US 11,051,892 B2
Control apparatus and tendon-driven device
Nobuhiko Hata, Newton, MA (US); Takahisa Kato, Brookline, MA (US); Ichiro Okumura, Abiko (JP); Kiyoshi Takagi, Tokyo (JP); and Hidekazu Kose, Atlanta, GA (US)
Assigned to Canon U.S.A., Inc., Melville, NY (US); and The Brigham and Women's Hospital, Inc., Boston, MA (US)
Filed by CANON U.S.A., INC., Melville, NY (US); and The Brigham and Women's Hospital, Inc, Boston, MA (US)
Filed on Sep. 19, 2014, as Appl. No. 14/491,796.
Claims priority of provisional application 61/880,692, filed on Sep. 20, 2013.
Claims priority of provisional application 61/935,677, filed on Feb. 4, 2014.
Prior Publication US 2015/0088161 A1, Mar. 26, 2015
Int. Cl. A61B 1/00 (2006.01); A61B 1/005 (2006.01); A61B 34/30 (2016.01); A61B 34/00 (2016.01); A61B 17/00 (2006.01)
CPC A61B 34/30 (2016.02) [A61B 1/0016 (2013.01); A61B 1/0055 (2013.01); A61B 1/0057 (2013.01); A61B 34/71 (2016.02); A61B 2017/00323 (2013.01); A61B 2034/301 (2016.02)] 25 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a tendon-driven device having a proximal end fixed mechanically and a distal end, comprising:
a bendable body, and
a tendon attached to and extending a length of said bendable body,
wherein multiple divisions can be described on said tendon-driven device between said distal end and said proximal end;
an actuator connected to said tendon, configured to actuate said tendon based on a control signal; and
a controller configured to send said control signal to said actuator for actuating said tendon based on the control signal, comprising a kinematic mapping unit that provides an estimate of angular displacement prior to actuation by the actuator, wherein the kinematic-mapping unit is configured for:
iteratively calculating tension values for the multiple divisions of the device from the proximal to distal end,
estimating an angular displacement at the distal end of said tendon-driven device using said tension values,
propagating a tension ratio between adjacent divisions of said tendon-driven device from the tension of the more proximally located division, the tension ratio generated from information of friction between said tendon and said division and angular displacements of the adjacent divisions; and
estimating the angular displacement in said divisions from said tension ratios,
wherein the tension ratios between at least one adjacent division of said tendon-driven device vary to account for friction between said tendon and said division and angular displacements of the adjacent divisions,
wherein the iterative calculation of tension values, estimating of angular displacement, propagating of tension ratio, and estimating of angular displacement is employed by the controller to actuate the tendon-driven device.