Safety device for protecting hazardous area of automatic working machine, in particular robot

Abstract

A safety device for protecting a hazardous area of an automated working machine, in particular a robot (18), comprises a plurality of sensors, each designed to monitor a defined spatial sector around the machine and to generate a sensor signal in each case when an object is detected in the respective defined spatial sector. The machine has a machine body portion (24) having a housing (56) and performing a rotational movement (22) about an axis of rotation (20) during machine operation. The safety device includes a load bearing structure that secures the sensor to the machine such that the sensor rotates together with the machine body portion (24) during operation of the machine. The carrier structure has a carrier base (54) that engages from the outside in a form-fitting manner around a housing (56) of the machine body portion (24).

Description

[0001] The present invention relates to a safety device for protecting a hazardous area of an automatically operating machine, in particular for protecting a hazardous area of a robot, wherein the machine has a machine body part which has a housing and performs a rotational movement about a rotational axis during machine operation. The safety device comprises a plurality of sensors, each of the plurality of sensors being configured to monitor a defined spatial sector in the vicinity of the machine and to generate a corresponding sensor signal when an object is detected in the corresponding defined spatial sector. The safety device comprises a support structure which fixes the plurality of sensors to the machine such that the plurality of sensors rotate together with the machine body part during machine operation, and the safety device comprises an evaluation and control unit which is configured to control the rotational movement of the machine body part in response to the sensor signals from the plurality of sensors.

[0002] Such a safety device is known from EP 3 909 727A1.

[0003] For many years, there has been a desire and an effort to protect the hazardous area caused by the rapid movement of a robot as simply and flexibly as possible in order to prevent accidents and injuries. In particular, there is a desire for a safety device that allows a person to remain in the vicinity of the robot and perform any activity, for example in order to enable a person and a robot to work together. This effort is known as human-robot collaboration. The two-part standard EN ISO 10218 defines the requirements for collaborative operation of robots. For example, in the case of contact between a robot and a person, a predefined contact force on the person must not be exceeded. Therefore, it is known that the position, force and / or torque and / or speed of the movement of parts of the robot or the robot body must be monitored and, if necessary, limited. Monitoring and limitation must also be ensured in the event of an error, for example if a component fails or in the case of a software error, i.e. it must be fail-safe.

[0004] In the following, the term "fail-safe" is used to mean that a component or arrangement meets the requirements of category 3 or the so-called performance level PL d according to standard EN ISO 13849-1 and / or the safety requirement level SIL 3 according to standard IEC 61508 and machine-specific industry standard EN 62061.

[0005] EP 3 909 727 A1 discloses a safety device with a total of six presence sensors, all of which are arranged on a U-shaped holder. On each of the two legs of the U-shaped holder, three presence sensors are arranged vertically, one above the other. The respective opposite sensors "look" in opposite directions and monitor the area at this side of the robot. The holder with the six presence sensors is arranged on a linkage between two rotary joints attached to the robot. The linkage moves in a direction opposite to the movement of the arm part, such that the holder with the presence sensors always remains in a horizontal position and maintains the vertical alignment of the sensors.

[0006] WO 2018 / 145990 A1 discloses another safety device for protecting a robot. On the one hand, the known device uses a sensor permanently installed in the footprint area of the robot, which can be, for example, a safety mat, a laser sensor, a camera or an ultrasonic sensor. The permanently installed sensor is used to monitor the footprint area around the robot. Additionally, the safety device of WO 2018 / 145990 A1 includes another sensor at the free end of the robot arm in the area of the so-called end effector. This other sensor is arranged vertically above the end effector and monitors an umbrella-shaped downward-facing sensor field. The additional sensor can be a laser sensor, a camera or an ultrasonic sensor. The ground-level sensor field of the permanently installed sensor can be divided into a number of concentric sub-circles, where each sub-circle is assigned a different safety level. Different safety levels can be associated with different movement speeds of the robot.

[0007] WO 2006 / 024431 A1 discloses yet another safety device for protecting a robot. The device includes eight ultrasonic proximity sensors permanently installed in the footprint area of the robot, each of the proximity sensors monitoring a defined sector. The monitored sectors are distributed around the robot like a fan within an angle of approximately 180°. The safety device further includes: a fence or a light barrier that prevents lateral approach to the robot behind the monitored sectors; and a rear-mounted laser scanner that monitors the fence area on the back of the robot at ground level. The safety controller ensures that the robot switches to a deceleration mode or even stops if a person moves into a sector within the current position range of the robot arm.

