Safety system for securing off an action area of a production system

Abstract

The invention relates to a safety system for securing off an action area of a production system, which safety system comprises a control device and at least one non-contact protective device by means of which, in an operating mode of the safety system, the action area of the production system is delimited at a safety boundary by the formation of a protective field at a distance from the action area, and the safety system, in the event that the safety boundary is breached, can be put into an alarm state in which a control signal for the production system can be provided by the control device. The problem addressed by the invention is that of providing a solution for securing off possible no-entry zones behind action area boundaries created by non-contact protective devices. This problem is solved in that the position of the non-contact protective device (2.1, 2.2, 2.3), for securing off a no entry zone (4) of the production system formed in the operating mode by the distance between action area (1.1) and safety boundary (1.2), can be adjusted in a driven manner and the protective field (5.1a, 5.1b, 5.2a, 5.2b, 5.3a, 5.3b) generated by the non-contact protective device (2.1, 2.2, 2.3), in an initiation mode of the safety system, can be conducted over the no entry zone (4) at least in regions by the driven adjustability of the non-contact protective device (2.1, 2.2, 2.3).

Description

[0001] Safety system for securing an operating area of ​​a production facility

[0002] The invention relates to a safety system for safeguarding an action area of ​​a production plant, which comprises a control device and at least one contactless protective device, by means of which, in an operating mode of the safety system, the action area of ​​the production plant is limited at a safety boundary by forming a protective field spaced apart from the action area, and the safety system can be put into an alarm state in the event of a violation of the safety boundary, in which alarm state a control signal for the production plant can be provided by the control device.

[0003] The requirements for the safeguarding of production facilities have increased steadily with the increasing use of autonomous material supply systems (automated guided vehicles, "AGVs") and the resulting new interfaces between such systems and the production facility they supply. Operators and maintenance personnel must be able to rely on the safety of a machine or facility. A multitude of laws, guidelines, and regulations, such as the DIN EN ISO 13849 standard for machine safety, specify the minimum safety requirements that must be met by both machine manufacturers and users. In the case of production facilities, the operating area of ​​these facilities, including the intralogistics material supply systems, must be safeguarded in particular.The operating range of a production plant is determined in particular by the area covered during operation of the production plant, in particular by moving parts of the production plant.

[0004] The technical implementation is achieved, for example, by means of non-contact protective devices (ESPDs), which, depending on the technology, can monitor differently shaped protected areas and whose design is subject to the device standard DIN EN IEC 61496-1 - 2021-06. A non-contact protective device (ESPD) is a protective device that detects the intrusion of a body part into a protective field using sensors that operate without direct mechanical contact. It can be based on various physical principles:

[0005] - optical (light curtain, safety laser scanner, infrared motion detector, digital cameras together with pattern recognition or image comparison)

[0006] - acoustic (via ultrasound)

[0007] - inductive (inductive proximity switch, only for electrically conductive objects) capacitive (capacitive distance sensor, only for distances that are small compared to the sensor diameter)

[0008] Safety laser scanners, for example, function in such a way that a light beam generated by a laser periodically sweeps across a monitoring area with the aid of a deflection unit. The light is remitted by objects in the monitoring area and evaluated in the scanner. In pulse-based methods, which are preferred in safety technology, the laser scanner measures the time it takes for an emitted light pulse to be received again. Since the laser scanner obtains angle and distance information, two-dimensional positions of objects in a monitoring area and thus also in the protective field can be determined. If the laser scanner detects an impermissible intrusion into the protective field, it triggers an emergency stop of the machine. A safety laser scanner of this type is known, for example, from DE 43 40 756 A1.

[0009] There are a variety of applications for safety laser scanners, both in and outside of industrial production environments. For example, DE 20 2012 101 250 U1 proposes a system for monitoring railway crossings, and EP 3 754 244 A1 describes a monitoring device for open areas of a production facility.

