Working device

Abstract

To provide a highly versatile operating device.SOLUTION: An operating device configured to operate in a workspace, comprises: a robot arm, which comprises a succession of arm elements mounted on one another in a rotatable way about respective axes of rotation and which carries an operation unit on its end; and at least one presence sensor prearranged for detecting the presence of an operator. The device is characterized in that it includes a positioning system, comprising a support by which the at least one presence sensor is carried and which is mounted on an arm element of the robot arm, according to a pre-set orientation and in such a way as to be orientable with respect to the arm element, and wherein the positioning system further comprises a positioning unit prearranged for rotating the support with respect to the arm element, as a result of a movement of the robot arm, so as to keep the pre-set orientation of the support unchanged.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a work device preset to operate in a work area accessible to work staff.

Background Art

[0002] In this context, there are known technical solutions that guarantee the safety of work staff or other operators. This is assumed to monitor the surrounding area of the work device and, when an operator approaching the device is detected, put the device in a stopped state or a low-speed operation mode.

[0003] This solution generally assumes that a plurality of presence sensors are present at a plurality of positions around the device so as to provide one or more monitoring areas.

[0004] On the other hand, in this art, work devices preset for comprehensive safety, especially for continuous human-machine interaction, are also known. This is generally referred to as a "collaborative robot", and various types of sensor systems (for example, composed of a force sensor, a proximity sensor, a contact sensor, or a combination thereof) are integrated therein. The system detects and recognizes commands for the device issued by the operator directly acting on the robot.

[0005] Considering the fact that the above-described first type of known solution may frequently require rearrangement and reprogramming of the presence sensors for reconfiguration of the monitoring area when a new task assigned to the work device, it has a drawback of being considerably low in versatility.

[0006] On the one hand, the solution with a collaborative robot has the drawback of being quite complex and similarly costly due to the means necessary for the robot to be directly and instantaneously interactive with the operator. However, this type of solution has not been proven to be capable of meeting the demand for industrial lines operating in high-production cycles.

[0007] Finally, a monitoring system for a robotic arm is also known from document number WO2018 / 145990A1, which combines a solution of providing a plurality of presence sensors around the robotic arm to define a given monitoring area with a solution of providing a presence sensor on the working unit of the robotic arm itself to define a movable monitoring area that is fixed to the working unit. This solution has the drawback of being of rather low versatility for the same reasons as those stated for the first type of known solution described above. Furthermore, it has been confirmed that the monitoring operation performed by the movable sensor provided on the working unit of the robot is not at all effective with respect to the purpose of guaranteeing a high level of safety to the operator.

Summary of the Invention

[0008] In this context, an object of the present invention is to provide a working device capable of eliminating the above-mentioned drawbacks.

[0009] The above object is achieved by a working device having the features described in claim 1.

Brief Description of the Drawings

[0010] Further features and advantages of the present invention will become apparent from the following description and the following attached drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0011] In the following description, various specific details are shown, but they are for the purpose of deeply understanding the embodiments.

[0012] The embodiments can be realized without one or more of the specific details, or can be realized by other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail so that various aspects of the embodiments are not obscured. The reference numerals used in this specification are provided merely for convenience. Therefore, they do not define the scope of the protected area or the embodiments.

[0013] As announced at the beginning, the present invention relates to a work device preset to operate in a work area accessible to the work staff.

[0014] The present invention is provided particularly in relation to applications in the fields of manufacturing and packaging in the food industry. However, the same teachings provided below can be applied to any other industrial field.

[0015] Generally, referring to FIGS. 1 to 4, the work device described in this specification includes a robotic arm 10 that carries a work unit 12 at its end.

[0016] The robot arm 10 includes a series of arm elements 10i (exemplified as the arm elements shown as 10I, 10II, and 10III). These are mutually coupled rotatably about their respective rotation axes Xi (exemplified as the rotation axes shown as X1, X2, and X3), and are driven individually or a plurality of elements are driven simultaneously so as to move the working unit 12 in space.

