MULTIAXIAL ROBOTIC ARM

Abstract

A robotic arm for automatically displacing an object between two locations based on a combination of pre-set instructional data and dynamically updated instructional data includes a robotic arm sensor for detecting objects located within a distance D.sub.rs from a reference point on the robotic arm and, the robotic arm sensor is configured to determine, based on receiving signals from the detected object, at least one of the distance to the detected object, the size of the detected object, and at least one physical property of the detected object.

Claims

1. A robotic arm for automatically displacing an object between two locations based on a combination of pre-set instructional data and dynamically updated instructional data, comprising: a first robotic arm section having a first longitudinal end configured to be coupled to a support structure, a third robotic arm section rotatably coupled at least indirectly to the first robotic arm section, a plurality of robotic arm sections, wherein each of the plurality of robotic arm sections are rotatably coupled via motorized single axis joints with respective single rotational axes, the plurality of robotic arm sections comprising an innermost longitudinal section rotatably coupled to the third robotic arm section via a motorized single axis joint with a respective rotational axis, an outermost longitudinal section and an intermediate longitudinal section rotationally fixed to the innermost longitudinal section via a single axis joint with a respective single rotational axis and to the outermost longitudinal section via a single axis joint with a respective rotational axis and a gripping tool rotatably coupled to a longitudinal end of an outermost longitudinal section of the plurality of robotic arm sections via a motorized multiple axis joint with respective multiple rotational axes, wherein the rotational couplings within the plurality of robotic arm sections and to the third robotic arm section are configured such that a longitudinal direction of the outermost longitudinal section intersects a rotational axis of the third robotic arm section, a robotic arm sensoring means for detecting objects located within a distance D.sub.rs from a reference point on the robotic arm and, the robotic arm sensoring means is configured to determine, based on receiving signals from the detected object, the distance to the detected object, the size of the detected object, and at least one physical property of the detected object.

2. The robotic arm in accordance with claim 1, wherein the rotational couplings within the plurality of robotic arm sections and to the third robotic arm section are configured such all single rotational axes of the plurality of robotic arm sections are oriented parallel to each other.

3. The robotic arm in accordance with claim 1, wherein the robotic arm further comprises: a second robotic arm section fixed with a non-zero angle to the first robotic arm section relative to the longitudinal direction of the first and second robotic arm sections and wherein the third robotic arm section is rotationally fixed to the second robotic arm section via a motorized joint.

4. The robotic arm in accordance with claim 1, wherein the multiple axis joint is configured to allow simultaneous rotation of the gripping tool around a first rotational axis and around a second rotational axis directed perpendicular to the first rotational axis, wherein the simultaneous rotation of the gripping tool around the first and second rotational axis is restricted to spherical coordinates in space.

5. The robotic arm in accordance with claim 1, wherein each single axis joint of the plurality of robotic arm sections comprises: a motorized swivel and a single axis control system for controlling rotational speed and direction of the motorized swivel in accordance with received instructional data.

6. The robotic arm in accordance with claim 1, wherein the multiple axis joint of the gripping tool comprises: a plurality of motorized swivels, and a multiple axis control system for controlling rotational speed and direction of each motorized swivel in accordance with received instructional data.

7. The robotic arm in accordance with claim 1, wherein the robotic arm sensoring means is arranged on at least one of the outermost longitudinal section and the gripping tool.

8. The robotic arm in accordance with claim 1, wherein the robotic arm sensoring means comprises at least one of: 2D camera, 3D camera, radar, laser, ultrasonic sensor, ultraviolet sensor and infrared sensor.

9. The robotic arm in accordance with claim 1, wherein the robotic arm comprises a control system comprising a plurality of modules, wherein at least one pre-processing module of the plurality of modules is configured to receive data generated by at least one sensoring means or at least one positioning means or a combination thereof and to select a data subset of the received data for further data processing, and wherein at least one processing module of the plurality of modules is configured to receive the data subset from the at least one pre-processing module and to use the data subset as input data in a computer program stored on a computer-readable data carrier in the at least one processing module, wherein the computer program comprises instructions which, when the program is executed by the at least one processing module, cause the computer program to provide as output instructional data for the movement of the robotic arm.

