Articulated arm robot and method for monitoring an articulated arm robot

Abstract

Articulated-arm robot (20) having a plurality of robot members (22) which are connected to one another by one joint (24) each and are driven by means of one electric motor (28) each and are configured for redundant monitoring of their operation, for which purpose two monitoring devices independent of one another are provided, namely a first monitoring device (34A, 40A, 44A) and a second monitoring device (34B, 40, 44B), wherein each monitoring device has: - a movement sensor, namely a first movement sensor and a second movement sensor (34A, 34B), for detecting the instantaneous position of the respective robot member (22); - a device for detecting the instantaneous force acting on the robot member (22), namely a first device and a second device (40A, 40B), wherein the two devices are based on different measuring principles; - an evaluation unit, namely a first evaluation unit (44A) for processing data from the first movement sensor (34A) and data from the first device (40A) and a second evaluation unit (44B) for processing data from the second movement sensor (34B) and data from the second device (40B). Redundant monitoring of the articulated-arm robot is thus achieved by two separate monitoring paths.

Description

Technical Field

[0001] The present invention relates to an articulated arm robot having multiple robot components connected to each other via joints, and these robot components being driven by motors, wherein the articulated arm robot is configured for redundant monitoring of its operation. Background Technology

[0002] Such articulated arm robots can be found, for example, in EP 1 445 075 B2.

[0003] Articulated arm robots typically have multiple robotic components, which are connected to each other via joints. These components form a chain of joints and are supported by each other, enabling each component to perform rotational movements relative to its adjacent component. The corresponding rotational movements are controlled by motors, which are, for example, directly disposed within the joints. For instance, the motor shaft extends parallel to the joint axis.

[0004] Especially for articulated arm robots that come into contact with or are close to people, such as medical robots that work on patients, high-precision positioning is required on the one hand, and reliable, trouble-free operation of the robot and its movements is required on the other hand to prevent danger to people.

[0005] In the aforementioned EP 1 445 075 B2, multiple distinct physical measurements are determined and compared within the framework of a redundant measurement system. This includes, in particular, evaluating the strain, position data, and motor current of the robot structure. Summary of the Invention

[0006] Therefore, the objective of this invention is to provide an articulated arm robot, particularly an articulated arm robot for medical applications, and a method for monitoring such an articulated arm robot to ensure high functional safety.

[0007] According to the present invention, this task is solved by an articulated arm robot having multiple robot components, which are connected to each other by joints and driven by motors, wherein the articulated arm robot is configured for redundant monitoring of its operation. For this purpose, two independent monitoring devices are constructed, namely a first monitoring device and a second monitoring device, each monitoring device having the following elements:

[0008] - A motion sensor, namely a first motion sensor and a second motion sensor, is used to detect the instantaneous position of the corresponding robot component, and in particular, to detect the instantaneous velocity.

[0009] - A device for detecting instantaneous forces and / or torques acting on robot components, comprising a first device and a second device, wherein the two devices are based on different measurement principles, and

[0010] - An evaluation unit, namely a first evaluation unit, for processing data from a first motion sensor and data from a first device, and a second evaluation unit for processing data from a second motion sensor and data from a second device. The two evaluation units are constructed independently and completely separately from each other, and are formed, for example, by two different component units. Each evaluation unit is suitably constructed for evaluation and data processing, and respectively has a computing unit, particularly a microchip, a memory, and an executable program for processing and evaluating the data.

[0011] According to the present invention, this task is also addressed by a method for monitoring a multi-axis articulated robot, which monitors the articulated robot during operation using the aforementioned two monitoring devices. The advantages and preferred embodiments for articulated robots described below also apply to this method.

[0012] It is important to emphasize that monitoring is performed using two independent and separate monitoring devices, thereby reliably and redundantly monitoring the operation of the articulated robot.

[0013] Articulated arm robots typically have a system with redundant construction for collision detection.

[0014] Of particular importance are the corresponding monitoring devices that evaluate both motion data and instantaneous data regarding force application. The evaluation of data concerning instantaneous forces acting on robot components or instantaneous torques is especially crucial for medical robots, enabling immediate collision detection and, if necessary, immediate cessation of movement. This device for detecting instantaneous forces is part of a collision detection system.

[0015] Preferably, the corresponding evaluation unit is configured to jointly evaluate the potential collision between the articulated robot and an object, using motion or position data instantaneously detected by the corresponding motion sensor and force data instantaneously detected by the corresponding device. Here, mutual verification or validation of the motion data detected by the corresponding motion sensor and the data detected by the force detection device is preferably performed. Therefore, the two datasets are used jointly for collision detection and collision monitoring. This achieves redundancy verification because two different datasets are used and, in particular, mutually verified. False alarms are avoided through mutual verification. Simultaneously, reliable collision detection is achieved by providing two different datasets, preferably even if one of the two detection devices fails. That is, preferably, conclusions about the collision hazard can be drawn from the motion data and from the force data—independently. This redundant data detection is achieved once by the motion sensor and once by the force detection device within each monitoring device.

