SYSTEMS FOR MONITORING THE OPERATION OF AN ENERGY SUPPLY CHAIN

Description

[0001] The invention generally relates to the monitoring of the operation of at least one energy guiding chain or a similar active or dynamic cable guiding device.

[0002] Cable drag chains are used to guide at least one supply line between a base or fixed point and a carrier that is movable relative to it. They typically form a movable strand, a stationary strand, and a deflection bend in between, with the deflection bend moving at half the speed of the carrier. The cable drag chain typically carries several supply lines, such as cables for electrical power and / or signal supply and hoses for supplying liquid or gaseous operating fluids.

[0003] During normal operation or when the energy chain is used as intended, the movable strand is pulled or pushed in the direction of travel by the driver. Due to friction and inertia, the chain generates a force that opposes the movement and, depending on its length and weight, is subjected to considerable tensile or compressive forces. Compressive forces in particular can lead to faults during operation, particularly in energy chains with high speeds and / or long travel distances. Normal operation of the energy chain can be disrupted due to wear, but also due to an external error or defect, for example a control error that leads to the maximum travel distance being exceeded, or due to an interfering object or obstacle. In such cases, the chain can develop faults, such as:to a breakout of the movable strand in the direction of thrust before the deflection bend, to a bend course deviating from the correct course, to an exit from a guide, etc. up to the breakage of the chain.

[0004] In this context, the invention particularly relates to a monitoring system for the early detection of such fault conditions. The system is equipped with at least one sensor that generates at least one output dependent on the condition of the energy chain and with an evaluation unit. The evaluation unit evaluates the sensor output to monitor whether a critical condition occurs during operation of the energy chain, in particular before the energy chain and the cables routed therein are damaged.

[0005] Such a system is already known from WO 2004 / 090375 A1 and has been successfully launched on the market by the applicant. One or more force sensors detect the forces acting on the energy chain. The evaluation unit compares the detected forces with a predetermined tolerance range to detect whether a malfunction has occurred.

[0006] A further development of the force sensor is proposed in WO 2013 / 156607 A1. For more reliable measurement, it is proposed to arrange several force transducers as sensors in the force transmission between the driver and the corresponding connection point or end fastening parts of the energy chain. The force transducers measure the force exerted on the energy chain at this end, which is monitored as a condition-dependent variable.

[0007] WO 2009 / 095470 A1 and EP 2 235 396 A1 also disclose a force measurement for the purpose of safety shutdown. In this case, the energy chain is separated from the supplied system, machine, or similar device depending on the forces acting on it.

[0008] These previously known approaches monitor for excessive forces occurring in order to intervene, if necessary, before damage, particularly before a break, occurs in the cable chain. Based on force measurement—that is, a quantitative measurement of the value—many malfunctions can be detected early.

[0009] WO 2009 / 095470 A1 (see p. 11) further proposes providing a number of contact elements along the travel path that can come into contact with the energy chain. These contact elements generate a signal, the evaluation of which can trigger a change in operation, in particular the aforementioned disconnection of the energy chain from the machine.

[0010] EP 1 521 015 A2 proposes providing a wear element whose wear representative of the condition of the energy chain is detected, for example, by a proximity switch. The subsequently published EP 3 408 561 B1 proposes determining the condition of an energy chain using several radio circuits integrated into the energy chain.

[0011] However, a reliable statement about the current state of the energy chain, in particular as to whether the energy chain as a whole shows a nominal course, cannot necessarily be made with the previously known systems.

[0012] Another approach, which is not based on an actual measurement in the sense of metrology, was proposed by the applicant in utility model DE 20 2004 005 858 U1. Here, for a selection of a few chain links of the energy chain, a simple, switch-like sensor is arranged on or in each chain link, with which a pivoting of the chain link beyond a certain angular range can be registered. For this purpose, a gravity switch designed as a mercury switch, for example, can be provided, which detects the spatial orientation of the respective chain link. Using a plurality of such sensors in the energy chain, the current position can only be monitored relatively roughly, in particular with regard to whether the deflection curve follows a nominal course. This solution is also complex, since the number of additional devices on or in the energy chain entails considerable cabling effort.

[0013] There are also systems of a different type that only detect a chain break that has already occurred. However, this does not allow for early detection, e.g., for preventive maintenance, and does not prevent an unwanted failure.

[0014] A first object of the present invention is therefore to propose a simple, yet robust solution for monitoring the operation of a power chain, one that requires little manufacturing effort. The system should also allow for early detection of fault conditions.

[0015] An independent second object of the invention is therefore to propose a monitoring system which enables a more precise statement about the current state of the energy chain, in particular about its course, without this being accompanied by a significantly increased cabling effort.

[0016] As a solution, the present invention proposes a monitoring system having the features of claim 1. Advantageous embodiments of this monitoring system are the subject of subclaims.

[0017] A third independent object of the invention is to propose a system that enables a statement to be made about the service life, in particular the remaining service life of the energy chain, for example for the purpose of preventive maintenance.

[0018] The energy guide chain is generally an active, dynamic cable guidance device for guiding at least one cable between a first connection point for connection to a base and a second connection point, which is movable relative thereto, for connection to a driver. Typically, the base is stationary and the driver is relatively movable, e.g., arranged on a moving part of a machine or system to be supplied. The energy guide chain can be moved along a travel path and, in a manner known per se, comprises a movable strand, a stationary strand and a deflection bend in between connecting the two strands. Typically, the movement of the energy guide chain takes place in one plane. However, the invention also includes paths with lateral movement or three-dimensional movement, e.g., in robots.

[0019] The generic monitoring system comprises any desired energy chain and at least one sensor in general, or specifically at least one measured value sensor that generates at least one output dependent on the state of the energy chain. Furthermore, the generic system evaluates this at least one output, preferably using a separate evaluation unit. The term "output" is generally understood here to mean information. This is typically transmitted via one or more electrical signals, digital or analog, to be evaluated. An evaluation unit spatially integrated in or on a sensor or in or on a sensor module with the measured value sensor is also within the scope of the invention.

