Abstract: A floor shape estimation system for a legged mobile robot, in particular a biped walking robot, which estimates a floor shape, more specifically a foot-to-foot floor inclination difference based on at least a control error of the total floor reaction force's moment and based on the estimated value and corrects a feet compensating angle based on the estimated value. Further, the system estimates a floor shape, more specifically a foot floor inclination difference based on at least a control error of the foot floor reaction force about a desired foot floor reaction force central point and corrects a foot compensating angle based on the estimated value. With this, it can accurately estimate the shape of a floor with which the robot is in contact. Further, if the floor shape is different from what has been supposed, it can produce the floor reaction force as desired by absorbing the influence of difference.

Abstract: In a posture control system of a mobile robot, when unexpected external force acts, it is configured to control to stabilize the posture of the robot driving the arm link such that, in response to a first external force that is a component in a predetermined direction of the unexpected external force, a second external force acts on the arm link in a direction orthogonal to the predetermined direction. With this, when the mobile robot is controlled to work that is likely to receive a reaction force from the object, even if the posture becomes unstable or the robot receives the unexpected reaction force acting from the object, it becomes possible to preserve the dynamic balance and to maintain a stable posture.

Abstract: A model's ZMP (full-model's ZMP) is calculated using a dynamic model (inverse full-model) 100c2 that expresses a relationship between a robot movement and floor reaction, a ZMP-converted value of full model's corrected moment about a desired ZMP is calculated or determined based on a difference (full-model ZMP's error) between the calculated model's ZMP and the desired ZMP, whilst a corrected desired body position is calculated or determined. Since the robot posture is corrected by the calculated ZMP-converted value and the corrected desired body position, the corrected gait can satisfy the dynamic equilibrium condition accurately.

Abstract: A floor shape estimation system for a legged mobile robot, in particular a biped walking robot, which estimates a floor shape, more specifically a foot-to-foot floor inclination difference based on at least a control error of the total floor reaction force's moment and based on the estimated value and corrects a feet compensating angle based on the estimated value. Further, the system estimates a floor shape, more specifically a foot floor inclination difference based on at least a control error of the foot floor reaction force about a desired foot floor reaction force central point and corrects a foot compensating angle based on the estimated value. With this, it can accurately estimate the shape of a floor with which the robot is in contact. Further, if the floor shape is different from what has been supposed, it can produce the floor reaction force as desired by absorbing the influence of difference.

Abstract: A floor shape estimation system for a legged mobile robot, in particular a biped walking robot, which estimates a foot-to-foot floor inclination difference based on at least a control error of the total floor reaction force's moment and corrects a feet compensating angle based on the estimated value. Further, the system estimates a foot floor inclination difference based on at least a control error of the foot floor reaction force about a desired foot floor reaction force central point and corrects a foot compensating angle based on the estimated value. Furthermore, it determines whether it is in a situation where the accuracy of estimation is liable to degrade based on at least a time of the gait of the robot and when it is in the situation, the system interrupts the estimation. With this, the system can accurately estimate the shape of floor with which the robot is in contact.

Abstract: In a legged mobile robot, in particular a biped robot having arms, the control is conducted such that the dynamic balance is preserved so as to keep a stable posture, even when the robot is subject to unexpected reaction force from an object. It is configured such that the difference or error (i.e., moment about the central point of total floor reaction force) between the desired object reaction force, and the actual value is determined and is distributed to the desired body position/posture and the desired feet position/posture, and based thereon, robot link joints are controlled to be driven.

Abstract: In a biped walking robot having a body and two articulated legs each connected to the body through a hip joint and having a knee joint and an ankle joint, connected by a shank link, a knee pad is mounted on the shank link as a landing/shock absorbing means at a position adjacent to the knee joint which is brought into contact with the floor when coming into knee-first contact with the floor such that the knee joint is to be positioned at a location forward of the center of gravity of the robot in a direction of robot advance, while absorbing impact occurring from the contact with the floor. With this, the robot can be easily stood up from an attitude with its knee joint regions in contact with the floor. Moreover, when coming into knee-first contact with the floor, it can absorb the impact of the contact to protect the knee joint regions and the floor from damage.

Abstract: An arm structure for anthropomorphic robots minimizes the occurrence of a singularity state of a shoulder joint assembly while the arm of the anthropomorphic robot is normally working, for thereby allowing the arm to operate smoothly. The position and posture of first through third joints (11), (13), (15) of a shoulder joint assembly (5) and the position of an elbow joint assembly (6) with respect to the third joint (15) are established such that the elbow joint assembly (6) is located above a horizontal plane lying through the point of intersection of the axes (10), (12), (14) of the first through third joints (11), (13), (15), while the shoulder joint assembly (5) is operated into a singularity state wherein the first axis (10) of the first joint (11) and the third axis (14) of the third joint (15) are aligned with each other and the elbow joint assembly (6) is positioned laterally of a torso (1).

Abstract: In a legged mobile robot, in particular a biped robot having arms, the control is conducted such that the dynamic balance is preserved so as to keep a stable posture, even when the robot is subject to unexpected reaction force from an object. It is configured such that the difference or error (i.e., moment about the central point of total floor reaction force) between the desired object reaction force and the actual value is determined and is distributed to the desired body position/posture and the desired feet position/posture, and based thereon, robot link joints are controlled to be driven.

