# US 11,442,475 B2 · Unmanned aircraft and method for controlling unmanned aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,475 B2 - Document ID: US11442475B2 - Status: Granted - Kind: B2 - Application number: 16/464,274 - Filed: 2017-10-23 - Published: 2020-09-10 - Granted: 2022-09-13 - Earliest claimed: 2016-12-12 - Assignees: Autonomous Control Systems Laboratory Ltd. - Applicants: Autonomous Control Systems Laboratory Ltd. - Inventors: Daisuke Iwakura; Yuji Ogawa; Nobuyuki Togashi - Web page: https://patentgrep.com/patent/US11442475B2 ## CPC - G05D 1/105: {specially adapted for unpowered flight, e.g. glider, parachuting, forced landing (parachutes per se B64D17/00)} - B64C 13/18: using automatic pilot - B64D 25/00: Emergency apparatus or devices, not otherwise provided for - B64U 10/16: with five or more distinct rotor axes, e.g. octocopters - G05D 1/0011: {associated with a remote control arrangement} - G05D 1/0676: {specially adapted for landing} - G08G 5/54: for approach or landing - B64U 50/19: using electrically powered motors - B64U 60/50: with landing legs - B64U 70/83: using parachutes, balloons or the like - B64U 2201/10: autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS] - B64U 2201/20: Remote controls - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B64C: AEROPLANES; HELICOPTERS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR - G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93}) ## Abstract An unmanned aircraft 1 according to an embodiment of the present invention provides an unmanned aircraft that properly makes a forced landing in case of an abnormality. The unmanned aircraft 1 is configured as a multicopter that flies with lift and thrust generated by rotation of six rotors 13. The unmanned aircraft 1 identifies a forced landing site in a case of having detected an abnormality during flight and controls motors 12 configured to drive the respective rotors 13, to make a landing at the identified forced landing site. The unmanned aircraft 1 is consequently enabled to make an autonomous forced landing at a specific site in case of an abnormality. ## Claims ### Claim 1 An unmanned aircraft including a plurality of rotors, the unmanned aircraft comprising: a plurality of motors configured to drive the plurality of rotors respectively; and a control unit configured to control at least the plurality of motors to automatically fly in accordance with information on a flight route to a destination site, the information on the flight route including one or more via-points and a correspondence relationship between the one or more via-points and a plurality of predetermined sites, such that each via-point is assigned a specific predetermined site of the plurality of predetermined sites, wherein in a case of having detected an abnormality during flight, the control unit identifies the specific predetermined site as a forced landing site from among the plurality of predetermined sites based on the correspondence relationship assigned for a most recent via-point that the unmanned aircraft has passed through among the one or more via-points, and controls at least part of the plurality of motors to make a landing at the identified forced landing site. ### Claim 2 (depends on 1) The unmanned aircraft according to claim 1, wherein at least part of the plurality of predetermined sites are one or more arbitrary sites set by an operator or one or more sites set on a map in advance. ### Claim 3 (depends on 1) The unmanned aircraft according to claim 1, further comprising a soft landing device for making a soft, landing, wherein in the case of having detected the abnormality during flight and a case that a landing at a specific forced landing site is impossible, the control unit actuates the soft landing device. ### Claim 4 (depends on 1) The unmanned aircraft according to claim 1, wherein the control unit is configured to detect the abnormality, based on information received from outside. ### Claim 5 (depends on 1) The unmanned aircraft according to claim 1, wherein the control unit is configured to control the motors via a motor driving control unit and detects an abnormality in one or more of the motors, based at least on operation information of the motors received from the motor driving control unit. ### Claim 6 (depends on 1) The unmanned aircraft according to claim 1, wherein the plurality of predetermined sites includes at least one of the one or more via-points. ### Claim 7 A method for controlling an unmanned aircraft including a plurality of rotors, the method comprising: in a case of having detected an abnormality during flight, identifying a forced landing site; and controlling at least part of a plurality of motors configured to drive the plurality of rotors respectively, to make a landing at the identified forced landing site, wherein the method further includes controlling at least the plurality of motors to automatically fly in accordance with information on a flight route to a destination site; the information on the flight route includes one or more via-points and a correspondence relationship between the one or more via-points and a plurality of predetermined sites such that each via-point is assigned a specific predetermined site of the plurality of predetermined sites; and identifying includes identifying the specific predetermined site as the forced landing site from among the plurality of predetermined sites based on the correspondence relationship assigned for a most recent via-point that the unmanned aircraft has passed through among the one or more via-points. ### Claim 8 (depends on 7) The method according to claim 7, wherein the plurality of predetermined sites includes at least one of the one or more via-points.