[0010] Safety laser scanners can generally be used to generate two-dimensional protective fields. By combining several two-dimensional protective fields, three-dimensional protective spaces can be created. These protective spaces, or the protective fields they generate, must have a distance from the hazardous system components (action zone) determined in accordance with DIN EN ISO 13855 - 2010-10 ("Safety of machinery - Positioning of protective devices with respect to approach speeds of body parts"). A prescribed minimum distance between the laser scanning fields and the action zone of the production system must be maintained so that a step-back zone is created between the laser scanning field(s) and the action zone.Particularly due to the inertia of drives and / or other mechanical systems of the production facility to be protected, the distance to be maintained between the laser scanning field and the action area of ​​the production facility can be so large that even a person can fit in the rear step zone. This is particularly problematic when initiating (switching on) the laser scanning field. If a person is completely in the rear step zone before the laser scanning field is initiated, they will not be detected when the laser scanning field is set up at the safety boundary. The action area is often also referred to as the danger area or hazard zone of the facility in question. Furthermore, it is known from the state of the art to use one or more additional ESPE, which are then arranged horizontally, for example, to monitor rear step zones during operation of the facility. However, this has two major disadvantages.On the one hand, the additional devices and their commissioning increase the costs of the security system. Furthermore, the additional devices require additional installation space for the security system, which is often unavailable.

[0011] Another option for securing access zones is the use of a camera system. However, such a system has three major disadvantages. First, camera systems are very expensive. Second, there are currently no camera systems available on the market that meet the required Performance Level d safety requirements for robot systems. Third, complex system movements cannot be distinguished from human movements, and programming them would be extremely complex and error-prone, making it unsuitable for large-scale production systems with a view to achieving high system availability.

[0012] The use of radar solutions for monitoring access zones during plant operation is also known from the state of the art. However, these systems also have a number of disadvantages. Firstly, such systems are extremely expensive. Furthermore, they are highly susceptible to failure, as steel plant components, in particular, reflect the radiation. This leads to poor availability of the safety system and thus of the plant equipped with the safety system. Furthermore, there is no clear status of moving plant components in the safety zone.

[0013] The object of the invention is to create a safety system for securing an operating area of ​​a production plant, which also enables the rear entry zone to be secured.

[0014] This object is achieved with a safety system having the features of claim 1. This safety system for safeguarding an operating area of ​​a production plant comprises a control device and at least one non-contact protective device. In one operating mode of the safety system, the operating area of ​​the production plant is limited at a safety boundary by the formation of a protective field formed by the non-contact protective device and spaced from the operating area. If the safety boundary is violated, the safety system can be put into an alarm state in which a control signal can be provided to the production plant by the control device. The control signal can be used, for example, to initiate an emergency stop of the production plant in order to bring it to a safe standstill.According to the invention, the non-contact protective device for protecting a rear step zone of the production plant formed in operating mode by the spacing between the action area and the safety limit is now adjustable in its position in a driven manner and the protective field generated by the non-contact protective device can thereby be guided at least in sections over the rear step zone in an initiation mode of the safety system via the driven adjustability of the non-contact protective device.

[0015] In the operating mode, the protective field is established at the designated safety boundary. "Established" in this sense means that the protective field is activated at the safety boundary. The initiation mode comprises establishing or making the laser scanning field available at the safety boundary to establish the operating mode. Within the meaning of the invention, establishing the protective field comprises activating the protective field and guiding it, at least in sections, across the rear step zone to the safety boundary.

[0016] Since the protective field generated by the electro-sensitive protective device can be guided at least partially over the rear step zone in the initiation mode of the safety system via the driven adjustability of the electro-sensitive protective device, the rear step zone can be scanned at least partially with the protective field. A person located in the rear step zone while the protective field is being established can thus be detected.

[0017] In one embodiment, the non-contact protective device is designed to be pivotable by a certain angle at least in one plane, and the protective field generated by the non-contact protective device can be pivoted by this angle relative to the action area in the initiation mode. By pivoting the protective field, the rear step zone is scanned at least in sections for the presence of people.

[0018] It is proposed that the non-contact protective device be driven by an electric motor or pneumatically and be able to pivot by the desired angle. This allows for the automated monitoring of the rear entry zones.

[0019] In a further embodiment, the non-contact protective device is driven in at least one spatial direction, designed to be linearly displaceable, and the protective field generated by the non-contact protective device can be displaced relative to the action zone by the same amount in the initiation mode. The ability to displace the non-contact protective device and thus the protective field offers a further option for monitoring the rear step zone when the non-contact protective device is initiated.

