Multi-level detection devices for safety devices for industrial machine or factory control

Abstract

A detection device for a safety apparatus for controlling an industrial machine or plant includes a read head adapted to associate with the receiving device of the safety apparatus to receive a presence signal including the identification code after positioning one of the movable actuators at a predetermined minimum distance from the read head, and a processing circuit integrated within the head, the processing circuit adapted to generate a plurality of output signals corresponding to respective command or signaling functions for one or more parts of the machine or plant, the processing circuit adapted to associate an individualized combination of the output signals with each of the identification signals for execution of each combination of functions determined for one or more of the movable actuators.

Description

[Technical Field]

[0001] The present invention relates to applications in the field of industrial electrical devices and is particularly aimed at multi-level detection devices for safety equipment designed for the control of industrial machines or plants, in particular their moving parts (e.g. access to safety perimeters).

[0002] The invention also relates to safety equipment including one or more of such detection devices and designed for the control of machines or industrial plants.

[0003] (Publicly known technology) As is known, in industrial machines and factories, various controls are commonly used, which allow intervention in one or more functions after receipt of a specific signal by the control system in operation.

[0004] For illustrative purposes only, examples of actions that may result from detection of a signal include stopping or starting (momentarily or periodically) one or more parts, modifying the behavior of one or more parts of a machine or plant, or generating a signal (visual, luminous, or audible) indicating a warning or alarm.

[0005] Generally, a distinction can be made between two types of control systems, depending on whether they are for standard function management or for so-called fail-safe or safety functions (i.e. applications involving potentially hazardous conditions).

[0006] Typical examples of these control systems include safety panels and perimeter-associated safety devices used for access control within an operating area (e.g., safety switches specifically designed to generate a machine stop if the controlled access is opened).

[0007] A further type of device is the safety sensor, which is used to detect specific movements of one or more parts of a machine or plant and, if fail-safe, must decide to stop the machine even if only one abnormality is detected.

[0008] The most sophisticated of these safety devices, whether switches or sensors, often include a read head that is highly sensitive in receiving signals from a moving element (e.g., an access door or a moving element on a machine or plant) to distinguish its presence and determine if a safe condition has occurred.

[0009] The most common systems for signal transmission are RFID-type systems, in which the RFID signal is transmitted by a transponder, which is associated with the moving part and also with a unique code adapted for reading by an evaluation unit connected to a read head.

[0010] The purpose of this aspect is to perform a detection function suitable for reliable signal transmission by the transponder in communication with the read head, thereby avoiding the possibility of interference by unauthorized parties.

[0011] In this way, the evaluation unit can use the signal and the associated unique identification code to establish which transponders are in the vicinity of a given read head and what actions are permitted for those transponders and associated moving parts to cause the expected behavior to occur.

[0012] These reading and recognition systems may also be designed to interact with transponders associated with portable actuators (eg, tokens) in the possession of an operator.

[0013] In this way, an authorized operator can send an identification signal to the evaluation unit by approaching a token or other device equipped with a transponder, and the evaluation unit will proceed with the action provided for that particular code only if it recognizes the identification code.

[0014] The system disclosed in US9423784 detects the safe installation status of an automated system with multiple sensors adapted to distinguish between different states of the system (both standard and fail-safe) and generates different actions based on the type of signal detected.

[0015] In particular, the system includes both a sensor having a read head that receives signals related to unsafe conditions and a sensor that is used to receive signals related to safety functions.

[0016] Additionally, the sensor used for the fail-safe function may also communicate with an operator operated token to verify that the operator is authorized to enter the safety perimeter of the system and, if so, grant access, resulting in a machine stop.

[0017] These sensors are connected to the same control unit which is adapted to distinguish between the types of sensors and to send signals to the system based on the inputs received as a result.

[0018] However, a limitation of known solutions is that although the read head is enabled to recognize a single identification code or even a larger number of identification codes, the actions it produces are always the same and therefore the final output is always the same.

[0019] Conversely, the device used to receive the signal cannot be programmed to produce different actions depending on the code of the incoming signal.

