Sensor roller for conveyor and storage equipment for transporting unit loads

Abstract

Sensor roller for conveying and storage equipment for transporting unit loads, which are equipped with a plurality of rotatably mounted rollers for supporting and transporting a unit load placed on them, wherein the sensor roller (1) has at least one sensor which sends a signal when it detects a unit load that has accumulated on the sensor roller (1), wherein the sensor roller (1) has, in addition to the sensor, current-generating elements and a transmitter as components arranged within the roller body of the sensor roller (1), characterized in that the transmitted signal is coded and has its own unique identifier, which is linked to a defined position of the sensor roller (1) in the conveying and storage equipment during installation, and that the sensor roller is provided with an internal energy storage device (17).for receiving the energy generated by a rotation of the sensor roller (1) and supplying it to the consumers of the sensor roller (1) as required, wherein electronics are provided for evaluating the current generation and information derived therefrom regarding the direction of rotation, rotational speed, etc. of the sensor roller (1).

Description

The present invention relates to a sensor roller for conveying and storage equipment for transporting unit loads, as described by independent claim 1. The digitalization of industry is also impacting intralogistics. There is a consensus within the industry that more data is needed to make targeted decisions, particularly in conveyor and storage systems. Ideally, this data should be available in real time and be able to be communicated between machines, preferably wirelessly. For the temporary storage of products, push-in storage systems with inclined roller conveyors are preferred. The fill level, or the position of available storage locations, is crucial for these systems. With these systems, this information is typically determined visually by warehouse personnel. Due to the limited visibility, a precise assessment is either impossible or at least difficult. Two loading and unloading methods are common. In a First In-First Out (FIFO) push-in storage system, pallets are placed at the highest point and then roll down to the lowest point. Additional pallets then roll down as far as possible and line up alongside the existing pallets. Retrieval then takes place at the lowest point. The second method is the First In-Last Out (FILO) push-in storage system. Pallets are placed at the lowest point.To insert further pallets, the next pallet pushes the existing one upwards and then sets it down. Removal then takes place at the bottom. Typically, the first pallet is separated from the following one by a separator to prevent them from piling up during removal. Furthermore, brake rollers are usually installed to prevent excessive speed for pallets following behind. When the foremost pallet is removed, all subsequent pallets in the channel move forward one position. For warehouses of this type, there are no solutions for transport rollers that report their status, i.e., whether a load is moving over the rollers or is currently positioned above them. Existing solutions from the field of powered conveyor systems are unsuitable because they are too expensive or do not provide sufficiently reliable data in warehouse environments due to monitoring difficulties. Solutions such as RFID technology are expensive when monitoring larger distances and are unreliable due to the shielding typically present. The use of light barriers presents problems such as cobwebs or general dirt. Radar technology is affected by shading from shelving. Furthermore, conventional monitoring systems require extensive cabling. Conversely, a suitable solution could easily be implemented in powered conveyor systems. Document DE 20 2017 106 949 U1 discloses a sensor for detecting an object on a roller conveyor, wherein the sensor comprises a first printed circuit board with a sensor element comprising at least one resonator and integrated into a roller of the roller conveyor, a power supply circuit for generating a high-frequency signal for a resonator, a receiving circuit for detecting a high-frequency signal from a resonator and an evaluation unit for detecting the object from influences of the object on a high-frequency signal from a resonator, wherein the sensor(10) comprises at least one further printed circuit board which is integrated into the roller, wherein the printed circuit boards are arranged along a longitudinal axis of the roller and in particular offset from the longitudinal axis. Document DE 20 2017 106 950 U1, which is filed by the same applicant as document DE 20 2017 106 949 U1, also discloses a sensor for detecting an object on a roller conveyor, wherein the sensor comprises a sensor element including a ground plane and at least one resonator, which is integrated into a roller of the roller conveyor, a power supply circuit for generating a high-frequency signal for a resonator, a receiving circuit for detecting a high-frequency signal from a resonator, and an evaluation unit for detecting the object from influences of the object on a high-frequency signal from a resonator, wherein the sensor element is arranged parallel to a longitudinal axis of the roller on the inside of the circumference of the roller and at least one part of the sensor element has a cross-section curved according to the circumference of the roller. The explicit task to be solved, as mentioned in the two aforementioned documents, is to improve the integration of a sensor into a roller of a roller conveyor, i.e., the arrangement of the sensors within the roller. Document DE 10 2014 109 402 A1 discloses a sensor for a roller conveyor with a transmitter, a receiver and a sensor element which is integrated into a