[0020] An evaluation unit can process status values ​​generated at the respective output. The evaluation unit can compare a set of status values ​​as a whole with an expected set. The evaluation unit can also, for example, compare each value individually with a predetermined target value or tolerance range or tolerance field. The evaluation unit always processes the outputs in order to detect at an early stage whether an error condition, e.g. an undesirable position or incorrect course, occurs during operation of the energy chain. If a discrepancy is determined to be critical, the evaluation unit can output a signal to stop the moving machine part to which the driver is connected, in order to prevent the energy chain from breaking. The processing can be based in particular on target or comparison values ​​that have been predetermined in a learning mode of the evaluation unit. This occurs, for example,by running through normal operation step by step and the evaluation unit recording the operating parameters required for evaluation, which are to be regarded as normal or reference values. FIRST ASPECT OF THE INVENTION

[0021] According to a first aspect of the invention (according to claim 1), the first aforementioned object is already achieved in that the at least one or more sensors are arranged stationary and form a detection path that runs essentially along the travel path of the energy chain. The detection path extends over a partial section of the travel path or over the entire error-prone part thereof. The detection path can, in particular, run parallel to, directly on, and / or spatially adjacent to the travel path. The sensor or the multiple sensors are arranged spatially fixed or stationary and can thus detect any deviation of the chain from the normal travel path, the travel path during error-free normal operation, without themselves moving with the movable energy chain.

[0022] According to the invention, the at least one or more stationary sensors can each react to the energy guide chain approaching the sensor and / or the energy guide chain touching the sensor. In other words, the respective sensor is designed such that it is able to recognize or detect the presence of the energy guide chain in its immediate vicinity. The sensor(s) could, for example, mechanically detect contact with the energy guide chain. However, to avoid wear, sensors that contactlessly register the presence of the energy guide chain in a predefined area, depending on the range of the sensor, are particularly preferred. The sensor(s) can be arranged such that they interact with the chain during normal operation and / or such that they interact with the chain in a fault state.

[0023] The monitoring system according to the invention offers a wide range of implementation options and a number of advantages compared to known monitoring systems. Firstly, the system is particularly robust, meaning it is less susceptible to failure, since the detection system itself—with the exception of the cable chain—does not require any moving parts. One or more stationary sensors can thus be arranged separately from the cable chain itself—rather than directly on or in the longitudinal sections or chain links potentially susceptible to fault conditions—and yet still serve to monitor the critical areas. This inherently protects the sensors themselves from the effects of fault conditions.

[0024] The sensor of the first aspect of the invention can therefore be located outside the chain or externally, unlike previous systems. This requires no, or at most, only minor, changes to the structure of the energy chain itself.

[0025] The detection path can be formed by one or more triggering, sensing elements or the like, which interact with a single sensor which, for example, converts a mechanical actuation into a signal.

[0026] Particularly preferably, the monitoring system according to the invention according to the first aspect comprises a plurality of individual sensors that are distributed in a stationary manner along the travel path in order to form the detection path based on the distribution, preferably parallel to the direction of travel. This allows the system to inherently detect status information relating to the momentary position of the energy chain relative to the detection path. The desired accuracy of detecting the position of the energy chain can be adjusted by the selected number of sensors or the spacing of the individual sensors from one another. Embodiments with several spatially discretely arranged sensors are particularly robust, since the failure of an individual sensor can only slightly affect the overall detection reliability and in any case does not necessarily lead to system failure.In this context, the term “multiplicity” means, in particular, a sufficiently large number so that, at least in the failure-prone longitudinal section of the energy chain, at least one sensor is always in interaction with the moving deflection bend.

[0027] Proven switches familiar to experts, which also generate discrete-value output signals, can be used as sensors. This simplifies the computational effort in the evaluation unit.

[0028] Preferred sensors are those that interact with the energy chain without contact, in particular contactless proximity switches. Particular preference is given to using optical proximity switches, preferably light sensors, i.e. optical sensors in which the optical transmitter and receiver are integrated into a single unit and preferably no reflector is required. Through-beam photoelectric sensors with a separate receiver or retro-reflective photoelectric sensors with an additional reflector can also be considered as optical proximity switches. A preferred alternative to these are capacitive proximity switches that can interact with the energy chain without contact. While this may require changes to the structure of the energy chain, other contactless proximity switches are also technically feasible, such as inductive proximity switches, reed switches, Hall sensors, or the like.Non-contact designs are particularly durable because they are wear-free and can be used flexibly with energy chains of various series, e.g. regardless of the design and size associated with the specific chain.

[0029] In a preferred embodiment of the monitoring system, the sensors are arranged at a height above the nominal length of the movable strand, laterally of the energy chain. In this embodiment, each sensor can detect an exceedance of a predetermined threshold as a fault condition of the chain. An advantage of this embodiment is that it is applicable to both cantilevered and sliding energy chains. This embodiment can be integrated into a guide trough and requires little additional manufacturing effort.

[0030] Furthermore, the sensors can be arranged at the height of the nominal course of the movable strand, laterally to the energy guide chain. In this case, the sensors register contact with or approach of the energy guide chain during normal operation, and a lack of approach or absence indicates a fault condition. Alternatively, the sensors can be arranged at the height of the nominal course of the stationary strand, laterally to the energy guide chain, which can be evaluated together with information about the current position or speed of the carrier. The position of the stationary strand itself can also be detected using sensors arranged opposite the stationary strand, i.e. directed towards the narrow sides of the chain links or the crossbars. In these embodiments, the sensors interact with the energy guide chain both during normal operation and in a fault condition, e.g. to approximately determine the position or travel speed of the deflection bend.This position can be directly compared with a target position, which, for example, depends on a known current position of the driver. The speed of the deflection arc should, for example, be half the speed of the driver during normal operation and is typically lower in a fault condition. The aforementioned designs can also be easily retrofitted into a guide trough or manufactured together with it.

