Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Masakazu Kawai

Yasushi Ikeuchi

Behzad Dariush

Hisashi Katoh

Toru Takenaka

Shinya Shirokura

Susumu Miyazaki

Masanori Takeda

Tsukasa Sugino

Hiroyuki Kaneko

Kenro Udono

Chiaki Tanaka

A control device for a bipedal mobile robot generates a desired motion of a bipedal mobile robot. When causing the robot to perform a one-leg hopping operation, a desired motion of the robot is generated such that the proximal end portion of a free leg of the robot is positioned at a relatively higher level than the proximal end portion of a supporting leg thereof in the state wherein the supporting leg has landed on a floor after leaving from the floor and such that the horizontal distance between the total center-of-gravity point of the robot and the proximal end portion of the supporting leg in the aforesaid state is shorter than the horizontal distance therebetween in a state wherein the robot is standing in an upright posture.

Control device and gait generating device for bipedal mobile robot

In a system for driving a mobile robot having a body, a plurality of legs each comprising a thigh link and a shank link, a first electric motor and a second motor for driving the thigh link in a forwarding direction, a power line connecting a power source to the first and the second motors, and a motor driver that supplies drive voltage to the first and second motors, a booster that boosts the drive voltage to be supplied to the first and second motors is provided such that the booster and the motor driver are installed in the thigh link where the first and second motors are installed, thereby enabling to satisfy both the low-voltage demand and high-voltage demand and to supply drive voltage to the motors effectively.

Driving system for mobile robot

The joint rotational angles of jointsandof each legof a bipedal walking bodyare detected to grasp the positions/postures of the corresponding rigid bodiesandof each legon a leg plane passing the jointsandof each leg. At the same time, the acceleration of a reference point (the origin of a body coordinate system BC) of the bipedal walking body, the floor reaction force acting on each legand the position of an acting point thereof are grasped in terms of three-dimensional amounts. Two-dimensional amounts obtained by projecting the acceleration, the floor reaction force and the position of the acting point thereof, and the positions/postures of the corresponding rigid bodies of eachonto the leg plane are used to estimate the moments acting on joints of each leg on the basis of an inverse dynamic model. The stability of the estimated values of joint moments can be improved while securing the accuracy of estimating the joint moments in the bending and stretching directions of each leg, considering three-dimensional motions of the bipedal walking body.

Method of estimating joint moment of bipedal walking body

A legged mobile robot and a control program for the robot cancel a spin force, which is generated by motions of a lower body (), a leg () or the like, by a twisting motion of an upper body () relative to the lower body () and a swinging motion of an arm ().

Legged mobile robot and control program for the robot

Displacements of respective joints corresponding to respective joint elements (Jand the like) of a rigid link model (S) representing a two-legged walking mobile body () are sequentially grasped. Also at the same time, values, in a body coordinate system (BC), of an acceleration vector of the origin of the body coordinate system (BC) fixed to a waist () as a rigid element, a floor reaction force vector acting on each leg (), and a position vector of the point of application of the floor reaction force vector are sequentially grasped. With the use of the grasped values, joint moments respectively generated in an ankle joint (), a knee joint (), and a hip joint () of each leg () are sequentially estimated based on an inverse dynamics model using the body coordinate system. The estimation accuracy of the joint moments of the leg can be enhanced by reducing arithmetic processing using tilt information of the two-legged walking mobile body relative to the gravity direction as much as possible.

Method of estimating joint moment of two-legged walking mobile body

While a biped walking mobile body is in a motion, such as level-ground walking, the position of the center of gravity (G0) of the biped walking mobile body, the position of an ankle joint () of each leg (), and the position of a metatarsophalangeal joint () of a foot () are successively grasped. The horizontal position of any one of the center of gravity (G0), the ankle joint (), and the metatarsophalangeal joint () is estimated as the horizontal position of a floor reaction force acting point on the basis of the combination of the contact or no contact with the ground at a spot directly below the metatarsophalangeal jointof the footand a spot directly below the ankle joint, which is detected by ground contact sensorsand, respectively, provided on the sole of the foot. The vertical position of the floor reaction force acting point is estimated on the basis of the vertical distance from the ankle joint () to a ground contact surface.

Method of assuming acting point of floor reaction force to biped walking mobile body and method of assuming joint moment of biped walking mobile body

A method and processor for obtaining torques to be applied to joints of a leg of a biped walking system include obtaining moments acting around the joints of the leg, using the vertical component of the ground reaction force acting on the leg at the point of application of the ground reaction force and incorporating the attitude of the leg and the vertical component of acceleration of the center of gravity of the whole body including the leg.

Method and processor for obtaining moments and torques in a biped walking system

A generated torque control method for a leg body exercise assistive apparatus enabling a person to make a leg motion in such a feeling that the person is not wearing the leg body exercise assistive apparatus as much as possible by reducing the weight of the leg body exercise assistive apparatus attached to the person acting on the person. On the assumption that a person (A) not wearing the assistive apparatus () is making the same motion as a leg motion of the person (A) wearing the leg body exercise assistive apparatus () during the leg motion of the person (A), an estimation is made for a person-side joint moment to be generated in each joint of the leg of the person (A), and on the assumption that the assistive apparatus () is independently making the same motion as the leg motion, an estimation is made for an apparatus-side joint moment to be generated in the joint regions (), (), and () of the leg sections of the assistive apparatus (). The estimated value of the apparatus-side joint moment is considered as a reference torque for torque generation means (), (), and (), and a torque formed by adding a torque according to the estimated value of the person-side joint moment to the reference torque is generated in the torque generation means (), (), and ().