[0017] In the illustrated example, the robot arm 10 is an articulated robot arm having six rotation axes. The illustrated robot arm is provided merely by way of example in any case. In fact, the working device described in this specification can assume several other types of robot arms, such as humanoid robots, SCARA robots, etc., which have or do not have a seventh translational axis for displacement of the robot between different workstations.

[0018] Referring again to the illustrated example, the robot arm 10 is preset to operate within the working space L in order to execute one or more tasks.

[0019] As described above, the solution described in this specification has been devised particularly in relation to the fields of manufacturing and packaging in the food industry. In this regard, the described tasks can relate, for example, to the processing, handling, and placement of products and / or parts of products, and / or packages and / or parts of packages, and / or manufacturing means and / or packaging means.

[0020] The working device can furthermore be operatively associated with other devices or machines for task execution, referred to as conveying devices such as, for example, conveyor belts, pallets, trolleys, benches, or further working devices.

[0021] For example, the working device described in this specification can be used for the lifting and placing operations of products.

[0022] In general, it should be understood that the use of the working device described in this specification is not limited to only the field of the food industry and can relate to any other field.

[0023] The working device described in this specification further comprises at least one presence sensor 14 for detecting the presence of a person or an object. As shown in more detail below, one or more sensors 14 determine a monitoring volume.

[0024] Compared with the prior art, the device described in this specification is characterized in that at least one presence sensor is carried by the robot arm itself by an arrangement system that can continuously maintain the presence sensor in a preset orientation regardless of the movement of the robot arm 10 within its working space L for task execution.

[0025] Generally, the described arrangement system comprises a support part on which at least one presence sensor 14 is carried and is orientably attached to an element 10i of the robot arm, and an arrangement unit preset to rotate the support part relative to the attached arm element 10i in response to the movement of the robot arm in order to maintain the same orientation of the support part.

[0026] Specifically referring to the illustrated example, the arrangement system comprises a support part 22 in which a plurality of sensors 14 are provided in two parallel rows. Specifically, the support part 22 is composed of a plate bent in a U shape having a base 22A and two side parts 22B orthogonal to the base 22A and facing each other. The two rows of sensors are attached to the two side parts 22B of the plate.

[0027] In the illustrated embodiment, the positioning unit is constrained with respect to the robotic arm 10 and includes a four-bar linkage 24 that carries the support portion 22. The mechanism 24 operates to maintain the support portion 22, and thus the sensors 14 arranged thereon, in a preset orientation. Accordingly, the two rows of sensors 14 extend in respective vertical directions Z1, Z2 that are set to be spaced apart in the horizontal direction Y (FIG. 2). The sensors 14 are symmetric with respect to the direction Y and define monitoring volumes S1, S2 that extend on both sides of the robotic arm 10 and extend across the area alongside the robot from the edge of the work space L (FIG. 4).

[0028] Specifically, referring to FIG. 3, the four-bar linkage 24 includes a first lever 24I that is attached to the coupling interface between the arm element 10I and the arm element 10II and is fixed to the arm element 10I according to the horizontal orientation. The mechanism 24 further includes a second lever 24II that is attached to the coupling interface between the arm element 10II and the arm element 10III and is rotatable about the rotation axis X3 with respect to these two elements. The arm element 10III is attached to the arm element 10II so as to be rotatable about the same axis. Finally, the mechanism 24 includes a third lever 24III that is rotatably connected at both ends to the ends of the two levers 24I and 24II.

[0029] The lever 24II has an eccentric portion 24IIA to which the support portion 22 is fixed. The support portion 22 is horizontally set and oriented such that the two rows of sensors 14 are maintained in the respective vertical directions Z1, Z2.

[0030] In view of the above, those skilled in the art will understand that the mechanism 24 is preset to change the configuration of its levers in response to the movement about the rotation axis X2 of the arm element 10II so as to maintain the support portion 22 in its horizontal orientation.

[0031] In this regard, FIGS. 5A and 5B show the robot arm 10 in a first state set such that the arm element 10II is inclined and oriented at an angle of about 20° with respect to the vertical, and in a second state set such that the arm element 10II is inclined and oriented at an angle of about 45° with respect to the vertical, respectively. From these figures, it is clear that the change in the position of the arm element 10II changes the configuration of the mechanism 24. As a result, the support portion 22 rotates with respect to the arm element 10II so as to maintain a horizontal state.