[0008] In principle, known safety devices are suitable for achieving safe operation of a robot. However, they partially impair the productivity of the robot because, for safety reasons, its movement speed is usually limited to a slower speed, even though this may not be necessary upon closer inspection. Additionally, some of the known safety devices require a large number of sensors to monitor the static spatial area around the robot, or they are developed specifically for a particular type of robot and cannot be used on another robot without costly adjustments.

[0009] Against this background, the object of the present invention is to provide a safety device of the type initially mentioned, which enables the protection of a robot or a similar machine in an effective manner. In particular, the object is to provide a safety device that enables high productivity of the robot without endangering the people in the vicinity of the robot, and which can be used in a cost-effective manner for a variety of robot types.

[0010] According to one aspect of the present invention, there is provided a safety device of the type initially mentioned for achieving the above object, wherein the support structure has a support base which is designed to enclose the housing of the machine body part in a form-fitting manner from the outside.

[0011] The sensors of the new safety device are rigidly connected to the rotating machine body part and thus change their current "observation direction" in response to the rotational movement of the machine body part. The spatial sector rotates together with the machine body part about the axis of rotation, and thus the spatial sector is quasi-stationary relative to the moving machine body part. However, the monitored spatial sector moves relative to a fixed point near the machine. This differentiates the new safety device from the concept of using fixed sensors to monitor a static spatial area. The new safety device enables the use with a relatively small number of sensors, which contributes to an effective and cost-effective implementation.

[0012] In addition, the sensor is mechanically connected to the moving machine body part via a new support structure. The machine is in particular a robot with serial kinematics, such as in particular an articulated arm robot or a SCARA robot, and in a preferred exemplary embodiment, the moving machine body part is the rotatable arm part of the robot. The serial kinematics includes a first axis of rotation and additional axes of rotation or rotational joints, and the arm part is connected via the first axis of rotation and the additional axes of rotation or rotational joints such that they can rotate or turn (relative to each other). In a preferred exemplary embodiment of the new safety device, the machine body part whose housing is surrounded in a form-fitting manner by the support base is the first axis of rotation of the robot, i.e., the axis of rotation that connects the robot to the fixed base. Attaching the support structure to the first axis of rotation or attaching it on the first axis of rotation has the advantage that the payload, i.e., the load that the robot can carry and handle, is only slightly reduced, if at all, by the support structure and the sensor. In a preferred exemplary embodiment, the support base surrounds the housing of the vertical axis of rotation, i.e., the machine body part that enables the machine to rotate about the vertical axis of rotation.

[0013] The housing of the machine body part is the outer shell or cladding that separates the machine body part from its surroundings. The support base advantageously matches the housing of the machine body part and is placed on the housing of the machine body part. It can be said that the support base "rides" on the machine body part when the machine body part rotates. In a preferred exemplary embodiment, the support base consists of several parts, where the several parts surround the housing of the machine body part like clamping elements. The advantage of this embodiment is that the support structure with the sensor can be very easily and cost-effectively adapted to various different robot types from different manufacturers and different robot sizes. In a preferred exemplary embodiment, it is sufficient to use 3D data of the housing, such as CAD data or 3D data captured with a 3D scanner, to construct the support base that matches the housing. In a preferred exemplary embodiment, the support structure also consists of several parts, and in addition to the support base, it includes additional elements to which the sensor is or can be attached. In this case, in order to adapt the support structure to another robot type or another robot size, it is sufficient to construct a matching support base.

[0014] Preferably, the sensors mentioned above are all radar sensors, because radar radiation with electromagnetic waves from the microwave range is very stable against fog, dust, dirt, splashing sparks or rain. In a preferred exemplary embodiment, the radar sensor operates at an operating frequency in the range of 10 GHz to 80 GHz, preferably at an operating frequency in the range between 20 GHz and 30 GHz or at an operating frequency in the range between 60 GHz and 70 GHz. Even when the environmental factors mentioned above impair the "clear view", these frequency ranges allow for the rapid and position-accurate detection of collision objects. This makes these sensors very suitable for harsh industrial environments. Alternatively, the sensors mentioned above can in principle be lidar sensors, cameras or ultrasonic sensors that operate using light from the optical and / or infrared wavelength ranges. For multiple sensors, a combination of different sensor principles can also be envisaged.

[0015] The new sensor device can be used very generally and cost-effectively on various machines. The co-rotating sensors enable effective protection, especially in the case of human-robot collaboration, and allow for high productivity. Thus, the above object is fully achieved.

[0016] In a preferred refinement, the support base forms an internal space that is designed to accommodate the machine body part in a tank-like manner.