[0020] From the above-mentioned state of the art, systems for managing access to work areas are also known, in which the authorization to enter a work area is generated as a function of a number of codes presented on a tag provided to the operator, which codes define the access authorization to this area and the skill level of the operator, in that certain actions are allowed or not depending on this skill level.

[0021] That is, in addition to being solely for operator control and not allowing customization of output management, these systems do not allow for output modification according to detected codes, but can only enable or disable certain features according to detected codes.

[0022] For example, the operator safety management system disclosed in US2009 / 072631 consists of various elements (eg, TAG, TAG reader, and analysis PLC).

[0023] The information contained in the tag is not evaluated at all by the TAG reader (i.e. by a sensor placed at the access location) and is transmitted to the PLC, which does not change its behavior depending on the detected TAG, but instead it is always the PLC that evaluates this data and decides on the corresponding action. Summary of the Invention

[0024] The object of the present invention is to overcome the above-mentioned deficiencies and to provide a detection device for safety equipment designed for the control of industrial machines or factories, which is characterized by high efficiency and relatively cost-effectiveness.

[0025] A particular object is to provide a detection device for safety equipment for the control of industrial machines or factories, whose behavior is adapted depending on an input signal.

[0026] Yet another object is to provide a detection device for safety equipment for the control of industrial machinery or factories that allows detecting different input signals and correlating different outputs.

[0027] A further object is to provide a detection device for a safety system for industrial machine or factory control that is user programmable.

[0028] These and other objects that will become more apparent hereinafter are achieved by a detection device as claimed in claim 1. The detection device as claimed in claim 1 may be associated with a safety apparatus, the safety apparatus including a receiving device adapted to be associated with a fixed part of a system or its safety perimeter, and a plurality of movable actuators, each adapted to transmit a respective presence signal including an identification code to the receiving device. The detection device includes a read head adapted to be associated with the receiving device of the apparatus to receive a presence signal including the identification code after positioning one of the movable actuators at a predetermined minimum distance from the read head, and a processing circuit integrated within the head. The processing circuit is adapted to generate a plurality of outputs corresponding to respective command or signaling functions for one or more parts of the machine or plant. The processing circuit is adapted to associate each of the identification signals with a customized combination of the output signals for execution of each combination of the determined functions for one or more of the mobile actuators.

[0029] Thanks to this combination of features, the same detection device (e.g., integrated into a switch or sensor) located on a particular part of the factory is adapted to transmit different signals based on the detected identification code.

[0030] Such uniqueness allows different responses to be set depending on the detected code, thus allowing, for example, different behaviors to be associated with different positions of the moving parts of the machine or plant.

[0031] As a typical, non-limiting example, according to two RFID tags in opposite positions that may be associated with a moving part of the factory (e.g., a sliding door), detection of one or the other tag may be associated with different states of the moving part and (consequently) different operating modes of the safety device.

[0032] Advantageous embodiments of the invention are obtained according to the independent claims. [Brief explanation of the drawings]

[0033] Further features and advantages of the present invention will become more apparent in view of the following detailed description of certain preferred and non-exclusive embodiments of systems integrating one or more devices according to the present invention, which are shown for purposes of illustration and not limitation and are provided in conjunction with the accompanying drawings, in which:

[0034] [Figure 1] 1 is a schematic diagram of an industrial plant with a safety perimeter in which the device according to the invention is applied; [Figure 2] 1 is a front view of a robot arm to which a device according to the present invention is applied; [Figure 3] FIG. 3 is a schematic top view of the robot arm of FIG. 2. [Figure 4] Schematic operating sequence of the device, showing the command associated with each position in a relative table. DETAILED DESCRIPTION OF THE INVENTION

[0035] (Best Mode for Carrying Out the Invention) The multi-level detection device for safety equipment according to the present invention is particularly designed to be associated with safety equipment used in the control of industrial machines or plants or parts thereof.

[0036] For purposes of example, and in accordance with the methods described in more detail below, safety equipment with detection devices may be associated with moving parts of a factory that are inherently dangerous, or may include panels, safety barriers, or other systems (used to control a safety perimeter to allow safe access within the perimeter at all times).

