US 11,999,062 B2
Robotic joint control
Edward John Mottram, Cambridge (GB); and Gordon Thomas Deane, Cambridge (GB)
Assigned to CMR SURGICAL LIMITED, Cambridge (GB)
Filed by CMR SURGICAL LIMITED, Cambridge (GB)
Filed on Oct. 27, 2020, as Appl. No. 17/081,120.
Claims priority of application No. 1915687 (GB), filed on Oct. 29, 2019.
Prior Publication US 2021/0122041 A1, Apr. 29, 2021
Int. Cl. B25J 9/16 (2006.01); A61B 34/30 (2016.01); B25J 13/02 (2006.01)
CPC B25J 9/1651 (2013.01) [A61B 34/30 (2016.02); B25J 9/1607 (2013.01); B25J 13/025 (2013.01); G05B 2219/40381 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for limiting joint velocity of a plurality of joints of a surgical robotic system, the surgical robotic system comprising a robot having a base and an arm extending from the base to an attachment for an instrument, the arm comprising a plurality of joints whereby the configuration of the arm can be altered, the method comprising:
obtaining joint states for a first group of k joints of the arm, where k>1; and
for each of the k joints:
determining from the obtained joint state a permitted range of motion for that joint;
deriving, using the permitted range of motion, a joint velocity limit for that joint;
selecting the minimum joint velocity limit of the k joints to be a common joint velocity limit used to limit each of the k joints individually;
calculating drive signals for driving the k joints to actuate at least one of the k joints wherein the velocity of each of the k joints is limited using the common joint velocity limit; and
controlling the arm to actuate at least one of the k joints in response to the drive signals.