[0016] To achieve exceptionally high redundancy and safety, two different devices for detecting transient forces were deployed for the two monitoring units. This means that transient forces are determined using two different measurement principles. By selecting different measurement principles, operational safety is further enhanced.

[0017] Using different measurement principles can be understood as evaluating different physical quantities through two devices, and these measurements allow for conclusions about the instantaneously applied force.

[0018] For example, according to a preferred embodiment, the instantaneously applied force is determined directly by a force measuring device, especially by a suitable direct force sensor, such as a force sensor.

[0019] According to another operating principle, deformation, such as tension or compression, of structural components, particularly robotic parts of articulated robots, is detected. Mechanical forces acting on robotic parts typically result in detectable mechanical deformation, from which conclusions about instantaneous forces can be drawn. In this measurement principle, appropriate strain sensors are therefore provided to measure the deformation. This can be achieved, for example, by using optical sensors, particularly optical waveguides. Strain is detected within the optical waveguide. The optical waveguide is, in particular, directly fixed to the robotic part and deforms with it. Alternatively, preferably at least one, and more preferably multiple, strain gauges are mounted on the robotic part.

[0020] It is also feasible to measure, for example, the motor current of a motor that generates the motion of a robot component, based on another measurement principle. If mechanical forces are applied to the robot component, this will cause a measurable change in the motor current.

[0021] To ensure operational safety, the acquired data—namely, motion data and force data—is evaluated by two monitoring devices. Once one monitoring device determines a critical operating state, it initiates safety measures, such as stopping the articulated robot's movement or returning it to a safe operating position. Preferably, the evaluation data from the two monitoring devices are also compared with each other. For this purpose, they can be in communication with each other or with a higher-level control unit.

[0022] According to a preferred embodiment, the first monitoring device has at least one strain sensor mounted on the robot component, particularly configured as a strain gauge. This strain sensor constitutes a first device for detecting instantaneous forces or instantaneous torques acting on the robot component. Suitably, multiple strain sensors, especially strain gauges, are mounted around the periphery of the articulated robot to reliably detect deformations in different directions.

[0023] As an alternative or optional supplement to at least one strain sensor, a force measuring device as described above is arranged as a first device for detecting instantaneous forces. This force measuring device is particularly mounted between the last robot component, especially the so-called robotic hand, and the working tool (end-effector) fixed thereon. Depending on the application, this involves different end-effectors. In medical applications, this could be, for example, a patient bed by which a patient is moved, for example, into a treatment or diagnostic system, or a diagnostic or treatment device (e.g., an irradiation device) that moves relative to the patient, or a medical device used to treat the patient.

[0024] In a preferred embodiment, the second monitoring device includes a current sensor for determining the motor current of the motor through which the robot component is driven. This current sensor constitutes a second device for detecting a momentary force or momentary torque acting on the robot component. Based on the measured momentary motor current, the momentary force or momentary torque can be determined in a manner known in the art.

[0025] In particular, the combination of strain sensors or force measuring devices with motor current assessment has enabled high operational safety for articulated arm robots.

[0026] Preferably, the two motion sensors are encoders, which detect the rotational motion of the motor shaft. This type of encoder ensures reliable position detection of the robot's instantaneous position. Furthermore, instantaneous velocity can typically be derived from the data from this encoder. The structure and function of such encoders are known in principle.

[0027] According to a preferred embodiment, data detected by a motion sensor is also used for collision detection. To this end, the data detected by the motion sensor is evaluated, for example, regarding instantaneous position and / or velocity and / or acceleration, and these determined quantities are assessed to detect a potential collision.

[0028] Independent of collision assessments, data from motion sensors are used to determine instantaneous position and / or velocity and / or acceleration, which is preferably used for the control and regulation of the articulated arm robot's motion.

[0029] In a preferred embodiment, the motion sensors are arranged at different locations, with the first motion sensor positioned far from the second motion sensor. This facilitates the independent detection of instantaneous motion data.

[0030] Specifically, the motion sensors are mounted on opposite sides of the motor. The first motion sensor is mounted on the input side of the motor, specifically on the input shaft, while the second motion sensor is mounted on the output side, specifically on the output shaft. The monitored robot component is driven via the output shaft. This is typically achieved through an intermediate connecting transmission mechanism. The second motion sensor is preferably positioned after the transmission mechanism.