[0037] In a further application, one or more detection devices are added to a machine that is provided with moving parts (such that a sensor is located on a fixed part and one or more actuators are located on a dangerous moving part), as will be explained more clearly below.

[0038] In its most common configuration, the safety apparatus includes a receiving device adapted to be associated with a fixed part of the plant or its safety perimeter, and a number of movable actuators adapted to be attached to a movable part of the machine or plant or a possible protective barrier.

[0039] These moving parts are adapted to selectively interact with a receiving device to transmit a respective presence signal containing a unique identification code to the receiving device, whereby said interaction results in the transmission of a particular output signal suitable for controlling a corresponding portion of the machine or plant or control circuit (e.g., a power circuit and / or a service circuit).

[0040] The recognition device therefore essentially comprises a readhead adapted to be associated with a receiving device of the safety device so as to receive a presence signal comprising an identification code from one of the actuators interacting with the receiving device each time the movable actuator is positioned at a predetermined minimum distance from the readhead.

[0041] The interior of the read head is integrated with processing circuitry adapted to generate a number of output signals corresponding to respective command or signaling functions for one or more parts of a machine or plant.

[0042] In particular, according to a particular feature of the invention, the processing circuitry is adapted to associate each identification signal with a customized combination of output signals stored therein for execution of the determined combination of functions for one or more of the movable actuators.

[0043] In this way, each actuator is associated with a particular combination of functions (and possibly even a single function) that are activated for one or more portions of the machine or plant and / or associated control, power circuits and / or service circuits.

[0044] The functions managed by the device can be either unsafe or standard (i.e., functions related to actions that are not dangerous to the operator but may be manufacturing defects), and safe or fail-safe (i.e., functions that prevent the operator from gaining access to the perimeter without shutting down the machine or plant or part thereof).

[0045] The processing circuit may be provided with a preset scheme during the manufacturing step, but more preferably the processing circuit is user or manufacturer programmable, allowing each user to associate a particular operating mode with each position of the moving part to be controlled according to their particular needs.

[0046] The combinations of various signals and functions that can be associated with each code are multiple and vary depending on the type of machine or plant.

[0047] For purposes of example only, the command signals generated by the processing circuitry may be commands for one or more standard and safe output activation / deactivation, commands for activating lights, commands for visual and / or audio signals, commands for activating or deactivating OSSD (Output Signal Switching Device) outputs, and commands for simultaneous transmission (on a unidirectional or bidirectional serial output or on a unidirectional or bidirectional safety bus) of codes to distinguish between different actuators.

[0048] In a first exemplary application, a safety device of the safety switch type with an associated detection device is adapted to be placed at an access of a safety perimeter of a machine or plant and comprises switching means suitable for switching one or more parts of the machine or plant from an operational state to a non-operational state (after opening or closing of the access controlled by the safety switch).

[0049] Examples of this safety switch are disclosed in WO2017208124 or WO2018055598, which always have the same applicant's name. In these documents, the switch is also provided with a door locking mechanism.

[0050] In such an application, the receiving device is adapted to be anchored to a fixed part of the access to be controlled, while one of the actuators is adapted to be anchored to a movable part of the access.

[0051] The switching means included in the receiving device is adapted to be operatively connected to one or more electric and / or electronic circuits for powering and / or controlling main and / or service and emergency circuits and / or a monitoring or control system for access to hazardous areas.

[0052] The switching means may be selected from those commonly used in the art and may vary (without any particular limitation) depending on the functionality of the switch.

[0053] The receiving device also includes operating means adapted to interact with the switching means when opening or closing access for opening or closing one or more circuits of the machine or plant occurs after an interaction between the switching receiving device and one of the actuators, again in accordance with known techniques.

[0054] In particular, the actuator arranged on the movable part is designed to interact with the switching means through the operating means (after the access has been opened or closed), thereby determining the opening or closing of one or more circuits according to the typical method for such safety switches.