[0031] Particularly preferably, the sensors interact with the deflection bend one after the other as the deflection bend traverses the detection section. This allows the current position of the deflection bend to be easily determined, at least roughly, and compared with a target position, or its speed can be approximately determined. This effect can be achieved with self-supporting cable guide chains if the sensors are arranged at a height between the nominal path of the moving strand and the nominal path of the stationary strand. With sliding cable guide chains, a detection section at the height of the nominal path of the moving strand is also possible.

[0032] The sensors are preferably arranged at a uniform distance from one another, with the minimum distance preferably being the link pitch (longitudinal) in the case of a link chain, or in any case the overall height (in the transverse plane) of the energy chain. The maximum distance should be less than or equal to twice the predetermined deflection curve radius, i.e. the radius below which the deflection curve cannot fall. In this way, a faulty route can always be reliably detected, since the energy chain cannot move undetected through a free space between two adjacent sensors. In many cases, however, a distance which is a multiple of the radius, e.g. 4 to 6 times the radius, is sufficient.

[0033] The sensors can be mounted on or in a guide trough in which the cable drag chain is laterally guided. The advantage of this is that the sensors can be manufactured and delivered together with the guide trough, reducing on-site installation effort. To further reduce effort, sensors that only need to be mounted on one side of the cable drag chain or guide trough are preferred, in order to react to the approach and / or contact of the cable drag chain.

[0034] The evaluation unit can continuously evaluate the encoder outputs during operation. The ongoing evaluation can be carried out discretely with sufficient frequency or continuously. The evaluation unit can have a memory in which nominal reference encoder outputs can be stored or pre-stored through a learning process in order to continuously compare the encoder outputs with the pre-stored nominal reference encoder outputs during operation. The reference encoder outputs can, for example, be generated during commissioning by a reference run of the chain or at the factory by a computer model. The evaluation unit can thus compare them with a nominal sequence predetermined for each direction of travel in order to monitor whether an error condition occurs. The nominal sequence can be determined and set in a learning mode during commissioning of the monitoring system for normal operation. A simple principle with detection of the position of the deflection bend requires, for example,only that the immediately adjacent sensor always responds next in the sequence. If an unexpected sensor responds, an error condition can be concluded.

[0035] If there are a large number of sensors, each of the sensors can be wired to the evaluation unit or one or more intermediate bus interface modules, bus couplers, or the like for communication via a field bus, preferably in a line topology (serial) and especially using two-wire technology, such as ASI bus, CAN bus, or similar. Other bus types, e.g., those according to the IEC 61158 standard, such as Interbus or Profibus, can also be considered. Especially with serial two-wire technology, the cabling effort is kept as low as possible. The stationary sensors are preferably supplied with power via the bus. A wireless interface, such as Wi-Fi, via which the sensors communicate with the evaluation unit is also conceivable. The wireless variant can particularly simplify the installation of the monitoring system on site.

[0036] The sensors can preferably be distributed along only one side of the energy chain or on both sides, e.g. alternately.

[0037] In an alternative embodiment with only one or a few sensors, the sensor has an elongated trigger element, in particular a trigger cord, which forms the detection path above the nominal path of the movable strand, opposite it, and switches when the trigger element is touched by the energy chain. The sensor reacts to contact by the chain, which can only occur if the chain is faulty. This is a particularly cost-effective embodiment because it requires only one sensor and no special evaluation is required. However, it can only detect the exceedance of a specific threshold. SECOND ASPECT OF THE INVENTION

[0038] According to a second aspect of the invention (according to claim 10), the second aforementioned object is already achieved by attaching a plurality of sensor modules not in a stationary manner, but distributed along the length of the energy chain to or in the energy chain. Thus, the sensor modules can each react to a local change in the state of the energy chain, in particular directly in the area of ​​the attachment location, even if this only affects a small, locally limited section of the energy chain.

[0039] The advantage of modular sensors, i.e., interchangeable, closed functional units with their own measurement sensor, is cost reduction even with a large number of sensor units in the energy chain, and a design that is suitable for a wide variety of existing chain series, even for retrofitting if necessary. "Multiplicity" is understood in particular to mean a sufficiently large number, selected so that at least one sensor module is always located in the movable deflection bend, at least in the failure-prone longitudinal section of the energy chain. For example, a sensor module can be attached to every nth chain link if the deflection bend comprises no more than n chain links.

[0040] The sensor modules are preferably designed so compactly that they can be installed in the cable compartment within the cable guide chain, taking up only a small amount of space, e.g., <10%. Sensor modules that can be mounted, e.g., snapped into, recesses on the chain links are also conceivable.

[0041] According to the second aspect of the invention, each sensor module has a communication unit that serves to transmit outputs to the evaluation unit, wherein the outputs depend on the measured variable. A separate communication unit can be provided directly in each sensor module, or several sensor modules can share a common communication unit in or on the energy chain. By appropriately selecting the technology of the communication unit, the manufacturing and installation effort can be kept manageable even with a relatively large number of sensor modules. In addition, a wide variety of output values ​​can be transmitted using suitable, standardized communication protocols, including various quantitative measured variables relating to the condition of the energy chain.

[0042] The communication unit can be designed for wireless data communication via radio or for wired data communication via a data bus. Wireless communication minimizes cabling requirements as much as possible. However, if a wired power supply for the sensor modules is desired anyway, a wired data bus, particularly a field bus for industrial automation, can be used. In both cases, the sensor modules preferably communicate via a communication protocol with error correction for data transmission. This inherently allows the communication unit to transmit and monitor reliably even in the presence of strong electromagnetic interference.

