A mobile robotic unit for performing industrial processing operations within a work environment, and related stabilizer arms with stationing feet

Abstract

A mobile robotic unit (1) configured for performing industrial processing operations within a work environment, comprising: - a plurality of retractable stationing feet (8) supported by respective stabilizer arms (9) extending from the frame (6) of the vehicle (3), - each stabilizer arm (9) comprising an automatic leveling assembly (13) associated with the retractable stationing foot (8), configured for detecting the contact position of the stationing foot (8) with the ground and stopping a lowering maneuver of the foot (8) in case of contact with the ground before reaching a stroke end position.

Description

[0001] “A mobile robotic unit for performing industrial processing operations within a work environment, and related stabilizer arms with stationing feet”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention generally refers to a mobile robotic unit comprising:

[0006] - a multi-axis manipulator robot carrying an operating head arranged to perform one or more of said operations,

[0007] - a vehicle comprising a frame called carrying said robot and advancing means configured for moving the vehicle on the ground.

[0008] The mobile robotic unit may be configured for performing construction and / or assembly and / or maintenance and / or repair and / or inspection operations within the work environment, for example within a ship or floating or semi-submersible offshore structures or inside an aircraft or inside a building structure or in an outdoor space.

[0009] The mobile robotic unit can be configured for performing any type of industrial processing with a continuous or discontinuous process, such as welding, sealing, riveting, nailing, screwing, cutting, sealant deposition, material addition by additive manufacturing technology, etc.

[0010] Prior art

[0011] A mobile robotic unit of the type indicated above, comprising a vehicle carrying a multi-axis manipulator robot, is for example disclosed in document CN 107 030 349 A. This document in fact illustrates a mobile robotic unit arranged to perform welding operations on internal work environment, particularly inside a ship.

[0012] Furthermore, there are various known solutions for creating stabilization means to assist the wheels of the vehicle, which can be actuated by means of electric or hydraulic actuators.

[0013] The present invention starts from the desire to manufacture a mobile robotic unit of the type indicated above which allows the vehicle to be stabilized in an extremely effective way, even in the event of movement of the vehicle on irregular ground, such as for example metal surfaces or surfaces made of other materials, as well as soil.

[0014] Object of the invention

[0015] The object of the present invention is to generally manufacture a mobile robotic unit of the type indicated above, which high flexibility and efficiency properties with regard to the stabilization of the vehicle before performing processing.

[0016] A further object of the invention is to manufacture a mobile robotic unit of the type indicated above which is extremely intuitive for the operators who control it, providing stabilization means that are particularly simple to implement.

[0017] A further object of the invention is to make the movement operations of the mobile robotic unit extremely easy, even passing through spaces having a limited width.

[0018] Summary of the invention

[0019] In order to achieve these aims, the invention has as its object a mobile robotic unit, having the features forming the subject matter of one or more of the following claims, which form an integral part of the technical teaching provided here in relation to the invention.

[0020] In particular, the object of the invention is achieved by a mobile robotic unit having the features set out in the attached claim 1 .

[0021] Brief description of the figures

[0022] Further features and advantages of the invention will emerge from the following description with reference to the attached drawings, provided purely by way of non-limiting example, in which:

[0023] - figure 1 is a perspective view illustrating a preferred embodiment of a vehicle according to the invention;

[0024] - figures 2,3 are sectional views illustrating some features of the vehicle, in relation to respective stabilizer arms;

[0025] - figures 4,5 are perspective views illustrating further features of the stabilizer arms to allow the passage of the vehicle through spaces having a limited width, and - figures 6A, 6B are schematic sectional views, on enlarged scale, which illustrate a part of a stabilizer arm, in a free, non-blocked position and a final blocked position, respectively.

[0026] Detailed description of embodiments

[0027] The following description illustrates various specific details aimed at an in-depth understanding of examples of one or more embodiments. The embodiments can be produced without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments.

[0028] The reference to “an / one embodiment” in this description is to indicate that a particular configuration, structure or feature described in connection with the embodiment is included in at least one embodiment. Therefore, phrases such as “in an / one embodiment”, possibly present in different places in this description, do not necessarily refer to the same embodiment.

