Method and system for calculating weight and center of gravity of object lifted by robot
AssigneeHyundai Motor Company
InventorWan Jae Shin
Life of this patent
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Abstract
A method for calculating weight and center of gravity of an object lifted by a robot includes lifting an object, measuring a change in angle of each joint through an angle sensor provided for each joint of the gripper in the event of the lifting, and calculating angular velocity and acceleration of each joint, calculating, via a controller, acceleration of the object, measuring an upper pressing force and a lower pressing force using force sensors installed on the joints, and calculating, via the controller, the weight of the object using a vertical component of the acceleration of the object, gravitational acceleration, and the upper and lower pressing forces.
Claims13
A method of controlling a system for calculating weight and 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 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;
- and
- 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.
A system for calculating weight and center of gravity of an object for a robot, the system comprising:
- an upper part and a lower part of a robot gripper made up of joints and links;
- drivers and angular sensors provided for the joints of the gripper;
- force sensors that are provided for the joints of the gripper and measure an upper pressing force with which the upper part presses an upper surface of the object and a lower pressing force with which the lower part presses a lower surface of the object;
- and
- a controller that i) controls the drivers such that the upper and lower parts of the gripper press the respective upper and lower surfaces of the object to grip and lift the object, ii) calculates angular velocity and angular acceleration of each joint using a change in angle of each joint, iii) calculates acceleration of the object using the angular velocity, the angular acceleration, and a Jacobian matrix of the gripper, and iv) calculates the weight of the object using a vertical component of the acceleration of the object, gravitational acceleration, and the upper and lower pressing forces.
Dependencies are inferred from the claim text.