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WO-2026096405-A1 - LOAD JAM DETECTOR

WO2026096405A1WO 2026096405 A1WO2026096405 A1WO 2026096405A1WO-2026096405-A1

Abstract

A mobile autonomous robot can include a pallet fork for lifting and carrying pallets. During pallet load operations, pallets may become jammed in the fork, which may be referred to as a load jam. To detect load jams, the mobile robots described herein may determine the velocity of a pallet relative to the mobile robot. When the velocity difference falls within a threshold amount, the mobile robot may determine that a load jam has occurred, and may cease or modify the pallet load operation. By autonomously detecting load jams, the mobile robot may increase safety and performance.

Inventors

  • KEATING, Geoffrey B.

Assignees

  • TERADYNE, INC.

Dates

Publication Date
20260507
Application Date
20251027
Priority Date
20241030

Claims (20)

  1. 1. A mobile robot, comprising: a set of wheels configured to move the mobile robot; a pallet fork configured to lift and carry pallets; a plurality of sensors comprising: at least one camera configured to output image data; and at least one second sensor configured to provide kinematic data; and at least one processor configured to: determine that a pallet load operation has initiated; identify a pallet surface; and determine a velocity of the pallet surface relative to the mobile robot during the pallet load operation using image data output from the at least one camera and kinematic data provided by the at least one second sensor.
  2. 2. The mobile robot of claim 1, wherein the at least one processor is further configured to: trigger an alarm condition based on the determined velocity of the pallet surface relative to the mobile robot; and based on the alarm condition, cease the pallet load operation.
  3. 3. The mobile robot according to any one of claims 1-2, wherein determining the velocity of the pallet surface relative to the mobile robot comprises determining whether a velocity of the pallet surface is within a threshold value of a velocity of the mobile robot.
  4. 4. The mobile robot of claim 3, wherein the at least one processor is further configured to: in response to determining that the velocity of the pallet surface is within the threshold value of the velocity of the mobile robot, trigger an alarm condition; and based on the alarm condition, cease the pallet load operation.
  5. 5. The mobile robot according to any one of claims 1-4, wherein: #14534563v2 determining the velocity of the pallet surface relative to the mobile robot comprises using an intensity camera to: select at least one point on the pallet surface; determine a position of the at least one point on the pallet surface in image data from at least two frames in time; and determine the velocity of the pallet surface relative to the mobile robot based on a difference in the position of the at least one point on the pallet surface in the image data from the at least two frames in time.
  6. 6. The mobile robot according to any one of claims 1-5, wherein: the at least one camera comprises a depth camera; the at least one second sensor comprises an odometry encoder; and determining the velocity of the pallet surface relative to the mobile robot comprises determining the velocity of the pallet surface relative to the mobile robot using the depth camera and the odometry encoder.
  7. 7. The mobile robot according to any one of claims 1-6, wherein: the at least one camera comprises an intensity camera; and identifying the pallet surface comprises identifying the pallet surface using the intensity camera.
  8. 8. The mobile robot according to any one of claims 1-7, wherein: the plurality of sensors comprises a depth camera and an intensity camera; and determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) the depth camera and (ii) the intensity camera.
  9. 9. The mobile robot according to any one of claims 1-8, wherein: the at least one camera comprises a depth camera and an intensity camera; the at least one second sensor comprises at least one of an ultrasonic sensor or a LiDAR sensor; and determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) the depth camera, (ii) the intensity camera, and (iii) the at least one of the ultrasonic sensor or the LiDAR sensor. #14534563v2
  10. 10. A method of detecting load jams during pallet load operations of a mobile robot, the method comprising: determining that a pallet load operation has initiated; identifying a pallet surface; and determining a velocity of the pallet surface relative to the mobile robot during the pallet load operation using image data output from at least one camera and kinematic data provided by at least one second sensor.
  11. 11. The method of claim 10, further comprising: detecting a pallet; positioning the mobile robot facing the pallet; and performing the pallet load operation.
  12. 12. The method according to any one of claims 10-11, further comprising: triggering an alarm condition based on the determined velocity of the pallet surface relative to the mobile robot; and based on the alarm condition, ceasing the pallet load operation.
  13. 13. The method according to any one of claims 10-12 wherein: determining the velocity of the pallet surface relative to the mobile robot comprises determining whether a velocity of the pallet surface is within a threshold value of a velocity of the mobile robot.
  14. 14. The method of claim 13, further comprising: in response to determining that the velocity of the pallet surface is within the threshold value of the velocity of the mobile robot, triggering an alarm condition; and based on the alarm condition, ceasing the pallet load operation.
  15. 15. The method according to any one of claims 10-14, wherein: determining the velocity of the pallet surface relative to the mobile robot comprises using an intensity camera to: select at least one point on the pallet surface; determine a position of the at least one point on the pallet surface in image data from at least two frames in time; and #14534563v2 determine the velocity of the pallet surface relative to the mobile robot based on a difference in the position of the at least one point on the pallet surface in the image data from the at least two frames in time.
  16. 16. The method according to any one of claims 10-15, wherein: determining the velocity of the pallet surface relative to the mobile robot comprises determining the velocity of the pallet surface relative to the mobile robot using a depth camera and an odometry encoder.
  17. 17. The method according to any one of claims 10-16, wherein: identifying the pallet surface comprises identifying the pallet surface using an intensity camera.
  18. 18. The method according to any one of claims 10-17, wherein: determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) a depth camera and (ii) an intensity camera.
  19. 19. The method according to any one of claims 10-18, wherein: determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) a depth camera, (ii) an intensity camera, and (iii) at least one of an ultrasonic sensor or a LiDAR sensor.
  20. 20. At least one non-transitory computer-readable storage medium having instructions encoded thereon that, when executed by at least one processor, cause the at least one processor to perform a method according to any one of claims 10-19. #14534563v2