10. The robotic arm in accordance with claim 9, wherein each single axis joint of the plurality of robotic arm sections comprises: a motorized swivel, and a single axis control system for controlling rotational speed and direction of the motorized swivel in accordance with received instructional data, and the multiple axis joint of the gripping tool comprises: a plurality of motorized swivels, and a multiple axis control system for controlling rotational speed and direction of each motorized swivel in accordance with received instructional data, wherein the at least one processing module is further configured to transmit via a transmitter processed data to control operations of at least one of the motorized swivels.

11. The robotic arm in accordance with claim 1, wherein the gripping tool further comprises: a gripping shaft, and an attachment device rotationally fixed to the gripping shaft via a motorized single axis joint.

12. A vessel comprising: a robotic arm in accordance with claim 1, and a deck onto which the first longitudinal end of the first robotic arm section is rotatably fixed.

13. A method for automatically displacing an object between two locations using a robotic arm on a vessel in accordance with claim 12, wherein the method comprises the following steps: A. manoeuvring the outermost longitudinal section by operating at least one motorized swivel located between the deck and the outermost longitudinal section to a first position where the gripper tool is arranged adjacent to the object to be displaced, B. releasably attaching the gripper tool to the object, C. manoeuvring the outermost longitudinal section with the object by operating the at least one motorized joints/swivels located between the deck and the outermost longitudinal section to a second position where the object is to be arranged, wherein at least one of the steps are activated and/or controlled based on positional data collected by a robotic arm sensoring means arranged on at least one of the outermost longitudinal section and the gripping tool.

14. The method in accordance with claim 13, wherein at least one of step A and C further comprises: checking at a predetermined frequency whether an object is obstructing the manoeuvring path by analysing output data from the robotic arm sensoring means arranged on at least one of the outermost section and the gripping tool.

15. A data processing apparatus comprising a processor configured to perform the steps A-C of claim 13.

16. Use of a robotic arm according to claim 1 for performing at least one of the following operations: washing of a fish cage by using the gripping tool as a washing device, transporting a rope eye attached to a mooring rope from a position on a floating vessel onto which the robotic arm is fixed to a bollard on a quay, transporting a rope eye attached to a mooring rope from a position on a quay onto which the robotic arm is fixed to a position on a floating vessel, transporting a rope eye attached to a mooring rope from a position on a deck of a floating vessel onto which the robotic arm is fixed to a bollard on a hull of the floating vessel, transporting objects between a fish carrier onto which the robotic arm is fixed and a fish cage, transporting objects between a service operation vessel onto which the robotic arm is fixed and a stationary offshore installation, transporting objects between a service operation vessel and a stationary offshore installation onto which the robotic arm is fixed, and transporting objects between two floating vessels, where the robotic arm is fixed to one of the two floating vessels.

17. The robotic arm in accordance with claim 1, wherein the first longitudinal end of the first robotic arm section is configured to be rotatably coupled to the support structure via a motorized joint.

18. The robotic arm in accordance with claim 17, wherein the rotational couplings within the plurality of robotic arm sections and to the third robotic arm section are configured such all single rotational axes of the plurality of robotic arm sections are oriented parallel to each other.

19. The robotic arm in accordance with claim 17, wherein the robotic arm further comprises: a second robotic arm section fixed with a non-zero angle to the first robotic arm section relative to the longitudinal direction of the first and second robotic arm sections and wherein the third robotic arm section (4) is rotationally fixed to the second robotic arm section via a motorized joint.

20. The robotic arm in accordance with claim 17, wherein the multiple axis joint is configured to allow simultaneous rotation of the gripping tool around a first rotational axis and around a second rotational axis directed perpendicular to the first rotational axis, wherein the simultaneous rotation of the gripping tool around the first and second rotational axis is restricted to spherical coordinates in space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0082] FIG. 1 illustrates in perspective an inventive robotic arm.

[0083] FIG. 2 illustrates schematically the rotational axes and the joints of the robotic arm of FIG. 1.

[0084] FIG. 3 illustrates in perspective details of a gripping tool attached via motorized swivels to an end of an inventive robotic arm.

[0085] FIG. 4 illustrates in perspective an example of a motorized single axis joint.

[0086] FIG. 5 illustrates in perspective a mooring system using the robotic arm of FIGS. 1 and 2, where a gripping tool at the end of the robotic arm is mooring a rope eye to a bollard on a quay.

[0087] FIG. 6 illustrates in perspective a mooring system using the robotic arm of FIGS. 1 and 2, where a gripping tool at the end of the robotic arm is mooring a rope eye to a bollard on the vessel's exterior hull.