[0032] Due to the above-described operation mode of the system for arranging the sensor 14, the monitoring volumes S1 and S2 are always maintained in a state adapted to the working space L.

[0033] It should be understood that the above-described arrangement unit constituted by the four-bar link mechanism 24 is merely exemplary.

[0034] In fact, it may be implemented in another configuration that performs the described function of maintaining the same orientation of the sensor 14.

[0035] For example, according to another embodiment shown in FIG. 6, the arrangement unit is constituted by a gyroscope system 44. The system includes a rotor 44I rotatably attached about a rotation axis I, and a movable frame 44II that carries the rotor 44I and defines one or two vibration axes. The rotation axis I can be oriented in space about the vibration axis. The support portion 22 is fixedly attached to the module of the movable frame that carries the rotor 44I.

[0036] According to the characteristic operation mode of the gyroscope system, the rotation axis I, and thus the support portion 22, is maintained in a preset orientation by the angular momentum generated by the continuous rotation of the rotor 44I about the rotation axis I, regardless of the movement for performing the task assigned thereto by the robot arm 10.

[0037] According to a further modification (shown in FIG. 7), the positioning unit includes an actuator 54 that moves the support portion 22 relative to the arm element to which it is attached, and a control unit (not shown) configured to control the actuator 54 based on a signal indicating the position within the space of the arm element so as to maintain the support portion 22 in a preset orientation.

[0038] In view of the above, it will be understood that the above-described preset orientations of the support portion 22 and the sensor 14 are preferably generally in a "horizontal" orientation. Thereby, the positioning unit is preset so as to intervene to maintain the above-described orientation from changing due to any movement of the arm element carrying the support portion 22 about a general non-vertical axis (note that the "horizontal orientation" here does not necessarily mean that the support portion and / or the sensor are arranged horizontally, but rather indicates a state related to the horizontal plane, and it is understood that the distance from any point of the support portion and the sensor to this plane is assumed to be fixed and invariant). On the other hand, the positioning unit does not intervene during movement about the vertical axis or during linear movement of the arm element, i.e., during movement that cannot change the above-described preset orientation.

[0039] In any case, the preset orientations of the support portion 22 and the sensor 14 can be of some other type, and an embodiment can also be envisioned in which the positioning unit is preset to maintain this other orientation in accordance with the above-described form.

[0040] It should be understood that it is advantageous for the support portion 22 to be attached to the apex of the robotic arm 10 arranged to operate within the working space L. Thereby, the sensor 14 can determine monitoring volumes S1, S2 for monitoring a relatively long extending region at a considerable distance from the working space L.

[0041] Generally, the solutions described herein contemplate the determination of at least one monitoring volume defined by at least one presence sensor carried by the above-described placement system. The number, shape, and dimensions of the monitoring volume can vary depending on the particular application.

[0042] The illustrated monitoring volumes S1, S2 are generally in the shape of a spherical sector (Figure 4). These are each formed as a set of sections (S1I, S1II, S1III and S2I, S2II, S2III) determined by a single sensor 14 respectively.

[0043] With particular reference to monitoring volume S1, a first section S1I, a second section S1II, and a third section S1III are included. Each section has a conical shape and is oriented by its geometric axis according to an angle defined with respect to the horizontal plane of the floor. The same angle gradually increases from the first section to the third section. The first section S1I is preset to identify the possibility of the operator's presence directly adjacent to the work space L. On the other hand, the second section S1II defines an intrusion area A1 into the monitoring area. This area is located at the maximum distance from the work space L, and it is possible to detect that the operator is approaching the work space through this area. The upward-facing third section S1III is preset to detect any objects from above approaching the work space L (for example, an overhead conveying system such as an overhead traveling crane or a suspended conveying line).

[0044] The monitoring volume S2 is formed by sections S2I, S2II, S2III of the same form.

[0045] In view of the above, it is clear that it is possible to provide a monitoring volume of any shape by combining a given number of sections determined by the corresponding number of presence sensors 14. On the other hand, it is also possible to provide a monitoring volume formed by a single section determined by a single presence sensor 14.

