Toyota Jidosha Kabushiki Kaisha

Masahiro Doi

Toshio Fukuda

Keisuke Suga

Yoshimi Kajitani

Yasuhisa Hasegawa

A robot that moves on a leg, the robot comprising: a calculation unit that calculates a floor reaction force moment around a vertical axis from a center of gravity and a ZMP trajectory of the robot and a moment orbit around the center of gravity, and obtains a correction amount of a moment vector around the center of gravity when the floor reaction force moment around the vertical axis exceeds a frictional limit; and a control unit that controls the robot based on the correction amount.

Robot

A prediction model for predicting a mobile robot state is constructed to represent a state change of the mobile robot in a prediction interval of a predetermined duration; time-series data on a control input to ensure stability of the mobile robot is obtained in the prediction interval using a predetermined stability evaluation criterion and a constraint condition based on a mechanical balance; a center-of-gravity trajectory of the mobile robot is obtained based on the time-series data and prediction model; a slack variable for relaxing a constraint is introduced into a constraint condition; a slack variable is introduced into the stability evaluation criterion such that the variable becomes zero when a solution to a stable trajectory is obtained under the constraint condition and a slack variable value is generated when the trajectory diverges under the constraint condition; and positions of contact points are changed so as to cancel the generated value.

Movement control method for mobile robot

Provided is a method of driving a joint device suitably used for a robot joint with improved back drivability. A first motor and a second motor are fixedly connected to a first link. An output shaft of the first motor is coupled to an internal gear of a differential speed reducer. An output shaft of the second motor is coupled to an external gear of the differential speed reducer. A second link is coupled to the internal gear of the differential speed reducer. When the first link and the second link are relatively stopped to keep a joint angle fixed, both of the first motor and the second motor are rotated with a rotational speed larger than zero, and the rotational speed of the first motor and that of the second motor are differentiated to stop the second link.

Method of driving joint device

A walking assist device which assists the knee joint with well synchronizing with the upper leg motion during the swing phase at low cost may be provided. The walking assist device comprises an upper link, a lower link, a rotary joint, an actuator, and a controller. The upper link is to be attached to an upper leg of a user. The lower link is to be attached to the lower leg of the user. The rotary joint swingably connects the lower link to the upper link. The rotary joint is coaxially aligned with the user's knee joint when the user wears the walking assist device. The actuator swings the lower link relative to the upper link. The controller controls the actuator so that the lower link guides the user's walking motion.

Walking assist device

Provided is a method for determining a grounding timing of a biped walking robot. Firstly, a ZMP equation which represents a trajectory of a center of gravity including a first single-leg grounded period in which the robot stands only with a first leg and a second single-leg grounded period in which the robot stands only with a second leg, following the first single-leg grounded period, is solved using a predetermined grounding timing. A second leg ZMP position representing a ZMP position in the second single-leg grounded period is then calculated. When the calculated second leg ZMP position is out of the second leg ZMP permissible area, the grounding timing is modified so that the second leg ZMP position is located in a second leg ZMP permissible area which is defined corresponding to a possible grounding area of the second leg.

Biped walking robot

In a robot with two or more leg links having ankle joint respectively and pivotably linked to a torso, the robot walks naturally by making the ankle joint of a grounded leg link rotate freely by using passive movement. A controller executes controlling operation of calculating target joint angles of remaining joints other than the ankle joint of the grounded leg link based upon the measured joint angles of the ankle joint of the grounded leg link in the lateral and forward direction. The target joint angles of the remaining joints are calculated so as to satisfy the following condition that a tilting angle of the torso matches a target tilting angle determined based upon the measured joint angle of the ankle joint of the grounded leg link in the forward direction, a cycle period of the idle leg link from lifting to grounding, and a target stride of the idle leg link.

Growing community of inventors

Chofu, Japan

Masahiro Doi