The present application relates to the field of robotics, such as robot arms that are part of collaborative robots, and more specifically reconfigurable robot arm using modular hardware.
Robotic arms are increasingly used in a number of different applications, from manufacturing, to servicing, and assistive robotics, among numerous possibilities. Traditionally, robotic hardware development is mostly done through simulation in CAD software. While these tools demonstrated their strength, it still remains desirable to build prototype arms to test them in the real world. This latter option is normally more complex as changing actuators or link length is cumbersome.
In one aspect, there is provided a motorized joint assembly for a modular robot arm comprising: a motorized unit having a first shell and a second shell rotatable relative to the first shell about a rotation axis, a motor disposed within and secured to one of the first shell and the second shell, the motor in driving engagement with the other of the first shell and the second shell; a first cap interface mounted on the first shell and a second cap interface mounted on the second shell, the first cap interface defining a first set of connectors for connecting structural members of the modular robot in a first orientation and a second set of connectors for connecting the structural members in a second orientation different than the first orientation.
In another aspect, there is provided a modular robot arm comprising: a base securable to a support, the base having a base motorized joint; an effector interface end; and at least one link connecting the effector interface end to the base, the at least one link including a proximal cap interface at a proximal end and connected to the base motorized joint, a distal cap interface at an opposite distal end and connected to a second motorized joint, and struts connecting the proximal cap interface to the distal cap interface, at least one of the proximal cap interface and the distal cap interface defining a first set of connectors and a second set of connectors, the struts selectively connected to the at least one of the proximal cap interface and the distal cap interface along a selective one of a first orientation via the first set of connectors and a second orientation different than the first orientation via the second set of connectors.
Many further features and combinations thereof concerning the present improvements will appear to those skilled in the art following a reading of the instant disclosure.
Referring to the drawings and more particularly to
Referring concurrently to
The cap interfaces 12 have a structural function in that they form the skeleton of the robot arm 10, by supporting the motorized joint units 14 (
The struts 13 also have a structural function, in maintaining the cap interfaces 12 spaced apart, and by having structural rigidity for the robot arm 10 to have negligible deformation when supporting its own weight and with a tool at the effector end 11A.
The cap interfaces 12 and struts 13 may contribute to the modularity of the robot arm 10. As described below, the cap interfaces 12 are configured to be connected to the struts at different orientations, to form elbow or wrist-style joints. The struts 13 may be of different lengths, for a length of the robot arm 10 to be set based on available space and/or desired working volume and/or intended use, for example.
The motorized joint units 14 interconnect adjacent cap interfaces 12, or a cap interface 12 with a hollow shell 10B, in such a way that a rotational degree of actuation is provided between adjacent cap interfaces 12 and/or shell 10B. According to an embodiment, the motorized joint units 14 may also connect a cap interface 12 to a tool at the effector end 11A, although other mechanisms may be used at the effector end 11A and at the base end 11B. The motorized joint units 14 may also form part of structure of the robot arm 10, as they interconnect adjacent cap interfaces 12.
In the illustrated embodiment of
Referring to
Referring to
For simplicity, exemplary components of the cap interfaces 12 will be given reference numerals in the 20s in the description. The cap interface 12 of
Connector slots 24 are defined in an outer surface of the receptacle body 20. The connector slots 24 are one possible connector configuration that may be present. The connectors 24 may be holes, blocks, tabs, posts, etc. For simplicity, the connector slots 24 are described herein although other types of connectors may be present. The connector slots 24 may be grouped in a first set S1 and a second set S2; the first set S1 being used for the transverse arrangement, while the second set S2 is used for the parallel arrangement. It is also contemplated to use other angled arrangements, as alternatives to the square and parallel arrangements, such as 45 degrees, as an example. In an embodiment, the receptacle body 20 has only one of the first sets S1 and second S2, with cap interfaces 12 being dedicated to either transverse arrangements or parallel arrangements. However, the configuration of the cap interface 12 of
The connector slots 24 have a contact surface 24A that may be contoured (e.g., partially peripherally enclosed) by walls 24B, In an embodiment, the contact surface 24A is generally flat, but may be arcuate, slotted, etc. Any suitable shapes are contemplated. Threaded hole(s) 24C are defined through the body 20 and extend from the contact surface 24A. These these threaded holes 24C are threadingly engageable by correspondingly threaded fasteners for securing the struts 13 to the body 20 via the connector slots 24. In the embodiment shown, each of the connector slots 24 includes a pair of the threaded apertures 24C sized to receive fasteners therein, for connection of the struts 13 to the cap interfaces 12. It will be appreciated that other fastening means to secure the struts 13 to the cap interfaces 12 are contemplated, such as, clips instead or in addition to fasteners.