[0088] FIG. 7 illustrates in perspective details of a gripping tool attached via motorized swivels to an end of an inventive robotic arm, where an attachment device constituting part of the gripping tool is holding a sheave fixed to a rope eye during mooring of the rope eye to a bollard.

[0089] FIG. 8 illustrates in perspective details of a gripping tool attached via motorized swivels to an end of an inventive robotic arm, where an attachment device constituting part of the gripping tool is approaching a sheave fixed to a rope eye.

[0090] FIGS. 9 (A) and (B) illustrate in perspective an inventive robotic arm fixed to a deck of a vessel's bow part and aft part, respectively.

DETAILED DESCRIPTION OF THE INVENTION

[0091] In the following, specific embodiments of the invention will be described in more detail with reference to the drawings. However, the invention is not limited to the embodiments and illustrations contained herein. It is specifically intended that the invention includes modified forms of the embodiments, including portions of the embodiments and combinations of elements of different embodiments. It should be appreciated that in the development of any actual implementation, as in any engineering or design project, specific decisions must be made to achieve the developer's specific goals, such as compliance with system and/or business related constraints. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication and manufacture for the skilled person having the benefit of this disclosure.

[0092] A specific embodiment of a robotic arm 1 in accordance with the invention is shown in FIGS. 1 and 2. A longitudinal end of a first robotic arm section 2 is rotationally coupled perpendicular to the deck 11, thus creating an upwards directed rotational axis 2a. A longitudinal end of a second robotic arm section 3 is fixed perpendicular to the other longitudinal end of the first robotic arm section 1, thereby forming a pivotable structure 2,3 which inter alia contributes to the robotic arms ability to avoid the above-mentioned obstruction elements 23.

[0093] Further, a third robotic arm section 4 is rotationally fixed to the other end of the second robotic arm section 3 with a rotational axis 4b oriented parallel to the upward direction rotational axis 2b of the first robotic arm section 2.

[0094] The first to third sections 2-4 thus form a pivotable base of the robotic arm 1 that may rotate relative to the deck 11 with an offset set by the length of the second section 3.

[0095] The rotational connections of both the first section 2 to the deck 11 and the third section 4 to the second section 3 are achieved by use of motorized joints 2a,4a such as motorized swivels 2a,4a equipped with a control system allowing automatic control of the swivels rotational direction and rotational velocity. The joints 2a,4a are preferably single axis joints, that is, joints that allows movement around one rotational axis only.

[0096] FIGS. 1 and 2 further show that the third section 4 is rotationally coupled to a set of robotic arm sections 5-7 mutually interlinked in an end-to-end fashion. Specifically, an end of an innermost longitudinal section 5 of the set is rotationally coupled via a motorized single axis joint 5a to the third section and rotationally coupled via a motorized single axis joint 6a at the other end to an end of an intermediate longitudinal section 6. Further, the other end of the intermediate section 6 is rotationally coupled via a motorized single axis joint 7a to an end of an outermost longitudinal section 7.

[0097] Additional intermediate longitudinal sections may be added in a similar end-to-end fashion between the innermost and outermost longitudinal sections if higher axes robotic arm is desired/needed.

[0098] With particular reference to FIG. 2, the direct consequence that all of the rotational axes 5b-7b involved for the set of interlinked robotic arm sections are aligned 5-7 causes the longitudinal direction 7c of the outermost section 7 to coincide with the rotational axes 4b of the third robotic arm section 4. If corrected for any offset between the ends of the intercoupling robotic arm sections (see FIG. 3), the rotational axis 4b of the third robotic arm section 4 and the longitudinal directions of the innermost, intermediate and outermost sections 5-7 creates the boundary of a common rotational plane 10 for set of robotic arm sections 5-7.

[0099] As seen in FIGS. 1 and 2, and further detailed in FIG. 3, a gripping tool 8,9 comprising a gripping shaft or link 8 and an attachment device 9 is rotationally coupled to the other end of the outermost longitudinal section 7 via one or more motorized joints 8a,8c. In the embodiment of FIG. 3 the attachment device 9 is a magnet. However, it may be any device enabling releasable attachment to an object. Other examples may be a claw or a hook.