[0017] In this refinement, the support base defines an internal space that, when the support structure is attached to the machine, to some extent accommodates the housing of the machine body part. In a preferred exemplary embodiment, the internal space is substantially cylindrical. Furthermore, in some exemplary embodiments, it is preferred that the internal space accommodates more than 50%, preferably more than 75%, of the housing of the moving machine body part. This refinement allows the support base to be attached very stably to the housing of the machine body part. The substantially cylindrical internal space can be used for various robot types and robot sizes and thus enables a cost-effective implementation and adaptation. To save material and weight, the tank-like receptacle can have openings or holes in the side wall, i.e., the "tank" can but does not have to be completely enclosed all around. In some exemplary embodiments, an externally completely enclosed internal space is advantageous in order to prevent chips or other contaminants from workpiece machining from accumulating at the location where the support base is attached to the machine body part.

[0018] In a further refinement, the support base has a first half-shell and a second half-shell that together are designed to surround the housing in a clamp-like manner.

[0019] In this improvement, the support base is substantially divided into two parts. In some preferred exemplary embodiments, the half-shells are bolted together. This improvement enables the support base to be installed on the machine body part very simply and also stably.

[0020] In a further improvement, the support base is designed to enclose the housing of the machine body part in two mutually different non-parallel planes.

[0021] Especially in robots with serial kinematics, such as articulated-arm robots, the machine body part enclosed by the support base is usually followed by another arm part, which has an orientation transverse to and usually orthogonal to the main direction or its axis of rotation of the machine body part. This improvement enables the support base to be fixed to the machine body part in a particularly stable manner, especially in the case where the non-parallel planes are perpendicular to the axis of rotation of the machine body part and the other arm part.

[0022] In a further improvement, the support structure includes a beam fixed to the support base, wherein at least one of the plurality of sensors is held at a distance from the support base via the beam.

[0023] This improvement makes it easy to place one or more sensors at a freely selectable height or a freely selectable distance from the moving part of the machine body. Therefore, this improvement makes it easier to optimize the spatial sector monitored by the sensors. For example, one or more sensors can be very easily positioned such that their field of view is not impaired or only insignificantly impaired by other machine components in this improvement.

[0024] In some preferred exemplary embodiments, the sensor device includes a plurality of sensors forming a first sensor group and a second sensor group, wherein the sensors of the first sensor group define a first sensor plane during machine operation, wherein the sensors of the second sensor group define a second sensor plane during machine operation, and wherein the first sensor plane is remote from the second sensor plane. For example, the first sensor plane may be vertically below the second sensor plane. By virtue of the improvement, such an arrangement of several sensors in different planes can be achieved very easily and cost-effectively, and the moving machine body part can be advantageously comprehensively protected with a small number of sensors. In a preferred exemplary embodiment, the first plane is close to the floor, i.e., the monitored spatial sector of the sensors from the first sensor group extends downward to the floor. It can be said that they rest on the floor. The sensors of the first sensor group advantageously have a main viewing direction substantially perpendicular to the axis of rotation. In contrast, in a preferred exemplary embodiment, the main viewing direction of the sensors of the second sensor group extends at an angle with respect to the main viewing direction of the sensors of the first sensor group, in particular at an angle with respect to the floor. The sensors of the first sensor group can be used to effectively monitor the spatial region around the moving machine body part, but not the moving machine body part itself. On the other hand, the sensors of the second sensor group can be used to monitor the spatial region in front of the moving machine body part in the radial direction, as if monitoring from above the diagonal, without the line of sight of the sensors of the second sensor group being blocked by the machine body part.

[0025] In a further improvement, at least one of the plurality of sensors is held on a support base.

[0026] This improvement enables the at least one sensor to be mounted very simply directly in the vicinity of the moving machine body part. Thus, the moving machine body part can be protected very effectively.

[0027] In some exemplary embodiments, the sensor device has three sensors with an omnidirectional vision covering approximately 270°. In particular, the plurality of sensors may include a first sensor that monitors a first defined spatial sector and generates a first sensor signal when an object is detected in the first spatial sector. Additionally, the plurality of sensors may include a second sensor that monitors a second defined spatial sector and generates a second sensor signal when an object is detected in the second spatial sector, and the plurality of sensors may include a third sensor that monitors a third defined spatial sector and generates a third sensor signal when an object is detected in the third spatial sector, wherein the first spatial sector, the second spatial sector, and the third spatial sector are different from each other, wherein the first spatial sector and the second spatial sector are adjacent to each other during machine operation, and wherein the second spatial sector and the third spatial sector are adjacent to each other during machine operation. Advantageously, the first spatial sector, the second spatial sector, and the third spatial sector are distributed around a rotation axis during machine operation such that when the machine body part rotates, the first spatial sector, the second spatial sector, and the third spatial sector follow each other in the current rotation direction. The above sensors can advantageously form a first sensor group near the ground and together monitor an azimuthal spatial sector that does not include the machine body part, such that the field of view of these sensors is unrestricted.