Abstract: An arm structure for anthropomorphic robots minimizes the occurrence of a singularity state of a shoulder joint assembly while the arm of the anthropomorphic robot is normally working, for thereby allowing the arm to operate smoothly. The position and posture of first through third joints (11), (13), (15) of a shoulder joint assembly (5) and the position of an elbow joint assembly (6) with respect to the third joint (15) are established such that the elbow joint assembly (6) is located above a horizontal plane lying through the point of intersection of the axes (10), (12), (14) of the first through third joints (11), (13), (15), while the shoulder joint assembly (5) is operated into a singularity state wherein the first axis (10) of the first joint (11) and the third axis (14) of the third joint (15) are aligned with each other and the elbow joint assembly (6) is positioned laterally of a torso (1).

Abstract: The posture inclination of the robot is detected, a moment of compensating total floor reaction force about a desired total floor reaction force central point is determined therefrom to be distributed to each foot such that the position/posture of the feet are rotated by predetermined amounts about the desired total floor reaction force central point and a desired foot floor reaction force central points respectively. And by parallel-translating the feet in phase, the force component of the actual total floor reaction force is also controlled. In addition, the internal force components (which do not influence on the actual total floor reaction force) generated by the actual foot floor reaction force are controlled independently.

Abstract: In a legged mobile robot, in particular in a biped robot, the feet position and/or posture is determined in such a manner that compensating moment of total floor reaction force about a desired total floor reaction force central point is determined, based upon the detected posture inclination of the robot, and is distributed to each of the feet such that each foot rotates respectively by predetermined angles about the desired total foot floor reaction force central point and a desired foot floor reaction force central point, in order to control the actual total floor reaction force and the actual foot floor reaction force acting on the robot properly such that it walks on a floor having not only a slope extending over a relatively long distance, but also existing locally. With this, it becomes possible to control the floor reaction force acting on the robot easily and properly, without causing any interference to occur.

Abstract: A legged moving robot has a plurality of movable legs for repeatedly touching and leaving a floor. A force sensor is mounted on each of the movable legs at a position spaced from a foot sole thereof toward a proximal end thereof, and detects at least a force and a moment based on a reactive force applied from the floor to the foot when the foot is landed on the floor. The foot is tilted along a ridge on the floor by actuators when the foot is landed on the ridge such as the edge of a stair. A position of the center of the reactive force applied from the floor to the foot is recognized on the basis of the force and the moment detected by the force sensor, in a plurality of tilted attitudes of the foot when the foot is tilted. A landed direction and/or a landed position of the foot with respect to the ridge is recognized on the basis of the position of the center of the reactive force recognized in the plurality of tilted attitudes of the foot.

Abstract: A legged moving robot has a plurality of movable legs extending downwardly from an upper body and having actuators associated respectively with joints thereof. A fall judging unit decides whether the robot is likely to fall down while the robot is operating. An actuator controller controls the actuators associated respectively with the joints of the movable legs to lower the center of gravity of the robot when the fall judging unit determines that the robot is likely to fall down.

Abstract: A legged moving robot has a plurality of movable legs for repeatedly touching and leaving a floor. An apparatus for detecting the landing position of a foot sole of each of the movable legs has a force sensor mounted on each of the movable legs at a position spaced from a foot sole thereof toward a proximal end thereof. The force sensor detects at least a perpendicular force perpendicular to the foot sole and a moment about an axis extending in a lateral direction of the foot sole and passing through a predetermined reference point on the foot sole. A time when the foot sole touches or leaves the floor is detected on the basis of the perpendicular force detected by the force sensor. A landing position for the foot sole to start touching or end leaving the floor is determined on the basis of the perpendicular force and the moment detected by the force sensor, at the detected time or in a predetermined time range near the detected time.

Abstract: A trajectory generation for a member such as a foot of a legged mobile robot. First, basic trajectories defining some typical motions of the foot including a constraint condition are established on a virtual plane or surface fixed on a coordinate system. The virtual plane is kept fixed on the ground until a time the foot is to be lifted. Then at this period free from the constraint condition, the coordinate system is displaced such that the virtual surface coincides with another point of the ground on which the foot is to be landed. A trajectory for a footrise to footfall is thus generated by combining the basic trajectories in the coordinate system and the amount of displacement of the coordinate system. Thus, the boundary conditions become extremely simple and hence, trajectory generation is greatly simplified. A real time trajectory correction can be conducted if desired.

Abstract: A gait generation for a biped mobile robot having a body and two legs each connected to the body and having a foot at its distal end in walking a terrain including a first surface and a second surface met at a dihedral angle such that the robot feet are in simultaneous contact with the different two surfaces. The centers of ground contact pressure distribution of the first and second surfaces are determined. A virtual third surface which assumes to vary from the first surface to the second surface is established. Then a virtual ZMP (Zero Moment Point) is assumed on the virtual third surface such that the virtual ZMP is displaced along a path obtained by connecting the centers of the ground pressure distribution of the first and second surfaces. And a gait for the robot is generated such that a ZMP kinematically determined from the motion of the robot coincides with the target ZMP.