculation determines the position of the first mobile robot, and when a marker confirming the position of the first mobile robot is not included in the acquired image, the control processor receives the position signal of the first mobile robot by changing the position calculation method, and wherein, when the position signal is not received, the control processor changes the position calculation method, receives the acquired image and determines the position of the first mobile robot according to the position of a marker extracted from the acquired image. ### Claim 2 (depends on 1) The mobile robot of claim 1, wherein upon an occurrence of a condition that the control processor changes the position calculation method of the first mobile robot a predetermined number of times, and upon an occurrence of a condition, the control processor controls the main body, such that the main body stops following the first mobile robot and outputs a warning. ### Claim 3 (depends on 2) The mobile robot of claim 2, wherein after stopping following the first mobile robot, when the first mobile robot is detected again while traveling, the control processor controls the main body, such that the main body follows the first mobile robot. ### Claim 4 (depends on 1) The mobile robot of claim 1, wherein the control processor sets the travel route with the first mobile robot as a target point and the main body follows the first mobile robot while maintaining a predetermined distance from the first mobile robot. ### Claim 5 (depends on 1) The mobile robot of claim 1, wherein, when a cooperative mode is set, the control processor controls the main body, such that the main body follows the first mobile robot, and when the first mobile robot is detected within the area in a state where the cooperative mode is not set, the control processor sets the cooperative mode. ### Claim 6 (depends on 1) The mobile robot of claim 1, wherein the image acquisition processor acquires an image including a ceiling on which a marker output from the first mobile robot is displayed, and the position signal uses any one of UWB, ultrasonic wave, infrared ray, and GPS. ### Claim 7 (depends on 1) The mobile robot of claim 1, wherein the driving processor transmits a driving force so that a rotation mop on which a cleaning cloth is attached rotates, and the main body moves while wet cleaning a floor surface with the cleaning cloth, and in the case of following the first mobile robot, the main body moves along the travel route and wet cleans an area in which dust is sucked by the first mobile robot. ### Claim 8 (depends on 1) The mobile robot of claim 1, wherein a marker is irradiated from the first mobile robot.