[0043] The measurement sensor can quantitatively record a measurement value, ie measure this measurement value in the sense of metrology.

[0044] For this purpose in particular, a preferred embodiment provides that each sensor module has at least one integrated circuit containing the measured value sensor. A wide variety of sensor technologies are already available in the form of integrated circuits, particularly using semiconductor technology, at low cost. This enables particularly small module sizes.

[0045] A sensor module with integrated circuit can be used as a measured value sensor, preferably at least: an acceleration sensor, in particular a 3-axis acceleration sensor, for quantitatively detecting a kinematic variable, in particular acceleration, speed, and / or position; a position sensor, e.g., a MEMS yaw rate sensor, for quantitatively detecting spatial orientation; and / or a height sensor for quantitatively detecting an absolute height in space; and transmit the corresponding outputs to the evaluation unit. Kinematic parameters, spatial position and / or absolute height of the distributed sensor module allow, individually or in combination, at least two of these These variables each provide a relatively precise statement about the current operating status of the energy chain and, in particular, reliable monitoring of whether this status is within predetermined nominal parameters. Acceleration sensors, in particular, can be used to determine relatively precisely whether the energy chain is exhibiting the desired normal behavior and also to detect critical deviations early on to prevent breakage or downtime.

[0046] As an alternative to more complex sensor modules with digital ICs, it is also conceivable for the sensor module to incorporate a proven analog position sensor, e.g., a potentiometer or similar, as a measurement sensor. This is particularly useful for quantitatively measuring the relative swivel angle between two adjacent links of the energy chain and transmitting the corresponding quantitative outputs to the evaluation unit. This makes it easy to detect, for example, whether an unwanted curvature is occurring in a section not currently in the deflection curve.

[0047] For power supply, each sensor module preferably has an energy storage device, especially its own energy storage device. This allows, for example, a wired power supply to be completely avoided. Wiring effort is also reduced if each sensor module has a circuit for contactless inductive energy transfer, especially with a receiving coil for near-field coupling. This also facilitates retrofitting or replacing the energy chain. This allows, for example, all sensor modules to be supplied via the same supply cable without the need for individual contacting.

[0048] To avoid additional cables in the energy chain, it is advantageous if the communication unit is designed for wireless communication, in particular via Wi-Fi according to IEEE 802.11, and the evaluation unit has a corresponding radio or Wi-Fi interface or is connected to a radio or Wi-Fi interface module.

[0049] Alternatively, the communication unit can be designed for wired communication via a field bus with a line topology, particularly using two-wire technology, such as an ASI bus, CAN bus, or similar. In this case, the evaluation unit should have a corresponding bus interface or be connected to a bus interface module.

[0050] Even with an industrial field bus with line topology, the wiring effort is reduced because all sensor modules can be connected to a common bus line.

[0051] In a preferred embodiment, the communication unit is realized in the form of an integrated circuit, in particular as a component of the sensor module, preferably in the same circuit which has the measured value sensor, or a separate integrated circuit connected to the latter, ie separate ICs, e.g. connected via I2C, can also be used in each sensor module.

[0052] To easily attach the sensor modules without changing the design of the cable drag chain, each sensor module can be integrated into a crossbar detachably attached to a link of the cable drag chain or into a separator detachably attached to a link of the cable drag chain. This allows for easy retrofitting of existing cable drag chains.

[0053] For sensor modules on or in the energy chain, the sensor modules are preferably arranged at a uniform distance from one another along the longitudinal direction of the energy chain. The distance is preferably less than or equal to the length of the deflection curve, in particular less than or equal to 1.6 times the deflection curve radius, in order to achieve sufficiently good position detection accuracy.

[0054] Various of the preferred features listed separately above for the first and second aspects can also be combined with the other aspect, as shown, for example, by data communication, but are each regarded independently as essential to the invention.

[0055] All embodiments are particularly advantageous for energy guiding chains with sliding or rolling upper strand, in particular for energy guiding chains with an approximately horizontal course which are designed for long travel distances, typically >5m, in particular >10m.

[0056] In addition, most of the proposed monitoring systems or arrangements allow for sufficiently accurate and continuous position determination, particularly of the deflection bend, relative to the travel path for monitoring a power chain. An unexpected change in the position of the deflection bend can easily detect a variety of malfunctions.

[0057] Systems according to the first and second aspects allow, in particular, function monitoring for the purpose of safety shutdown. THIRD ASPECT OF THE INVENTION

[0058] The third aspect enables, among other things, the usage-dependent prediction of the remaining service life of energy chains and the cables contained therein.

[0059] According to the independent third aspect of the invention (according to claim 20), the third aforementioned object is already achieved in a system according to the preamble of claim 20 in that at least one sensor module is arranged at an end region of the movable strand which has the second connection point, or else on the driver. The proposed sensor module has at least one sensor for quantitatively detecting a kinematic variable, such as acceleration, speed and / or position, of the driver-side end region of the movable strand and a communication unit for transmitting output data from the sensor, i.e. data based on sensor outputs as a function of detected kinematic variables, to an interface and / or an evaluation unit for further data processing.

[0060] Simply by continuously recording data relating to the dynamic behavior of the energy chain, such as the number of back-and-forth travel cycles performed, or more precise data on the actual travel distance, a prediction of the remaining service life or remaining service life can be calculated, e.g., by comparing it with empirical data from a virtual service life calculation (if applicable). A sensor module as suggested above allows the expansion or retrofitting of an energy chain with a data logger for recording the kinematic operating behavior. The memory does not necessarily have to be implemented in the sensor module, since the data can be continuously transmitted to a higher-level processing or evaluation unit via the communication unit.