[0028] Advantageously, the monitored spatial sectors are adjacent to each other in the rotation plane of the machine body part and follow each other when the machine body part rotates. The rotation plane is substantially perpendicular to the rotation axis, particularly orthogonal to the rotation axis. This means that the monitored spatial sectors sweep through the entire same spatial region one after another along the current rotation direction. The corresponding subsequent or previous spatial sectors allow for high productivity because a slow creep speed or a safety stop is only triggered when an object to be protected, such as a person or a part of the human body, is directly within the movement range of the moving machine body part. Due to the arrangement of the moving spatial sectors, the movement path of the machine body part can be divided into very critical and less critical spatial regions in a very simple and cost-effective manner. Compared with known safety devices, the safety distance for triggering the safety function can be reduced. Slow movement at an unnecessary low speed can be minimized. At the same time, the rotating spatial sectors mean that if a person is directly in front of the machine body part in the current rotation direction, a safety stop or a creep speed can be triggered at any time.

[0029] In a preferred exemplary embodiment, the sensors each monitor a pie-shaped spatial sector extending beyond an azimuthal opening angle from the respective sensor, the azimuthal opening angle being greater than the opening angle in height. The azimuthal opening angle is preferably in the rotational plane of the respective sensor. The opening angle in height is preferably defined parallel to the rotational axis. In some advantageous exemplary embodiments, the azimuthal opening angle lies in the range between 20° and 120°, and the opening angle in height lies in the range between 10° and 30°. Adjacent spatial sectors may overlap at their respective boundaries. Preferably, the angular range in which adjacent spatial sectors overlap is smaller compared to the respective opening angles. In a preferred exemplary embodiment, the azimuthal overlap angle of two adjacent spatial sectors is at most 20%, preferably at most 10%, of the respective azimuthal opening angle. Thus, each of the three sensors mentioned above monitors more than half of the spatial sector specifically allocated to it. Preferably, each of the three sensors mentioned above monitors more than 75% of the spatial sector specifically allocated to it.

[0030] By reducing or even avoiding unnecessary error stops and slow running speeds of the machine and triggering the safety function only in necessary cases in the form of a stop or slow running speed by the new safety device, this improvement makes a favorable contribution to maximizing the productivity of the machine.

[0031] In a further improvement, the support structure has a friction-enhancing intermediate element intended to be placed between the support base and the housing.

[0032] The intermediate element can be an insert made of an elastic material such as rubber, sponge rubber or a fabric-like material such as felt material. The intermediate element can be arranged over a large area in the interior space of the support base and, in particular, covers more than 50% of the contact surface between the housing of the machine body part and the support base. Alternatively, the intermediate element can include a plurality of intermediate elements arranged at a number of individual contact points. In some exemplary embodiments, the intermediate element can be placed around the machine body part as a loose insert before the support base is mounted to the machine body part. In other exemplary embodiments, the intermediate element can be attached to the contact surface of the support base, for example, by means of an adhesive connection, before assembly. Compared to an installation without an intermediate element, the friction-enhancing intermediate element increases the contact friction between the housing of the machine body part and the support base. In addition to the form-fit, this improvement also makes a favorable contribution to achieving a stable, torsion-resistant connection between the support base and the housing of the machine body part by implementing an (increased) frictional connection. In a preferred exemplary embodiment, the housing of the machine body part is "suction-fitted" into the support base by means of the intermediate element.

[0033] In a further improvement, the support base is configured to be attached to the machine body part in a non-destructive and detachable manner.

[0034] This improvement is advantageous because it facilitates maintenance and, if necessary, repair of the machine in the area of the axis of rotation. Furthermore, if new safety devices are required, for example for a new use of the machine, the machine can be converted very easily.

[0035] In a further improvement, the evaluation and control unit has a fail-safe first evaluation and control unit and a non-fail-safe second control unit, wherein the second control unit controls the movement of the machine body part in response to an operating program and in response to a binary enable signal from the first evaluation and control unit, and wherein the first evaluation and control unit generates the binary enable signal in response to a plurality of sensors.

[0036] As mentioned above, in this case, "fail-safe" means that the first evaluation and control unit meets the requirements of Category 3 or the so-called Performance Level PL d according to the standard EN ISO 13849-1 and / or the Safety Integrity Level SIL 3 requirements according to the standard IEC 61508 or the machine-specific industry standard EN 62061. In contrast, the second control unit does not meet these requirements. Therefore, it is a so-called standard control unit that basically controls the desired operating sequence of the machine according to the operating program. This improvement enables the machine to operate safely and productively in a cost-effective manner. In particular, through this improvement, machines that were previously protected in different ways can be retrofitted with new safety devices and thus achieve increased productivity without significant changes to the desired operating sequence.