roller of the roller conveyor, arranged between rollers of the roller conveyor or on the roller conveyor and is provided with an evaluation unit for detecting objects located on the roller conveyor on the basis of a sensor signal from the sensor element, wherein the sensor element has an antenna element, the sensor signal is a high-frequency signal fed into the antenna element by the transmitter, radiated and subsequently received again in the receiver via the antenna element, and wherein the evaluation unit is designed to detect the presence of objects on the basis of influences on the high-frequency signal. The task to be solved by this document is to enable reliable presence detection of objects on a roller conveyor, whereby the core idea of ​​this document is the detection of the presence of objects based on the influences of the high-frequency signal. Document EP 2 918 523 A1 finally discloses a capacitive sensor for a roller of a roller conveyor, which has a plurality of measuring electrodes and a measuring unit for determining capacitances between measuring electrodes in order to detect an object located on the roller conveyor by means of capacitance changes, wherein at least some of the measuring electrodes are arranged to rotate with the roller. There is therefore a concrete need for a cost-effective and wireless solution that requires no electrical power supply to monitor a conveyor and storage system for transporting unit loads and provide information such as the inventory of each individual storage channel based on physical inspection (continuous inventory) or via level indicators in the storage system, on the forklift, or directly on the racking channel, indicating blocked pallets within the respective channel. These blockages can release uncontrollably and, if no brake rollers are used, can cause not only structural damage but also serious accidents. Being able to provide this information in real time would significantly improve the safety of the storage system for the end customer, while simultaneously increasing the system's functionality and availability. This problem is solved by the features of the independent patent claims, with suitable embodiments being described by the features of the dependent patent claims. The system envisages a sensor roller for conveying and storage equipment for transporting unit loads, which is equipped with a plurality of rotatably mounted rollers to support and transport a unit load placed on it, wherein the sensor roller has at least one sensor which sends a signal when it detects a unit load that has accumulated on the sensor roller, wherein the sensor roller has, in addition to the sensor, current-generating elements and a transmitter as components arranged within the roller body, so that it is energy self-sufficient, cable-free and freely positionable in the conveying path. A sensor roller according to the present invention enables evaluations that provide status data of the storage and conveying equipment, such as: - stock level of each individual channel of the warehouse (permanent inventory); - current display of the fill level of each individual channel to prevent damage to goods or the racking system, due to the fact that, for example, during storage, it is unknown to the forklift driver and not visually apparent whether the intended channel can actually still accommodate a pallet or is already full; - information about blockages, e.g., due to pallets with broken skids or protruding nails that may not be able to move independently or in an uncontrolled manner. In a preferred embodiment of the sensor roller, it is provided that the current-generating elements are designed as an electrical generating unit that converts the rotation of the sensor roller body rotation into current. Furthermore, it may be provided that the transmitter is designed as a bidirectional radio device for generating a radio signal, which can be uniquely assigned to a specific sensor roller and can be transmitted multiple times, via the determined roller information, which is triggered by the rotational movement or the rolling over or stopping of goods on the sensor roller and transmitted to at least one receiver. The sensor roller according to the invention can also be characterized in that it is further equipped with at least capacitive or pressure-measuring sensors to increase the information content of the detection. In a further preferred embodiment of the sensor roller, it can also be characterized in that the pressure sensor is designed as a strain gauge arranged in the axial region of the sensor roller, which detects a change in weight applied to it via a mechanical deformation of the axial region. Alternatively, the pressure sensor can also be designed as a piezoelectric or force-sensing resistor, which detects a change in weight applied to it via its mechanical deformation. In the case of using a capacitive sensor, this can be designed as an element that detects a change in the capacitive field between a metallic casing tube of the sensor roller and the frame of the conveying and storage equipment, whereby an internally installed electronics establishes a connection to the metallic casing of the sensor roller and to the metallic frame. The signal sent by the sensor in the sensor roller is coded and has its own unique identifier, which is linked during installation to a defined position of the sensor roller within the conveyor and storage system. Thus, each signal identifier is assigned a defined position. The coded signal preferably also provides information on standstill or movement, direction of rotation, rotational speed, and number of revolutions of the sensor roller, and therefore on the path of the goods. Alternatively, instead of movement information, an additional occupancy sensor can provide a signal indicating the presence of goods on the sensor