[0061] Particularly preferably, an acceleration sensor, in particular a 3-axis acceleration sensor, is provided as the sensor for detecting kinematic variables of the moving chain end. This allows for precise determination of the total travel distance (distance traveled) of the carrier-side chain end during operation through multiple integration. This allows precise conclusions to be drawn about the wear status based on knowledge of the intended application conditions. An acceleration sensor can also provide further wear-relevant data, such as force ratios (tensile / thrust forces) or vibration data from ongoing operation. Furthermore, an acceleration sensor inherently allows for reliable detection of partial distances, since in many applications the energy chain travels more than just complete strokes between the two end positions.

[0062] As an alternative to an acceleration sensor, other sensors are also conceivable, such as displacement sensors, such as incremental encoders, or position sensors such as GPS position measuring devices or the like, which allow continuous recording of the travel path or current position.

[0063] To process the sensor output, a computing unit such as a microprocessor, DSP, ASIC or similar may be provided in the acceleration sensor, which supplies prepared or already processed measurement data to the communication unit.

[0064] To assign recorded data to the specific customer application or the relevant energy chain, the sensor module, in particular the communication unit, can have a predefined, e.g., permanently pre-programmed, unique identifier, which can be used to uniquely identify the sensor module ("sensor number"). A simple implementation for this purpose can be the unique device address already available for addressing communication in most protocols, such as Wi-Fi, ZigBee, CAN bus, or similar. This allows the link to application-specific information such as chain type, dimensions (width, length, etc.), load weight, etc., which influence the service life, e.g., using a suitable database or in the computing or evaluation unit.

[0065] To optimize service life prediction, it is advantageous if the sensor module includes at least one additional sensor for quantitatively recording operating and / or environmental parameters. A temperature sensor, in particular, allows for improvements by considering aging models. Other operating and / or environmental parameters that can be recorded include vibrations, structure-borne noise, dust levels, etc. Vibrations can be recorded using the provided acceleration sensor or an additional piezo sensor.

[0066] Also according to the third aspect, the communication unit can be designed as an integrated circuit for wireless communication with a radio interface, e.g. according to Wi-Fi, Bluetooth, ZigBee or the like, or for communication via a wired bus, such as a CAN bus or other suitable industrial or field bus.

[0067] For the initial installation of existing energy chains or for retrofitting already installed energy chains, it is advantageous if the sensor module is integrated into its own housing and can be releasably attached to a link of the energy chain, in particular to a crosspiece, by means of a suitable connection. Furthermore, other features of the sensor module according to the second aspect described above as preferred can also be applied to the third aspect.

[0068] In a further development, an evaluation or computing unit with an interface to the communication unit(s) is provided, which collects the transmitted data from all existing sensor modules and carries out the service life calculation as an independent solution or forwards the data for this purpose, e.g. to a cloud solution.

[0069] The third aspect also offers particular advantages for energy chains for long travel distances, which are typically designed with a sliding or rolling upper run.

[0070] The system according to the third aspect is particularly suitable for determining the traveled distance for predicting the service life of the energy chain, so that it can be replaced before a failure occurs, for example. Furthermore, the system allows the collection of application data to optimize the prediction models. When a specified service life, calculated from the ongoing measurement using the sensor module, is reached, the computing or evaluation unit can issue a message.

[0071] Further advantageous features and effects of the invention are explained in more detail below using some preferred embodiments with reference to the accompanying drawings. FIG.1A-1B :as a schematic sketch in side view of a first embodiment of a monitoring system with stationary sensors along the travel path with a communication bus in the form of a block diagram; FIG.2 : as a schematic diagram in side view a second embodiment of a monitoring system with stationary sensors along the travel path; FIG.3 : as a schematic diagram in side view a third embodiment of a monitoring system with stationary sensors along the travel path; FIG.4 : as a schematic diagram in side view a fourth embodiment of a monitoring system with stationary sensors along the travel path; FIG.5 : as a schematic diagram in side view of a fifth embodiment of a monitoring system with a stationary sensor and a triggering element along the travel path; FIG.6A :as a schematic diagram in side view of a first embodiment of a monitoring system with a plurality of sensor modules distributed lengthwise in the energy chain, which are designed for radio communication; FIG.6B-6C : possible designs of sensor modules as schematic block diagrams; FIG.7 : as a schematic diagram in side view a second embodiment of a monitoring system with a plurality of sensor modules distributed lengthwise in the energy chain, which are designed for communication via a wired bus; FIG.8 : as a schematic diagram in side view of an embodiment of the system according to the third aspect, with several energy guiding chains, each having a driver-side sensor module that communicates with an evaluation unit; and FIG.9 : another design of a sensor module as a schematic block diagram.

[0072] Throughout all drawings, identical reference symbols indicate features with equivalent properties or effects. Repetition has been avoided for convenience.

[0073] In the FIG.1-7 is an energy guiding chain, generally designated 1, shown with a horizontal stationary strand 11, also called the lower strand when arranged horizontally, a movable strand 12, also called the upper strand when arranged horizontally, and with - as a variable-position transition between them - a movable, approximately U-shaped deflection bend 13 that ensures a predefined radius of curvature. Here, a so-called "sliding," i.e., non-self-supporting, energy guiding chain 1 for long travel distances, typically >3 m, is shown. In such energy guiding chains 1, the movable strand 12 can slide or roll on the stationary strand 11. Known skids or rollers are not shown. The predefined radius of curvature of the deflection bend 13, to protect the guided cables (not shown), is significantly larger than the contact distance between the strands 11, 12.However, the invention is in principle also suitable for self-supporting energy chains or vertical applications (not shown).

[0074] The end region of the stationary strand 11 forms a first connection point of the energy chain 1 and is attached to a base that is spatially fixed to the surroundings and forms the fixed point 2 of the energy chain 10. The end region of the movable strand 12 forms a second connection point of the energy chain 1 and is attached to a driver 4 that is movable relative to the fixed point 2, namely, it is connected to the moving part to be supplied, e.g., of an industrial machine or system.