Referring more particularly to
According to an embodiment, all of the cap interfaces 12 of the robot arm 10 are the same, whereby all motorization units 14 can be the same and used interchangeably at any joint between the cap interfaces 12. In such an arrangement, a single type of cap interfaces 12 and of motorization units 14 may be kept in inventory for practical reasons. This may reduce part counts and may reduce costs. In another embodiment, the cap interfaces 12 may be geometrically similar to one another, but with a reduction of size from proximal to distal, with the distal cap interfaces 12 being typically smaller than the proximal cap interfaces 12, as the motorization units 14 being closed to the base end 11B may be required to output more torque to support a greater part of the robot arm 10. Motorization units 14 could come in different sizes in such an arrangement.
Referring to
Each of the first and second sets of connectors S1, S2 are herein distributed circumferentially around a first axis A1 and a second axis A2, respectively. The first and second axes A1, A2 are non-parallel to one another. Herein, the first and second axes A1, A2 are perpendicular to one another. In the present embodiment, the second axis A2 is parallel to the axis of rotation X. In the embodiment shown, a number of the connectors of the first set of connectors S1 corresponds to a number of the connectors of the second set of connectors S2. To enable that the struts 13 may be selectively connected to either the connectors of the first set S1 or of the second set S2, each of first distances S1D1, S1D2 between the first axis A1 and the connectors of the first set S1 of connectors equals an associated one of second distances S2D1, S2D2 between the second axis A2 and the connectors of the second set S2 of connectors. In the depicted embodiment, each of the contact surfaces 24A of the connectors 24 of the first set S1 is oriented in a respective one of first directions D11, D12 and each of the contact surfaces 24A of the connectors 24A of the second set S2 is oriented in a respective one of second directions D21, D22. The first directions D11, D12 and the second directions D21, D22 are radial relative to the first axis A1 and the second axis A2, respectively. Herein, their directions are solely radial. It will be appreciated that, alternatively, each of the first directions D11, D12 may be different from one another and equal to an associated one of the second directions D21, D22.
Referring to
In
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The tube 31 is open ended so as to receive connector tabs 30 at its opposed ends. The tube 30 spaces apart the connector tabs 30 by select distances. The tubes 31 may be made of any appropriate material. In an embodiment, the tubes 31 may be plastic or metal extrusions. In another embodiment, the tubes 31 are made of composite materials, such as carbon fiber or fiberglass tubes, with a high stiffness to weight ratio. Other materials are contemplated as well. It is also contemplated to allow the tubes 31 to be cut to an appropriate length, though the tubes 31 could be available in a subset of lengths.
The number of struts 13 in each link 10A may be the same or may differ in a same robot arm 10. According to an embodiment, there may be a greater number of struts 13 proximally as the base end 11B may have to bear a greater load, notably that of the robot arm 10. In an embodiment, there are at least two struts 13 between each set of cap interfaces 12. The presence of pairs of holes 24C and 30C, of the alignment features 24D and 30D, and/or abutment between walls 24B and periphery 30B may contribute to a bracing effect between the cap interfaces 12 of a same link 10A.
Referring to
Referring to
A base mount 60 in such an embodiment is defined by a plate 61 with connectors, in the form of female tubes 62, for receiving the tubes 31 therein. Alternatively, the connectors may be plugs that may be received in the free ends of the tubes 31. There may be more connectors 62 than on the cap interfaces 12″, to allow versatility in the connection of struts to the base mount 60. The base mount 60 may be wall mounted for example, or may be mounted to any appropriate structure as detailed above. Holes 63 may be present for the anchoring of the plate 61 to a flat surface, as one possibility to secure the base mount 60 to a structure.
