US 11,717,966 B2
Method and computing system for determining a value of an error parameter indicative of quality of robot calibration
Atilla Saadat Dehghan, Tokyo (JP); and Kei Usui, Tokyo (JP)
Assigned to MUJIN, INC., Tokyo (JP)
Filed by MUJIN, INC., Tokyo (JP)
Filed on Apr. 29, 2021, as Appl. No. 17/244,224.
Claims priority of provisional application 63/021,089, filed on May 7, 2020.
Prior Publication US 2021/0347054 A1, Nov. 11, 2021
Int. Cl. B25J 9/16 (2006.01); B25J 9/06 (2006.01); B25J 13/08 (2006.01); B25J 9/12 (2006.01)
CPC B25J 9/1664 (2013.01) [B25J 9/06 (2013.01); B25J 9/12 (2013.01); B25J 9/1633 (2013.01); B25J 9/1692 (2013.01); B25J 13/085 (2013.01); B25J 9/1641 (2013.01); G05B 2219/37373 (2013.01); G05B 2219/39181 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computing system comprising:
a non-transitory computer-readable medium;
at least one processing circuit configured to perform the following when the non-transitory computer-readable medium is storing sensor data which includes: (i) a set of movement data indicative of an amount or rate of relative movement between a pair of immediately adjacent arm segments of a robot arm that is occurring or has occurred via a joint of the robot arm, and (ii) a set of actuation data indicative of overall torque or overall force at the joint in a time period during which the relative movement is occurring or has occurred:
dividing the sensor data into training data and test data by: (i) selecting, as the training data, movement training data and corresponding actuation training data, wherein the movement training data is a first subset of the set of movement data, and wherein the actuation training data is a first subset of the set of actuation data, and (ii) selecting, as the test data, movement test data and corresponding actuation test data, wherein the movement test data is a second subset of the set of movement data, and wherein the actuation test data is a second subset of the set of actuation data;
determining, based on the movement training data and the actuation training data, at least one of: (i) a friction parameter estimate associated with friction between the pair of immediately adjacent arm segments, or (ii) a center of mass (CoM) estimate associated with one of the pair of immediately adjacent arm segments;
determining actuation prediction data based on the movement test data and based on the at least one of: (i) the friction parameter estimate or (ii) the CoM estimate, wherein the actuation prediction data is a prediction which is indicative of the overall torque or overall force at the joint at different points in time;
determining residual data, which includes residual data values describing deviation between the actuation prediction data and the actuation test data corresponding to the different points in time, respectively;
determining, based on the residual data, a value for an error parameter which describes the residual data values;
determining whether the value of the error parameter exceeds a defined error threshold; and
outputting an indication of whether the value of the error parameter exceeds the defined error threshold.