# US 9,616,573 B2 · Robot control apparatus, robot control method, program, recording medium and robot system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,616,573 B2 - Document ID: US9616573B2 - Status: Granted - Kind: B2 - Application number: 14/403,817 - Filed: 2013-05-23 - Published: 2015-06-11 - Granted: 2017-04-11 - Earliest claimed: 2012-05-25 - Assignees: The Ritsumeikan Trust - Applicants: The Ritsumeikan Trust - Inventors: Sadao Kawamura; Hiroyuki Onishi - Web page: https://patentgrep.com/patent/US9616573B2 ## CPC - B25J 9/1697: {Vision controlled systems} - G05B 2219/39393: Camera detects projected image, compare with reference image, position end effector - G05B 2219/42034: Pi regulator - Y10S 901/02: Arm motion controller - Y10S 901/28: Joint - Y10S 901/47: Optical - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract An end effector can be removed to a target position and calibration loads can be reduced, even if there is an error in a kinematic operation in a robot main body and/or cameras. A positional deviation integral torque obtained by integrating a value corresponding to a positional deviation is applied to joints while being superimposed with torques based on angular deviations. If movements of the joints stop or are about to stop before the end effector reaches a target position due to an error in a kinematic operation, the positional deviation integral torque increases with time, to move said joints and move the end effector to the target position. Thus, the end effector can be reliably moved to the target position by the positional deviation integral torque, and calibration loads can be reduced. ## Claims ### Claim 1 A robot control apparatus that controls a robot configured to include a freely displaceable joint and move an end effector according to a displacement of the joint, comprising: an imager to image a reference position provided on the robot while capturing the reference position and a destination of the reference position in a field of view; a displacement amount detector to detect a displacement amount of the joint; a positional deviation acquirer to acquire a positional deviation from the destination for the reference position based on an imaging result of the imager; an application amount calculator to calculate a first application amount from a result of acquiring a value of integral acquired by performing an integral operation on a value corresponding to the positional deviation for the reference position and a second application amount by performing a proportional operation on a value corresponding to a displacement amount deviation between a detected displacement amount by the displacement amount detector and a target displacement amount which is the displacement amount of the joint when the reference position coincides with the destination, each of said first and second application amount being a force or a torque applied to the joint to displace the joint; and a drive controller to move the reference position to the destination thereof by applying the first application amount and second application amount to the joint. ### Claim 2 (depends on 1) The robot control apparatus according to claim 1, controlling the robot to move the end effector according to a rotation of the joint, wherein: the imager images the reference position provided on the end effector while capturing the reference position and the destination of the reference position; the displacement amount detector is an angle detector to detect a rotation angle of the joint; and the application amount calculator is a torque calculator to calculate a first torque as the first application amount by performing the integral operation on the value corresponding to the positional deviation and a second torque as the second application amount by performing the proportional operation on a value corresponding to an angular deviation between a detected angle by the angle detector and a target angle as the target displacement amount which is the rotation angle of the joint when the reference position is at the destination; and the drive controller controls a joint drive mechanism to drive the joint so as to apply the first and second torques to the joint. ### Claim 3 (depends on 2) The robot control apparatus according to claim 2, wherein: the application amount calculator calculates a third torque by performing a proportional operation on the value corresponding to the positional deviation; and the drive controller controls the joint drive mechanisms so that the third torque is further applied to the joint. ### Claim 4 (depends on 2) The robot control apparatus according to claim 2, wherein the application amount calculator calculates the first torque by performing the integral operation on the positional deviation multiplied by a transposed Jacobian matrix. ### Claim 5 (depends on 1) The robot control apparatus according to claim 1, controlling the robot in which the end effector is attached to one end of an arm that has a plurality of the joints and has six or more degrees of freedom and to which a plurality of the reference positions including three or more reference positions are set, wherein the imager images the three or more reference positions while capturing the destination of each of the three or more reference positions that include at least two positions set on the end effector side from a tip joint closest to one end side out of the joints in the field of view; the positional deviation acquirer acquires the positional deviation for each reference position; the application amount calculator calculates the first application amount and the second application amount for each joint; and the drive controller controls a location and a posture of the end effector in three dimensions by applying the first application amount and second application amount to the plurality of the joints to move the three or more reference positions toward the destinations thereof. ### Claim 6 (depends on 5) The robot control apparatus according to claim 5, wherein the drive controller moves each of the three or more reference positions including a specific reference position that is at a position other than the at least two positions and on