Method and apparatus for repositioning a mislocated object with a robot hand

A method for translating an object held by at least two fingers of a robot hand at a predetermined gripping force to a predetermined position relative to a fixed point of the robot hand, the method comprising:

• sensing the position of each finger relative to the fixed point of the robot hand;
• for each finger, determining whether said finger is at the lesser distance from the predetermined position;
• selecting the finger at the lesser distance as the finger to be position-controlled and selecting the other finger as the finger to be force-controlled;
• moving said position-controlled finger toward the predetermined position;
• controlling movement of said position-controlled finger according to the position of said position-controlled finger relative to the fixed point of the robot hand;
• sensing the gripping force between said force-controlled finger and the object;
• controlling movement of said force-controlled finger according to said gripping force sensed between said force-controlled finger and the object;
• stopping movement of said position-controlled finger when the object reaches the predetermined position relative to the fixed point of the robot hand;
• and
• when said position-controlled finger is stopped and the predetermined gripping force is applied to the object, then stopping said force-controlled finger.

An apparatus for translating an object held by at least two fingers of a robot hand, to a predetermined position relative to a fixed point of the robot hand, the apparatus comprising:

• means for sensing the position of each finger relative to the fixed point of the robot hand;
• finger differentiation means for identifying the finger at the greater distance from the predetermined position as the position-controlled finger and for identifying the other finger as the force-controlled finger;
• means for moving each finger;
• means for controlling movement of said position-controlled finger according to the position of said position-controlled finger relative to the fixed point of the robot hand;
• means for sensing the force between said force-controlled finger and the object;
• and
• means for controlling movement of said force-controlled finger according to the force sensed between the force-controlled finger and the object.

An apparatus for translating an object held by at least two fingers of a robot hand, to a predetermined position relative to a fixed point of the robot hand, the apparatus comprising:

• means for sensing the position of each finger relative to the fixed point of the robot hand;
• finger differentiation means for identifying the finger at the lesser distance from the predetermined position as the position-controlled finger and for identifying the other finger as the force-controlled finger;
• means for moving each finger;
• means for controlling movement of said position-controlled finger according to the position of said position-controlled finger relative to the fixed point of the robot hand;
• means for sensing the force between said force-controlled finger and the object;
• and
• means for controlling movement of said force-controlled finger according to the force sensed between the force-controlled finger and the object.