Abstract: An allowable ranges of a horizontal component of the translation floor reaction or a floor-surface-parallel component of the translation floor reaction force of a legged mobile robot 1 or a horizontal component of a total center-of-gravity acceleration or a floor-surface-parallel component of a total center-of-gravity acceleration of the robot 1 (hereinafter referred to as a friction force component) is set, and a provisional movement of the robot 1 is determined so as to satisfy a predetermined dynamical equilibrium condition. When the friction force component determined by this provisional movement departs from the allowable range, a rate of change of an angular momentum around the center of gravity of the robot 1 is changed from the provisional movement so as to satisfy the dynamical equilibrium condition while limiting the friction force component within the allowable range to thereby determine a movement of a desired gait.

Abstract: A legged mobile robot which permits improved follow-up of an actual floor reaction force to a desired floor reaction force and which can be stably controlled is provided. According to a robot 1 in accordance with the present invention, a deformation amount (mechanism deformation amount) of a compliance mechanism 42 that occurs due to a desired floor reaction force of a foot (ground contacting portion) 22 is determined, and the operation of a leg 2 is controlled such that the foot 22 lands onto a floor at a predetermined velocity in a vertical direction or in a direction perpendicular to the floor surface on the basis of a component of the mechanism deformation amount in the vertical direction or a component thereof in the direction perpendicular to the floor surface.

Abstract: When gait parameters for specifying a gait to be generated of a mobile robot (1) are determined, the values of the priority parameters of the gait parameters are updated from the values of the priority gait parameters of predetermined base gait parameters such that the priority parameters approach and reach the original required values step by step. For every update, out of non-priority parameters other than the priority ones, the parameters to be sought are determined by seeking so that the parameters may satisfy the gait boundary condition on the dynamic model of the robot (1). Thus, the new gait parameters including the determined parameters and the updated priority parameters are determined. Lastly, the gate of the mobile robot (1) is generated using dynamic model and the new gait parameters determined when the priority parameters are made to agree with the requested value.

Abstract: A landing shock absorbing device 18 disposed in a foot mechanism 6 of a leg of a robot, wherein an inflatable bag-like member 19 (variable capacity element) is provided at a bottom face side of the foot mechanism 6. The bag-like member 19 is constructed of an elastic material such as rubber. The air in atmosphere may flow into and out of the bag-like member 19 by inflow/outflow means 20 equipped with a solenoid valve 27, and the like. In a lifting state of the foot mechanism 6, inflow of the air into the bag-like member 19 is controlled, thereby controlling the final height of the bag-like member 19 in an inflated state to the height in response to a gait type of the robot. While properly reducing an impact load during a landing motion of the leg of a legged mobile robot depending on the gait type of the robot, stability of a posture of the robot may easily be secured, resulting in allowing a configuration to be lighter in weight.

Abstract: A permissible range of a restriction object amount, which is a vertical component of a floor reaction force moment or a component of the floor reaction force moment in floor surface normal line direction, or a vertical component of an angular momentum changing rate of the robot or a component of the angular momentum changing rate in floor surface normal line direction, is set, and at least a provisional instantaneous value of a desired motion is input to a dynamic model so as to determine an instantaneous value of a model restriction object amount as an output of the dynamic model. An instantaneous value of a desired motion is determined by correcting the provisional instantaneous value of the desired motion such that at least the instantaneous value of the model restriction object amount falls within the permissible range.

Abstract: There are provided device for determining a desired trajectory of a translation floor reaction force's vertical component of a legged mobile robot 1, a vertical component of the total center-of-gravity acceleration or a body acceleration vertical component of the robot 1, device for determining a desired vertical position of the total center-of-gravity of the robot 1 or a body 24 thereof so as to satisfy the desired trajectory, and means for determining a desired vertical position of the total center-of-gravity of the robot 1 or the body 24 thereof based on a geometrical condition concerning a joint of a leg 2. Depending on the gait mode, such as walking or running, one of the desired vertical positions is selected, or the desired vertical positions are combined by taking the weighted average thereof or the like, thereby determining a final desired vertical position.

Abstract: In a legged mobile robot, a pivoting motion of a foot (22) relative to a leg is controlled such that, from an intermediate time point in a period of departure of a leg from a floor to a starting time point of a period of landing of the leg on the floor, an angle (?) of inclination of the foot (22) of the leg relative to the floor surface gradually approaches zero. This eases impact to the foot of the leg at the time of landing on the floor and prevents a slip or spin of the sole, thereby enabling stable walking or running.