[0037] Preferably, the first evaluation and control unit generates two mutually redundant binary enable signals, each of which can have a high signal level (on state) or a low signal level (off state). The high signal level indicates that the first spatial sector guided particularly in the rotational direction is free. Then, the second control unit can rotate the machine body part at a high rotational speed if this is anticipated in the desired operating sequence. Thus, the high signal level is a fail-safe enable signal for the high rotational speed. On the other hand, the low signal level indicates that the enable signal no longer exists, which means that the second control unit moves the machine body part at most at a limited slow rotational speed. Preferably, the first evaluation and control unit generates two redundant binary enable signals, each of which has a test pulse, i.e., a defined pulse from the high signal level to the low signal level. The test pulse enables the detection of a fixed high-level error in the output circuit of the first evaluation and control unit. Preferably, the test pulses of the two mutually redundant binary enable signals are out of phase with each other, which enables a favorable cross-circuit detection. This improvement enables a simple hard-wired signal exchange between the first evaluation and control unit and the non-fail-safe second control unit.

[0038] In a further improvement, the evaluation and control unit is configured to limit, in a fail-safe manner, the rotational speed of the machine body part about the axis of rotation in response to a sensor signal from a sensor.

[0039] In this improvement, the machine body part moves at a reduced rotational speed compared to a faultless operation. When an object is detected in the corresponding spatial sector guided in the rotational direction, the so-called slow travel speed of the machine body part makes a beneficial contribution to maintaining the productivity of the machine, despite the slower movement due to the risk of collision in the spatial sector guided in the rotational direction.

[0040] In a further improvement, at least one of the plurality of sensors has a first detection area and a separate second detection area within the associated spatial sector, where the first detection area is closer to the sensor than the second detection area, where the sensor generates a separate sensor signal for each of the two detection areas, and where the evaluation and control unit is configured to control the rotation of the machine body part based on the separate sensor signals.

[0041] In this improvement, the spatial sector of at least one sensor is divided into two different distance ranges. Advantageously, all sensors from multiple sensors have such a first detection area and a separate second detection area within the corresponding monitored spatial sector. This improvement enables the evaluation and control unit to trigger different reactions in a simple manner based on the distance of an object in the monitored spatial sector. Advantageously, the evaluation and control unit can generate optical and / or acoustic warning signals at a greater distance to prevent a person from entering the working area of the machine further. On the other hand, when an object is detected at a shorter distance, the evaluation and control unit can immediately reduce the movement speed of the machine body part and / or stop the movement of the machine body part. Alternatively, once a warning signal is generated, the evaluation and control unit can also reduce the rotational speed of the machine body part. This improvement helps to achieve high productivity and the safe operation of the machine.

[0042] It should be understood that, without departing from the scope of the present invention, the features mentioned above and the features to be described below can be used not only in the combinations indicated in each case, but also in other combinations or alone.

[0043] Exemplary embodiments of the present invention are shown in the drawings and are explained in more detail in the following description. It is shown as:

[0044] Figure 1 an exemplary embodiment of a new safety device on an articulated robot,

[0045] Figure 2 is Figure 1 a safety device, in which three monitored spatial sectors are schematically shown,

[0046] Figure 3 is Figure 1 a safety device, in which three additional monitored spatial sectors are schematically shown,

[0047] Figure 4 is Figure 1 an articulated arm robot which has Figure 1 a half shell of the support base of the safety device, and

[0048] Figure 5 is Figure 1 the support base of the safety device having two half shells.

[0049] In Figure 1In it, an exemplary embodiment of the new safety device is generally designated by reference numeral 10. In this exemplary embodiment, the safety device 10 includes six radar sensors 12-1, 12-2, 12-3, 12-4, 12-5 and 12-6, hereinafter collectively designated by reference numeral 12, and a fail-safe evaluation and control unit 14 which in this case is connected to the radar sensors 12 via a serial bus connection 16 (only schematically shown here). In a preferred exemplary embodiment, the serial bus connection 16 is based on the CAN bus protocol, which enables very efficient data transmission between the serially connected sensors and the evaluation and control unit 14. In some exemplary embodiments, the evaluation and control unit 14 includes a fail-safe controller called PNOZmulti 2, which is commercially available from the applicant Pilz GmbH&Co KG located in 73760 Ostfildern, Germany.