[0020] One embodiment provides that the non-contact protective device is driven by a linear axis or a telescopic axis and can be moved linearly.

[0021] It is proposed that the linear axis or telescopic axis be driven by an electric motor or pneumatically. This allows for the automation of monitoring the rear entry zones.

[0022] Of course, the pivoting of the non-contact protective device can also be combined with the linear displacement of the non-contact protective device.

[0023] An advantageous embodiment provides that the non-contact protective device has at least one evaluation unit for evaluating the signals emitted by the non-contact protective device, and that this evaluation unit is connected to the control device. This enables a compact design.

[0024] Furthermore, the object is achieved by a method having the features of claim 8. This method for securing an operating area of ​​a production plant operates with a safety system which, in an operating mode, provides a protective field at a safety boundary, spaced from the operating area, by means of a non-contact protective device. If the safety boundary is violated, the safety system is placed in an alarm state, in which a control signal is provided to the production plant by a control device of the safety system. In an initiation mode of the safety system, the protective field is established at the safety boundary.According to the invention, in the initiation mode, the contactless protective device is now adjusted in a driven manner and the protective field generated by the contactless protective device is guided with the driven adjustment of the contactless protective device at least in sections over a rear step zone formed between the action area and the spaced-off safety boundary up to the safety boundary.

[0025] Here, too, a person in the rear step zone can be detected when the protective field is created. In one embodiment, the non-contact protective device is pivoted by a driven angle in at least one plane in the initiation mode, with the generated protective field being pivoted by precisely this angle away from the action area to the safety boundary. By pivoting the protective field, it is possible to monitor the area of ​​the rear step zone created by the distance regulations for the presence of people.

[0026] In a further embodiment, it is provided that the non-contact protective device is driven in the initiation mode at least in one spatial direction, linearly displaced, wherein the generated protective field is displaced by precisely this displacement away from the action area to the safety limit.

[0027] The safety system according to the invention and the method according to the invention thus enable the safeguarding of a rear step zone in that at least one protective field is moved between at least two positions in the initiation mode and thus the protective field sweeps over the rear step zone at least in sections.

[0028] It is proposed that both the safety system and the process use non-contact protective devices that operate optically, acoustically, inductively or capacitively.

[0029] In an advantageous embodiment, the non-contact protective device is a laser scanner that forms a laser scanning field as a protective field.

[0030] A further embodiment provides that the non-contact protective device comprises a light beam source and a light receiver, thus forming a light curtain as a protective field.

[0031] In a further embodiment, the non-contact protective device is an ultrasonic motion detector that generates a protective field of ultrasonic waves.

[0032] An embodiment of the invention is described below with reference to the drawings. They show:

[0033] Fig. 1 is a perspective view of a production facility designed as a logistics unit,

[0034] Fig. 2 is a further perspective view of the logistics unit according to Fig. 1, Fig. 3 is a plan view of the logistics unit according to Fig. 1.

[0035] Fig. 1 shows a perspective view of a production plant designed as a logistics unit 1. This logistics unit 1 can, for example, be a container changing system for providing containers with production parts on a production line, which can be automatically loaded using an industrial truck (FFFZ). The container changing system itself is not shown in the illustration. Only a roll-up protection gate of the container changing system is visible. Moving parts (not shown) of the container changing system form an action area 1.1 of the production plant, which represents a danger zone for plant operators. In order to prevent injury to a plant operator from moving parts, a safety system is provided to safeguard the action area 1.1 of the production plant.

[0036] The safety system comprises a control device and at least one non-contact protective device. In the illustrated embodiment, three non-contact protective devices formed as laser scanners 2.1, 2.2, 2.3 can be seen. The laser scanners 2.1, 2.2, 2.3 generate three protective fields designed as laser scanning fields 5.1, 5.2, 5.3, which, in an operating mode of the safety system of the production plant, are arranged at a safety boundary 1.2 spaced from the action area 1.1. If the safety boundary 1.2 is violated (e.g., a plant operator enters the laser scanning field), the safety system can be put into an alarm state in which a control signal can be provided for the production plant by the control device. This control signal can then, for example, trigger a plant stop, so that the moving parts of the production plant are stopped and the plant operator is not endangered.