Generated torque control method for leg body exercise assistive apparatus

A method for obtaining an assist torque to be applied to a human joint, in a human assist system for applying an assist torque to the human joint to reduce load of muscles, and the human assist system are provided. The method comprises the step of obtaining a moment due to gravity, acting on a joint of each human segment, based on equations of force and moment balance on each segment. The method further comprises the step of obtaining an assist torque to be applied to the joint to compensate for the moment due to gravity, acting on the joint. The human assist system comprises a motor for delivering an assist torque to a joint and a motor driver for driving control of the motor. The system further comprises a controller for determining a desired value of an assist torque, comprising a processor and a memory. The controller is configured to obtain a moment due to gravity, acting on a joint of each human segment, based on equations of force and moment balance on each segment and then to obtain an assist torque to be delivered to the joint to compensate for the moment due to gravitational acceleration at the joint. The method provides a natural subdivision between the voluntary actuators which are responsible for forward progression of motion and the assist actuators which are responsible for preserving static equilibrium. This subdivision may mitigate the interference between voluntary control and artificial control.

Gravity compensation method in a human assist system and a human assist system with gravity compensation control

While a biped walking mobile body is in a motion, including level-ground walking, the position of the center of gravity (G) of the biped walking mobile body, the position of an ankle joint () of each leg (), and the position of a metatarsophalangeal joint () of a foot () are successively grasped, and the horizontal position of a floor reaction force acting point of the leg () in contact with the ground is estimated on the basis of the relative positional relationship among the aforesaid positions. Depending on whether the center of gravity (G) is behind the ankle joint (), between the ankle joint () and the metatarsophalangeal joint (), or before the metatarsophalangeal joint () with respect to the advancing direction of the biped walking mobile body, the horizontal position of the ankle joint (), the center of gravity (G), or the metatarsophalangeal joint () is defined as the horizontal position of a floor reaction force acting point. The vertical position of the floor reaction force acting point is estimated on the basis of the vertical distance from the ankle joint () to a ground contact surface.

Whether a motion state of leg bodies () is a single stance state or a double stance state is sequentially determined and a total reaction force (F) is estimated on the basis of an equation of motion for a center of gravity (G) of a bipedal walking body (). If the motion state is the single stance state, then the estimated value of the total floor reaction force (F) is directly used as an estimated value of the floor reaction force of the leg body (). If the motion state is the double stance state, then a floor reaction force (Fr) of the leg body () at the rear side is determined, using measurement data of elapsed time of the double stance state and moving speed of a bipedal walking body () and pre-established characteristic data, and the floor reaction force (Fr) is subtracted from the total floor reaction force (F) to determine a floor reaction force (Ff) of the leg body () at the front side. Thus, it is possible to provide a method that allows floor reaction forces acting on leg bodies of a bipedal walking body, such as a human being, and moments acting on joints of the leg bodies to be determined in real time with high accuracy by a relatively simple technique.

Method of estimating floor reactions of bipedal walking body, and method of estimating joint moments of bipedal walking body

It is determined whether the motion state of legsis a one-leg supporting state or a two-leg supporting state, and a total floor reaction force is estimated based on a motion equation of the center of gravity of a bipedal movable body. If the motion state of legsis the one-leg supporting state, the estimated value of the total floor reaction force is used as an estimated value of the floor reaction force on the legwhich is landed. When the motion state changes to the two-leg supporting state, a vertical component of the floor reaction force on the rear leg is estimated from the MP height of the front leg based on a predetermined correlation between the MP height of the front leg and the vertical component of the floor reaction force on the leg.

Method of estimating floor reaction of bipedal movable body

A method and processor for obtaining torques to be applied to joints of a leg of a biped walking system are provided. The method comprises the steps of obtaining moments acting around the joints of the leg, using the vertical component of the ground reaction force acting on the leg at the point of application of the ground reaction force, the vertical components of forces acting on the joints of the leg and a term of the acceleration of gravity and without using the horizontal components of the forces acting on the joints of the leg and a term of acceleration except the term of the acceleration of gravity and obtaining the torques to be applied to the joints of the leg, based on the moments acting around the joints of the leg. The vertical component of the ground reaction force acting on the leg, is obtained based on which leg or legs are in contact with the ground. The processor is configured to perform the above steps.

A method is presented for determination of single stance or double stance state of leg bodies of a bipedal mobile body (BMB). In a single stance state, a floor reaction force acting on a leg body touching the ground is estimated based on an equation of motion for the center of gravity (GO) of a BMB. In a double stance state, floor reaction forces, Fr and Ff respectively, acting on the leg bodies are estimated based on an equation of motion for GO of a BMB and an expression of relation between components of Fr and Ff on the respective leg bodies and positions of ankle portions of the leg bodies relative to the GO of the BMB. Further, based on an inverse dynamics model, knee and hip joint moments of each leg body are estimated using floor reaction force values.

Growing community of inventors

Wako, Japan

Masakazu Kawai