WO2017221171A1

WO2017221171A1 - Collaborative robot, signalling system and process of signalling a displacement of a collaborative robot

Info

Publication number: WO2017221171A1
Application number: PCT/IB2017/053697
Authority: WO
Inventors: Fabio Facchinetti
Original assignee: Alumotion S.R.L.
Priority date: 2016-06-21
Filing date: 2017-06-21
Publication date: 2017-12-28
Also published as: WO2017221171A9; ITUA20164576A1

Abstract

Collaborative robot (1) comprising a base (2) and at least one articulated arm (3) having at least one joint (5), the articulated arm (3) being configured for defining a plurality of work positions (Wl, W2) with respect to the base (2), the collaborative robot comprising a signalling device (15) coupled to the articulated arm (3), the signalling device (15) having a light signalling crown (16) comprising light spots (17) or perimetral sectors (18), which are activated in relation to a displacement direction (D) of a terminal part (10) of said articulated arm (3) from a work position (Wl) to a following work position (W2).

Description

"COLLABORATIVE ROBOT, SIGNALLING SYSTEM AND PROCESS OF SIGNALLING A DISPLACEMENT OF A COLLABORATIVE ROBOT"

* * * *

TECHNICAL FIELD

The present invention refers to a collaborative robot, a corresponding signalling system and a process of signal^¬ ling a displacement of a collaborative robot.

PRIOR ART

As it is known, the conventional robots used for autom- atizing a manufacturing process, have a work space defined by perimetral protections or fences. Such fences are required also by the safety standards and for protecting persons and objects in proximity to the robot space.

Recent developments have led to implement a type of collaborative robots, which can interact with a human in a shared work space.

The collaborative robots do not require perimetral pro^¬ tections and therefore they require high level control sys^¬ tems which enable to ensure the safety of humans in the shared work space, by re-addressing or guiding the collabo^¬ rative robots.

The collaborative robots provided with such control systems even though they are satisfying from different points of views, exhibit some disadvantages. Some solutions provide to constantly monitor the shared space with suitable provided sensors for acting in case of a non-programmed movement of a robot .

The technical problem underlying the present patent ap^¬ plication consists of devising a simple and efficient col^¬ laborative robot which enables to dynamically evidence the robot space, for protecting the persons which can share the same work space, and which has structural and operative fea^¬ tures such to meet the required needs, in order to overcome the cited disadvantages with reference to the prior art.

Brief summary of the invention

The Applicant has observed that the collaborative robot can be made more efficient by adopting a signalling system which notifies the work space that the robot must occupy for executing the required machinings .

Therefore, the object of the present invention is a collaborative robot as defined by claim 1, and by the pre^¬ ferred embodiments thereof described in the dependent claims .

Moreover, it is an object of the invention a signalling system as defined by claim 8 and by the embodiments described in the dependent claims.

It is also an object of the invention a signalling process as defined in claim 11 and in the dependent claims.

Brief description of the drawings

Further characteristics and advantages of the invention will appear from the following description of a preferred embodiment and variants thereof given in an exemplifying way with reference to the attached drawings, wherein:

Figure 1 perspectively illustrates a bottom view of a robot according to an embodiment;

Figure 2 illustrates the robot in Figure 1 in a top perspective view;

Figure 3 and 4 illustrate respectively a perspective view and a front view and a rear view of an embodiment of a signalling device;

Figure 5 illustrates a perspective view of an exploded configuration of the signalling device in Figure 3;

Figure 6 illustrates a block diagram of the collabora^¬ tive robot system according to the present invention;

Figure. 7 and 8 illustrate block diagrams of the oper^¬ ation of the collaborative robot according to the present invention .

DETAILED DESCRIPTION

With reference to such drawings, 1 generally indicates a robot of a collaborative robot type according to the pre^¬ sent invention.

In the following description, the collaborative robot is called robot 1.

The robot 1 comprises a base 2 lying on an abutment plane P . Moreover, the robot 1 comprises an articulated arm 3 and a joint 6 which is interposed between an end 7 of the articulated arm 3 and the base 2.

In the illustrated embodiment, the articulated arm 3 comprises a first portion 4 and a second portion 5 of the arm coupled to each other by a double- joint 9.