roller. The sensor roller according to the invention can also preferably be designed as a supporting conveyor roller corresponding to the other conveyor rollers of the conveying and storage equipment, wherein the sensor roller utilizes the existing installation spaces, grid dimensions and similar fastening devices and can thus be positioned variably. The sensor roller is also equipped with an internal energy storage device to absorb the energy generated by its rotation and supply it to the sensor roller's components as needed. This energy enables the processor to start, evaluate the movement and charge states, and then aggregate, encode, and transmit the signals. Afterward, the processor is de-energized and can be restarted after a predetermined period. This variable time frame is a key feature in storage systems, allowing them to operate independently of maintenance intervals such as battery replacement or recharging. The sensor roller according to the invention is further characterized by the fact that electronics for evaluating the current generation and derived information on direction of rotation, rotational speed, etc. are provided in the sensor roller itself. In a particularly preferred embodiment, the sensor roll is designed such that the energy-generating element, the sensor(s), the signal-sending element and the electronics for evaluation are combined as an integral unit in a cartridge for arrangement within a roll casing. With all the features described above, cost-effective, continuous physical monitoring of changes at all storage locations can be provided. This has the advantage of enabling continuous inventory tracking. The downtime required for manual inventory is thus eliminated. Full storage channels are marked accordingly, preventing any attempt to store goods there. Damage to goods or storage locations can therefore be almost completely eliminated. Malfunctions of stationary pallets can be reported immediately and rectified promptly. This increases the functionality and availability of the entire conveyor and storage system in which the sensor roller is used. With the invention as described here, it is possible to physically monitor every pallet or storage location. Also planned are conveying and storage facilities for the transport of unit loads, which include at least one sensor roller as described above. In a preferred embodiment of the conveying and storage equipment according to the invention, it is provided that the plane on which the sensor roller touches the pallet is arranged slightly higher than the conveying surface formed by the support rollers in order to transmit the frictional forces. The conveying and storage equipment according to the invention can also be characterized by the fact that at least one sensor roller has a slightly larger diameter compared to the surrounding conveying rollers. Finally, the conveying and storage equipment can also be characterized by the fact that at least one stationary receiving unit is provided for receiving the signal emitted by the at least one sensor roller and for forwarding it to a data processing system. Further features and advantages of the present invention will become apparent from the following description of a preferred embodiment with reference to the accompanying drawings; therein: - Fig. 1 shows a schematic representation of an embodiment of the sensor roller according to the invention with rotation detection and occupancy sensor; and - Fig. 2 shows a schematic representation of the arrangement of a sensor roller according to Fig. 1 in a conveyor section of a conveying and storage system as a load-bearing roller; - Fig. 3 shows a schematic representation of the arrangement of a sensor roller according to Fig. 1 in a conveyor section of a conveying and storage system as a non-load-bearing roller. Fig. 1 shows a schematic representation of a preferred embodiment of the sensor roller 1 according to the invention, which has a modular design. On one side, a stationary axle arm 5 is visible, secured to the side profiles 3 by means of a nut 7. A bearing shell ring 8 with a ball bearing 15 for the outer tube 12 is mounted on the stationary axle arm 5. On the other side, a stationary axle arm 6 is visible, secured to the side profiles 3 by means of a nut 7. The stationary axle arm 6 is rotationally symmetrical but has a flattened section in the direction of the axis 14, which receives and aligns the positively locked, fixed bearing shell ring 9. A planetary gear 13 is arranged between the stationary axle arms 5 and 6 and the rotating outer tube 12. The planetary gear 13 is driven by the outer tube 12 via a clamping set 10.The displacement of all rotating elements on the axis 14 with the also positively locked base support 25 is preferably effected by means of ball bearings 15, the bearings being sealed against dirt and dust. A generator 16 is also provided as an energy generation unit between the stationary axis arms 5 and 6 and the rotating casing tube 12 of the sensor roller 1, which generates energy from a rotary motion or from a bending alternating stress. Also visible is a short-term energy storage device 17, here in the form of a capacitor in combination with suitable charging and discharging functionality, which is arranged on the fixed axis 14 with base support 25 at the output of the generator 16. Also arranged on the stationary axle boom 6 is an evaluation electronics 18, which in the illustrated embodiment is designed as a sensor encoder, for detecting the strength of the rotational movement, i.e. the rotational speed, as well as the direction of rotation and / or instead of the movement information, by means of an additional occupancy sensor 19, provides a signal about the presence of an upright item. Figure 1 also shows a microcontroller 20 with a transmitter unit 21, which is also arranged on the stationary axis 