[0100] In contrast to the joints within the set of robotic arm sections 5-7 and to the third section, the motorized joint 8a,8c between the gripping shaft or link 9 and the end of the outermost section 7 preferably includes a multiple number of swivels 8a,8c that allows the gripping shaft 8 to rotate around deviating rotational axes 8b,8d. FIGS. 1-3 illustrate the most preferred embodiment where the joints 8a,8c includes two motorized swivels configured to allow rotation of the gripping shaft 8 around two rotational axes directed perpendicular to each other. The resulting superimposed rotation pattern would thus follow spherical coordinates/sphere 8e. If desired, the gripping shaft 8 may be made length adjustable, for example by making the gripping shaft 8 telescopic.

[0101] The coupling between the attachment device 9 and at the other end of the gripping shaft 8 is preferably also made rotational by use of a motorized single axis joint 9a, thereby allowing the attachment device 9 to rotate around a rotational axis 9b. The joint 9a may be placed anywhere on the gripper tool 8,9 as long as it results in a rotation of the attachment device 9 that may be operated independently of the operation of the joints 8a and 8c. In the example of FIG. 3, the motorized single axis joint 9a is arranged adjacent to the motorized joint 8a,8c.

[0102] As an example of a motorized single axis joint, a rotational coupling between the innermost longitudinal section 5 and the intermediate longitudinal section 6 is shown in FIG. 4. For this particular swivel arrangement 6a, the sections 5,6 are relatively displaced along the rotational axis 6b. The controlled rotation is achieved by use of a system comprising cog wheels coupled to suitable motors such as programmable stepper motors.

[0103] FIG. 5 shows an example of use of the inventive robotic arm 1 described above; mooring a vessel 20 to a quay 24. The first robotic arm section 2 is rotationally fixed to a deck 11 or a hull 12 of the vessel 20 in a position where the attachment device 9 is within reach of the position of a rope eye 25a of a mooring line 25.

[0104] The mooring procedure of the vessel 20 to the quay 24 may proceed as follows: [0105] The motorized joints 2a,4a-7a of the robotic arm 1 is operated to move the outermost section 7 with the attached gripper tool 8,9 at its end from a folded, parked position to a position where the attachment device 9 of the gripper tool 8,9 is located adjacent to the rope eye 25a. Image and/or position generating sensors 28,29 (see FIG. 8), hereinafter referred to as the sensor system 28,29, may be used to detect e.g. deck structures 23 (see FIG. 9) not registered in an available database and/or to verify correct entry in such database, thereby allowing the robotic arm 1 to make necessary movements to avoid undesired impacts. The sensor system 28,29 may also be used to locate the exact location of the rope eye 25a or any gripping structure 30 adjacent or on the rope eye 25a. The sensory system 28,29 may for example contain one or more of a 2D camera, a 3D camera, a radar, a laser, an ultrasonic sensor, an ultraviolet sensor and an infrared sensor. A specific example can be the use of a LIDAR. [0106] If needed, one or more of the motorized joints 8a,8c,9a are operated to perform further adjustment of the position of the attachment device 9 relative to the rope eye 25a or gripping structure 30 to ensure that the attachment device 9 is close enough, and in a favourable orientation, to allow releasable coupling with the rope eye 25a/gripping structure 30. [0107] The releasable coupling is established, for example by activating an electromagnet or operating a claw. [0108] The motorized joints 2a,4a-7a of the robotic arm 1 is operated to transport the rope eye 25a and the attached mooring line 25 to a position adjacent a bollard 26 on the quay 24. As for the first step, the sensor system 28,29 may be used to detect the position and the size of the bollard 26 to enable mooring and/or to detect the positions and the sizes of other type of obstacles such that the robotic arm 1 may make necessary adjustments to avoid undesired impacts. [0109] One or more of the motorized joints 2a,4a-7a of the robotic arm sections 2-7 and/or one or more of the motorized joints 8a,8c,9a of the gripping tool 8,9 are operated to guide the rope eye 25a around the bollard 26. For example, the mutual operation of the motorized joints 2a,4a-7a, 8a,8c,9a may first align the rope eye 25a until the opening is facing the side of the bollard 26, then guide the rope eye 25a around the bollard 26 by translational and/or rotational movement towards the bollard 26. [0110] The coupling between the attachment device 9 and the rope eye 25a or gripping structure 30 is released, for example by sending a signal to the electromagnet or by opening the claw. [0111] The motorized joints 2a,4a-7a is operated to move the robotic arm 1 back to its parked, folded position on the deck 11.

[0112] FIGS. 6-8 show another example of use of the inventive robotic arm 1 described above; parking or removing a rope eye 25a to/from a dedicated bollard 26 fixed in a recess 12a of a vessel's 20 exterior hull 12.