[0029] Furthermore, particular conformations, structures or features can be combined appropriately in one or more embodiments and / or associated with the embodiments in a different way from how illustrated here, so for example a feature exemplified here, in relation to a figure, may be applied to one or more embodiments exemplified in a different figure.

[0030] The references illustrated here are for convenience only and therefore do not limit the extent of protection or the scope of the embodiments.

[0031] Seeing in particular the figure 1 , reference 1 indicates the mobile robotic unit configured for performing industrial processing operations within a work environment, such as for example construction and / or assembly and / or maintenance and / or repair and / or inspection within the work environment.

[0032] The mobile robotic unit 1 can be configured for performing any type of processing with a continuous / discontinuous process, such as for example welding, sealing, riveting, nailing, screwing, cutting, sealant deposition, material addition by additive manufacturing technology, etc.

[0033] Figure 1 illustrates an embodiment relating to a mobile robotic unit 1 for performing welding operations, in particular arc welding. However, this example is not to be construed restrictive at all, since, as indicated above, the invention is applicable to any type of industrial processing with continuous or discontinuous process.

[0034] According to the present invention, the mobile robotic unit 1 comprises a multi-axis manipulator robot 2 carrying an operating head 4, and a vehicle 3 on which the robot 2 is mounted. The operating head 4 comprises processing means arranged for performing a plurality of construction and / or assembly and / or maintenance and / or repair operations within a work environment.

[0035] In a preferred embodiment, the work environment consists of a ship structure and the mobile robotic unit 1 is designed to perform the assembly of parts of a ship under construction.

[0036] With reference to figure 1 in which the mobile robotic unit 1 is shown, the robot 2 is a multi-axis manipulator robot having a base 2’ and a column rotatably mounted on the base 2’ around a first vertically directed axis. Robot 2 has a 2” arm mounted in an articulated way on the column around a second axis directed horizontally; the reference 2”’ indicates a forearm mounted on said 2” arm. The forearm 2”’ is articulated around a third axis also directed horizontally; the forearm 2” also has the possibility of rotating around its longitudinal axis, and is equipped at its end with a wrist mounted with the possibility of rotating around two mutually orthogonal axes. According to a per se known technique, each of the six axes of the robot 2 is controlled by a respective electric motor. The electric motors of the robot 2 are controlled in a per se known manner by an electronic control unit. At the distal end of the wrist of the robot 2 there is a flange for attaching the operating head 4 carrying processing means for performing operations with a continuous or discontinuous process. Preferably, the attachment flange is a sensorized flange to avoid any collisions with external objects.

[0037] In the embodiment illustrated in figure 1 , the operating head 4 comprises welding means, preferably a welding torch 5 arranged to perform arc welding with metal under gas protection (MIG / MAG). Of course, the invention also concerns the case in which welding means configured for performing other types of welding are provided (for example laser welding, resistance welding, etc.). As indicated previously, the multi-axis manipulator robot 2 is carried by a vehicle indicated as a whole with the reference 3.

[0038] Again with reference to figure 1 , the vehicle 3 comprises a frame 6 and advancing means 7 configured for moving the vehicle on the ground. Preferably, the advancing means 7 are a pair of tracks configured to allow easy movement of the robotic unit 1 even on deformable and poorly cohesive soils. Of course, instead of tracks, the vehicle 3 can provide other types of advancing means 7.

[0039] In a preferred embodiment of the invention, the vehicle 3 is configured to be wire-guided or remote-controlled by an operator 0. However, note that the vehicle 3 can be configured to move automatically in a predetermined or programmed way, to autonomously reach different zones of a work area in which to perform various processing operations.

[0040] According to a further feature illustrated in figure 1 , the mobile robotic unit 1 can be mechanically connected - by means of a trailer configuration - to a service trolley 10. Preferably, the latter has at least one support portion designed to support, at an ergonomic height for the operator O, several components to control the unit 1 , comprising a human-machine interface (HMI) 12 configured to allow an operator 0 to program and control the work cycles.

[0041] According to a basic feature of the present invention, the vehicle 3 comprises a plurality of stationing feet 8 respectively supported by stabilizer arms 9 extending from the frame 6. Preferably, the stabilizer arms 9 are in a position of mutual symmetry with respect to the center line of the mobile robotic unit 1 , and create a total of four stabilization points for the vehicle on the ground.