[0037] In the embodiment shown, the security system has three laser scanners 2.1, 2.2, 2.3, each providing a laser scanning field 5.1, 5.2, 5.3, thus creating a three-dimensional, secured space. However, the invention is not limited to this embodiment. The security system can also have more or fewer than three laser scanners 2.1, 2.2, 2.3. In the embodiment shown, the laser scanners 2.1, 2.2, 2.3 are attached to a support frame 3 in the upper area of ​​the logistics unit 1. However, the invention is not limited to this. The laser scanners 2.1, 2.2, 2.3 can also be attached to a suitable location on the support frame on the side or in the lower area of ​​the logistics unit 1. The number and arrangement of the laser scanners 2.1, 2.2, 2.3 ultimately depends on the extent and geometry of the area of ​​operation 1.1 to be secured. To safeguard against an in operating mode by the spacing between action area 1.1 and safety boundary 1.2, at least one of the laser scanners 2.1, 2.2, 2.3 of the sensor device is adjustable in its position by a drive, and the laser scanning field 5.1, 5.2, 5.3 generated by this laser scanner 2.1, 2.2, 2.3 can be guided at least in sections over the rear step zone 4 in an initiation mode of the safety system via the driven adjustability of the laser scanner 2.1, 2.2, 2.3. When initiating the laser scanning field 5.1, 5.2, 5.3, the laser scanning field 5.1, 5.2, 5.3 is thus built up at the safety limit 1.2, wherein according to the invention the laser scanner is drivenly adjusted in the initiation mode and the laser scanning field 5.1, 5.2, 5.3 generated by the laser scanner is moved with the driven adjustment of the laser scanner at least in sections over a safety limit spaced between the action area 1.1 and the distance.

[0038] 1.2 formed rear step zone is led away from the action area 1.1 to the safety boundary 1.2.

[0039] In the illustrated embodiment, the laser scanners 2.1, 2.2, 2.3 of the sensor device are designed to be pivotable at least in one plane by an angle θ (pivot angle), and the laser scanning field 5.1, 5.2, 5.3 generated by the laser scanners 2.1, 2.2, 2.3 can be pivoted by precisely this angle θ relative to the action area 1.1 in the initiation mode. The laser scanners 2.1, 2.2, 2.3 are pivotable by pneumatic drive. However, the invention is not limited to a pneumatic drive. For example, the drive can also be electric.

[0040] With this version, the laser scanners 2.1, 2.2,

[0041] 2.3 is pivoted in the initiation mode by the angle 6, wherein the generated laser scanning fields 5.1a, 5.1b, 5.2a, 5.2b, 5.3a, 5.3b (Fig. 2, Fig. 3) are pivoted by precisely this angle 6 up to the safety limit 1.2 and in the process sweep over the rear step zone 4 at least in sections. The laser scanners 2.1, 2.2, 2.3 do not necessarily all have to be pivoted by the same angle 6. The pivot angle 6 of the respective laser scanners 2.1, 2.2, 2.3 is essentially based on the dimensioning of the rear step zone or assigned section of the rear step zone assigned to the respective laser scanner 2.1, 2.2, 2.3.

[0042] Fig. 2 shows a further perspective view of the logistics unit 1 according to Fig. 1. This illustration shows, highlighted for laser scanner 2.2, the vertical laser scan field 5.2a and the laser scan field 5.2b pivoted by the pivot angle 6 with the associated rear step zone 4.2. Fig. 3 shows the previously described arrangement of the laser scanners 2.1, 2.2, 2.3 again in a plan view. In operating mode, the laser scanner 2.1 generates the vertical laser scan field 5.1a, which is pivoted in initiation mode from position 5.1b away from the work area to the safety boundary 1.2 (at position 5.1a). This applies analogously to the laser scanner 2.2 with the laser scan field at positions 5.2a and 5.2b as well as to the laser scanner 2.3 at positions 5.3a and 5.3b. In interaction, the laser scanners 2.1, 2.2, 2.3 secure the entire rear entry zone 4 of the logistics unit 1.