[0046] Sensor 14 can be of any known type suitable for the above-mentioned purpose. For example, the corresponding sensor can be a module that transmits and receives electromagnetic waves and is preset to determine the position and / or velocity of an object. This is achieved by analyzing one or more characteristics of the signal generated by receiving the electromagnetic wave transmitted by the module and reflected by the object itself. This wave can be, for example, a radio wave or a microwave. Commercially available sensor types suitable for the described purpose include the safety radar sensor LBK (registered trademark) manufactured by LEUZE. Another type is composed of a position and displacement laser sensor.

[0047] Those skilled in the art will understand that the (above-mentioned) section of the monitoring volume is determined by the beam of the electromagnetic wave emitted by the emitter and receiver modules. Therefore, the dimensions and shape of the section depend on the type of sensor used.

[0048] As a known method, during operation, the monitoring volume provided by the device is used to construct the safety status of the personnel of the work staff who can approach or access the work space L.

[0049] Specifically, the control unit 100 of the device can be configured to control different operating states of the robotic arm 10 according to the signal from the sensor 14. The criteria and forms for intervening in the operation of the robotic arm 10 can be constructed according to the criteria currently adopted in various countries and various work fields.

[0050] For example, referring to the applications shown in FIGS. 1 to 4, the control unit 100 of the device can control the operation of the robotic arm 10. This results in control according to the low-speed displacement mode at the moment when the sensor 14 detects that the operator crosses the intrusion area A1, and a full-stop command for the robotic arm 10 is issued at the moment when the sensor 14 detects the presence of an operator in the work area close to the work space L monitored by the monitoring volume S1I.

[0051] Of course, without detracting from the principles of the present invention and without departing from the scope of the present invention as defined by the appended claims, the details of construction and embodiments may vary greatly from those purely described and illustrated by way of example.

Claims

1. A work device configured to operate within a work space, comprising: A robotic arm having a series of arm elements attached to each other so as to be rotatable about respective axes of rotation, and carrying a work unit at its end; At least one presence sensor preset to detect the presence of an operator; The work device comprises an arrangement system that carries the at least one presence sensor and has a support portion attached to an arm element of the robotic arm in a preset orientation so as to be orientable with respect to the arm element, and the arrangement system further has an arrangement unit preset to rotate the support portion with respect to the arm element in response to the movement of the robotic arm so as to maintain the preset orientation of the support portion identical, a work device.

2. The work device according to claim 1, wherein the support portion is attached to an intermediate arm element of the series of arm elements of the robotic arm.

3. The robotic arm is an articulated robotic arm having a series of six arm elements attached to each other so as to be rotatable about six respective axes of rotation, and the support portion is attached to a second arm element starting from the base to which the robotic arm is attached. The work device according to claim 1 or 2.

4. The work device according to any one of claims 1 to 3, wherein the at least one presence sensor determines a monitoring volume oriented laterally with respect to the robotic arm and defines an intrusion area for detecting an operator approaching the work space.

5. The work device according to claim 4, comprising a plurality of presence sensors arranged relative to each other so as to form at least one monitoring volume having a given dimension and shape.

6. The work device according to any one of claims 1 to 5, wherein the presence sensor is a module for transmitting and receiving electromagnetic waves.

7. The work device according to any one of claims 1 to 6, wherein the arrangement unit is connected to the support portion and the arm element to which the support portion is attached, and operates to rotate the support portion with respect to the arm element in response to the movement of the arm element about each respective axis of rotation so as to maintain the support portion in the preset orientation, and has a four-bar linkage mechanism. Claim 8 The positioning unit according to any one of claims 1 to 7, having a gyroscope system that carries the support part and operates to maintain the support part in the preset orientation according to the movement of the robot arm. The working device described. Claim 9 The positioning unit according to any one of claims 1 to 8, having an actuator that moves the support part relative to the arm element to which it is attached, and according to the position of the arm element, to maintain the support part in the preset orientation. A control unit configured to control the actuator. The working device described. Claim 10 The working device according to any one of claims 1 to 9, comprising a control unit configured to drive the robot arm to a safe state according to a signal from the at least one presence sensor.

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