[0042] According to a feature detailed below and partially illustrated in figure 1 , the stabilizer arms 9 are configured as movable between a lowered horizontal position to enable contact with the ground by means of the stationing feet 8, and a raised position substantially extended along a vertical direction with respect to the ground, to allow the vehicle 3 to easily pass through spaces of limited width. In other words, according to the features described below, the stabilizer arms 9 are connected in an articulated manner to a respective support portion 6’ of the frame 6, so as to be able to rotate around an articulation axis, and create different operating positions depending on the needs.

[0043] According to a basic feature of the invention, when the stabilizer arms 9 are in the lowered horizontal position, the stationing feet 8 can be actuated so as to vary their protrusion with respect to the stabilizer arm 8 which supports them, and achieve the contact with the ground. In other words, the stationing feet 8 are configured as retractable, being mobile between a raised position substantially close to the respective arm 8 (figure 2) and a lowered position further away from the respective arm 8 (see figure 3), and vice versa.

[0044] According to a further peculiar feature of the present invention, each stabilizer arm 9 comprises an automatic leveling assembly 13 associated with the retractable stationing foot 8, configured for detecting the contact position of the stationing foot 8 with the ground and stopping a lowering maneuver of the foot 9 in case of contact with the ground before reaching a stroke end position. From this perspective, in order to control the operation of the automatic leveling assembly 13, the mobile robotic unit 1 comprises at least one electronic control unit configured and programmed to send control signals to the assembly 13, in accordance with the related commands given by an operator.

[0045] These features relating to the automatic leveling of the stationing feet 9 are important in the case of a work environment with uneven ground, to guarantee effective stabilization of the vehicle even in unfavorable conditions, before performing a processing with the robot.

[0046] Figures 2, 3 are sectional views illustrating a preferred embodiment of an arm 9 and the related automatic leveling assembly 13. In particular, figure 2 illustrates a stabilizer arm 9 with the stationing foot 8 in a raised position with respect to the ground, while figure 3 illustrates the same stabilizer arm 8 with the stationing foot 9 in a lowered position for the contact with the ground.

[0047] With reference to this embodiment, the automatic leveling assembly 13 can comprise:

[0048] - a screw-nut screw coupling comprising a screw 14 axially extended along the stabilizer arm 8 and a nut screw 15 slidingly engaged on the screw 14;

[0049] - at least one actuator 16 for driving in rotation the screw 14; - a bushing 17 freely movable along the screw 14 and spaced apart from the nut screw 15;

[0050] - at least one connection element 18 provided for mechanically connecting the bushing 17 and the nut screw 15, in such a way that the nut screw and the bushing are configured to slide integrally along the screw following the operation of the actuator 16;

[0051] - an elastic element 19 interposed between the nut screw 15 and the bushing 17;

[0052] - wherein the bushing 17 is connected to the stationing foot 8 by means of a drive mechanism 20 of the foot kinematic arranged for driving the movement of the foot 8 between a raised position with respect to the ground and a lowered position in contact with the ground (and vice versa), and

[0053] - at least one sensor 21 adapted for detecting the approach of the nut screw 15 to the bushing 17 following contact of the stationing foot 8 with the ground, in order to stop the actuator 16 and the lowering maneuver of the foot before reaching a stroke end position of the nut screw 15.

[0054] According to these features, to start a lowering maneuver of the foot 8, the electronic control unit sends a control signal to the actuator 16. During the lowering maneuver of the foot 8 caused by the activation of the screw- nut screw mechanism, in the case in which the foot 8 contacts the ground, the bushing 17 stops in a certain position along the screw due to the mechanical resistance generated by the contact of the foot 8 with the ground, since the bushing 17 is mechanically connected to the foot 8 by means of said drive mechanism 20 of the foot kinematic. After the bushing 17 has been locked, the actuator 16 continues to drive in rotation the screw 14 until it reaches a contact position - or at least a proximity position - between the nut screw 15 and the bushing 17. The sensor 21 detects this contact position and consequently it sends a warning signal to the electronic unit to stop the operation of the actuator 16.