[0075] In a manner known per se, the driver 4 moves according to the FIG.1-7 drawn double arrows in a forward and backward direction and pulls or pushes the energy chain 1. In FIG.1-7 The driver 4 and thus the position of the energy chain 10 is shown purely as an example, only for illustration purposes as a snapshot or instantaneous intermediate positions. The energy chain 1 is designed for a quasi-plane movement along the forward and backward direction, ie with strands 11, 12 remaining parallel, and essentially consists of chain links (not shown in detail) which are arranged, for example, perpendicular to the plane of the FIG.1-7 pivoting parallel pivot axes are angled against each other. The energy guide chain 1 can be used in all embodiments in a FIG.1B be guided laterally along the guide channel 5 shown schematically in more detail.

[0076] A rare but particularly in long or fast moving energy chains 1 possible fault condition (indicated as a "lightning") is shown here purely schematically and in an exaggerated representation only FIG.1A and FIG.5 , whereby a portion of the movable strand 12 rises in an undesirable manner. The other figures show a normal course of the energy chain 1.

[0077] In the embodiment according to FIG.1A-1B A monitoring system 10 is provided with a plurality of sensors 15-1 to 15-n fixedly mounted on the guide trough 5. The sensors 15-1 to 15-n are wired to a bus interface 18 via a fieldbus 16. To increase the address space of the bus interface 18, a group of several sensors 15-i is connected to the fieldbus 16 via a suitable bus coupler 17. The bus interface 18 is wired to an evaluation unit 6 for data communication. In the event of a malfunction of the energy chain 1, the evaluation unit 6 sends a corresponding signal to the controller 7 of the machine or system supplied by the energy chain 1.

[0078] In the monitoring system 10 after FIG.1A-1B Non-contact optical sensors 15-i, such as light switches, are provided. The sensors 15-i are, as shown in FIG.1B As can be seen, the beam path 19 is arranged so that the beam path 19 lies slightly above the nominal path of the movable strand 12. The beam path 19 runs somewhat perpendicular to the direction of travel. The sensors 15-i respond when a portion of the deflection arc 13 passes through the corresponding beam path 19. The position of the connecting end on the driver 4 can also be detected. Furthermore, the corresponding sensors 15-i react when a section of the movable strand 12 deviates from the nominal path upwards.

[0079] Accordingly, in the exemplary embodiment according to FIG.1A-1B The evaluation unit 6 can detect the current position of the deflection bend 13 and compare this with an expected target position and / or detect whether the movable strand 12 deviates from the target position. The deflection bend 13 should always show a continuous change in position, and no sensor 15-i may be triggered between the deflection bend 13 and the driver 4.

[0080] As a detection path, a plurality of sensors 15-1 to 15-n are mounted on the guide trough 5, distributed along the travel path of the energy chain 1. The sensors 15-i can be manufactured and delivered together with the guide trough 5, optionally including the fieldbus connections, e.g., with bus couplers 17 and bus interface 18. The energy chain 1 can be replaced without making any changes to the monitoring system 10. As an alternative to light sensors as sensors 15-i, other non-contact proximity switches can also be used. The uniform spacing between the sensors 15-i along the travel path is preferably selected to match the specified radius in the deflection curve 13, so that its current position can be determined with sufficient accuracy.

[0081] A suitable fieldbus 16 is particularly suitable for a proven industry-standard bus, e.g., an ASI bus with a line topology, preferably with a power supply for the participants. A design with wireless communication between the sensors 15-i and the evaluation unit 6 is also conceivable, using a suitable interface module instead of the bus interface 18.

[0082] The example according to FIG.2 essentially corresponds to the above. The monitoring system 20 differs primarily in that the plurality of stationary sensors 25 are arranged at the level of the nominal course of the movable strand 12 when the latter is diverting or picking up on the stationary strand 11. This allows the evaluation unit 6 to monitor the nominal course of the movable strand 12 and, for example, compare it with a previously learned target course. In this embodiment, the current position of the deflection bend 13 can also be detected and monitored based on the free space in the deflection bend 13.

[0083] The embodiment according to FIG.3 differs in that the sensors 35-i of the monitoring system 30 are located opposite the crosspieces of the stationary run 11, for example by fastening to the underside of the guide trough 5 (cf. FIG.1B ).

[0084] Together with information about the current position of the carrier 4, for example from the system control 7, the monitoring system 6 can also check the desired course of the movable strand 12 and / or the deflection bend 13 based on the output of the sensors 35-i.

[0085] In the further embodiment according to FIG.4 A smaller number of sensors 45-1 to 45-n are arranged at a greater distance above the deflection bend 13 along the travel path. The sensors 45-1 to 45-n can be designed, for example, as metal detectors, capacitive proximity detectors, or the like. Here, the evaluation unit 6 can compare a vector of analog signal values ​​from the sensors 45-1 to 45-n with a target vector. In the event of an unexpected jump in a vector component beyond a threshold value, the evaluation unit 6 can conclude that the energy chain 1 is malfunctioning.

[0086] In the above embodiments, the distribution of sensors 15-i... 45-i along the travel path forms a detection path. Each sensor 15-i... 45-i reacts individually and locally to the approach of the energy chain 1. Mechanical actuation by contact, for example, a switching contact, is also conceivable, but is more susceptible to wear.

[0087] Another simplified embodiment of a monitoring system 50 is shown in FIG.5 This requires only one electromechanical sensor 55, which has an elongated trigger element 57. The trigger element 57 extends along the travel path of the movable strand 12. The trigger element 57 can be designed as a trigger cord similar to a trip wire. The trigger element 57 is arranged above the nominal path of the movable strand 12, opposite it, and itself forms the detection path. If a section of the movable strand 12 touches the trigger element 57, the sensor 55 is triggered and signals this to the evaluation unit 6, which thereby concludes that there is a malfunction. Analogous to FIG.5 A light barrier (not shown) aligned parallel to the direction of movement can also form the detection path and react without contact.