The first portion 4 comprises the end 7 of the articu^¬ lated arm 3, and is associated to the joint 6. The second portion 5 comprises the opposite end 8 of the articulated arm 3, and is associated to a triple- joint 11. The triple- joint 11 is associated, in turn, to a terminal portion 10 of the robot 1 at which a tool is associated, for example a pliers or something else, not illustrated in the figures.

The joint 6, the double-joint 9 and triple-joint 11 are configured for moving the first portion 4 and second portion 5 in order to define a plurality of work positions of the articulated arm 3 with respect to the base 2.

According to an embodiment, the robot 1 comprises a signalling device 15 coupled to the articulated arm 3 in proximity to the terminal part 10 of the robot 1.

The signalling device 15 exhibits a perimetral light signalling crown 16. The light signalling crown 16 comprises a plurality of light spots 17 perimetrally disposed and con^¬ figured for being singularly activated or grouped in perime- tral sectors 18. The light spots 17, singularly or grouped in perimetral sectors 18, are activated in relation to the displacement direction D, with respect to said base 2, of the terminal part 10 of said articulated arm 3 from a work position Wl to a following work position W2.

The displacement direction D of the terminal part 10 is suitably identified by Cartesian coordinates with respect to a Cartesian system (X, Y) comprised in the plane P and the center C thereof (X0, Y0) is a central point of the base 2.

The light spot 17 corresponding to the displacement direction D is identified by polar coordinates with respect to a local polar reference system (r, θ) , defined at the light signalling crown 16. The local polar reference system exhibits as reference point 0' the center of the light sig- nailing crown 16 and a predetermined azimuthal axis with respect to it a displacement azimuthal angle Θ is defined by conventionally considering positive the angles having an anti-clockwise direction.

In other words, the displacement direction D of the terminal part 10 on the plane P, enables to define a corre^¬ sponding displacement azimuthal angle Θ on the light signal^¬ ling crown 16. Therefore, a discretization by mapping the value of the displacement azimuthal angle Θ, enables to identify a corresponding displacement light spot 17 on the light signalling crown 16, in other words a corresponding displacement perimetral sector 18.

If the work position Wl and the following work position W2 of the terminal part 10 of the articulated arm 3 are disposed on a direction perpendicular to the plane P, all the light spots 17 are activated.

The signalling device 15, as schematically illustrated in Figure, from 3 to 5, has a substantially cylindrical- shape body having an axis A-A. The signalling device 15 comprises, with a substantially sandwich arrangement, a joining flange 21 interposed between a first flange 19 and second flange 20 axially integrally coupled by the joining flange 21, on the axis A-A.

The light signalling crown 16 substantially exhibits an annular shape and is axially mounted on the axis A-A. The signalling crown 16 is disposed outside the joining flange 20 and comprises the plurality of the perimetrally disposed light spots 17 preferably implemented by light emission di^¬ odes, LEDs. Moreover, each light spot 17 can comprise one or more LEDs individually activable from each other.

Each electronic module 22 is interposed between the first flange 19 and the light signalling crown 16 and is configured for activating corresponding light spots 17 in relation to suitable received signals.

A substantially transparent protecting panel 23 is dis- posed outside the light signalling crown 16 for protecting the light spots 17.

In the embodiment illustrated in the figures, the sig^¬ nalling device 15 is associated to the terminal part 10 of the articulated arm 3, and the second flange 20 is associated to a tool which is coupled to the robot 1 and is used for performing the required operations/machinings . The tool is not illustrated in the attached figures.

In the illustrated embodiment, the terminal part 10, signalling device 15, and tool are axially disposed in re- lation to each other along a direction generated by the axis A-A when the cylindrical body of the signalling device 15 is associated to the terminal part 10.

The signalling device 15 is integral with the terminal part of the robot 1 and therefore with the tool. In this way, it is considered that the tool is provided with the aka TCP, this English acronym stands for Tool Center Point on the axis A-A.

When the tool is moved by the robot 1 along a displace^¬ ment direction D, from the work position Wl to the following work position W2, the signalling device 15 activates a cor^¬ responding light spot 17 or a corresponding perimetral sec^¬ tor 18, in order to signal the displacement of the tool and of the terminal part 10.

The light signalling crown 16, suitably commanded, in- dicates by a light signalling, the displacement direction D of the terminal part 10. The light spots 17 are selectively detected and in relation to the displacement direction D.