the tip joint or on an other end side opposite to the one end side from the tip joint toward the destination thereof. ### Claim 7 (depends on 6) The robot control apparatus according to claim 6, wherein the specific reference position is set on a specific joint or on the other end side from the specific joint which is a third joint from the one end side out of the plurality of the joints. ### Claim 8 (depends on 7) The robot control apparatus according to claim 7, wherein the specific reference position is set on the one end side from the joint which is the third joint from the other end out of the plurality of the joints. ### Claim 9 (depends on 7) The robot control apparatus according to claim 7, wherein the application amount calculator calculates the first application amount by adding a result of multiplying the value of integral for the specific reference position by a 1st weigh coefficient and a result of multiplying the value of integral for the reference positions other than the specific reference position by a 2nd weigh coefficient, and the 1st weigh coefficient is larger than the 2nd weigh coefficient. ### Claim 10 (depends on 5) The robot control apparatus according to claim 5, wherein the application amount calculator calculates a third application amount from a result of acquiring a proportional value, which is acquired by performing a proportional operation on the value corresponding to the positional deviation, for each reference position and the drive controller further applies the third application amount to the plurality of the joints. ### Claim 11 (depends on 5) The robot control apparatus according to claim 5, wherein the application amount calculator calculates the first application amount by acquiring the value of integral by performing an integral operation on the positional deviation multiplied by a transposed Jacobian matrix. ### Claim 12 A robot control method that controls a robot configured to include a freely displaceable joint and move an end effector according to a displacement of the joint, comprising: a step of imaging a reference position provided on the robot while capturing the reference position and a destination of the reference position in a field of view; a step of acquiring a positional deviation from the destination for the reference position based on an imaging result of the reference position; a step of acquiring a detected displacement amount by detecting a displacement amount of the joint; a step of calculating a first application amount from a result of acquiring a value of integral acquired by performing an integral operation on a value corresponding to the positional deviation for the reference position and a second application amount by performing a proportional operation on a value corresponding to a displacement amount deviation between the detected displacement amount and a target displacement amount which is the displacement amount of the joint when the reference position coincides with the destination, each of said first and second application amount being a force or a torque applied to the joint to displace the joint; and a step of moving the reference position to the destination thereof by applying the first application amount and second application amount to the joint. ### Claim 13 A non-transitory computer-readable recording medium having recorded thereon a robot control program that causes a computer to control a robot configured to include a freely displaceable joint and move an end effector according to a displacement of the joint, causing the computer to perform: a step of imaging a reference position provided on the robot while capturing the reference position and a destination of the reference position in a field of view; a step of acquiring a positional deviation from the destination for the reference position based on an imaging result of the reference position; a step of acquiring a detected displacement amount by detecting a displacement amount of the joint; a step of calculating a first application amount from a result of acquiring a value of integral acquired by performing an integral operation on a value corresponding to the positional deviation for the reference position and a second application amount by performing a proportional operation on a value corresponding to a displacement amount deviation between the detected displacement amount and a target displacement amount which is the displacement amount of the joint when the reference position coincides with the destination, each of said first and second application amount being a force or a torque applied to the joint to displace the joint; and a step of moving the reference position to the destination thereof by applying the first application amount and second application amount to the joint. ### Claim 14 A robot system, comprising: a robot configured to include a freely displaceable joint and move an end effector according to a displacement of the joint; an imager to image a reference position provided on the robot while capturing the reference position and a destination of the reference position in a field of view; a displacement amount detector to detect a displacement amount of the joint; a positional deviation acquirer to acquire a positional deviation from the destination for the reference position based on an imaging result of the imager; an application amount calculator to calculate a first application amount from a result of acquiring a value of integral acquired by performing an integral operation on a value corresponding to the positional deviation for the reference position and a second application amount by performing a proportional operation on a value corresponding to a displacement amount deviation between a detected displacement amount by the displacement amount detector and a target displacement amount which is the displacement amount of the joint when the reference position coincides with the destination, each of said first and second application amount being a force or a torque applied to the joint to displace the joint; and a drive controller to move the reference position to the destination thereof by applying the first application amount and second application amount to the joint.