The base mount 60 may be used as an alternative to the docking cradle or base shown in
Referring to
In 220, the geometry data of the robot arm is obtained, namely, the number of joints, the size of the motorization units 14 at the joints, the distance between links (e.g., the distance between rotational planes at the ends of any link), the orientation of the rotational axes. The geometry data may be based on the hardware that is used, for instance by having the user enter information about the selection of components via a user interface. Hence, the geometry data may define the overall configuration of the robot arm (e.g., the number of DOFs, serial or SCARA type, etc.), the number of motorized joints 14, the size of each motorized joint 14, the length of the links 10A, 10B between pairs of the motorized joints 14, the transverse, parallel or other angled arrangement (i.e., relative orientation between joints), the type of end effector at effector end 11A, the type of base at base end 11B. In one embodiment, the user enters the robot arm configuration using for example a word processor software. In another embodiment, the geometry data is entered using a graphical user interface (GUI), for example with drop-down menus, text boxes, widgets, etc. In another embodiment, the geometry data specific to the created robot arm 10 may be generated by having the user clicking and dragging icons on a graphical interface.
Once the geometry data is obtained, the processing unit may virtually assemble the various components to build the desired robot arm, in 221. In this step, a subassembly may first be generated and then attached to a previous subassembly. The processor unit may display the virtual model of the robot arm 10. This may allow the user to verify the model against a constructed version of the robot arm 10, if already built. Alternatively, it may allow the user to play with a virtual model of the robot arm 10 before constructing it. When assembling the robot arm 10 in 221, the processing unit may determine the overall dimensions, the workspace, the degrees of freedom and the link interferences can be checked. This may be achieved by performing a movement simulation of the robot arm 10 assembled in 221, and may include the possibility of having a user operating the movement simulation with a user interface, such as a joystick, keyboard, touchscreen, etc.
In 222, the processing unit obtains inertia data, mass properties, rigidity of the links 10A, 10B between the parts of motorized joint units 14 etc for the components of the virtual robot arm 10. For instance, the inertia data, mass properties, rigidity of the links 10A, 10B is obtained from a database containing component specifications, e.g., manufacturing specs. The processing unit may generate an inertial model and/or a rigidity model of the robot arm 10. The inertial model impacts the operation of the robot arm 10, notably the torque required at the joints.
In 223, the processing unit may suggest modifications to the robot arm 10, notably by the addition or subtraction of struts 13, the use of larger or smaller motorization units 14, the substitution of components to achieve a similar workspace for lessened complexity, etc.
In 224, with a finalized robot arm 10, the processing unit 10 generates a control model specific to the finalized robot arm 10. The control model may be computer-readable program instructions executable by a processing unit on the robot arm 10, to control the robot arm 10 as a function of its specific geometry. The control model may including a calibration configuration for the calibration of the robot arm at operation. In 225, the control model may be output and programmed into processing unit of the controller of the robot arm 10, if 220-224 were not performed directly into the robot arm 10. In 226, with the control model in the controller of the robot arm 10, the controller may operate the robot arm 10 as a response to teleoperation instructions from a user, or to further programming from the user, in a real or virtual environment.
For creating and assembling an articulated robot arm a number of motorized joints of various sizes is determined; a number of link members of various lengths is obtained and releasably attached to the base end; a first number of link members of a first length is releasably attached on one end to said first motorized joint; a second motorized joint of any size is determined and releasably attached on the other end to the said first number of said link members of said first length; a Nth motorized joint of any size is determined and releasably attached on the other end to the said N−1th number of link members of said N−1th length; a wrist member is releasably attached to the Nth motorized joint; wherein each of the N motorized joints can be of any size; each of the N−1 link members between each pair of the N motorized joints can be of various lengths as long as the length is the same between a specific pair of motorized joints; each of the N−1 number of link members between each pair of the N motorized joints can be of various quantities.
For automatically generating the tool, control and calibration configuration files of a robot arm a robot arm description file is created; a CAD model of the robot arm is generating automatically based on the robot arm description file; the URDF file is automatically created based on the CAD model; the tool, control and calibration configuration files automatically generating based on the URDF file.
The robot arm description file may be created by using a word processor software. The method of claim 39 wherein the robot arm description file is created by using a drop-down menu interface. The robot arm description file may be created by clicking and dragging icons from a graphical interface. The robot arm description file may be created by using voice commands through an interface.
Embodiments disclosed herein includes:
A. A motorized joint assembly for a modular robot arm comprising: a motorized unit having a first shell and a second shell rotatable relative to the first shell about a rotation axis, a motor disposed within and secured to one of the first shell and the second shell, the motor in driving engagement with the other of the first shell and the second shell; a first cap interface mounted on the first shell and a second cap interface mounted on the second shell, the first cap interface defining a first set of connectors for connecting structural members of the modular robot in a first orientation and a second set of connectors for connecting the structural members in a second orientation different than the first orientation.