Abstract: A gait generating system for a mobile robot has n dynamic models and determines a first gait parameter defining a desired gait such that the boundary condition of a gait on a first dynamic model is satisfied. The first gait parameter is corrected step by step by using an m-th dynamic model (m: integer satisfying 2?m?n), which is each dynamic model other than the first dynamic model, and an m-th gait parameter that satisfies the boundary condition on the m-th dynamic model is determined. The m-th gait parameter is determined by correcting an object of an (m?1)th gait parameter to be corrected on the basis of the degree of deviation of the gait generated on the m-th dynamic model by using the (m?1)th gait parameter from the boundary condition. A final determined n-th gait parameter and an n-th dynamic model are used to generate a desired gait.

Abstract: A gait generation device for setting a translation floor reaction force's horizontal component (component concerning a friction force) applied to a robot 1, a limitation-target quantity, such as a ZMP, and an allowable range, for determining at least a provisional instantaneous value of a desired floor reaction force and a provisional instantaneous value for a desired movement of the robot 1, that receives at least the provisional instantaneous value for the desired movement and determines a model floor reaction force instantaneous value with the aid of a dynamics model.

Abstract: A gait generation device for generating a desired gait which includes floating periods in which all the legs 2, 2 of a legged mobile robot 1 float in the air and landing periods in which at least one leg 2 is in contact with a floor which appear alternately generates the desired gait in such a manner that, at least when shifting from the floating period to the landing period, the velocity of an end portion 22 of a landing leg with respect to the floor and the acceleration thereof with respect to the floor is substantially 0 at the instant of landing. After both the velocity of the end portion of the leg with respect to the floor and the acceleration thereof with respect to the floor are determined to be substantially 0, a movement of the body of the robot with the desired gait is determined in such a manner that the horizontal component of a moment produced about the desired ZMP by the resultant force of gravity and an inertial force applied to the robot 1 is substantially 0.

Abstract: When generating a gait for a legged mobile robot 1 which has floating periods in which all the legs 2 of the robot float in the air and landing periods in which any of the legs 2 is in contact with the floor appearing alternately, a desired ZMP is set at any point in time in the floating periods and the landing periods, and a desired gait is generated in such a manner that the horizontal component of the moment produced about the desired ZMP by the resultant force of gravity and an inertial force caused by a movement of the robot with the desired gait is 0. The desired ZMP is set to be substantially continuous for all the periods in the gait. Furthermore, as a dynamics model for determining the desired gait, an approximate model is used which is arranged so that the moment, about a certain point of application, of the resultant force of the inertial force and gravity calculated using the model depends on the position of the point of application.

Abstract: An allowable range of a frictional force component, such as a horizontal component of a translation floor reaction force, applied to a legged mobile robot 1 is set, and a provisional movement with a current time gait of the robot 1 is determined so as to satisfy a condition concerning the allowable range and a dynamical equilibrium condition that a moment produced about a point of application of a provisional desired floor reaction force substantially agrees with a provisional desired floor reaction force moment. The provisional movement is determined by adjusting movements in two movement modes which are different in ratio between the translation floor reaction force and the floor reaction force moment.

Abstract: A gait generating system for a mobile robot has n dynamic models and determines a first gait parameter defining a desired gait such that the boundary condition of a gait on a first dynamic model is satisfied. The first gait parameter is corrected step by step by using an m-th dynamic model (m: integer satisfying 2?m?n), which is each dynamic model other than the first dynamic model, and an m-th gait parameter that satisfies the boundary condition on the m-th dynamic model is determined. The m-th gait parameter is determined by correcting an object of an (m?1)th gait parameter to be corrected on the basis of the degree of deviation of the gait generated on the m-th dynamic model by using the (m?1)th gait parameter from the boundary condition. A final determined n-th gait parameter and an n-th dynamic model are used to generate a desired gait.

Abstract: By using a first dynamic model of a moving robot 1, a provisional motion, which indicates a provisional value of a desired motion of the robot 1, is created such that a desired value of a floor reaction force moment horizontal component and a permissible range of a translational floor reaction force horizontal component are satisfied on the first dynamic model. The difference between a floor reaction force produced on a second dynamic model, which has a dynamic accuracy that is higher than that of the first dynamic model, by the provisional motion and a floor reaction force produced on the first dynamic model is defined as a floor reaction force error. Based on this floor reaction force error, the provisional motion is corrected on the first dynamic model to generate a desired motion. The desired motion is generated such that the value obtained by adding the floor reaction force error to the floor reaction force generated on the first dynamic model satisfies the aforesaid desired value and permissible range.