[0088] The following are based on FIG.6-7 Embodiments according to the second aspect of the invention are explained by way of example. In the monitoring system 60 according to FIG.6 A plurality of sensor modules 65-1 to 65-n are distributed along the length of the energy chain 1. The sensor modules 65-1 to 65-n travel along with the energy chain 1. They can thus locally, relating to a specific longitudinal section of the energy chain 1, record a state variable, in particular a kinematic parameter, of the energy chain 1 using an integrated measurement sensor and continuously communicate this to the evaluation unit 6. For this purpose, each sensor module 65-1 to 65-n has FIG.6B-6C a suitable communication unit 65B, which is preferably integrated into each sensor module 65-i.

[0089] In the example after FIG.6 The communication unit 65B is designed for wireless data transmission via Wi-Fi. Known 3-axis acceleration sensors are particularly suitable as measurement value sensors 65A. These allow the quantitative recording of a kinematic value relating to a local area, e.g., a chain link, of the energy chain 1, to which the respective sensor module 65-i is attached. Additionally or alternatively, position sensors for recording spatial orientation and / or height sensors can also be considered as measurement value sensors 65A. All sensor modules 65-i continuously transmit output values ​​to the evaluation unit 6, e.g., clocked at a sufficiently high frequency. The evaluation unit 6 is connected to the communication units 65B via a suitable radio interface 68 for data transmission.To avoid incorrect error assumptions, in this example, a time average, a moving average or similar can be calculated from the output values ​​of each sensor module 65-i in order to check only for sudden changes.

[0090] A multitude of 65-i sensor modules with 65A measurement transducers for measuring a state variable allows precise information about the current state of the energy chain 1 during operation. This can be continuously compared by the evaluation unit 6 with predetermined nominal values ​​to detect a fault condition early in the event of critical deviations.

[0091] FIG.6B und FIG.6C show two possible embodiments for sensor modules 65-i. Here, an integrated circuit or IC 651 can comprise both the measured variable sensor 65A and the communication unit 65B as functional units. If necessary, further auxiliary circuits 65C, e.g., for power supply from an energy storage device (not shown), signal conditioning, and the like, can be implemented in this IC 651. According to FIG.6C An integrated circuit 652 with the measured variable sensor 65A and, if necessary, auxiliary circuits 65C is implemented separately from an IC which forms the communication unit 65B.

[0092] Alternatively to wireless communication, wired communication is also possible, for example, via an industrial or field bus suitable for higher data rates. A corresponding monitoring system 70 shows FIG.7 , wherein the sensor modules 75-1 to 75-n are connected to a bus interface 78 via a wired field bus 76. The field bus 76 is preferably implemented with a line topology using two-wire technology, which minimizes cabling effort within the energy chain 1. In addition to data transmission, the power supply of the sensor modules 75-i can also be provided via lines of the field bus 76, e.g. similar to FIG.1 , take place.

[0093] Here, the data transmission of quantitative measured values ​​from the individual sensor modules 75-i to the evaluation unit 6 takes place via the bus interface 78, e.g. similar to FIG.1 .

[0094] The following is based on FIG.8 an embodiment according to the third aspect of the invention is explained by way of example.

[0095] According to FIG.8 On the energy guiding chains 1 near the driver 4 there is only one sensor module 865, e.g. with the design according to FIG.6 The sensor modules 865 are releasably attached, for example, to the end fastening member of the movable strand 12.

[0096] The energy guiding chains 1 are designed with a sliding upper strand 12 as intended. Other features of the energy guiding chains 1 correspond to those described above.

[0097] The features of the sensor module 865 correspond, for example, to those as FIG.6 explained above. Each sensor module 865 has at least one sensor 65A ( FIG.6 ), which continuously detects a current movement variable of the end region of the movable strand 12 driven by the driver 4. A 3-axis acceleration sensor can be used as sensor 65A. Other sensors for measuring distance, speed, and / or acceleration, or a combination thereof, are also possible as possible kinematic parameters with respect to the driver-side end of the energy guide chains 1.

[0098] Furthermore, each sensor module 865 has a suitable communication unit 65B ( FIG.6 ) for transmitting collected and, if necessary, processed output data as a function of recorded kinematic variables to an interface of the evaluation unit 86. Communication of the data with the computer-based evaluation unit 86 can take place via a radio channel 82, e.g., using Wi-Fi, ZigBee, or another suitable protocol, e.g., at periodic intervals. Each communication unit 65B has a unique, predefined address that can be used as an identifier for the sensor module 865. The evaluation unit 86 uses this to assign the recorded data to a specific energy chain 1, e.g., using a suitable table or database.

[0099] Alternatively, communication can also be wired, e.g. via an addressable CAN bus 83 or the like, which also supplies the sensor module 865 with power.

[0100] The data output of the sensor modules 865 allows the evaluation unit 86 to independently determine the movement behavior of the energy chains 1. Alternatively, the system 80 allows higher-level software, e.g., a cloud application 85 to which the evaluation unit 86 is connected, e.g., via the Internet, to determine, among other things, the actual traveled distance for the purpose of service life prediction. Using a cloud application 85, data collection for model optimization is also possible, for example.

[0101] The system 80 thus allows, among other things, the usable remaining service life of individual energy chains 1 to be continuously predicted based on the previous use-dependent, application- and operation-specific movement behavior of the respective energy chain 1.