[0031] To detect motion data as independently as possible, the two motion sensors are constructed differently from each other. This further improves operational safety. Therefore, different measurement principles are used in the two monitoring devices for detecting motion data and force data, thus achieving high redundancy through the use of different measurement principles.

[0032] In particular, one motion sensor, such as the first or second motion sensor, is configured as an incremental encoder and thus as an incremental encoder, while the other motion sensor, namely the second or first motion sensor, is configured as an absolute encoder and thus as an absolute encoder.

[0033] As an alternative or supplement, the two encoders also differ in the number of read heads. These read heads are used to detect motion, particularly rotational motion, within the encoder. Preferably, one encoder has only one read head, while the other has two.

[0034] In a suitable implementation, multiple, and in particular all, robot components are respectively assigned, as described above, a first motion sensor and a second motion sensor, as well as a first device and a second device. Data from all the first motion sensors and the first device are evaluated by a first evaluation unit, and data from all the second motion sensors and the second device are evaluated by a second evaluation unit. This approach creates two completely separate monitoring paths, which are also based, in particular, on different measurement principles used for detecting motion and force data.

[0035] Preferably, the two evaluation units are constructed differently. That is, at least some, and preferably all, of the components of the evaluation units are different from each other. Alternatively or supplementarily, the two evaluation units are from different manufacturers.

[0036] For data communication and data transmission between components, a bus system (data bus) is preferred, where data transmission follows a predetermined data protocol. Preferably, different bus systems are used in the articulated robot, especially for data connections with the evaluation unit, which are made through two different bus systems. One bus system is preferably based on the Ethernet protocol, and the other is based on a non-Ethernet protocol. The other bus system is, for example, constructed for serial data transmission and is preferably based on the EIA-xxx standard (also known as the RS-xxx standard). In particular, the other bus system is based on the EIA-485 standard.

[0037] Preferably, a redundant braking device with two brakes is also provided for the corresponding drive unit and thus the corresponding motor. These brakes are respectively configured for applying braking force in a non-electric manner, wherein the two brakes are preferably based on different operating principles, so that the corresponding braking force of the two brakes is applied through different operating principles.

[0038] This is understood here as the force used to generate braking force being produced through different physical means. Different operating principles include, for example, the application of magnetic force, aerodynamic force, hydraulic pressure, or mechanical spring force.

[0039] Such braking devices are described in detail in the applicant's German patent application entitled "Articulated Arm Robot," official application number 10 2023 211164, dated November 10, 2023. The disclosure of that application is incorporated herein by reference. This particularly relates to... Figure 2 and Figure 3 The accompanying drawings and these Figure 2 and Figure 3 These are hereby cited and incorporated into this application.

[0040] A corresponding brake typically has two braking components, namely, a movable and a fixed braking component, wherein the braking force or braking torque is properly transmitted from the fixed braking component to the other braking component.

[0041] Typically, two braking components are mechanically pressed together to generate braking force, thereby producing a braking effect through friction between the two braking components. This pressing force that generates braking force is generated, in particular, through one of the working principles described above.

[0042] By using different working principles, the risk of failure is reduced, thereby improving functional safety.

[0043] In a preferred embodiment, one of the brakes is a spring-force-actuated brake, wherein the braking force is generated by the spring force. Here, the two brake mating parts are pressed together by the spring force.

[0044] In a further preferred development, another type of brake is a magnetic brake, in which the braking force is generated by magnetic force.

[0045] In a preferred embodiment, a permanent magnet is used for this purpose. Here, preferably—similar to a spring-driven brake—one brake element is pressed against another brake element by magnetic force.

[0046] Two non-electric brakes continuously apply force to the brake mating parts through the aforementioned working principle, thereby generating a braking effect. To control the braking effect during normal operation, in a preferred embodiment, each brake is equipped with an electromagnet. This electromagnet controls the braking force of the corresponding brake and switches it to the open position. Thus, an electrically controlled magnetic force is generated by the electromagnet, acting on each brake mating part. The electrically controlled force is opposite to the continuous, non-electrically generated force. Therefore, the braking force is adjustable, and in particular, the braking effect can be completely canceled.

[0047] In a preferred embodiment, the brake is mounted on the shaft of the drive unit. Therefore, the braking force is applied to the shaft of the drive unit.

[0048] Preferably, at least one brake, and more preferably two brakes, each has a movable brake disc movable along an axis, which engages with a fixed brake disc fixedly connected to the shaft. The movable and fixed brake discs are two braking components of the respective brake. A non-electrically generated force acts on the movable brake disc and in the direction of the fixed brake disc. The aforementioned electromagnet acts in the opposite direction, so that the movable brake disc is pulled away from the fixed brake disc when the electromagnet is activated. The movable brake disc is, for example, movably supported on the shaft of a motor or otherwise supported.