[0043] The setup of the laser scanning fields 5.1a, 5.2a, 5.3a at the safety boundary 1.2 can be achieved, for example, by switching on the laser scanners 2.1, 2.2, 2.3, first generating the laser scanning fields 5.1b, 5.2b, 5.3b, which are then pivoted to the safety boundary 1.2, thus forming the laser scanning fields 5.1a, 5.2a, 5.3a. It would also be conceivable for the laser scanners to be aligned upon switching on such that the laser scanning fields 5.1a, 5.2a, 5.3a are generated at the safety boundary 1.2. Subsequently, the laser scanners 2.1, 2.2, 2.3 are pivoted so that the alignment of the laser scanning fields 5.1b, 5.2b, 5.3b is assumed. The laser scanners are then pivoted back again, so that the alignment of the laser scanning fields 5.1a, 5.2a, and 5.3a is restored. In both cases, the switched-on laser scanners are pivoted away from the action area 1.1 toward the safety boundary 1.2.

[0044] In the illustrated application example, this scanning of the rear entry areas 4 occurs regularly after an industrial truck enters, before hazardous, automatic conveying processes between the FFZ and the container transfer system begin. During operation of the container transfer system or the automatic conveying processes, the vertical scanning fields 5.1a, 5.2a, and 5.3a remain active. Should a person from outside breach one of the scanning fields 5.1a, 5.2a, and 5.3a, all relevant movement axes are immediately switched to emergency stop.

[0045] In a further embodiment not shown, the laser scanners 2.1, 2.2, 2.3 of the sensor device are driven at least in one spatial direction, are designed to be linearly displaceable, and the laser scanning field 5.1, 5.2, 5.3 generated by the laser scanners 2.1, 2.2, 2.3 in the initiation mode is displaceable by precisely this displacement relative to the action area 1.1. The laser scanners 2.1, 2.2, 2.3 are driven by a linear axis or a telescopic axis, and are linearly displaceable, although the invention is not limited thereto. In order to secure a rear entry zone 4 formed in the operating mode by the spacing between the action area 1.1 and the safety limit 1.2, in this embodiment at least one of the laser scanners 2.1, 2.2, 2.3 of the sensor device is driven in the initiation mode at least in one spatial direction and displaced linearly, wherein the laser scanning field 5.1, 5.2, 5.3 is shifted by this same shift from the action area 1.1 to the safety limit 1.2.

[0046] Advantageously, an evaluation unit for evaluating the light signals emitted by the laser scanners 2.1, 2.2, 2.3 is integrated into the laser scanners 2.1, 2.2, 2.3 of the sensor device itself, with the respective evaluation unit being connected to the control device. However, it is not mandatory that the evaluation unit be integrated into the laser scanners 2.1, 2.2, 2.3.

[0047] The non-contact protective device is not limited to laser scanners 2.1, 2.2, 2.3. In embodiments not shown, this can also be implemented in other optical or acoustic, inductive, or capacitive ways. For example, the non-contact protective device (2.1, 2.2, 2.3) can comprise a light beam source and a light receiver, thus forming a light curtain as a protective field. Alternatively, the non-contact protective device (2.1, 2.2, 2.3) can have an ultrasonic motion detector that generates a protective field formed by ultrasonic waves.

[0048] The invention is not limited to a production plant designed as a logistics unit 1.

[0049] List of reference symbols Logistics unit of a production plant Action area Safety limit Laser scanner, non-contact protective device Laser scanner, non-contact protective device Laser scanner, non-contact protective device Support frame for laser scanner Rear step zone Rear step zone to laser scanner 2.2 Scan field scanner 2.1 vertical Scan field scanner 2.1 pivoted Scan field scanner 2.2 vertical Scan field scanner 2.2 pivoted Scan field scanner 2.3 vertical Scan field scanner 2.3 pivoted Pivoting angle of the scan field

Claims

Patent claims 1. Safety system for safeguarding an action area (1.1) of a production plant (1), which comprises a control device and at least one non-contact protective device (2.1, 2.2, 2.3), by means of which, in an operating mode of the safety system, the action area (1.1) of the production plant is limited at a safety boundary (1.2) by forming a protective field spaced from the action area (1.1), and the safety system can be put into an alarm state in the event of a breach of the safety boundary (1.2), in which alarm state a control signal can be provided for the production plant by the control device, characterized in that the non-contact protective device (2.1, 2.2, 2.3) for safeguarding an area defined in the operating mode by the spacing between the action area (1.1) and the safety boundary (1.2) formed rear step zone (4) of the production plant is adjustable in its position by a driven mechanism and the protective field (5.1a, 5.1b, 5.2a, 5.2b, 5.3a, 5.3b) generated by the contactless protective device (2.1, 2.2, 2.3) can be guided at least in sections over the rear step zone (4) in an initiation mode of the safety system via the driven adjustability of the contactless protective device (2.1, 2.2, 2.3).