The light signalling crown 16 enables to communicate, by activating a corresponding light spot 17, the work space which the robot 1 requires for performing suitable machin- ings on a workpiece.

The robot 1 can also have a sound signaler, not shown in the figures, configured for being activated in combina^¬ tion with the light signalling crown 16 or alone, for sig- nailing a displacement of the robot 1 along the displacement direction D, from the work position Wl to the following work position W2.

Moreover, the present invention refers to a collabora^¬ tive robot system 28 comprising a collaborative robot 1, of the above described type, and a control device 30 configured for commanding and controlling the collaborative robot 1 provided with the signalling device 15.

In an embodiment, illustrated in Figure 7, the control device 30 comprises a first module 31 configured for con- trolling the process of the robot 1, and a second module 32 configured for commanding the signalling device 15.

The first module 31 and second module 32 both comprise at least one microcontroller.

The first module 31 has a program code configured for generating sequences of instructions for operating the robot 1. The first module 31 is associated to and communicates with the robot 1 by a first communication system 33, pref^¬ erably a cable, configured for outputting respective command signals to the robot 1.

Particularly, the first module 31 commands and controls all the functions of the robot 1.

The second module 32 is an interface module between the first module 31 and signalling device 15.

The first module 31 and second module 33 are coupled to each other by a second bus communication system 34 configured for supporting a real-time data transfer. In an embodiment, the second communication system 34 is of the IPC type, this acronym stands for Inter-Process Communication.

The second module 32 is associated to the signalling device 15 by a third communication system 35, preferably a cable. Particularly, the third communication system 35 is configured for outputting respective command signals to the electronic module 22, for suitably activating the light spot 17 on the light signalling crown 16 in relation to respective signals received from the first module 31.

The control device 30 is suitably activated by an ac^¬ tivation command ON/OFF, operated by an user, and enables to command the robot 1 and, particularly, the joints, so that the terminal part 10 is capable of performing predefined operations by a provided tool. According to a further embodiment, the collaborative robot system 28 can generate instructions which are suitably stored for performing corresponding and predetermined ma- chinings on a work piece. In this case, the robot 1 comprises a first pushbutton, not illustrated in the figures, config^¬ ured for activating an operative mode of the robot 1 itself, the so-called "freedrive" mode. Such operative mode, wherein the electric motors of the robot 1 are substantially posi^¬ tioned in a "idle" mode, is particularly useful and efficient during a programming procedure of the articulated arm 3 of the robot 1, wherein the work positions for performing the machinings on the workpiece, are acquired: work position Wl and following work position W2. Unlike the prior art, the pushbutton positioned in proximity to the terminal part 10 of the articulated arm 3 enables a more comfortable and efficient use of it.

Moreover, the robot 1 can comprise a second pushbutton, which is disposed in proximity to the first pushbutton and configured for activating a plurality of further spot lights disposed as a loop on the lower face of the signalling device 15.

Figure 8 schematically illustrates a process 100 of signalling a displacement of the system 28, and particularly of a collaborative robot 1, according to the present inven- tion, for signalling predetermined machinings on a work- piece .

The collaborative robot 1 substantially comprises a base 2 and an articulated arm 3 associated to the base 2.

The process 100 provides of associating to a terminal part 10 of the articulated arm 3, a signalling device 15 having a light signalling crown 16.

The process 100 comprises a step 101 of activating the control device 30.

Therefore, the process 100 comprises an initialization step 102 for executing a first control on the robot 1. In such initialization step 102, the first module 31 is config^¬ ured for processing predetermined initialization instruc^¬ tions enabling to perform a first check for controlling and testing the robot 1.

Then, the process 100 comprises a processing step 103 wherein the first module 31 is configured for processing predetermined operative instructions for machining the work- piece and outputting corresponding command signals to the robot 1.

At the same time, the process comprises a verifying step 104 wherein each operative instruction of the machining step 103 is processed by the second module 32 for evaluating if such instruction comprises a displacement instruction of the terminal part 10 of the robot 1 according to a displace^¬ ment direction (D) .

If the result of the verifying step 104 is negative, NO, the following instruction is analyzed by returning to the machining step 103.