[0049] The fixed brake disc is mechanically fixed to the shaft, for example, by means of a mounting flange or by welding. However, preferably, the fixed brake disc is an integral component of at least a portion of the shaft.

[0050] In a preferred embodiment, the fixed brake disc is arranged between the two movable brake discs. Therefore, the fixed brake disc forms a common brake disc for both brakes.

[0051] Preferably, the shaft of the drive unit is constructed as a hollow shaft, at least in the brake region. This provides additional usable internal cavity. In a preferred embodiment, the shaft is constructed as a hollow shaft only in the brake region. In this case, the hollow shaft is connected to at least one other part of the shaft (which is in particular not constructed as a hollow shaft) in a torsion-resistant manner, for example by a flange or also by welding. Alternatively, the entire shaft of the drive unit is constructed as a hollow shaft.

[0052] In a suitable implementation, electrical wires connected to the electromagnet are guided through a hollow shaft. These electrical wires are used to control the electromagnet.

[0053] In addition, hollow shafts offer the possibility of integrating other functions, such as arranging or designing sensors, cooling elements, etc.

[0054] Each drive unit has an output shaft that drives the adjustment movement of the corresponding robot component. In addition to the motor, the drive unit usually also has a transmission mechanism connected after the motor.

[0055] Different variations are available for positioning the two brakes:

[0056] According to a preferred embodiment, the two brakes are arranged together on one side of the motor. For example, on the input side, i.e., the side opposite the output shaft, and especially the side opposite the transmission mechanism. Alternatively, the two brakes are arranged together on the output side, i.e., after the motor, wherein they are preferably positioned between the motor and the transmission mechanism.

[0057] As an alternative to being jointly positioned on one side of the motor, the two brakes are arranged spaced apart from each other on opposite sides of a component of the drive unit. They are specifically positioned on opposite sides of the motor, or alternatively on opposite sides of the transmission mechanism. Preferably, one brake is positioned on the input side of the motor, and the other brake is positioned on the output side of the motor, particularly between the motor and the transmission mechanism.

[0058] In a preferred embodiment, two redundant position sensors are assigned to each brake to detect its instantaneous position. Redundancy ensures reliable detection. Preferably, the two position sensors are configured differently. This ensures high fail-safety. For example, the two position sensors are based on different (physical) operating principles and / or switched on with opposite switching logic, such that one sensor is closed under normal conditions and the other is open under normal conditions.

[0059] The task according to the invention is also solved by an articulated arm robot having a redundantly designed system for its operation. The correspondingly redundant system has multiple system components. To ensure high fault tolerance, according to another aspect of the invention, the two redundant systems are typically constructed differently from each other.

[0060] By employing this fundamental design principle—that redundant systems are not constructed identically but differently—high fault tolerance is achieved. For example, design flaws or programming errors that might cause the failure of one redundant system are unlikely to occur in another, differently constructed system due to design considerations. Here, "differently constructed systems" is understood as: at least some functionally identical and therefore redundant system components of the two systems are constructed differently. Preferably, multiple, and especially all functionally identical, system components of the two systems are constructed differently.

[0061] In a preferred embodiment, the system components with different configurations are based on different operating principles, as described in more detail above, for example, incorporating braking devices, motion sensors, and / or devices for detecting instantaneous forces.

[0062] As alternatives or supplements, the various system components differ in that they come from different manufacturers, for example.

[0063] In particular, the articulated robot is configured with redundant control units and / or redundant evaluation units as described above. The articulated robot is controlled by the control units. Suitably, these control units and / or evaluation units are also redundantly designed, and are further preferably different from each other. This means that the individual components, such as hardware and / or software, are constructed differently. As a complement or alternative, the software and / or hardware come from different manufacturers.

[0064] Preferably, the multiple system components in the two redundant systems, and more preferably all system components, are configured differently from each other. This ensures high, fail-safe redundancy overall.

[0065] This fundamental principle is not limited to applications in articulated arm robots, but can be applied universally to equipment and machines.