[0050] In this case, the sensors 12 are arranged on the articulated arm robot 18 and can thus rotate with the robot 18 about the axis of rotation 20 of the robot 18. In this case, the axis of rotation 20 is the first axis of rotation among several axes of rotation of the robot 18, and the axis of rotation 20 extends perpendicular to the floor or base on which the robot 18 and its base are placed here.

[0051] In some exemplary embodiments, the robot 18 can perform pick-and-place tasks, whereby it rotates about the axis of rotation 20 in alternating directions. The corresponding current direction of rotation is indicated by reference numeral 22. As is known to those skilled in the art, the robot 18 has several arm portions which are rotatably connected to each other via rotational joints. Some of these arm portions are designated herein by reference numerals 24, 25, 26 (see also Figure 4)). The rotation of the arm portions 24, 25, 26 relative to each other and the rotation of the robot 18 about the axis of rotation 20 are hereby controlled by the non-fail-safe control unit 28. The control unit 28 can be a conventional robot controller, such as is usually provided by the manufacturer of the robot 18 and supplied together with the robot. The control unit 28 controls the desired operating sequence of the robot 18 in a manner known per se according to an operating program that is usually loaded into the control unit 28. In some preferred exemplary embodiments, the evaluation and control unit 14 of the robot and the operating control unit 28 can communicate with each other via a bidirectional connection 29. In some exemplary embodiments, the connection 29 can include, for example, a fail-safe bus connection based on the fail-safe Ethernet protocol. In a preferred exemplary embodiment, the connection 29 includes two or more redundant binary enable signals 29a, 29b, so-called OSSD signals, such as those provided by the applicant's fail-safe small controller PNOZmulti 2.

[0052] Depending on the operating situation, the movable arm portions form a contour 30 that is directed in the current direction of rotation 22 and that can exert a high contact force on a person or an object (not shown here) in the event of a collision within the rotation range of the robot 18. To prevent this, the sensors 12 each monitor a defined, assigned spatial sector 32. In Figure 1 FIG., the first spatial sector 32-1, the second spatial sector 32-2, and the third spatial sector 32-3 are each indicated by a dashed line. For example, the first sensor 12-1 monitors the first spatial sector 32-1, the second sensor 12-2 monitors the second spatial sector 32-2, and the third sensor 12-3 monitors the third spatial sector 32-3. The three spatial sectors 32-1, 32-2, and 32-3 are adjacent to each other, and the sensors 12-1, 12-2, and 12-3 define a plane 34 which, in this case, is close to the ground and substantially parallel to the ground. Figure 2 The three spatial sectors 32-1, 32-2, and 32-3 are shown in a perspective view.

[0053] As can be seen from Figure 2As can be seen, the monitored spatial sectors 32-1, 32-2, and 32-3 overlap a certain distance in the adjacent area, such that the three sensors 12-1, 12-2, and 12-3 together cover a continuous angular range of rotation 36 here, which angular range of rotation 36 here surrounds the robot 18 on three sides. In the illustrated exemplary embodiment, the spatial sectors 32-1, 32-2, and 32-3 together cover an angular range of rotation 36 of approximately 270°. In this case, each of the three sensors 12-1, 12-2, and 12-3 monitors the assigned spatial sectors 32-1, 32-2, and 32-3, and the corresponding sectors cover approximately one-third of the angular range of rotation 36. The jointly monitored angular range of rotation 36 extends in the azimuthal direction and does not include the robot 18. Thus, in this exemplary embodiment, the arm portions 25, 26 - and more generally, the robot 18 - do not produce any radar reflections that can be detected by the sensors 12-1, 12-2, and 12-3.

[0054] In some exemplary embodiments, it has proven very advantageous to divide the azimuthal spatial sector 36 into three monitored spatial sectors 32-1, 32-2, 32-3 of approximately equal size in order to monitor the angular range of rotation of the robot 18 using a small number of sensors, such that the robot 18 can operate with a high level of productivity. Advantageously, if the immediately preceding spatial sector in the current direction of rotation is "idle", i.e., the assigned sensor does not detect any potential collision objects in the spatial sector it is monitoring, the fail-safe evaluation and control unit 14 generates the above-mentioned enabling signal. Thus, for example, if the robot 18 rotates clockwise in a defined operating situation, the evaluation and control unit 14 generates the above-mentioned enabling signal if the spatial sector 32-1 is idle, i.e., if the first sensor 12-1 does not detect a collision object in the spatial sector 32-1. Conversely, if the robot 18 rotates counterclockwise in another operating situation and the spatial sector 32-3 is idle, i.e., if the third sensor 12-3 does not detect a collision object in the spatial sector 32-3, the evaluation and control unit 14 generates the above-mentioned enabling signal. Regardless of this exemplary embodiment, in additional exemplary embodiments in which the machine body portions 24, 26 pass through an angular range of rotation of less than or equal to 300° during the intended operation, it is advantageous if the safety device 10 monitors the angular range of rotation using three, four, or at most five spatial sectors that together cover the entire angular range of rotation.

