# US 11,432,697 B2 · Robot cleaner and a 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 11,432,697 B2 - Document ID: US11432697B2 - Status: Granted - Kind: B2 - Application number: 16/508,487 - Filed: 2019-07-11 - Published: 2020-03-12 - Granted: 2022-09-06 - Earliest claimed: 2018-09-06 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Donghoon Kwak; Kyoungsuk Ko; Sungwook Lee - Web page: https://patentgrep.com/patent/US11432697B2 ## CPC - A47L 9/2805: {Parameters or conditions being sensed} - A47L 11/4011: {Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor} - A47L 9/2852: {Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles} - A47L 9/2857: {User input or output elements for control, e.g. buttons, switches or displays} - A47L 11/4061: {Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated} - G05D 1/0242: {using non-visible light signals, e.g. IR or UV signals} - G05D 1/0246: {using a video camera in combination with image processing means} - G05D 1/028: {using a RF signal} - 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 1/0295: {by at least one leading vehicle of the fleet} - A47L 2201/04: Automatic control of the travelling movement; Automatic obstacle detection - Y02B 40/00: Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers - 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) - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A cleaning system may include a first mobile robot, a communication unit configured to communicate with a second mobile robot that emits a second signal, and a controller configured to recognize the location of the second mobile robot using the second signal, and control a moving speed of the first mobile robot such that the second mobile robot follows a trajectory corresponding to the movement of the first mobile robot based on the recognized location. The controller may transmit a first signal to the second mobile robot in response to the first mobile robot approaching the second mobile robot to within a distance less than a threshold distance from the second mobile robot, and control avoidance moving of the first mobile robot and the second mobile robot based on the second signal of the second mobile robot responding to the first signal. ## Claims ### Claim 1 A cleaning system including a plurality of mobile robots, the cleaning system comprising: a driving unit configured to move a main body of a first mobile robot; a communication unit configured to communicate with a second mobile robot; and a controller configured to: recognize the location of the second mobile robot using a second signal emitted by the second mobile robot; control a moving speed of the main body such that the second mobile robot follows a trajectory corresponding to the movement of the main body based on the recognized location; transmit a first signal to the second mobile robot in response to the main body approaching the second mobile robot in a first direction to within a distance less than a first threshold distance to the second mobile robot; and control avoidance moving of the main body and the second mobile robot based on the second signal of the second mobile robot emitted in response to the first signal, wherein the controller is further configured to carry out the avoidance moving based on the second signal when the main body moves in a direction away from the second mobile robot subsequent to the movement of the second mobile robot and end the avoidance moving at a time when a signal emitted from the second mobile robot is sensed at a rear side of the main body relative to the direction of movement of the main body. ### Claim 2 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to transmit the first signal while reducing a moving speed of the main body when the main body approaches the second mobile robot to within the distance less than the first threshold distance. ### Claim 3 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to output a control command to stop the moving of the main body while the second mobile robot moves away from the main body based on the second signal. ### Claim 4 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to reduce the moving speed of the main body according to the first signal, and maintain the reduced moving speed while the second mobile robot moves away from the main body based on the second signal. ### Claim 5 (depends on 1) The cleaning system according to claim 1, wherein the controller is further configured to output a control command to stop the moving of the main body when the avoidance moving is ended, and the second mobile robot follows a trajectory corresponding to the movement of the main body prior to the avoidance moving. ### Claim 6 (depends on 1) The cleaning system according to claim 1, wherein the controller is further configured to control the second mobile robot to perform a rotational motion based on the second signal, and output a control command to stop the moving of the main body while the rotational motion is carried out. ### Claim 7 (depends on 1) The cleaning system according to claim 1, wherein the controller is further configured to control the driving unit such that the main body moves without deviating from a current moving path in response to whether the second mobile robot has moved away from the main body during the avoidance moving. ### Claim 8 (depends on 1) The cleaning system according to claim 1, wherein the controller is further configured to control the avoidance moving such that the main body moves in a direction away from the second mobile robot in response to whether information indicating an unavoidable state of the second mobile robot is included in the second signal. ### Claim 9 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to restrict the second mobile robot from following a trajectory corresponding to the avoidance moving of the main body based on the second signal when the main body performs avoidance moving away from the second mobile robot based on the second signal. ### Claim 10 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to control the second mobile robot to perform a rotational motion for following a trajectory corresponding to the movement of the main body at a current location during avoidance moving when the main body performs avoidance moving away from the second mobile robot based on the second signal. ### Claim 11 (depends on 1) The cleaning system according to claim 1, wherein the controller is configured to stop the moving of the main body in response to whether information indicating an unavoidable state of the second mobile robot is included in the second signal, and control the second mobile robot to move a current moving path while controlling the second mobile robot to move in a direction away from the main body until moving out of the moving path of the main body. ### Claim 12 A method of controlling a plurality of mobile robots, the method comprising: moving a first mobile robot; receiving a second signal at the first mobile robot, the second signal being emitted by a second mobile robot such that the first mobile robot recognizes the location of the second mobile robot; controlling the second mobile robot to follow and move in a trajectory corresponding to the movement of the first mobile robot based on the recognized location of the second mobile robot; controlling the first mobile robot to transmit a first signal to the second mobile robot in response to the first mobile robot approaching the second mobile robot in a first direction to within a distance less than a first threshold distance from the second mobile robot; and controlling avoidance moving of the first mobile robot and the second mobile robot based on the second signal of the second mobile robot emitted in response to the first signal, wherein said controlling the avoidance moving comprises moving the first mobile robot in a direction away from the second mobile robot subsequent to the movement of the second mobile robot and ends at a time when a signal emitted from the second mobile robot is sensed at a rear side of the first mobile robot relative to the direction of movement of the first mobile robot. ### Claim 13 (depends on 12) The method of claim 12, wherein the method further includes transmitting the first signal while reducing a moving speed of the first mobile robot when the first mobile robot approaches the second mobile robot to within the distance less than the first threshold distance. ### Claim 14 (depends on 12) The method of claim 12, wherein said controlling the avoidance moving comprises outputting a control command to stop the moving of the first mobile robot while the second mobile robot moves away from the first mobile robot based on the second signal. ### Claim 15 (depends on 12) The method of claim 12, wherein said controlling the avoidance moving comprises reducing the moving speed of the first mobile robot according to the first signal, and maintaining the reduced moving speed of the first mobile robot while the second mobile robot moves away from the first mobile robot based on the second signal. ### Claim 16 (depends on 12) The method of claim 12, further comprising: outputting a control command to stop the moving of the first mobile robot such that the second mobile robot follows a trajectory corresponding to the movement of the first mobile robot prior to the avoidance moving when the avoidance moving based on the second signal ends. ### Claim 17 A cleaning system including a plurality of mobile robots, the cleaning system comprising: a driving unit configured to move a main body of a first mobile robot; a communication unit configured to communicate with a second mobile robot; and a controller configured to: recognize the location of the second mobile robot using a second signal emitted by the second mobile robot; control a moving speed of the main body such that the second mobile robot follows a trajectory corresponding to the movement of the main body based on the recognized location; transmit a first signal to the second mobile robot in response to the main body approaching the second mobile robot in a first direction to within a distance less than a first threshold distance to the second mobile robot; and control avoidance moving of the main body and the second mobile robot based on the second signal of the second mobile robot emitted in response to the first signal, wherein the controller is further configured to control the second mobile robot to follow the trajectory corresponding to the movement of the main body while a length of the trajectory satisfies a determined follow-up distance range, wherein the determined follow-up distance range is a distance range between a first distance and a second distance, wherein the second distance is longer than the first distance.