On the contrary, if the result of the verifying step 104 is positive, YES, an analyzing step 105 is provided wherein the displacement instruction is analyzed for output- ting an activation signal to the signalling device 15 for selectively activating the light spot 17 or perimetral sec^¬ tor 18 in said light signal crown (16) which corresponds to the displacement direction D of the terminal part 10 com^¬ prised in the analyzed displacement instruction.

The analyzing step 105, performed by the second module 32, comprises a query sub-step 106, a conversion sub-step 107, and a correlation sub-step 108 for selecting the cor^¬ responding light spot 17.

The query sub-step 106 provides of querying to the first module 31 the work position Wl and following work position W2 and the respective displacement speeds vl and v2 , of the terminal part 10 of the robot 1, which are identified based on the Cartesian system (X, Y) comprised in the plane P which comprises the base 2 of the robot 1. In this way, the dis^¬ placement direction D of the terminal part 10 of the robot 1 comprised in the displacement instruction, is determined. The conversion sub-step 107 provides of converting the Cartesian coordinates of the following work position W2 in order to express them with reference to the local polar reference system (r, θ) , defined, as hereinbefore described, at the light signalling crown 16, in other words at the so- called TCP (Tool Center Point) of the robot 1.

The correlation sub-step 108 provides of defining the displacement azimuthal angle Θ from the polar center 0' dis^¬ posed on the axis A-A and also provides of discretizing the value of the displacement azimuthal angle Θ for determining the corresponding displacement of the light spot 17 present on the light signalling crown 16.

If the work position Wl and following work position W2 are disposed on a direction perpendicular to the plane P, the correlation sub-step 108 provides of activating all the light spots 17.

The present invention can have several variants. For example, the base 2 of the robot 1 can be of a stationary or movable type, moreover, the articulated arm 3 can comprise a different number of portions and joints according to the required needs.

The light spots 17 can be made by a single LED or the light signalling crown 16 can have a perimetral filling of light spots 17. The light beam generated by each light spot 17 can be predetermined or selectable as a function of a predetermined movement of the robot 1. The light generated by the light spots 17 can have a fixed or varying intensity, adapted to reproduce a white light or a rainbow, with a fixed or varying intensity.

Moreover, it is possible to associate to a specific operation instruction an arbitrary switching-on of the light spots 17 or the switching-on of a buzzer. In this way, it is possible to provide one or more predefined switching-on modes of the light spots 17 or perimetral sectors 18 which are taken in the presence of emergency operative conditions with a possible request of a downtime of the robot 1, inde^¬ pendently from the implementation of the process 100.

DETERMINING THE ANGLE

For determining the displacement azimuthal angle Θ, the orientation of the components, in other words of the polar coordinates of the instant speed of the tool by the Cartesian coordinates associated to the base 2 of the robot 1 is shown. In this way, the arc tangent of the ratio of the coordinate y and coordinate x enables to determine the displacement azimuthal angle Θ.

The first module 31 and first communication system 33 are implemented by enabling a real-time two-way communica^¬ tion with the robot 1, for example comprising a real-time = [χ,γ,ζ,α,β,γ], δχ = [χ,γ,ζ,ά,β,γ]. socket RTDE, which enables to detect a sextuple of values comprising the positions and speeds of the local polar ref^¬ erence system:

The angular components of such values follow the axis - angle convention:, in other words the vector:

τ = [α,β,γ] which can be seen as r = [v₀,v ₁,ν₂]θ ,

wherein the versor [VQ,V₁,V₂] indicates the rotation axis, while Θ indicates the rotation.

The vector [VQV-LV^ can be calculated as:

while Θ

Therefore, a rotation matrix R representing the rota^¬ tion of the tool with reference to the base 2 is obtained, in other words the transformation between the coordinates of the local polar coordinate system with respect to the Car^¬ tesian coordinate system, as illustrated in Figure 3.

Vl(l-Cg) + Cg l¾

R = - Cg) + V₂Sg

V₀V₂(1 - Cg) - V-LSQ V

V₂(1 - Cg) + V₀Sg - Cg ) +

Wherein: ce - cos(0) and se = sin(0) .

