# US 9,429,948 B2 · Humanoid robot having fall-management capabilities, and method for managing said falls > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,429,948 B2 - Document ID: US9429948B2 - Status: Granted - Kind: B2 - Application number: 13/819,345 - Filed: 2011-08-11 - Published: 2013-09-05 - Granted: 2016-08-30 - Earliest claimed: 2010-08-27 - Assignees: Aldebaran Robotics - Applicants: David Gouaillier - Inventors: David Gouaillier - Web page: https://patentgrep.com/patent/US9429948B2 ## CPC - B62D 57/032: with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) - G05D 1/00: Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots (drive control systems specially adapted for autonomous road vehicles B60W60/00) - G06F 11/30: Monitoring - Y10S 901/01: Mobile robot - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract The invention relates to a humanoid robot endowed with particular capabilities for managing falls. The risks of falling limit the development of the mass-market use of humanoid robots. In the prior art, the modalities for detecting falls are not well suited to the case of very dynamic robots since the center of mass is very often outside their support polygons. The modalities for managing falls are also poorly suited to robots which must be economical in their computation resources. According to the invention, the conventional support polygon is supplemented with effectors for which it is determined that they are sufficiently close to the ground. Protection strategies are implemented, chosen from a set of strategies defined by a classification of the angles of fall. ## Claims ### Claim 1 A humanoid robot configured to move on a surface comprising: a first sensing capability configured to detect a contact of at least one first extremity of the robot with said surface, a first processing capability configured to compute a position of a point of projection of a center of mass of said robot with respect to a first support polygon comprising said one first extremity, and a second processing capability configured to determine a proximity of at least one second extremity of said robot with said surface, wherein at an output of the first processing capability configured to compute the position of the point of projection of the center of mass of said robot with respect to a support polygon, a module for monitoring and initiating a group of actions for protecting against falls, at least one of said actions being triggered when the first processing capability provides at least one output characteristic of a fall state of the robot in which the point of the projection of the center of mass of the robot is outside a second support polygon, and wherein said first processing capability is further configured to compute a position of the projection of the center of mass of said robot with respect to the second support polygon, said second polygon being deduced from the first polygon by adding to the latter points of projection on said surface of said second at least one extremity of said robot belonging to a group of extremities of said robot detected at a height less than threshold h0 with said surface, at a computing cycle when the point of projection of the center of mass with respect to the first polygon is computed, the threshold h0 being higher than zero, wherein an output of said computation by the first processing capability is used to trigger a fall detection if the projection of the center of mass does not fall within the first support polygon and does not fall within the second support polygon. ### Claim 2 (depends on 1) The humanoid robot of claim 1, wherein the second processing capability configured to compute the proximity of said at least one second extremity with said surface receives as an input the position of said at least one second extremity with respect to said surface, said position being provided as an output of a geometric model of the robot comprising at least the position in space of said extremity in a reference frame of the robot. ### Claim 3 (depends on 2) The humanoid robot of claim 2, wherein the condition according to which a second extremity of the robot is at a height less than threshold h0 with said surface is characterized by a distance threshold chosen as a function of criteria belonging to a group of criteria comprising at least the size of the robot and the maximum swing in height of lower limbs of the robot. ### Claim 4 (depends on 1) The humanoid robot of claim 1, wherein said at least one first extremity is a foot of the robot, said foot comprising at least one pressure force sensor. ### Claim 5 (depends on 1) The humanoid robot of claim 1, wherein said at least one second extremity is a hand of the robot. ### Claim 6 (depends on 1) The humanoid robot of claim 1, further comprising, as input of the first processing capability configured to compute the position of the point of projection of the center of mass of said robot with respect to a support polygon, a module for filtering postures of the robot by comparing, according to a predefined criterion, a distance between geometric models of said postures and the geometric models of reference postures where fall detection computation is not carried out. ### Claim 7 (depends on 1) The humanoid robot of claim 1, further comprising an inertia measurement unit providing the first processing capability configured to compute the position of the point of projection of the center of mass of said robot with a vertical axis whose angle with the axis connecting the thorax and a foot of the robot in contact with the ground and with an angle of rotation to be applied to the axis of projection of the center of mass of the robot. ### Claim 8 (depends on 1) The humanoid robot of claim 1, wherein the group of