Description

Atorney Docket No. T0529.70177WOOO Date of Deposit: October 27, 2025 LOAD JAM DETECTOR CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation claiming the benefit of U.S. Application Serial No. 18/932,516, filed October 30, 2024, under Attorney Docket No. T0529.70177US00, and entitled “LOAD JAM DETECTOR,” which is hereby incorporated herein by reference in its entirety. BACKGROUND Field [0002] The present technology relates to mobile robots having pallet forks and to methods and apparatus for determining and whether a pallet load operation has a jam. Related Art [0003] Mobile robots can move autonomously or through guidance to complete one or more actions. High payload mobile robots can carry a load and move the load from one location to another. BRIEF SUMMARY [0004] According to aspects of the disclosure, there is provided a mobile robot, comprising: a set of wheels configured to move the mobile robot; a pallet fork configured to lift and carry pallets; a plurality of sensors comprising: at least one camera configured to output image data; and at least one second sensor configured to provide kinematic data; and at least one processor configured to: determine that a pallet load operation has initiated; identify a pallet surface; and determine a velocity of the pallet surface relative to the mobile robot during the pallet load operation using image data output from the at least one camera and kinematic data provided by the at least one second sensor. [0005] In some embodiments, determining the velocity of the pallet surface relative to the mobile robot comprises determining whether a velocity of the pallet surface is within a threshold value of a velocity of the mobile robot. [0006] In some embodiments, the at least one processor is further configured to: in response to determining that the velocity of the pallet surface is within the threshold value of the #14534563v2 - 1 - velocity of the mobile robot, trigger an alarm condition; and based on the alarm condition, cease the pallet load operation. [0007] In some embodiments, determining the velocity of the pallet surface relative to the mobile robot comprises using an intensity camera to: select at least one point on the pallet surface; determine a position of the at least one point on the pallet surface in image data from at least two frames in time; and determine the velocity of the pallet surface relative to the mobile robot based on a difference in the position of the at least one point on the pallet surface in the image data from the at least two frames in time. [0008] In some embodiments, the at least one camera comprises a depth camera; the at least one second sensor comprises an odometry encoder; and determining the velocity of the pallet surface relative to the mobile robot comprises determining the velocity of the pallet surface relative to the mobile robot using the depth camera and the odometry encoder. [0009] In some embodiments, the at least one camera comprises an intensity camera; and identifying the pallet surface comprises identifying the pallet surface using the intensity camera. [0010] In some embodiments, the plurality of sensors comprises a depth camera and an intensity camera; and determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) the depth camera and (ii) the intensity camera. [0011] In some embodiments, the at least one camera comprises a depth camera and an intensity camera; the at least one second sensor comprises at least one of an ultrasonic sensor or a LiDAR sensor; and determining the velocity of the pallet surface relative to the mobile robot comprises fusing kinematic data provided by (i) the depth camera, (ii) the intensity camera, and (iii) the at least one of the ultrasonic sensor or the LiDAR sensor. [0012] According to aspects of the disclosure, there is provided a method of detecting load jams during pallet load operations of a mobile robot, the method comprising: determining that a pallet load operation has initiated; identifying a pallet surface; and determining a velocity of the pallet surface relative to the mobile robot during the pallet load operation using image data output from at least one camera and kinematic data provided by at least one second sensor. [0013] In some embodiments, the method further comprises: detecting a pallet; positioning the mobile robot facing the pallet; and performing the pallet load operation. [0014] In some embodiments, determining the velocity of the pallet surface relative to the mobile robot comprises determining whether a velocity of the pallet surface is within a threshold value of a velocity of the mobile robot. [0015] In some embodiments, the method further comprises: in response to determining that the velocity of the pallet surface is within the threshold value of the velocity of the mobile #14534563v2 robot, triggering an alarm condition; and based on the alarm condition,