Patent ID: 9399293
Filing Date: 2016-07-26
CPC Classification: B25J,G05B

Claim Text:
1. A method of controlling a system for calculating weight and/or center of gravity of an object for a robot, the method comprising: pressing respective upper and lower surfaces of the object via upper and lower parts of a robotic gripper to grip the object; lifting the object with the gripper; measuring, during lifting of the object, a change in angle of each joint of the gripper through an angle sensor provided for each joint of the gripper and calculating angular velocity and angular acceleration of each joint; calculating, via a controller, acceleration of the object using the angular velocity, the angular acceleration and a Jacobian matrix of the gripper; measuring an upper pressing force with which the upper part of the gripper presses the upper surface of the object and a lower pressing force with which the lower part of the gripper presses the lower surface of the object using force sensors installed on the joints; calculating, via the controller, the weight of the object using a vertical component of the acceleration of the object, a gravitational acceleration and the upper and lower pressing forces; calculating, via the controller, an angular acceleration at which the object rotates around the center of gravity from positional changes of points at which the upper and lower parts of the gripper come into contact with the respective upper and lower surfaces of the object; and calculating, via the controller, the center of gravity of the object from the calculated weight of the object, the calculated angular acceleration, the calculated upper and lower pressing forces, and positions of the points at which the upper and lower parts of the gripper come into contact with the respective upper and lower surfaces of the object.