B. A modular robot arm comprising: a base securable to a support, the base having a base motorized joint; an effector interface end; and at least one link connecting the effector interface end to the base, the at least one link including a proximal cap interface at a proximal end and connected to the base motorized joint, a distal cap interface at an opposite distal end and connected to a second motorized joint, and struts connecting the proximal cap interface to the distal cap interface, at least one of the proximal cap interface and the distal cap interface defining a first set of connectors and a second set of connectors, the struts selectively connected to the at least one of the proximal cap interface and the distal cap interface along a selective one of a first orientation via the first set of connectors and a second orientation different than the first orientation via the second set of connectors.
Embodiments A and B may include any of the following elements, in any combinations:
Element 1: the base hosting the first motorized joint contains the modular robot arm controller. Element 2: the base hosting the first motorized joint has a quick connect mechanism to attach it to a docking cradle. Element 3: the docking cradle contains the modular robot arm controller. Element 4: the controller is external of the robot arm. Element 5: the mounting interface fixed at the end of the at least one link member has a corresponding protrusion. Element 6: the protrusion and the corresponding notch are shaped like a pyramid, a cube, a prism, etc. Element 7: the at least one link member and its mounting interface are constructed in one solid piece. Element 8: the two or more mounting notches are spaced evenly on the cap. Element 9: the two or more mounting notches are not spaced evenly on the cap. Element 10: the at least one ring is round shaped. Element 11: the at least one ring is shaped like a square, a rectangle, a triangle, an ellipse, etc. Element 12: the base is mounted on a mobile platform. Element 13: the tubes or bars are made of polymeric material, metallic material, composite material, etc. Element 14: the struts have a circular, rectangular. Element 15: the connectors of the first set of connectors are distributed circumferentially around a first axis and the connectors of the second set of connectors are distributed about a second axis non-parallel to the first axis. Element 16: the first axis is parallel to the rotation axis and wherein the second axis is perpendicular to the first axis. Element 17: a number of the first set of connectors corresponds to a number of the connectors of the second set of connectors, each of first distances between the first axis and the connectors of the first set of connectors equals an associated one of second distances between the second axis and the connectors of the second set of connectors. Element 18: the first distances extend from the first axis to first contact surfaces of the first connectors and wherein the second distances extend from the second axis to second contact surfaces of the second connectors. Element 19: each of the first contact surfaces is oriented in a respective one of first directions and each of the second contact surfaces is oriented in a respective one of second directions, the first directions and the second directions being radial relative to the first axis and the second axis. Element 20: the first contact surfaces and the second contact surfaces define alignment features. Element 21: the first orientation is normal to the second orientation. Element 22: the connectors of the first set of connectors are slots defined in an outer face of the first cap interface, the connectors of the second set of connectors being slots defined in an outer face of the second cap interface. Element 23: the connectors are female tubular members. Element 24: the struts are releasably attached to the at least one of the proximal cap interface and the distal cap interface. Element 25: both the proximal cap interface and the distal cap interface defines the first set of connectors and the second set of connectors. Element 26: the first orientation is parallel to an axis of rotation of a corresponding one of the base motorized joint and the second motorized joint and the second orientation is perpendicular to the axis of rotation. Element 27: the connectors of the first set of connectors are distributed circumferentially around a first axis and the connectors of the second set of connectors are distributed about a second axis non-parallel to the first axis. Element 28: a number the connectors of the first set of connectors corresponds to a number of the connectors of the second set of connectors, each of first distances between the first axis and the connectors of the first set of connectors equals an associated one of second distances between the second axis and the connectors of the second set of connectors. Element 29: the first distances extend from the first axis to first contact surfaces of the first connectors and wherein the second distances extend from the second axis to second contact surfaces of the second connectors. Element 30: each of the first contact surfaces is oriented in a respective one of first directions and each of the second contact surfaces is oriented in a respective one of second directions, the first directions and the second directions being radial relative to the first axis and the second axis. Element 31: the connectors of the first set of connectors are slots defined in an outer face of the first cap interface, the connectors of the second set of connectors being slots defined in an outer face of the second cap interface. Element 32: the connectors are female tubular members.
As can be seen therefore, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.
This application claims priority from U.S. patent application 62/849,304 filed on May 17, 2019. Its content is incorporated herewith in its entirety.
Number | Date | Country | |
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62849304 | May 2019 | US |