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EP-4735216-A1 - METHOD FOR TRACKING A MOBILE ROBOT

EP4735216A1EP 4735216 A1EP4735216 A1EP 4735216A1EP-4735216-A1

Abstract

Method for tracking a mobile robot (2), wherein the mobile robot (2) comprises a robot base (5) and a multi-axis robot arm (6) arranged on the robot base (5), wherein an optical marker is mounted on the robot arm (6), with the steps: - providing a tacheometer (3), wherein the tacheometer (3) is configured to track the optical marker (4); - moving the optical marker (4) along a first circular arc (34) by means of the robot arm (6); - moving the optical marker along a second circular arc by means of the robot arm (6); - tracking the optical marker (4) by means of the tacheometer (3) in at least three positions (35) along the first circular arc (34) and in at least three further positions (39) along the second circular arc (37) relative to the tacheometer (3); and - determining a position and an orientation of the robot base (5) based on the tracked at least three positions (35) and the tracked at least three further positions (39) of the optical marker (4).

Inventors

  • MIETH, Gabriel

Assignees

  • Baubot GmbH

Dates

Publication Date
20260506
Application Date
20240628

Claims (15)

  1. 1. Method for tracking a mobile robot (2) , in particular a mobile construction robot at a construction site, wherein the mobile robot (2) comprises a robot base (5) and a multi-axis robot arm (6) arranged on the robot base (5) , wherein an optical marker is mounted on the robot arm (6) , with the steps: - providing a tacheometer (3) , in particular at the construction site, wherein the tacheometer (3) is configured to track the optical marker (4) ; - moving the optical marker (4) along a first circular arc (34) by means of the robot arm (6) ; - moving the optical marker (4) along a second circular arc (37) by means of the robot arm (6) ; - tracking the optical marker (4) by means of the tacheometer (3) in at least three positions (35) along the first circular arc (34) and in at least three further positions (39) along the second circular arc (37) relative to the tacheometer (3) ; and - determining a position and an orientation of the robot base (5) based on the tracked at least three positions (35) and the tracked at least three further positions (39) of the optical marker ( 4 ) .
  2. 2. Method for tracking a mobile robot according to claim 1, characterized in that the first circular arc (34) is located in a first plane (36) and the second circular arc (37) is located in a second plane (38) , wherein the first plane (36) is transverse, in particular perpendicular, to the second plane (38) .
  3. 3. Method for tracking a mobile robot according to anyone of the previous claims, characterized in that the multi-axis robot arm (9) comprises a plurality of links (7) connected by joints (8) , wherein exactly one of the joints (8) is actuated for moving the optical marker (4) along the first circular arc (34) and exactly one of the joints (8) is actuated for moving the optical marker (4) along the second circular arc (37) .
  4. 4. Method for tracking a mobile robot according to claim 3, characterized in that the multi-axis robot arm (6) comprises at least a first link (21) and a second link (22) , wherein the first link (21) is connected to the robot base (5) via a first joint (23) , wherein the second link (22) is connected to the first link (21) via a second joint (24) , and wherein the following steps are performed for tracking the optical marker (4) : Actuating the second joint (24) for moving the optical marker (4) along the first circular arc (34) , Actuating the first joint (23) for rotating the second joint (24) such that the first plane (36) is transverse, in particular perpendicular, to the second plane (38) , and Actuating the second joint (24) for moving the optical marker (4) along the second circular arc (37) .
  5. 5. Method for tracking a mobile robot according to claim 3, characterized in that the multi-axis robot arm (6) comprises at least a first link (21) and a second link (22) , wherein the first link (21) is connected to the robot base (5) via a first joint (23) , wherein the second link (22) is connected to the first link (21) via a second joint (24) , and wherein the following steps are performed for tracking the optical marker (4) : Actuating the second joint (24) for moving the optical marker (4) along the first circular arc (34) , and Actuating the first joint (23) for moving the optical marker (4) along the second circular arc (37) .
  6. 6. A mobile robot (2) , in particular a mobile construction robot, comprising: - a robot base (5) ; - a multi-axis robot arm (6) arranged on the robot base (5) , wherein the robot arm (6) comprises a plurality of links
  7. (7) connected by joints (8) , and - an optical marker (4) mounted on the robot arm (6) , the optical marker (4) being arranged for tracking with a tacheome- ter ( 3 ) , characterized in that the mobile robot (2) is configured to move the optical marker (4) along a first circular arc (34) and a second circular arc (37) , respectively. Tracking system (1) for tracking a mobile robot (2) , in particular a mobile construction robot at a construction site, comprising : - a tacheometer (3) configured to track an optical marker (4) ; and - a mobile robot (2) according to claim 6.
  8. 8. Tracking system according to claim 7, characterized in that one of the links (7) is configured as a rocker arm (9) , wherein the optical marker (4) is mounted on the rocker arm (9) .
  9. 9. Tracking system (1) according to claim 8, characterized in that the multi-axis robot arm (6) comprises at least a first link (21) and a second link (22) , wherein the first link (21) is connected to the robot base (5) via a first joint (23) , wherein the second link (22) is connected to the first link (21) via a second joint (24) , wherein the second link (22) is configured as the rocker arm (9) .
  10. 10. Tracking system (1) according to claim 9, characterized in that the first joint (23) provides a first degree of freedom of movement, wherein the second joint (24) provides a second degree of freedom of movement, such that the movement of the rocker arm (9) with respect to the robot base (5) has the first degree of freedom and the second degree of freedom.
  11. 11. Tracking system (1) according to anyone of claims 8 to 10, characterized in that the rocker arm (9) comprises a distal end (29) and a proximal end (28) relative to the robot base (5) , wherein the optical marker (4) is arranged at the distal end (29) of the rocker arm (9) .
  12. 12. Tracking system according to anyone of claims 8 to 11, characterized in that the optical marker (4) is mounted on the rocker arm (9) via an elongated member (10) .
  13. 13. Tracking system according to claim 12, characterized in that the elongated member (10) comprises a proximal end (11) and a distal end (12) with respect to the robot base (5) , wherein the optical marker (4) is arranged at the distal end (12) of the elongated member (10) .
  14. 14. Tracking system according to claim 13, characterized in that the distal end (12) of the elongated member (10) extends beyond the distal end (29) of the rocker arm (9) .
  15. 15. Tracking system according to anyone of claims 12 to 14, characterized in that the elongated member (10) comprises a main part (26) and an end part (27) , wherein the end part (27) is connected to the main part (26) via an adjustable swivel joint (30) , wherein the optical marker (30) is arranged on the end part (27 ) .