Therefore, pre-multiplying the Cartesian components of the speed of the tool or light signalling crown 16 for the inverse matrix of R, obtains the speed in local polar coor^¬ dinates, which represent the local displacement of the ter^¬ minal part 10 of the articulated arm 3 of the robot 1. [x_ry_rz_r] = R^_1[x,y,z]

From the rotated components, it is possible to calculate the displacement azimuthal angle Θ by the following formula:

Θ = atan ^

Considering the polar system associated with the base 2, the azimuth coordinates allow to discriminate arc or spherical movements of the terminal part 10 of the articu^¬ lated arm 3 which can be dangerous to an operator.

Referring to Figure 3, the displacement azimuth angle θ' of the terminal part 10 of the articulated arm 3 allows to define in advance the work space required by the robot 1 to perform the appropriate workings on the workpiece. The activation of the corresponding light spot 17 on the terminal part 10 of the articulated arm 3 will inform the operator in advance .

DISCRETIZATION

The discretization enables to determine the light spot 17 or perimetral sector corresponding to the displacement azimuthal angle Θ.

According to an embodiment, the light spots 17 are in^¬ crementally numbered in an anti-clockwise direction, the light spot 17 "zero" being positioned at the azimuthal axis, wherein the displacement azimuthal angle Θ is zero.

In an embodiment, it is considered an even number of light spots 17 equal to 32 and by considering the displace^¬ ment azimuthal angle Θ, the discretization thereof is given by :

1

Dividing Θ for 3227Γ

and only the integer part is considered in the division.

If, during the displacement of the terminal part 10, the displacement azimuthal angle Θ is astride one of the limits dictated by the discretization, in order to avoid a dancing activation during the movement of the robot 1 with a fast change of the switching-on of the light spots 17 caused by a negligible displacement of the terminal part 10, it is preferred to define a minimum displacement threshold

1 which corresponds to the value of the angle given by 32^· As it can be appreciated from before, the collaborative robot and the associated signalling system according to the present invention, enables to overcome the above-mentioned disadvantages .

Particularly, by the signalling device, the collabora^¬ tive robot enables to warn, by a corresponding light and/or sound signalling, an operator about a possible displacement which is required by the operative steps and more particu^¬ larly, enables to signal the direction of such displacement.

Advantageously, the displacement direction of the robot enables to select the corresponding light spots or perime- tral sectors by generating a corresponding light signalling. A person skilled in the field, in order to satisfy contingent and specific needs, could introduce several changes and variants to the above described robot and light system .

Claims

1. Collaborative robot (1) comprising a base (2) and at least one articulated arm (3) having at least one joint (5), said articulated arm (3) being configured for defining a plurality of work positions (Wl, W2) with reference to said base (2), characterized by comprising a signalling device (15) coupled to a terminal part (10) of said articulated arm (3), said signalling device (15) having a light signalling crown (16) comprising light spots (17) or perimetral sectors (18), said light spots (17) or perimetral sectors (18) being activated in relation to a displacement direction (D) and to a work space of said terminal part (10) of said articulated arm (3) from a work position (Wl) to a following work posi^¬ tion (W2), said work space being the space requested from said articulated arm (3) for performing appropriate workings on the workpiece.

2. Robot according to claim 1, characterized in that each perimetral sector (18) comprises one or more light spots (17), said light spots (17) being implemented by LED and being activable separately from each other.

3. Robot according to claim 1, characterized in that said displacement direction (D) is identified by correspond^¬ ing Cartesian coordinates on said plane (P) , said light spots (17) or perimetral sectors (18) being activated in relation to a displacement azimuthal angle (Θ) identified on said light signalling crown (16), said displacement azimuthal an^¬ gle (Θ) being obtained as a function of said Cartesian co^¬ ordinates of said displacement direction (D) .

4. Robot according to claim 1, characterized in that said work space is determined with respect to a polar ref^¬ erence system associated to said base (2) for determining the polar coordinates of said terminal part (10) of said articulated arm (3) from said work position (Wl) to said following work position (W2) .

5. Robot according to claim 1, characterized by com^¬ prising comprises real-time detection means of detected mag^¬ nitudes (Wl, W2 , vl, v2) that are associated to said artic^¬ ulated arm (3), conversion means (32, 35) being associated to said detection means for processing said detected magni- tudes (Wl, W2 , vl, v2) and for determining an azimuth dis^¬ placement angle (θ') of said terminal part (10) with respect to a polar system associated with said base (2)

6. Robot according to claim 1, characterized in that said signalling device (15) has a cylindrical-shaped body with an axis (A-A) and comprises a joining flange (21) in^¬ terposed between a first flange (19) and a second flange (20) axially and integrally coupled on said axis (A-A), said light signalling crown (16) exhibiting an annular shape and being disposed externally of the joining flange (20), said light spots (17) being perimetrally disposed.