[0066] System components, particularly at least one, more, or all of the components already described above, specifically:

[0067] a. A braking device with a redundant design featuring two brakes based on different operating principles;

[0068] b. Redundant monitoring of the operation of an articulated arm robot with two different monitoring devices;

[0069] c. Different control or evaluation units;

[0070] d. Motion sensors with different structures are used to detect the instantaneous position of corresponding robot components;

[0071] e. Various devices for detecting instantaneous forces acting on robot components;

[0072] f. Different position sensors are used to detect the position of components of the braking device;

[0073] g. Different bus systems used for data transmission. Attached Figure Description

[0074] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. These drawings are shown in a simplified manner:

[0075] Figure 1 A simplified side view of the articulated arm robot is shown;

[0076] Figure 2 It is a schematic block diagram representation of an articulated arm robot with two independent monitoring devices;

[0077] Figure 3 It is a schematic partial block diagram of an articulated arm robot with two independent monitoring devices, based on an alternative implementation variant;

[0078] Figure 4 , 5 Alternative variants of the articulated arm robot are shown; and

[0079] Figure 6 It is a simplified side view of a drive unit with a braking device having two brakes of different constructions. Detailed Implementation

[0080] exist Figure 1 as well as Figure 4 and Figure 5 The image shows an articulated arm robot 20, which is used in particular as a medical robot for medical applications. The articulated arm robot 20 is a multi-axis robot with multiple robotic components 22, which are connected to each other via joints 24.

[0081] In one embodiment, the articulated arm robot 20 has, for example, a base 26 on which a base serving as a first robot component 22 is rotatably arranged about a vertical axis of rotation via a first joint 24. On this base, a swing arm serving as a second robot component 22 is pivotally oriented about a horizontal axis around a second joint 24. At the end of the swing arm, a robot arm serving as another robot component 22 is rotatably supported about a third joint 24. Finally, a robot hand serving as another robot component 22 is rotatably supported about another joint 24 on the robot arm. This robot hand has a rotatable mounting flange at its front end for securing tools. For medical robots, this could be, for example, a medical device or a patient bed.

[0082] During operation, the individual robot components 22 adjust relative to each other around their respective joints 24. For this purpose, each joint is assigned a separate electric drive unit for performing the adjustment movements. The articulated arm robot 20 is typically controlled by a control unit not shown in detail here.

[0083] As a supplement to or alternative to rotational adjustment about a rotational axis, at least one robot component 22 may also be translatably adjustable. This is achieved, in particular, by an additional translational drive unit or by a combined drive unit configured to perform both rotational and translational movements. Figure 5 A variation of the implementation is shown, in which a robot component 22 (right half of the figure) can translate along, for example, a guide rail.

[0084] For this type of articulated arm robot 20, the movement process is monitored for safety reasons. Especially for articulated arm robots 20 that work near people or even on patients, such as medical robots, a high level of functional safety must be ensured.

[0085] Combination Figure 2 as well as Figure 3 The following section describes in more detail the operation monitoring of the articulated arm robot 20 and the necessary equipment for it:

[0086] exist Figure 2 as well as Figure 3 In the simplified block diagram of the articulated arm robot 20, each joint 24 is schematically represented by a box, which shows multiple components. The joints 24 are connected to each other by simplified robot components 22. In this embodiment, only three joints 24 are shown in total.

[0087] In practice, various components are usually arranged inside the corresponding joint 24.

[0088] This specifically involves the individual motors 28, on the output side of which a transmission mechanism 30 is connected. The corresponding robot components 22 are driven via output shafts 32.

[0089] On the output side, a first encoder 34A, serving as a first motion sensor, is mounted after the transmission mechanism 30. This encoder detects the movement of the output shaft 32 to determine the position and / or velocity of the corresponding robot component 22. According to... Figure 3 In the variant, the first encoder 34A is represented by two boxes, thereby illustrating a configuration with two read heads.

[0090] according to Figure 2 On the input side of the motor 28, opposite to the transmission mechanism 30, a braking device with two redundant brakes 64A and B, and a second encoder 34B serving as a second motion sensor, are mounted on the input shaft of the motor 28 (not shown in detail here). Figure 3 In a variant, the encoder preferably has a read head. Furthermore, in this embodiment, a braking device with two brakes 64A and B is arranged between the motor 28 and the transmission mechanism 30.

[0091] The motor 28, transmission mechanism 30, output shaft 32, and braking device, together with encoders 34A and 34B, form a corresponding drive unit 62 (see [link]). Figure 6 Tool 38 is typically fixed to the last joint 24 via a mounting flange.

[0092] The two encoders 34A and 34B are preferably configured differently, wherein one encoder 34A is preferably configured as an incremental encoder 34A and the other encoder 34B is preferably configured as an absolute encoder 34B. The incremental encoder 34A detects and transmits relative position changes, while the absolute encoder 34B provides the absolute position of the robot component 22 as a measurement result.