Description

Method for Tracking a Mobile Robot The disclosure concerns a method for tracking a mobile robot , a tracking system with a tacheometer and a mobile robot as well as a mobile robot , in particular a mobile construction robot , comprising : - a robot base ; - a multi-axis robot arm arranged on the robot base , wherein the robot arm comprises a plurality of links connected by j oints , and - an optical marker mounted on the robot arm, the optical marker being arranged for tracking with a tacheometer . Mobile robots are used to automate especially repetitive and physically demanding tasks , for example at construction sites . For example , a mobile construction robot may drill holes at predefined positions or mount anchors . Such mobile construction robots are configured to autonomously move around the construction site , locate the predefined positions at which a speci fic task is to be performed, and consequently perform the respective task . By means of such a robot , manpower can be deployed more ef ficiently and the construction can be sped up drastically . Typically, such mobile robots comprise a base , a propulsion system for moving the robot , as well as a robot arm with an end effector . The robot arm needs to comprise multiple axis so that the robot is able to move the end ef fector in various positions and orientations with respect to the robot base . The kinematic chain of the robot arm typically comprises a rocker arm, which is pivotably connected to the base , and a boom arm, which is pivotably connected to the rocker arm . Once the construction robot is in the vicinity of a position, where a task is to be completed, the robot moves the robot arm so that by means of the end ef fector the respective task can be done . It is crucial to determine the exact location of the mobile construction robot at the construction site for several reasons . First and foremost , precision is decisive with respect to construction proj ects . It is necessary to ensure that the location of , for example , the drilled holes are precisely at their intended location to avoid errors and costly delays . In addition, ensuring the exact location of the drilling can help to provide increased safety on the construction site . Accurate positioning of anchors can help to avoid collisions with other equipment or structures and can also help to prevent inj uries to workers . Finally, knowing the exact location of the drilling is also necessary for documentation purposes , as it can provide a clear record of the work that has been completed and the progress of the proj ect . Therefore , both ef ficiency and precision are decisive in this context . Mobile robots are also used for other purposes than construction, where it is also essential to know the position of the robot . For example , mobile robots can be used for transportation of goods or cleaning purposes , for example . Known solutions from the prior art to track construction robots , in particular mobile construction robots , can be categori zed in two groups . Solutions relating to the first group comprise an active optical sensor disposed on a mobile robot in combination with stationary passive elements , such as markers or reflectors , for example at the construction site . In contrast , the second group comprises a passive optical element disposed at the mobile construction robot and a stationary active optical sensor, such as a total station, at the construction site . A position-measuring system for measuring the position of a mobile machine tool relating to the first group is for example known from WO 2022 096 337 Al . A mobile machine tool is equipped with a position measuring system, which is configured to measure the position of the mobile machine tool with respect to (passive ) markings at the construction site . A similar method for speci fying a position of an instrument head of a robot is known from WO 2021 058 569 Al . The instrument head comprises a distance measuring device with a number of distance measuring sensors . Based on measurements by means of the distance measuring sensors and a known geometry model of the construction site , the position of the instrument head is determined . A disadvantage of these methods is that rather sensitive optical sensors need to be deployed at the robot . In case the robot is configured to perform heavy tasks such as drilling, the sensors may be af fected by vibrations and contamination by dust . Especially the sensors of WO 2021 058 569 Al are located directly at the instrument head, which in the context of drilling is subj ect to particularly severe vibration and dust contamination . Examples for solutions relating to the second group are known from WO 2016 066 615 A2 , CN 113 280 807 A and WO 2020 038 779 Al . WO 2016 066 615 A2 shows a mobile robotic drilling apparatus for drilling ceilings and walls at a construction site . The apparatus comprises a robotic arm mounted to a substructure . A laser total station