[0055] In one or more embodiments, the sensor 21 is a contact sensor or a proximity sensor configured for detecting contact - or the approach above a threshold value - between the nut screw 15 and the bushing 17. The contact sensor 21 is then configured to send a relative signal to the electronic control unit programmed to receive said signal and control the stop of the actuator 16, before reaching a stroke end position of the nut screw 15.

[0056] In one or more embodiments, the actuator 16 is an electric gearmotor axially connected to the screw 14. The actuator 16 is advantageously positioned along an end portion of the stabilizer arm 9 fixed to the support portion 6’ of the frame 6.

[0057] In one or more embodiments, the mechanical connection element 18 between the nut screw and the bushing is provided by a plurality of connection screws, arranged radially around the screw 14 and axially extended between the bushing 17 and the nut screw 15, in such a way that, following the translation movement of the nut screw 15, the bushing 17 slides integrally along the screw 15. Of course, the translation of the bushing 17 following the movement of the nut screw 15 occurs in both directions of actuation (i.e. from left to right in figure 2 to lower foot 8, and from right to left in figure 3 to raise foot 8).

[0058] In one or more embodiments, the elastic element 19 is a spring axially mounted along the screw 14 between the nut screw 15 and the bushing 17, in such a way that, when the nut screw 15 begins an approach stroke towards the bushing 17, the spring compresses tending to dampen the contact between the nut screw 15 and the bushing 17. From this perspective, the sensor 21 can also be configured for detecting the compression of the spring beyond a predetermined value and at the same time send a warning signal to the unit control E in order to stop the actuator 16. Note also that the electronic unit E can be configured to continue to actuate the actuator 16 after the signal from the sensor 21 , for a limited time, to ensure a decoupling from the ground of the striking surface of the advancing means 7.

[0059] As indicated previously, the bushing 17 is connected to the stationing foot 8 by means of a drive mechanism 20 of the foot kinematic, arranged for driving the movement of the foot 8 between a raised position with respect to the ground and a lowered position in contact with the ground (and vice versa).

[0060] In one or more embodiments, as illustrated in figures 2,3, the drive mechanism 20 of the foot kinematic is substantially a pantograph mechanism comprising a pair of levers mutually and pivotally connected around an articulation axis I oriented transversely with respect to the longitudinal direction of the stabilizer arm 9.

[0061] More specifically, each pair of levers can include:

[0062] - a first lever 22 having a lower end carrying the stationing foot 8 and an upper end connected to the bushing 17 freely movable along the screw 14;

[0063] - a second lever 23 having a lower end pivoted to the first lever 22 substantially at an intermediate position of the first lever, and an upper end pivoted to a terminal end of the stabilizer arm 9.

[0064] In light of the configuration indicated above, the drive mechanism 20 is substantially Y-shaped, in which a lower end of the mechanism is defined by the stationing foot 8, while spaced upper ends of the mechanism are respectively connected to the bushing 17 and to a terminal end of the stabilizer arm 9.

[0065] It will therefore be appreciated that, depending on the features described previously, the mobile robotic unit 1 is designed to guarantee an automatic stabilization operation on any type of surface, even irregular, without however having to require the operator’s attention to stop the stationing feet 8 before a stroke end position.

[0066] As indicated previously, the stabilizer arms 9 are configured as movable between a lowered horizontal position to enable contact with the ground by means of the stationing feet 8, and a raised position substantially extended along a vertical direction with respect to the ground to allow the easy passage of the vehicle 3 through spaces having a limited width.

[0067] Figures 4-6B illustrate various features relating to these features aimed at minimizing the size of the unit 1 during the movement of the vehicle 1.

[0068] According to a first feature, each stabilizer arm 9 comprises locking means which can be activated to lock the arm 9 into at least one of the lowered position and the raised position, and deactivated to allow the movement of the arm 9 from one of the aforementioned positions to the other.

[0069] In one embodiment, as illustrated in figures 4.5, the locking means of each arm 9 can comprise at least one adjustment lever 24 suitable for locking the arm 9 in the lowered horizontal position and unlocking the arm 9 from said position before the movement in its raised vertical position. The lever 24 controls the movement of a locking element 25 designed to lock the arm 9 in the lowered horizontal position. The locking element 15 can be made in the form of a locking pin that can be secured in a respective locking seat. Therefore, in operation, when the stabilizer arm 9 is moved from the raised position towards the horizontal stabilization position, once the horizontal final position has been reached, the lever 24 must be actuated to lock the arm 9 in that position. Vice versa, before moving the stabilizer 9 towards the raised position, the adjustment lever 24 must be actuated to release the locking element 25.