[0113] As for the example in FIG. 5, the first robotic arm section 2 is rotationally fixed to a deck 11 or a hull 12 of the vessel 20 in a position where the attachment device 9 is within reach of the position of a rope eye 25a of a mooring line 25, for example within reach of a rope eye 25a moored to a bollard 26 on a quay 24.

[0114] The parking procedure may proceed in a similar manner as for the above described procedure for mooring a mooring line 25 to a quay 24 (FIG. 5).

[0115] Other examples of use of the robotic arm 1 may be [0116] washing of a fish cage by using the attachment device 9 as a washing device, [0117] transporting objects 30 between a fish carrier onto which the robotic arm 1 is fixed and a fish cage, [0118] transporting objects 30 between a service operation vessel onto which the robotic arm 1 is fixed and a stationary offshore installation, [0119] transporting objects 30 between a service operation vessel and a stationary offshore installation onto which the robotic arm 1 is fixed and [0120] transporting objects 30 between two floating vessels 20, where the robotic arm 1 is fixed to one of the two floating vessels 20.

[0121] FIGS. 9A and 9B show a robotic arm 1 installed on a deck 11 of a vessel 20 at vessel's bow 21 and the vessel's aft 22, respectively. The remaining parts of the deck 11 is seen to contain numerous deck structures 23 that may act as potential obstruction elements during operation of the robotic arm 1. Such deck structures 23 include both fixed structures such as the deck infrastructure and removable objects such as containers, personnel, etc. It is thus considered advantageous that robotic arms such as the inventive robotic arm 1 have a high degree of manoeuvrability to minimize the risk of undesired impacts. This is of particular importance when aiming for autonomous or near autonomous operation since there is little or no possibility of manual interference.

[0122] It is appreciated that certain features of the invention, which, for clarity, have been described above in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which, for brevity, have been described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

LIST OF REFERENCE NUMERALS/LETTERS

[0123]

TABLE-US-00001  1 Robotic arm  2 First robotic arm section  2a Motorized joint (between first robotic arm section and deck)  2b Rotational axis of first robotic arm section  3 Second robotic arm section  4 Third robotic arm section  4a Motorized joint (between second and third arm sections)  4b Rotational axis of third robotic arm section  5 Innermost longitudinal section (of plurality of robotic arm sections)  5a Motorized single axis joint (between third robotic arm section and innermost section)  5b Single rotational axis of innermost section  6 Intermediate longitudinal section (of plurality of robotic arm sections)  6a Motorized single axis joint (between innermost and intermediate sections)  6b Single rotational axis of intermediate section  7 Outermost longitudinal section (of plurality of robotic arm sections)  7a Motorized single axis joint (between intermediate and outermost sections)  7b Single rotational axis of outermost longitudinal section  7c Longitudinal direction of outermost longitudinal section  8 Gripping shaft/link (of gripping tool)  8a Motorized single axis joint (of motorized multiple axis joint)  8b First single rotational axis of gripping shaft/link (of multiple rotational axes)  8c First motorized single axis joint (of motorized multiple axis joint)  8d Second single rotational axis of gripping shaft/link (of multiple rotational axes)  8e Spherical coordinates in space, sphere showing rotational restriction of gripping shaft/link  9 Attachment device (of gripping tool)/magnet/claw/hook  9a Motorized joint (of attachment device)  9a Rotational axis of attachment device (and possibly also gripping shaft/link) 10 Common rotational plane for plurality of robotic arm sections 11 Deck (of vessel 20) 12 Hull (of vessel 20) 12a Recess in hull 20 Vessel 21 Bow portion (of vessel 20) 22 Aft portion (of vessel 20) 23 Infrastructure (on deck 11) 24 Quay 25 Mooring rope 25a Rope eye 26 Bollard 28 Image generating sensors/robotic arm sensoring means 29 Position generating sensors/robotic arm positioning means 30 Object to be transferred/sheave I First rotation joint (between deck and first robotic arm section) II Second rotation joint (between second and third robotic arm section) III Third rotation joint (between third robotic arm section and innermost section) IV Fourth rotation joint (between innermost and intermediate section) V Fifth rotation joint (between intermediate and outermost section) VI Sixth rotation joint (between outermost section and gripping shaft/link) VII Seventh rotation joint (between gripping shaft/link and attachment device) VIII Eighth rotation joint