Abstract: Ground contact portions 10 are classified into a tree structure such that each of the ground contact portions 10 of a mobile body 1 (mobile robot) equipped with three or more ground contact portions 10 becomes a leaf node and that an intermediate node exists between the leaf node and a root node having all the leaf nodes as its descendant nodes. On each node (a C-th node) having child nodes, the correction amounts of the desired relative heights of the ground contact portions 10 of the C-th node are determined such that the relative relationship among the actual node floor reaction forces of the child nodes of the C-th node approximates the relative relationship among the desired node floor reaction forces of the child nodes of the C-th node, and joints of the mobile body 1 are operated so that a desired relative height obtained by combining the correction amounts is satisfied.

Abstract: A landing shock absorbing device 18 disposed in a foot mechanism 6 of a leg of a robot, wherein an inflatable bag-like member 19 (a variable capacity element) is provided at a ground-contacting face side of the foot mechanism 6. The bag-like member 19 is constructed of an elastic material such as rubber and has a restoring force. An interior portion of the bag-like member 19 is communicated with the atmosphere side through a flow passage 20. During a landing motion of the leg, the bag-like member 19 makes contact with the ground to be compressed, and the air in the interior portion thereof flows out into the atmosphere through the flow passage 20, so that its outflow resistance is generated. Accordingly, a landing shock is reduced. In a lifting state of the leg, the restoring force of the bag-like member 19 allows the bag-like member 19 to be inflated while the air flows into the interior portion thereof.

Abstract: A control system for a mobile robot is provided with a base body 53 and a plurality of link mechanisms 52 and 54 connected thereto. A sensor 90 for detecting external forces is provided on a predetermined portion (knee) between the base body 53 and a distal portion (foot) 58 of the link mechanism (leg) 52. In a motion posture in which a robot 61 has a predetermined portion (knee) in contact with the ground, the displacement of at least a joint 55 between the base body 53 and the predetermined portion (knee) is controlled so as to bring an external force (floor reaction force) detected by the sensor 90 close to a desired external force. In a state wherein a portion other than a distal portion of a leg or arm of the robot 61 is in contact with a floor or the like and subject to an external force, the external force acting on the portion other than the distal portion of the leg or arm is properly controlled, thereby maintaining a stable posture of the robot 61.

Abstract: To generate a desired gait of a robot 1 such that a permissible range of a predetermined component (a translational floor reaction force horizontal component or the like) of a floor reaction force acting on the mobile robot 1, a gait generating system for a mobile robot creates a provisional motion, which indicates a provisional value of a desired motion, and repeats processing for correcting the provisional motion by using a first dynamic model and a second dynamic model having a dynamic accuracy that is higher than that of the first dynamic model until a predetermined condition is satisfied, thereby obtaining a final corrected motion as the desired motion.

Abstract: Ground contact portions are categorized in a tree structure manner such that all of the ground contact portions of a mobile body (mobile robot) equipped with three or more ground contact portions become leaf nodes and that an intermediate node exists between the leaf nodes and a root node having all the leaf nodes as its descendant nodes. On each node (a C-th node) having child nodes, the correction amounts of the desired relative heights of the ground contact portions of the C-th node are determined such that at least the difference between an actual posture inclination and a desired posture inclination of a predetermined portion, such as a base body, (posture inclination difference) is approximated to zero, and joints of the mobile body 1 are operated so that a desired relative height obtained by combining the correction amounts is satisfied.

Abstract: On the basis of at least a difference between a desired state amount related to a posture of a robot 1 about a vertical axis or a floor surface normal line axis and an actual state amount of the robot 1 and a permissible range of a restriction object amount, namely, a vertical component of a floor reaction force moment or a component of the floor reaction force moment in a floor surface normal line direction to be applied to the robot 1, instantaneous values of a desired motion and a desired floor reaction force are determined such that a difference between a floor reaction force moment balancing with the desired motion on a dynamic model and a floor reaction force moment of the desired floor reaction force approximates the aforesaid difference to zero, while having the restriction object amount, which is associated with the desired floor reaction force, fall within the permissible range.