US 12,279,838 B2
Arm device, control method, and program
Kotaro Tadano, Tokyo (JP)
Assigned to RIVERFIELD INC., Tokyo (JP)
Appl. No. 16/962,658
Filed by RIVERFIELD INC., Tokyo (JP)
PCT Filed Sep. 4, 2019, PCT No. PCT/JP2019/034771
§ 371(c)(1), (2) Date Jul. 16, 2020,
PCT Pub. No. WO2020/050314, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. 2018-167288 (JP), filed on Sep. 6, 2018.
Prior Publication US 2021/0361363 A1, Nov. 25, 2021
Int. Cl. A61B 34/30 (2016.01); A61B 17/29 (2006.01); A61B 90/50 (2016.01); B25J 9/02 (2006.01); B25J 9/10 (2006.01); B25J 13/08 (2006.01)
CPC A61B 34/30 (2016.02) [A61B 17/29 (2013.01); A61B 90/50 (2016.02); B25J 9/02 (2013.01); B25J 9/1065 (2013.01); B25J 13/085 (2013.01); A61B 2034/301 (2016.02)] 13 Claims
OG exemplary drawing
 
1. An arm device supporting a surgical tool and configured to control a position and/or a posture of the surgical tool, the arm device comprising:
a joint portion configured to be rotated to thereby change the position and/or the posture of the surgical tool;
a rotary actuator configured to generate an actuator driving force that exerts a torque that rotates the joint portion;
an estimator configured to estimate an external force applied to the surgical tool;
a calculator configured to obtain, based on a weight of the surgical tool and the external force estimated by the estimator, a value of the actuator driving force; and
a controller configured to control the actuator driving force, and thereby rotate the joint portion, based on the value of the actuator driving force obtained by the calculator;
wherein the surgical tool comprises a bend portion, the bend portion being configured to bend in a transverse direction away from a longitudinal direction of the surgical tool, and the surgical tool comprises a surgical tool actuator configured to generate a bend portion driving force that bends the bend portion;
wherein the estimator is configured to estimate the external force applied to the surgical tool using information on a load supplied to the surgical tool actuator; and
wherein forces acting on the arm device satisfy the following formulas:
ft+fp+fr+W=0
ln×ft+lpn×fp+lgn×W+mr=0
according to which:
mr=−ln×ft−lgn×W,
ft represents a force acting on a tip of the surgical tool,
fp represents a force acting on a pivot position of the surgical tool,
fr represents a force acting on a rear end of the surgical tool,
W represents a force acting on a center of gravity of the surgical tool,
mr represents a moment produced in the joint portion,
ln×ft represents a moment resulting from ft,
lpn×fp is a moment resulting from fp, and
lgn×W is a moment resulting from W.