[0093] Within the box representing joint 24, structural components of robot component 22 are also schematically shown, on which strain gauges 40A are mounted as strain sensors, forming a first device for detecting forces acting on the respective robot component 22. In an embodiment, for example, three strain gauges 40A are schematically shown by a triangle. In an embodiment, strain gauges 40A are connected to an associated measurement acquisition unit 42. Alternatively or supplementarily, in an alternative embodiment, the force measuring device is arranged as a first device for detecting instantaneous forces or as another first device. The force measuring device is arranged between the last robot component, particularly the so-called robot hand, and the working tool (end effector) fixed thereon.

[0094] In addition, each motor 28 is equipped with a current sensor 40B, which detects the instantaneous motor current of the motor 28. The current sensor 40B forms a second device for detecting the force acting on the corresponding robot component 22.

[0095] The respective drive units assigned to the corresponding joints 24, including the first and second motion sensors (encoders 34A, 34B) and the first and second devices (strain gauge 40A and current sensor 40B), are preferably the same for all joints 24.

[0096] For monitoring purposes, two evaluation units 44A and 44B are also constructed. The first evaluation unit 44A receives (measurement) data from all the first encoders 34A and all the strain gauges 40A. Based on this data, the first evaluation unit 44A performs an evaluation of the instantaneous position and / or velocity of the corresponding robot component 22, and especially of the forces acting instantaneously on the robot component 22.

[0097] Similarly, the second evaluation unit 44B receives (measurement) data from all the second encoders 34B and all the current sensors 40B, and performs an evaluation based on this data, similar to the first evaluation unit 44A.

[0098] According to Figure 3 In this variant, two separate data paths are formed within the joint 24 (represented by the box), each leading to a joint-specific interface 46A and B. These are, in particular, data or communication interfaces that communicate with the two evaluation units 44A and 44B. Furthermore, the first system component (first encoder 34A, first brake 64A, first device (strain gauge 40A)) is connected to the first interface 46A. Conversely, the second system component (second encoder 34B, second brake 64B, second device (current sensor 40B)) is connected to the second interface 46B.

[0099] Each interface 46A, 46B is also connected to the evaluation units 44A, B assigned to it. The two interfaces 46A, B and / or the two evaluation units 44A, B are preferably connected to each other via a communication connection, especially for comparing their respective data.

[0100] In appropriate further development, in particular, data communication between interfaces 46A, B and evaluation units 44A, B is carried out through different bus systems 48A, 48B, especially through a first bus system 48A constructed as an Ethernet bus and a second bus system 48B constructed as an RS-485 bus.

[0101] The first evaluation unit 44A, together with the first motion sensor (first encoder 34A) and the first device (strain gauge 40A), and in accordance with... Figure 3 In the variant, the first monitoring device is formed together with the first interface 46A and the first bus system 48A. Correspondingly, the second evaluation unit 44B, together with the second motion sensor (second encoder 34B) and the second device (current sensor 40B), and in accordance with... Figure 3In the variant, the second monitoring device is formed together with the second interface 46B and the second bus system 48B.

[0102] This creates two redundant monitoring paths, ensuring safe monitoring of operations. It is important to emphasize that the individual sensor devices used in the two monitoring paths are independent of each other and, more importantly, based on different measurement principles.

[0103] Furthermore, it is important to emphasize that, as a fundamental design principle for the safe operation of the articulated robot 2, the robot features a redundant system design with multiple system components, which are therefore redundantly constructed with each other. The redundantly constructed system components are each designed to perform the same function, and in particular, the articulated robot 2 can continue to operate even if one of the two redundant system components fails.

[0104] The system components herein are either the first component of the aforementioned first monitoring device and the first brake 64B, or the second component of the aforementioned second monitoring device and the second brake 64B.

[0105] At least some, preferably many, and especially all of these system components are constructed differently from each other, as previously described.

[0106] Combination Figure 6 The following describes a braking device 60 with a redundant design having two brakes 64A and 64B, which operate according to different physical principles:

[0107] The redundant braking devices 60 are each configured as part of the drive unit 62. The adjustment movements of the corresponding robot components 22 are performed by the respective drive units 62. The drive units 62 are specifically arranged directly in the joints 24.

[0108] The redundant braking device 60 has two brakes 64A and 64B, which are configured to apply braking force non-electrically. The two brakes 64A and 64B and the generation of braking force are based on different operating principles.

[0109] In the illustrated embodiment, the drive unit 62 has a motor 28 on a common shaft 66 and a transmission mechanism 30 connected thereto on its output side. A portion of the shaft 66, referred to as the output shaft 32, drives the robot component 22 and is connected to it via a suitable, for example, flexible, shaft connection.

[0110] In one embodiment, the braking device 60 is arranged on the portion formed by the input side of the shaft 66, and is therefore opposite to the output side.