[0055] According to a particularly preferred embodiment, the read head houses a receiver with an antenna of the RFID type (Radio Frequency Identification), while the actuator is a tag / RFID type transponder adapted to transmit a respective presence signal.

[0056] Alternatively, the transponder and RFID antenna may be replaced by a communication system selected from data transmission devices whose operation is via radio, Hall effect, magnetic fields, ultrasound, etc.

[0057] On the other hand, in a second particularly preferred embodiment, the receiving device is a sensor or is integrated into a sensor (for example of the kind described in WO2013098788) with an integral read head and the actuator is always associated with one or more moving parts of a machine or plant.

[0058] That is, the information contained in the tag is evaluated by sensors placed in the access, which therefore directly change their behavior depending on the tag detected.

[0059] Also in this case, in a preferred embodiment, the readhead includes an RFID antenna, while the actuator is an RFID tag.

[0060] FIG. 1 shows a first application of the device according to the invention.

[0061] In particular, the illustrated system 1 comprises a machine 2 arranged within a barrier or protective perimeter 3. The barrier or protective perimeter 3 comprises a movable access 4 associated with a detection device according to the present invention.

[0062] In this case, the detection device comprises, for example, a fixed sensor or read head 5 located on a fixed portion of the barrier 3 to selectively interact with two movable sensors 6 and 7 located on the access 4 in positions to distinguish between two different positions of the access 4 (i.e., closed and fully open access).

[0063] In this embodiment, the detection device is connected by a bus 8 to an mt 9 (possibly with a PLC 10 for its programming) for monitoring and control of the access 4 (i.e. to a security system to ensure that all safe conditions are observed for interaction with the power and / or signal communication circuits 11 of the machine 2), so as to intervene and interrupt the operation of the machine 2 or parts thereof or send a predetermined signal if an unsafe condition is detected.

[0064] In the illustrated example, the possible operating modes allow the opening of access 4, for example allowing input by one or more operators into periphery 3, which determines an interruption of communication between fixed sensor 5 and first movable actuator 6, resulting in a machine stop.

[0065] When the access 4 is fully open, a second movable actuator 7 corresponds to the fixed sensor 5, which allows the operator to insert his or her unique tag or identification code into an appropriate safety control unit 12 of the access 4 (which is also connected to power and / or signal circuits 11) (to perform some action on the machine 2, such as slow safe movement or connection of an enabling switch or further safety operation).

[0066] In this state, the access 4 remains open to allow the operator to exit the perimeter 3 at all times.

[0067] To avoid accidental or negligent closure of access 4 while an operator is still within perimeter 3 (resulting in an unsafe restart of machine 2), when fixed sensor 5 detects no contact with second movable actuator 7, it blocks all slow movement and queries safety control unit 12 for tags entered by all operators (to allow restart of machine 2 only after all of the above tags have been received and to confirm that all operators have left perimeter 3).

[0068] The secure control unit 12 of the access 4 may be a unit distinct from the various sensors as shown, or may be integrated with the fixed sensors 5 .

[0069] On the other hand, in FIG. 3, an application in which the device of the present invention is applied to a robot arm is illustrated.

[0070] In this application, the device has a fixed sensor 13 adapted to selectively interact with three separate movable actuators 14, 15 and 16 associated with different portions of a movable arm 17, such that each position of the arm 17 corresponds to an interaction of the fixed sensor 13 with a different movable actuator and resulting action.

[0071] In the table of FIG. 4, the possible actions associated with the interaction between the fixed sensor 13 and the different movable actuators 14, 15 and 16 are shown.

[0072] For example, interaction between the fixed sensor 13 and the central movable actuator 14 may result in activation of two outputs OS1 and OS2 and resulting mechanical movement, while the auxiliary signaling output O3 is turned off. The signaling light 18 present on the fixed sensor 13 will be a first color.

[0073] After the rotation of the arm 17 has transported one of the two movable lateral actuators 15 at the fixed sensor 13 (which may for example correspond to an unsafe state of the movable arm 17), the two outputs OS1 and OS2 may be deactivated and a signal may be sent by an auxiliary output O (configured as a serial bus) with the possible generation of a text string and different coloring of the signal communication light 18 present on the fixed sensor 13.