[0055] As can also be seen in Figure 2 In this case, the monitored spatial sectors 32-1, 32-2, 32-3 each have a shape similar to a slice of pie or cake, i.e., corresponding to a sector of a circle in a plan view, but limited in height. In other words, inFigure 1 The azimuth opening angle 38 indicated with reference numeral 38 for the spatial sector 32 - 3 is greater than the opening angle 40 in altitude.

[0056] In a preferred exemplary embodiment, some or even all of the plurality of sensors 12-1 to 12-6 have a first detection area 42 and a separate second detection area 44 (in Figure 1 1). The first detection area 42 is positioned closer to the respective sensor than the second detection area 44. The respective sensor generates a separate sensor signal for each of the two detection areas 42, 44, and the evaluation and control unit 14, 28 is configured to control the rotation of the machine body part 24, 26 in response to the separate sensor signals. The separate detection areas 42, 44 make it possible to take into account the current distance of the potential collision object to the robot 18 when controlling the rotational movement. For example, if an object is detected in the further second detection area 44, the evaluation and control unit 14, 28 can only trigger a visual and / or acoustic warning signal, and only the object detection in the first detection area 42 triggers a reduction of the current rotation speed or even an emergency stop. In a further exemplary embodiment, the evaluation and control unit 14, 28 can be configured to limit the current rotation speed of the machine body part or reduce it to a slow speed if an object is detected in the further detection area 44, while always triggering an emergency stop if an object is detected in the closer detection area 42. In principle, the monitored spatial sector can also have more than two separate detection areas which are staggered in distance, whereby the evaluation and control units 14, 28 are configured to control the rotational movement of the machine body part in response to the azimuthal position of the object (detected by means of the corresponding spatial sector or sensor signal) and by means of the corresponding distance (detected by means of the corresponding detection area).

[0057] exist Figure 1 In the exemplary embodiment shown in , the safety device 10 has two sensor groups with a total of 6 sensors. Sensors 12-1, 12-2 and 12-3 form a first sensor group and define a plane 34 close to the ground. Sensors 12-4, 12-5 and 12-6 are arranged on a platform 50 above the sensors 12-1, 12-2 and 12-3 and form a second sensor group. The platform 50 is held on a support base 54 via a beam 52. In this case, the sensors 12-4, 12-5 and 12-6 define a plane 46, which is located vertically above the plane 34. In this exemplary embodiment, the sensor 12-6 is even arranged to be slightly higher than the plane 46.

[0058] In the exemplary embodiment shown here, the beam 52 is a telescopic beam having a beam length that can be variably adjusted. This makes it possible to adjust the distance of the platform 50 from the support base 54. Advantageously, the distance between the sensor plane 34 and the sensor plane 46 can thus be adjusted in response to the height of the robot 18, such that the sensors 12-4, 12-5, and 12-6 have a substantially unobstructed field of view passing through the robot 18 and its arm portions.

[0059] As can be seen from Figure 1 and Figure 3 the sensors 12-4, 12-5, 12-6 of the second sensor group jointly monitor another azimuthal space sector 48, which extends behind the robot 18 or its arm portions from the perspective of the sensors 12-4, 12-5, 12-6. Thus, as Figure 2 shown in, the space sector monitored by the sensors 12-4, 12-5, 12-6 particularly covers the gap left by the azimuthal space sector 36.

[0060] Figure 4 The robot 18 without the safety device 10 is shown, but with a half-shell 54a of the support base 54 on the housing 56 of the machine body portion 24. Otherwise, the same reference numerals denote the same elements as before. Figure 5 The half-shell 54a and the second half-shell 54b are shown, which can be placed on the housing 56 of the machine body portion 24 from the outside as separate components in order to mount the support base 54 on the machine body portion 24. As can be seen from Figure 4 and Figure 5 the half-shells 54a, 54b in this exemplary embodiment together form an internal space 58 in which the housing 56 of the machine body portion 24 can be almost completely received.

[0061] In some preferred exemplary embodiments, a friction-enhanced, particularly rubber-like intermediate element 60 can be arranged in the internal space 58 of the support base 54, and it can "fill" the internal space 58 to some extent. In some exemplary embodiments, the internal space 58 is substantially complementary to the housing 56 of the machine body portion 24, such that the housing 56 is received in the internal space 58 in a form-fitting and precise-fitting manner. The optional intermediate element 60 can advantageously compensate for small deviations between the actual shape of the internal space 58 and the actual shape of the housing 56 and contribute to a particularly torsion-resistant and stable connection.