[0102] FIG.9 shows a further development of a sensor module 965, which comprises an acceleration sensor 65A and a communication unit 65B, e.g. according to FIG.6 Furthermore, a sensor 65E is provided for the quantitative recording of operating and / or environmental parameters, e.g., a temperature sensor. A computing unit 65D, e.g., a microprocessor or DSP, is provided to condition the output signals of the sensors 65A, 65E, which continuously processes and conditions the outputs digitally, e.g., smoothes acceleration measurements and averages temperature values. The computing unit 65D generates output data from this and supplies it for forwarding to the communication unit 65B. In the sensor module 965, too, all components 65A... 65E can be partially separate or integrated, e.g., implemented in the form of integrated circuits, e.g., as a fully integrated ASIC solution. Additional measurement data from the second sensor 65E allow the evaluation unit 86 or a cloud application 85 to make better predictions of the remaining service life or to perform further model optimization. Bezugszeichenliste

[0103] FIG.1-6 1 Energy chain 2 Fixed point 4 Carrier 5 Guide trough 6 Evaluation unit 7 Control system 11 Stationary strand 12 Movable strand 13 Deflection bend FIG.1A-1B 10 Monitoring system 15-1... 15-n encoder 16 Fieldbus 17 Bus coupler 18 Bus interface 19 Beam path FIG. 2-4 20; 30; 40 Monitoring system 25-1... 25-n; 35-1... 35-n; 45-1... 45-n Encoder FIG.5 50 Monitoring system 55 Sensor 57 Trigger element FIG.6A-6C 60 Monitoring system 65-1 to 65-n Sensor modules 65A Measurement sensor 65B Communication unit 65C Auxiliary circuits 651; 652 Integrated circuit 68 Radio interface FIG. 7 70 Monitoring system 75-1 to 75-n Sensor modules 76 Fieldbus 78 Bus interface FIG.8 1 Cable guide chain 2 Fixed point 4 Carrier 11, 12 Trusses 13 Deflection bend 80 Monitoring system 82 Radio channel 83 CAN bus 85 Cloud application 86 Evaluation unit 865 Sensor module FIG.9965 Sensor module 65A Acceleration sensor 65B Communication unit 65C Auxiliary circuits 65D Computing unit 65E Temperature sensor 68 Radio interface

Claims

1. Monitoring system (10; ... 50) for the operation of an energy chain for the guidance of at least one line, such as e.g. a cable, hose or the like, between a first connection point for the connection to a base (2), and a second connection point, which is relatively moveable thereto, for the connection to a driver (4), including an energy chain (1) which is displaceable along a displacement path while forming a moveable strand (12), a stationary strand (11) and a deflection arc (13) therebetween; at least one or multiple sensors which respectively generate at least one output dependent upon the condition of the energy chain; and an evaluation unit (6) which evaluates the at least one output of the sensor(s), in order to monitor whether an error condition occurs in the operation of the energy chain; characterized in that the at least one or the multiple sensor(s) (15-i; ... 45-i; 55) are arranged stationary, form a detection path along the displacement path of the energy chain (1) and respectively react to an approach of the energy chain (1) to the sensor and / or to a contact of the sensor by the energy chain.

2. Monitoring system according to claim 1, characterized in that the sensors (15-i; ... 45-i) interact with the energy chain in a contactless manner.

3. Monitoring system according to claim 2, characterized in that the sensors (15-i; ... 45-i) are configured as contactless proximity switches, preferably as optical proximity switches.

4. Monitoring system according to claim 1, 2 or 3, characterized in that the sensors (15-i) are arranged at a height above the nominal course of the moveable strand (12).

5. Monitoring system according to any one of claims 1 to 4, characterized in that the sensors (15-i; ... 35-i) are arranged at regular intervals, wherein the interval preferably is larger than a link separator of the energy chain (1) and / or preferably smaller than or equal to 6 times the amount of the deflection arc radius, in particular twice the amount of the deflection arc radius.

6. Monitoring system according to any one of claims 1 to 5, characterized in that the evaluation unit (6) comprises a storage, in which nominal reference sensor outputs can be stored, in order to continuously compare the outputs of the sensors (15-i; ... 45-i) to the nominal reference sensor outputs during operation.

7. Monitoring system according to any one of claims 1 to 6, characterized in that a plurality of sensors (15-i; ... 45-i) are provided, and - are wired with the evaluation unit (6) for communication via a fieldbus (16), preferably with linear bus topology, e.g. ASI bus, CAN bus or the like; or - communicate with the evaluation unit via a wireless interface (68).

8. Monitoring system according to claim 7, characterized in that at least one interface module, in particular a bus interface module (18) or a radio interface module (68), is connected with the evaluation unit (6), wherein the sensors (15-i;... 45-i) communicate with the evaluation unit via the interface module.

9. Monitoring system according to any one of claims 1 to 8, characterized in that the sensors (15-i;... 45-i) are distributed along the energy chain.

10. Monitoring system according to any one of claims 1 to 9, characterized in that the sensors (15-i; ... 45-i) are attached to a guide trough, in which the energy chain (1) is guided laterally.

11. Monitoring system according to claim 10, characterized in that the sensors (15-i; ... 45-i) are attached unilaterally to the guide trough.

12. Monitoring system according to any one of claims 1 to 11, characterized in that a plurality of stationary arranged sensors (15-i;... 45-i; 55) form a detection path, which - extends at least over a partial section of the displacement path of the energy chain (1); and / or - runs parallel to the displacement path, directly along the displacement path and / or spatially adjacent to the displacement path.

13. Monitoring system according to claim 1, characterized in that the sensor (55) comprises an elongate trigger element (57), in particular a trigger cord, which, above the nominal course of the moveable strand, forms the detection path opposite this moveable strand, and triggers upon a contact of the trigger element by the energy chain (1).

14. Monitoring system according to any one of the preceding claims 1 to 13, characterized in that the energy chain (1) is configured with sliding-off or rolling-off upper strand (12), in particular for long displacement paths.