Surgical robot arm

A surgical robot arm, on which a surgical instrument is mounted, the surgical robot arm comprising:

• a base link including an extension portion extending in one direction and a roll rotation base portion disposed at one end of the extension portion and formed to have a predetermined angle with the extension portion;
• a first link coupled to the roll rotation base portion of the base link and configured to be roll-rotatable around a first axis;
• a second link coupled to the first link and configured to be linearly movable along a second axis which is formed to have a predetermined angle with respect to the first link;
• and
• an instrument mounting link axially coupled to the second link only by a link rotation shaft formed in a third axis direction, including a guide rail extending in a fourth axis direction, and configured to be rotatable around the link rotation shaft,
• wherein the first link includes:
• a first region coupled to the base link in a direction parallel to the first axis,
• a second region connecting the first region and a third region, and configured to linearly move along a seventh axis with respect to the first region, and
• the third region coupled to the second link at one end and coupled to the second region at another end by a roll rotation shaft, and configured to be rotatable around the second axis with respect to the second region,
• wherein a remote center of motion (RCM) is formed on a trocar into which the surgical instrument is inserted, and the RCM is disposed on an extension line of the first axis,
• wherein the surgical instrument includes an end tool at one end and other end of the surgical instrument is coupled to the instrument mounting link,
• wherein the trocar is disposed closer to the one end of the surgical instrument than the other end of the surgical instrument,
• wherein the second axis, the third axis, and the fourth axis intersect at a point on the trocar,
• wherein the trocar and the surgical instrument inserted thereinto are controlled to rotate around the RCM,
• wherein during an RCM motion around the RCM in a first direction which is a rotational direction about an axis substantially parallel to the second axis, at least one of a roll rotational motion of the first link with respect to the base link, a rotational motion of the instrument mounting link with respect to the second link, and a linear motion of the second link with respect to the first link is controlled to maintain a position of the RCM, and
• wherein during an RCM motion around the RCM in a second direction which is a rotational direction about an axis substantially parallel to the third axis, at least one of the linear motion of the second link with respect to the first link and the rotational motion of the instrument mounting link with respect to the second link is controlled to maintain the position of the RCM.