[0062] As particularly in Figure 5As can be seen, in this exemplary embodiment, the support base 54 surrounds the housing 56 of the machine body portion 24 in two different planes 62, 64. In this case, each of the two half-shells 54a, 54b has a substantially semi-circular edge 66, 68. The semi-circular edge 66 of the half-shells 54a, 54b lies in a plane 62 that is substantially perpendicular to the axis of rotation 20 of the machine body portion 24. In contrast, the semi-circular edge 68 of the half-shells 54a, 54b lies in a plane 64 that is substantially parallel to the axis of rotation 20 of the machine body portion 24. In the exemplary embodiment shown here, the half-shells 54a, 54b each have a flange-like protrusion 70, which allows the two half-shells 54a, 54b to be screwed together after the half-shells 54a, 54b have been placed on the housing 56 of the machine body portion 24 from the outside.

[0063] As shown in Figure 5 the mounting surface is indicated by reference numeral 72, where one of the sensors 12 can be directly attached to the support base 54 so as to rotate with the machine body portion 24 during machine operation. Another internal space formed by the half-shells 54a, 54b is indicated by reference numeral 74, into which the beam 52 can be inserted.

Claims

1. A safety device for protecting a dangerous area of an automatic operating machine, in particular for protecting a dangerous area of a robot (18), the machine comprising a machine body part (24) having a housing and performing a rotational movement (22) about a rotational axis (20) during machine operation, the safety device comprising a plurality of sensors (12-1 to 12-6), each of the plurality of sensors (12-1 to 12-6) being configured to monitor a defined spatial sector (32-1, 32-2, 32-3) in the vicinity of the machine and to generate a corresponding sensor signal when an object is detected in the corresponding defined spatial sector (32-1, 32-2, 32-3), the safety device comprising a support structure (50, 52, 54) that fixes the plurality of sensors to the machine such that the plurality of sensors (12-1 to 12-6) rotate with the machine body part (24) during machine operation, and the safety device comprising an evaluation and control unit (14, 28) configured to control the rotational movement of the machine body part (24) in response to the sensor signals of the plurality of sensors (12-1 to 12-6), characterized in that, The support structure (50, 52, 54) has a support base (54) which is designed to enclose the housing (56) of the machine body part (24) in a form-fitting manner from the outside.

2. The safety device according to claim 1, wherein, The support base (54) forms an internal space (58) which is designed to receive the machine body part (24) in a tank-like manner.

3. The safety device according to claim 1 or 2, characterized in that, The support base (54) has a first half-shell (54a) and a second half-shell (54b) which together are designed to enclose the housing (56) in a clamp-like manner.

4. The safety device according to any one of claims 1 to 3, characterized in that The support base (54) is designed to enclose the housing (56) of the machine body part (24) along two mutually different non-parallel planes (62, 64).

5. The safety device according to any one of claims 1 to 4, characterized in that The support structure includes a beam (52) fixed to the support base (54), wherein at least one of the plurality of sensors (12-4, 12-5, 12-6) is held at a distance from the support base (54) via the beam (52).

6. The safety device according to any one of claims 1 to 5, characterized in that, At least one of the plurality of sensors (12-1, 12-2, 12-3) is held on the support base (54).

7. The safety device according to any one of claims 1 to 6, characterized in that, The support structure includes a friction-enhancing intermediate element (60) intended to be placed between the support base (54) and the housing (56).

8. The safety device according to any one of claims 1 to 7, characterized in that, The support base (54) is configured to be attached to the machine body part (24) in a non-destructive, detachable manner.

9. The safety device according to any one of claims 1 to 8, characterized in that, The evaluation and control unit has a fail-safe first evaluation and control unit (14) and a non-fail-safe second control unit (28), wherein the second control unit (28) controls the movement of the machine body part (24) in response to an operating program and in response to binary enable signals (29a, 29b) from the first evaluation and control unit (14), and wherein the first evaluation and control unit (14) generates the binary enable signals (29a, 29b) in response to the plurality of sensors.

10. An automatically operating machine having a machine body part (24) which performs a rotational movement (22) about a rotational axis (20) during machine operation, and the automatically operating machine having a safety device (10) according to any one of claims 1 to 9.

11. The automatic operation machine according to claim 10, wherein, The machine body part (24) is a robot arm part of a robot having serial kinematics.

12. The automatic operation machine according to claim 11, wherein, The serial kinematics includes a first rotational axis (20) and additional rotational axes (21), and wherein the first rotational axis (20) connects the robot arm part (24) to a fixed base.

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