[0111] Alternatively, according to a preferred variant, the braking device is arranged between the motor 28 and the transmission mechanism 30.

[0112] In one embodiment, shaft 66 has a portion configured as a hollow shaft 72 on which the braking device 60 is mounted. The hollow shaft 72 is connected to the rest of shaft 66 in a suitable manner, for example, via a flange.

[0113] A fixed brake disc 74 is fixedly connected to the hollow shaft 72 in its middle. Movable brake discs 76A and 76B, which are movably supported in the longitudinal direction of the hollow shaft 72, are respectively positioned on both sides of it.

[0114] Each movable brake disc 76A, 76B is assigned an electromagnet 78A, 78B.

[0115] A non-electrically generated force acts on each movable brake disc 76A, 76B, directed toward the fixed brake disc 74. For one movable brake disc 76A, this force is applied by means of a spring element 80. For the other movable brake disc 76B, this force is applied by means of a permanent magnet 82. The permanent magnet may be embedded in the movable brake disc 76B, or form a carrier on which brake pads are arranged.

[0116] To control the braking force, two electromagnets 78A and 78B are used to controllably generate a force opposite to the spring force or the force of the permanent magnet.

[0117] Two electromagnets 78A and 78B are controlled by a conductor 84. The conductor 84 extends to the electromagnets 78A and 78B within the cavity of the hollow shaft 72.

[0118] Furthermore, position sensors 86 are preferably arranged to detect the corresponding positions of the movable brake discs 76A and 76B relative to the fixed brake disc 74. For example, electromagnets 78A and 78B are controlled based on these position sensors 86A and 86B.

[0119] Preferably, each movable brake disc 76A, 76B is assigned two position sensors 86A, 86B. Preferably, these position sensors are not only redundant but also have different configurations. In particular, position sensor 86 monitors the air gap between the movable brake disc 76A, 76B and the fixed brake disc 74. The two redundant position sensors 86A, 86B assigned to each brake 64A, 64B are preferably configured with opposite logic, such that one sensor is closed in the normal state and the other is open in the normal state.

[0120] List of reference numerals

[0121] 20 articulated arm robots

[0122] 22 Robot Components

[0123] 24 joints

[0124] 26 bases

[0125] 28 motors

[0126] 30 Transmission Mechanism

[0127] 32 Output shaft

[0128] 34A First Encoder

[0129] 34B Second Encoder

[0130] 38 tools

[0131] 40A strain gauge

[0132] 40B Current Sensor

[0133] 42 Measurement value acquisition device

[0134] 44A First Assessment Unit

[0135] 44B Second Assessment Unit

[0136] 46A First Interface

[0137] 46B Second Interface

[0138] 48A First Bus System

[0139] 48B Second Bus System

[0140] 60 Braking device

[0141] 62 drive units

[0142] 64A, B brakes

[0143] 66 axes

[0144] 72 Hollow Shaft

[0145] 74 Fixed brake disc

[0146] 76A, B Movable Brake Discs

[0147] 78A, B electromagnets

[0148] 80 Spring Components

[0149] 82 permanent magnet

[0150] 84 wires

[0151] 86A, B position sensors

Claims

1. An articulated arm robot (20) having a plurality of robot components (22), the plurality of robot components being connected to each other by joints (24) and driven by motors (28), the articulated arm robot being configured for redundant monitoring of its operation, characterized in that, The system comprises two independent monitoring devices: a first monitoring device (34A, 40A, 44A) and a second monitoring device (34B, 40, 44B). Each monitoring device has the following features: - A motion sensor, namely a first motion sensor and a second motion sensor (34A, 34B), is used to detect the instantaneous position of the corresponding robot component (22); - A device for detecting instantaneous forces acting on a robot component (22), namely a first device and a second device (40A, 40B), wherein the first device and the second device are based on different measurement principles; - An evaluation unit, namely a first evaluation unit (44A), for processing data from a first motion sensor (34A) and data from a first device (40A), and a second evaluation unit (44B), for processing data from a second motion sensor (34B) and data from a second device (40B).

2. The articulated arm robot (20) according to the preceding claims, wherein the corresponding evaluation units (44A, 44B) are configured to evaluate data instantaneously detected by the corresponding motion sensors (34A, 34B) and data on the force instantaneously detected by the corresponding devices (40A, 40B) together to detect possible collisions between the articulated arm robot (20) and objects, and in particular to perform mutual verification.

3. The articulated arm robot (20) according to any one of the preceding claims, wherein the first monitoring device (34A, 40A, 44A) has at least one strain sensor mounted on the robot component (22) as a first device for detecting instantaneous force, the strain sensor being configured in particular as a strain gauge (40A), or alternatively as a force measuring device.