2. Safety system according to claim 1, characterized in that the at least one contactless protective device (2.1, 2.2, 2.3) is designed to be pivotable by an angle (6) at least in one plane, and the protective field (5) generated by the contactless protective device (2.1, 2.2, 2.3) is pivotable by precisely this angle (6) relative to the action area (1.1) in the initiation mode.

3. Safety system according to claim 2, characterized in that the contactless protective device (2.1, 2.2, 2.3) can be pivoted by an electric motor or pneumatically driven.

4. Safety system according to claim 1, characterized in that the at least one contactless protective device (2.1, 2.2, 2.3) is driven at least in one spatial direction, is designed to be linearly displaceable and the protective field (5) generated by the contactless protective device (2.1, 2.2, 2.3) is displaceable in the initiation mode by precisely this displacement relative to the action area (1.1).

5. Safety system according to claim 4, characterized in that the contactless protective device (2.1, 2.2, 2.3) is driven by means of a linear axis or a telescopic axis and can be linearly displaced.

6. Safety system according to claim 5, characterized in that the linear axis or the telescopic axis is driven by an electric motor or pneumatically.

7. Safety system according to one of the preceding claims, characterized in that the contactless protective device (2.1, 2.2, 2.3) has at least one evaluation unit for evaluating the signals emitted by the contactless protective device (2.1, 2.2, 2.3) and that this evaluation unit is connected to the control device.

8. Safety system according to one of the preceding claims, characterized in that the contactless protective device (2.1, 2.2, 2.3) operates optically, acoustically, inductively or capacitively.

9. Safety system according to claim 8, characterized in that the contactless protective device (2.1, 2.2, 2.3) is a laser scanner and this forms a laser scanning field as a protective field or that the contactless protective device (2.1, 2.2, 2.3) comprises a light beam source and a light receiver and thus a light curtain is formed as a protective field or that the contactless protective device (2.1, 2.2, 2.3) has an ultrasonic motion detector and thus a protective field formed from ultrasonic waves is generated.

10. Method for securing an action area (1.1) of a production plant (1) with a safety system which, in an operating mode, provides a protective field at a safety boundary (1.2) at a distance from the action area (1.1) by means of a non-contact protective device (2.1, 2.2, 2.3), wherein the safety system is put into an alarm state in the event of a violation of the safety boundary (1.2), in which alarm state a control signal for the production plant is provided by a control device of the safety system, and wherein the protective field is in an initiation mode of the safety system at the safety boundary (1.2), characterized in that in the initiation mode the contactless protective device is adjusted in a driven manner and the protective field generated by the contactless protective device is adjusted by the driven adjustment of the contactless protective device at least in sections via a path between the action area (1.1) and. rear step zone (4) formed by a distanced safety boundary (1.2) is led to the safety boundary (1.2).

11. Method according to claim 10, characterized in that the contactless protective device (2.1, 2.2, 2.3) is pivoted in the initiation mode at least in one plane by an angle (6), wherein the generated protective field (5) is pivoted by precisely this angle (6) up to the safety limit (1.2).

12. Method according to claim 10, characterized in that the contactless protective device (2.1, 2.2, 2.3) is driven in the initiation mode at least in one spatial direction, is linearly displaced, wherein the generated protective field (5) is displaced by precisely this displacement up to the safety limit (1.2).

13. Method according to one of claims 10 to 12, characterized in that the contactless protective device (2.1, 2.2, 2.3) operates optically, acoustically, inductively or capacitively.

14. The method according to claim 13, characterized in that the contactless protective device (2.1, 2.2, 2.3) is a laser scanner and this forms a laser scanning field as a protective field or that the contactless protective device (2.1, 2.2, 2.3) comprises a light beam source and a light receiver and thus a light curtain is formed as a protective field or that the contactless protective device (2.1, 2.2, 2.3) has an ultrasonic motion detector and thus a protective field formed from ultrasonic waves is generated.

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