7. Robot according to claim 6, characterized by com^¬ prising an electronic module (22) configured for activating said light spots (17) in relation to said received signals.

8. Robot according to claim 1, characterized by com- prising an acoustic indicator configured for being activated in coordination with said light signalling crown (16) or individually for signalling the displacement of said Robot (1) along said displacement direction (D) .

9. Robot according to claim 4, characterized in that said terminal part (10) of said articulated arm (3) comprises at least a pushbutton that is activated to activate a pro^¬ gramming procedure thereby the detected magnitudes (Wl, W2, vl, v2) are detected by means of said detection means.

10. Signal system (28) comprising a collaborative robot (1) , made according to one or more of claims from 1 to 9, characterized by comprising a control device (30) compris^¬ ing :

- a first module (31) which is configured for commanding and controlling said robot (1) and is associated to said robot (1) by a first communication system (33) ;

- a second module (32) which is configured for command^¬ ing said signalling device (15) and is associated to the signalling device (15) by a third communication system (35);

- both said first module (31) and said second module (32) comprising at least one microcontroller.

11. System according to claim 10, characterized by com^¬ prising at least one pushbutton configured for activating a programming procedure of said collaborative robot (1) de^¬ tecting said work position (Wl), said following work posi- tion (W2) and said work space of said articulated arm (3) .

12. Signalling device (15) for a collaborative robot (1) that comprises a base (2) and at least one articulated arm (3) having at least one joint (5), said articulated arm (3) being configured for defining a plurality of work posi- tions (Wl, W2 ) with reference to said base (2), said signal^¬ ling device (15) characterized in that is coupled to a ter^¬ minal part (10) of said articulated arm (3) and comprises a light signalling crown (16) having light spots (17) or perimetral sectors (18) being adapted to be activated in relation to a displacement direction (D) and to a work space of said terminal part (10) of said articulated arm (3) from a work position (Wl) to a following work position (W2), said work space being the space requested from said articulated arm (3) to perform appropriate workings on the workpiece, the work space being defined through polar coordinates with reference to said base (2) .

13. Process (100) of signalling a displacement of a collaborative robot (1) comprising a base (2) and an artic^¬ ulated arm (3) associated to said base (2), characterized by: - associating to a terminal part (10) of said articu^¬ lated arm (3) a signalling device (15) having a light sig^¬ nalling crown (16);

and of providing:

- a verifying step (104) wherein each operative in^¬ struction comprised in a working step (103) is processed for evaluating if said operative instruction comprises an in^¬ struction for displacing said terminal part (10) from a work position (Wl) to a following work position (W2), said veri- fying step (104) providing:

an analyzing step (105) of a displacement instruction for determining a displacement direction (D) and a work space requested to said articulated arm (3) to perform appropriate workings on a workpiece and determining a corresponding se- lective activation signal for selectively activating a spot light (17) or perimetral sectors (18) in said light signal^¬ ling crown (16) .

14. Process (100) according to claim 13, characterized in that said analyzing step (105) comprises:

- a query sub-step (106) wherein said work position

(Wl), said following work position (W2) and corresponding displacement speeds (vl, v2) are identified by Cartesian coordinates on a plane (P) that comprises said base (2) for determining said displacement direction (D) of said terminal part (10) and wherein is identified said work space by polar coordinates with reference to a polar system associates to said base (2) ;

- a conversion sub-step (107) which provides to convert said displacement direction (D) in a displacement azimuthal angle (Θ) in said light signalling crown (16) ;

- a correlation sub-step (108) which provides to select the corresponding light spot (17) or perimetral sector (18) of said light signalling crown (16) corresponding to said displacement azimuthal angle (Θ) comprised in said displace^¬ ment instruction.

15. Process (100) according to claim 14, characterized in that said correlation sub-step (108) provides to activate all the light spots (17) when said work position (Wl) and said following work position (W2) are disposed on a direction perpendicular to said plane (P) .