4. The articulated arm robot (20) according to the preceding claims, wherein the second monitoring device (34B, 40, 44B) as a device for detecting instantaneous force has a current sensor (40B) for determining the motor current of the motor (28).

5. The articulated arm robot (20) according to any one of the preceding claims, wherein the two motion sensors are encoders (34A, 34B) and are used to detect the rotational motion of the shaft of the motor (28).

6. The articulated arm robot (20) according to any one of the preceding claims, wherein motion sensors (34A, 34B) are arranged in different positions, particularly on the opposite side of the motor (28).

7. The articulated arm robot (20) according to any one of the preceding claims, wherein the motion sensors (34A, 34B) are configured differently from each other.

8. The articulated arm robot (20) according to any one of the preceding claims, wherein one motion sensor is configured as an incremental encoder (34A), the other motion sensor is configured as an absolute encoder (34B), and / or the encoders (34A, 34B) differ in the number of read heads.

9. The articulated arm robot (20) according to any one of the preceding claims, wherein a plurality of, in particular all, robot components (22) are respectively assigned a first motion sensor and a second motion sensor (34A, 34B), and a first device and a second device (40A, 40B), and data from all the first motion sensors (34A) and the first device (40A) are evaluated by a first evaluation unit (44A), and data from all the second motion sensors (34B) and the second device (40B) are evaluated by a second evaluation unit (44B).

10. The articulated arm robot (20) according to any one of the preceding claims, wherein the two evaluation units (44A, 44B) are constructed differently from each other and, in particular, are from different manufacturers.

11. The articulated arm robot (20) according to any one of the preceding claims, wherein a different bus system is used for data communication, particularly with the evaluation unit (44A, 44B).

12. The articulated arm robot (20) according to any one of the preceding claims, wherein the robot components (22) are driven by electric drive units (62), each of which has a motor (28), wherein at least one drive unit (62) has a redundant braking device (60) with two brakes (64A, B), each brake being configured to apply braking force non-electrically, characterized in that, The two brakes (64A, B) are based on different operating principles, so the corresponding braking forces of the two brakes (64A, B) are applied through different operating principles.

13. A method for monitoring a multi-axis articulated arm robot (20) having a plurality of robot components (22) connected to each other by a joint (24) and driven by a motor (28), wherein monitoring is performed by means of a first monitoring device (34A, 40A, 44A) and a second monitoring device (34B, 40B, 44B), and each monitoring device has - A motion sensor, namely a first motion sensor and a second motion sensor (34A, 34B), is used to detect the instantaneous position of the corresponding robot component (22). - A device for detecting instantaneous forces acting on robot component (22), namely a first device and a second device (40A, 40B), wherein the two devices (40A, 40B) are based on different measurement principles, and the instantaneous forces acting on robot component (22), especially deformations, are measured by the two devices (40A, 40B). - An evaluation unit, namely a first evaluation unit (44A) that evaluates data from a first motion sensor (34A) and data from a first device (40A), and a second evaluation unit (44B) that evaluates data from a second motion sensor (34B) and data from a second device (40B).

14. An articulated arm robot (20), particularly an articulated arm robot according to any one of claims 1 to 12, having a system with a redundant design for the operation of the articulated arm robot (20), wherein the corresponding redundant system has a plurality of system components, characterized in that, At least one of the system components of the two redundant systems is constructed differently.

15. The articulated arm robot (20) according to the preceding claims, characterized in that, System components with different structures are based on different working principles.

16. The articulated arm robot (20) according to any one of the preceding two claims, characterized in that, The corresponding redundant system has a control unit and / or evaluation unit, wherein the control units and / or evaluation units of the two redundant systems are different from each other, and in particular from different manufacturers.

17. The articulated arm robot (20) according to any one of claims 14 to 16, characterized in that, Preferably, multiple system components in two redundant systems, especially all system components in two redundant systems, are different from each other.

18. The articulated arm robot (20) according to any one of claims 14 to 17, characterized in that, The system component is one or more of the following components, preferably all of them: a. A braking device (60) with a redundant design having two brakes (64A, 64B) based on different operating principles; b. Redundant monitoring of the operation of an articulated arm robot (20) with two monitoring devices, which are different from each other; c. Different control or evaluation units (44A, B); d. Motion sensors (34A, 34B) with different configurations are used to detect the instantaneous position of the corresponding robot components (22); e. Various devices for detecting instantaneous forces acting on robot components (22); f. Different position sensors (86A, B) are used to detect the position of components of the braking device (60); g. Different bus systems used for data transmission.

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