[0074] If the arm 17 rotates in the opposite direction and the other of the two movable lateral actuators 16 corresponds to the fixed sensor 13 (which may correspond to a safe state of the movable arm 17), activation states of the two outputs OS1 and OS2 and transmission of a signal by the auxiliary output O3 become possible, possibly generating further text strings and further contextually different colorings of the signal communication light 18 located on the fixed sensor 13.

[0075] Obviously, the number of movable actuators may be varied (e.g., increased) to distinguish between different numbers of positions of the movable parts of the system and to associate specific combinations of behaviors with each position (according to a scheme that may also be customized by the end user or manufacturer).

Claims

1. 1. A detection device for a safety arrangement for the control of industrial machinery or plant, the safety arrangement comprising: a receiving device adapted to be associated with a fixed part of the machinery or plant or its safety perimeter; and a plurality of movable actuators each adapted to transmit a respective presence signal to the receiving device together with a unique identification code of the presence signal, the detection device comprising: a read head adapted to be integrated with the receiving device of the safety device to receive a presence signal including the identification code after positioning one of the movable actuators at a predetermined minimum distance from the read head; a processing circuit integrated within said readhead, said processing circuit adapted to generate a plurality of output signals corresponding to respective command or signalling functions for one or more parts of said machine or plant; Including, wherein the processing circuitry is adapted to generate an individualized combination of the output signals for each of the presence signals for execution of each combination of the functions determined for one or more of the movable actuators.

2. 10. The device of claim 1, wherein the processing circuitry is programmable and customizable by a user and / or a manufacturer.

3. 2. The device of claim 1, wherein the processing circuit is adapted to activate or deactivate a system OSSD (Output Signal Switching Device) output and to transmit, on a serial output or safety bus, codes for distinguishing between different movable actuators.

4. 4. A device according to claim 1, wherein the read head contains a receiver selected from an RFID type antenna, a magnetic or electromagnetic sensor, an optical sensor, via radio, via Hall effect, via ultrasound.

5. A safety device for controlling a machine or industrial plant, comprising: a receiving device adapted to be placed on a fixed part of the machine or plant or on a protective barrier of said machine or plant; a plurality of movable actuators adapted to selectively interact with said receiving device to transmit respective presence signals to said receiving device, each presence signal including its unique identification code; an identification device associated with said receiving device and having a read head, said read head adapted to receive said presence signal including said identification code after positioning one of said movable actuators at a predetermined minimum distance from said read head, and a processing circuit integrated within said read head, said processing circuit adapted to generate, also via a safety bus, a plurality of output signals corresponding to respective command or signaling functions for one or more parts of said machine or plant; Including, the processing circuitry is adapted to generate an individualized combination of the output signals for each of the presence signals for execution of each combination of the functions determined for one or more of the movable actuators. A safety device characterized by:

6. 6. The safety arrangement of claim 5, wherein the receiving device is selected from a safety proximity switch and a safety proximity sensor, whether or not the door is equipped with a door locking mechanism.

7. 6. A safety arrangement according to claim 5, wherein the receiving device is a sensor with an integral read head and the movable actuator is associated with one or more moving parts of a machine or plant.

8. 6. A safety device according to claim 5, characterized in that the receiving device is a safety switch adapted to be placed at an access of the safety perimeter of the machine or plant and equipped with switching means suitable for switching one or more parts of the machine or plant between an operational state and a non-operational state after opening and closing of the access served by the safety switch.

9. 9. A safety device according to claim 8, characterized in that at least one of the movable actuators is associated with a movable part of a security perimeter adapted to close the access and transmit a presence signal to a read head when the access is closed.

10. 10. The safety device of claim 9, wherein each of the movable actuators includes a respective tag / RFID (Radio Frequency Identification) transponder adapted to transmit the respective presence signal or a transmitter selected from a data transmitting device operating via radio waves, via Hall effect, via magnetic field, or via ultrasound.

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