A biped walking humanoid robot is disclosed having an arrangement whereby shocks acting on various parts of the robot when it falls can be relieved and its state of fall can then be detected. The robot has a body ( 11 ) capable of bending forward, a pair of legs ( 12 L, 12 R) attached to a lower part of the body at a pair of opposite sides thereof, respectively, a pair of arms ( 13 L, 13 R) attached to an upper part of the body at a pair of opposite sides, respectively, and a head ( 14 ) attached to an upper end of the body, each of the legs having a upper leg ( 15 L, 15 R) attached to the body so as to be pivotally movable relative thereto triaxially, a lower leg ( 16 L, 16 R) attached to a lower end of the upper leg so as to be pivotally movable relative thereto monoaxially and a foot ( 17 L, 17 R) attached to a lower end of the lower leg so as to be pivotally movable relative thereto biaxially, each of the arms having an upper arm ( 25 L, 25 R) attached to the body so as to be pivotally movable relative thereto biaxially, a lower arm ( 26 L, 26 R) attached to the upper arm so as to be pivotally movable relative thereto monoaxially and a hand ( 27 L, 27 R) attached to the lower hand so as to be pivotally movable relative thereto biaxially, the robot also having drive means ( 23 L, 23 R, 24 L, 24 R; 21 L, 21 R; 19 L, 19 R, 20 L, 20 R, 18 L, 18 R; . . . ) associated with the feet, the lower legs and the upper legs of the legs, the hands, the lower arms and the upper arms of the arms and a body bending-forward region for pivotally moving them, respectively, a control stage ( 51 ) for controlling driving actions of the drive means, and a contact detector ( 40 ) mounted at each of an outer elbow surface area formed between the upper and lower arms, and an outer wrist surface area between the lower arm and the hand of each of the arms, and a lower toe surface area of the foot, a lower heal surface area of the foot, an outer knee surface area between the upper and lower legs of each of the legs, and a hip surface area and a back surface area of the body, the contact detector at each of these surface areas comprising a casing portion ( 41 ) made of a material forming an outer covering surface area of the robot, a pressure sensor ( 42 ) for sensing a pressure acting on the casing portion and a shock absorbing material ( 43 ) for absorbing a shock acting on the casing portion. Thus, when the biped walking humanoid robot is having a fall, the state or type of this fall can be determined by the control stage in response to a contact signal detected by the pressure sensor in the contact detector at a relevant part of the abovementioned robot parts which is brought into contact with the floor or ground. Then, on the basis of the type of the fall determined, the control stage is allowed to act on the drive means to move the arm and leg parts suitably so as to cause the robot to take a corrective falling action to have a safety fall and then to move to taking a rising action to get up on its feet.
Two-leg walking humanoid robot