[0070] Similarly, the locking means can further comprise further adjustment elements 29 suitable for locking a respective stabilizer arm 9 in the raised vertical position.

[0071] According to a further feature, each stabilizer arm 9 can comprise an elastic resistance mechanism adapted for coming into contact with at least one part of the arm 9 during a final phase of the lowering maneuver of the arm 9, from the raised position to the lowered horizontal position. This elastic resistance mechanism is designed to signal to the operator that the horizontal final position has actually been reached, before actuating the locking means.

[0072] According to the embodiment illustrated in figures 5-6B, the elastic resistance mechanism is included inside the support portion 6’ of the frame 6 suitable for supporting the stabilizer arm 9.

[0073] This mechanism can include a cam element 26 operatively associated with a compression resistant spring 27 extended along a horizontal direction substantially parallel to the longitudinal axis of the arm 9 in the lowered horizontal position. The cam element 26 is pivotally connected around an articulation axis II, to rotate from a raised position of maximum space illustrated in Figure 6A to a lowered position of minimum space illustrated in Figure 6B, and vice versa. In its raised position, the cam element 26, for example having a substantially trapezoidal shape, is configured to keep the stabilizer arm 9 slightly raised with respect to its horizontal final position, through contact between an upper portion 26’ of the cam element 26 protruding towards the arm 9 and the lower surface of the arm 9. To lock the arm 9 in the final lowered position, the operator will therefore have to exert a final pressure force on the arm 9 to overcome the resistance of the cam element 26 and the spring 27 associated with it.

[0074] According to a further feature still illustrated in figures 6A, 6B, each stabilizer arm 9 also comprises an auxiliary sensor 28 configured for detecting the displacement of the cam element 26 in the lowered position of minimum space. This auxiliary sensor 28 is configured to send an acknowledgment signal to the control unit, regarding the locking in the final horizontal stabilization position of the arm 9, which will enable the operation of the automatic leveling assembly 13 previously described.

[0075] It will therefore be appreciated that the elastic resistance mechanism included in each arm 9 also performs a safety function aimed at preventing the stabilization of the unit 1 with arm 9 not correctly stabilized in its horizontal final position.

[0076] Thanks to the features described previously, the mobile robotic unit according to the invention allows to achieve a series of important advantages, comprising:

[0077] - providing high flexibility and efficiency properties with regard to the stabilization of the vehicle before performing processing;

[0078] - being extremely intuitive for the operators who control it, providing stabilization means that are particularly simple to implement and equipped with safety functions; and

[0079] - making the movement of the mobile robotic unit extremely easy, even passing through spaces having a limited width.

[0080] According to a further optional feature, the feet 8 can be in the form of electromagnetic elements, which can be activated after being placed on a floor made of ferromagnetic material, in order to stably anchor the feet themselves to the floor, when it is necessary to carry out operations which involve the application of significant forces tending to generate by reaction a tendency for the vehicle to move from its correct position.

[0081] Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what has been described and illustrated, without thereby departing from the scope of the present invention, as defined in the attached claims.

Claims

CLAIMS1. A mobile robotic unit (1 ) for performing industrial processing operations within a work environment, comprising:- a multi-axis manipulator robot (2) carrying an operating head (4) arranged to perform one or more of said operations,- a vehicle (3) comprising a frame (6) carrying said robot (2) and advancing means (7) configured for moving the vehicle (3) on the ground, characterized in that:- the vehicle (3) comprises a plurality of retractable stationing feet (8) supported by respective stabilizer arms (9) extending from the frame (6),- each stabilizer arm (9) comprising an automatic leveling assembly (13) associated with the retractable stationing foot (8), configured for detecting the contact position of the stationing foot (8) with the ground, and stopping a lowering maneuver of the foot (8) in case of contact with the ground before reaching a stroke end position.

2. The mobile robotic unit (1 ) according to claim 1 , characterized in that said vehicle (3) is configured to be wire-guided or remote-controlled by an operator or equipped with autonomous driving, so as to be movable close to a predeterm ined work area of the work environment, and therefore locked in that position before performing a process.