actions for protecting against falls comprises at least a disabling of a slaving of articulations of legs of the robot, a placing in a posture of protection of at least one element belonging to the group comprising at least a head, arms and pelvis, and the disabling of the articulations of at least one element belonging to said group. ### Claim 9 (depends on 1) The humanoid robot of claim 1, wherein the first processing capability further provides the module for monitoring the group of actions for protecting against falls, for a state characterizing a fall state of the robot, with an angle characterizing the direction of fall in a reference frame of the robot, the value of said angle of fall with respect to chosen reference values determining the choice of the protection actions in the group of actions for protecting against falls to be executed. ### Claim 10 (depends on 8) The humanoid robot of claim 8, wherein, when an angle of fall determines a forward fall, the placing in a posture of protection of the head consists of placing the head substantially rearward, the placing in a posture of protection of the arms consists of placing the arms substantially forward to damp the forward fall and protect the head, and the placing in a posture of protection of the pelvis consists of closing the pelvis. ### Claim 11 (depends on 8) The humanoid robot of claim 8, wherein, when an angle of fall determines a fall to the left or the right, the placing in a posture of protection of the head consists of placing the head substantially forward, the placing in a posture of protection of the arms consists of grouping the arms together substantially toward the body, and the placing in a posture of protection of the pelvis consists opening the pelvis in order for a back of the robot to be a first point of contact with the ground. ### Claim 12 (depends on 8) The humanoid robot of claim 8, wherein, when the angle of fall determines a rearward fall, the placing in a posture of protection of the head consists of placing the head substantially forward, the placing in a posture of protection of the arms consists of bringing the arms substantially rearward, and the placing in a posture of protection of the pelvis consists of closing the pelvis to group the legs of the robot together. ### Claim 13 A method for managing the falls of a humanoid robot capable of moving on a surface and comprising a first sensing capability configured to detect a contact of at least one first extremity of the robot with said surface, said method comprising: computing the position of the point of projection of a center of mass of said robot with respect to a first support polygon comprising at least said at least one first extremity; determining a proximity of at least one second extremity of said robot with said surface; and determining a position of a projection of the center of mass of said robot with respect to a second support polygon, said second polygon being deduced from the first polygon by adding to the latter points of projection on said surface of said at least one second extremity of said robot belonging to a group of extremities of said robot detected at a height less than threshold h0 with said surface, the threshold h0 being higher than zero, wherein an output of the computing the proximity of at least one second extremity of said robot is used to trigger a fall detection if the projection of the center of mass does not fall within the first support polygon and does not fall within the second support polygon. ### Claim 14 A robotic control system comprising at least one processor and a computer program comprising program code instructions that, when executed, cause the at least one processor to execute a method for managing the falls of a humanoid robot capable of moving on a surface and comprising a first sensing capability configured to detect a contact of at least one first extremity of the robot with said surface, the method comprising: computing the position of the point of projection of a center of mass of said robot with respect to a first support polygon comprising at least said at least one first extremity; determining a proximity of at least one second extremity of said robot with said surface; and determining a position of a projection of the center of mass of said robot with respect to a second support polygon, wherein an output of the computing the proximity of at least one second extremity of said robot is used to trigger a fall detection if the projection of the center of mass does not fall within the first support polygon and does not fall within the second support polygon, and wherein said program code instructions being adapted for allowing the management of falls of the humanoid robot, said program code instructions comprising a first processing capability configured to compute the position of the point of projection of the center of mass of said robot with respect to the first support polygon, said program code instructions further comprising a second processing capability for detection data of the proximity of the at least one second extremity of said robot with said surface and a module for computing the position of projection of the center of mass of said robot with respect to said second support polygon, said second polygon being deduced from the first polygon by adding to the latter points of projection on said surface of said at least one second extremity of said robot belonging to a group of extremities of said robot detected at a height less than threshold h0 with said surface. ### Claim 15 (depends on 1) The humanoid robot of claim 1, wherein said second at least one extremity is at a height less than threshold h0 with said surface, and said second at least one extremity is not in contact with said surface.