3. The mobile robotic unit (1 ) according to claim 1 , characterized in that the automatic leveling assembly (13) comprises:- a screw-nut screw coupling comprising a screw (14) axially extended along the stabilizer arm (8) and a nut screw (15) slidably engaged on the screw (14),- at least one actuator (16) for driving in rotation the screw (14),- a bushing (17) freely movable along the screw 14 and spaced apart from the nut screw (15),- at least one connection element (18) provided for mechanically connecting the bushing (17) and the nut screw (15),- wherein the bushing (17) is connected to the stationing foot (8) by means of a drive mechanism (20) of the foot kinematic arranged for driving the movement of the foot (8) between a raised position with respect to the ground and a lowered position in contact with the ground, and vice versa,and- at least one sensor (21 ) adapted for detecting the approach of the nut screw (15) to the bushing (17) following contact of the stationing foot (8) with the ground, in order to stop the actuator (16) and the lowering maneuver of the foot before reaching a stroke end position of the nut screw (15).

4. The mobile robotic unit (1 ) according to claim 3, characterized in that said sensor (21 ) is a contact sensor or a proximity sensor, configured for detecting the contact or the approach above a threshold value between the nut screw (15) and the bushing (17).

5. The mobile robotic unit (1 ) according to claim 3 or 4, characterized in that the mechanical connection element (18) is provided by a plurality of connection screws arranged radially around the screw (14) and axially extended between the bushing (17) and the nut screw (15).

6. The mobile robotic unit (1 ) according to any one of claims 3-5, characterized in that the automatic leveling assembly (13) comprises an elastic element (19) interposed between the nut screw (15) and the bushing (17).

7. The mobile robotic unit (1 ) according to claim 3, characterized in that the drive mechanism (20) of the foot kinematic is substantially a pantograph mechanism comprising a pair of levers mutually and pivotally connected around at least one articulation axis (I).

8. The mobile robotic unit (1 ) according to claim 7, characterized in that each pair of levers comprises:- a first lever (22) having a lower end carrying the stationing foot (8) and an upper end connected to the bushing (17) freely movable along the screw (14);- a second lever (23) having a lower end pivoted to the first lever (22) substantially at an intermediate position of the first lever, and an upper end pivoted to a terminal end of the stabilizer arm (9).

9. The mobile robotic unit (1 ) according to any of the preceding claims, characterized in that the stabilizer arms (9) are configured as movable between a lowered horizontal position to enable contact with the ground by means of the stationing feet (8), and a raised position substantially extended along a vertical direction with respect to the ground,to enable easily passing of the vehicle (3) through openings of limited width.

10. The mobile robotic unit (1 ) according to claim 9, characterized in that each stabilizer arm (9) comprises locking means which can be activated to lock the arm (9) into at least one of the lowered position and the raised position, and deactivated to enable movement of the arm (9) from one of the aforementioned positions to the other.

11. The mobile robotic unit (1 ) according to claim 10, characterized in that each stabilizer arm (9) comprises an elastic resistance mechanism adapted for coming into contact with at least one part of the arm (9) during a terminal phase of the lowering maneuver of the arm (9), so as to signal to the operator the achievement of the final position, before actuating the locking means.

12. The mobile robotic unit (1 ) according to claim 11 , characterized in that the elastic resistance mechanism comprises a cam element (26) operatively associated with a compression resistant spring (27), the cam element (26) being pivotally connected around an articulation axis (II), to rotate from a raised position of maximum space adapted for keeping the stabilizer arm (9) raised with respect to its horizontal final position, to a lowered position of minimum space adapted for locking of the arm (9), and vice versa.

13. The mobile robotic unit (1 ) according to claim 11 , characterized in that each stabilizer arm (9) comprises an auxiliary sensor (28) configured for detecting the displacement of the cam element (26) in the lowered position of minimum space, and sending an acknowledgment signal that the arm (9) has been locked into the horizontal final position.

14. The mobile robotic unit (1 ) according to claim 13, characterized in that said auxiliary sensor (28) is programmed for enabling the operation of the automatic leveling assembly (13)15. The mobile robotic unit (1 ) according to claim 1 , characterized in that the feet (8) are electromagnetic.

Images