14 with base support 25. The microcontroller 20 serves to forward the prepared information, which is provided with a unique identifier. Finally, an antenna 22 is arranged in the area of ​​the fixed axle boom 6. The outer tube 12 of the sensor roller 1 can be made of plastic tubes or of, preferably, galvanized steel tubes. The fixed base support 25, secured by positive locking, allows the electronic components to be mounted without rotational influences and keeps the antenna 22, mounted on the electronics, in an optimal radiation position relative to the side profiles 3. The fixed bearing ring 9, secured by positive locking, serves to align the load application perpendicular to the occupancy sensor 19. The positive locking of the fixed axle arm 6, extending outwards, then ensures the correct and reproducible positioning of the sensor roller 1 relative to the side profiles 3. When a pallet passes over the sensor roller 1, the outer tube 12 is set into rotation. The rotation is then transmitted to the planetary gear 13 via the connection between the outer tube 12 and the clamping assembly 10. The planetary gear 13 increases the rotation and directs it to the generator 16. The generator 16 is connected on its mounting side to the stationary base support 25 and thus to the side profiles 3. The generated energy is collected and temporarily stored in the energy storage unit 17. When sufficient energy is available, it is supplied to the electronic components for system startup. Once the electronic components are started, the evaluation electronics 18 begin analyzing the rotational states, and the load sensor 19 determines the pressure or deformation within the measuring area, thus identifying the load situation.The collected information is then evaluated, encoded, and transmitted via radio signal from the transmitter unit 21 with its connected antenna 22. For redundancy, the radio signals are transmitted multiple times. A receiver 23 within range picks up the radio signals and forwards them to an operational computer system. The transmitted information is stored for further use outside the reel and is used for displays, continuous inventory, or fault detection. Once the energy storage device 17 is depleted, the electronic components are de-energized until the next rotation of the outer tube 12. This process can then be repeated at any desired interval. The capacitive solution has a similar setup; however, instead of evaluating a load sensor 19, a capacitive field is established between the outer tube 12 and the side profiles 3. When a pallet is placed on the sensor roller 1, this capacitive field changes, thus detecting the load. To capacitively connect the outer tube 12, the clamping set 10 is equipped with metallic contacts that are pressed against the outer tube 12 and the connection to the planetary gear. The contact is transferred via the numerous contact points of the metallic planetary gear 13 to the stationary part of the planetary gear 13 and then connected to the electronic components via a cable. The other contact to the side profiles 3 is made via the stationary axle arm 6 and the nut 7. A cable is attached to the stationary axle arm 6 and connected to the electronic components. The same principle applies to the spring roller in Fig. 2, however, the load of the pallet is not transferred via the sensor roller 1 into the side profiles 3 and the roller conveyor modules 4. Fig. 2 shows a schematic representation of the arrangement of a sensor roller 1 according to Fig. 1 in a conveyor line of a conveying and storage system as a supporting role. The sensor roller 1 is installed as a load-bearing roller in roller conveyor modules 4, with at least one sensor roller 1 per channel. Preferably at every second storage location, and particularly preferably at every storage location. The sensor roller 1 is mounted in a frame 2, which allows for robust attachment to the side profiles 3 of the roller conveyors and simultaneously enables a floating mounting and free positioning of the sensor roller 1. Sensor roller 1 is installed once per pallet space, or possibly only in every second pallet space, and uses appropriate evaluation logic to detect every change in the load status of all pallets. These states are reported via a standard interface to a higher-level computer system 24 for further evaluation. Fig. 3 shows a schematic representation of the arrangement of a sensor roller 1 according to Fig. 1 in a conveyor line of a conveying and storage system as a non-load-bearing roller. The sensor roller 1 is installed as a non-load-bearing roller in roller conveyor modules 4, with at least one sensor roller 1 per channel. Preferably at every second storage location, and particularly preferably at every storage location. The sensor roller 1 is not subjected to the weight of the stored pallets. It is pressed against the pallet skids with a defined preload by a spring-loaded fixing 11 on the side profiles 3. Sensor roller 1 is installed once per pallet space, or possibly only in every second pallet space, and uses appropriate evaluation logic to detect every change in the load status of all pallets. These states are reported via a standard interface to a higher-level computer system 24 for further evaluation. Figures 2 and 3 also show a receiver 23 for receiving the signals from the sensor roller 1 and forwarding them to a central computer system 24. Preferably, the information from the sensor rolls 1 is processed centrally for feedback to the company's accounting and warehousing systems as well as to logistics, whereby, for example, a display unit can be provided on the forklift in the warehouse that shows the forklift driver the current occupancy of the warehouse. Number list: 1 Sensor roller 2 Frame 3 Side profiles 4 Roller conveyor module 5 Fixed axle arm 6 Fixed axle arm 7 Nut 8 Bearing shell ring 9 Fixed bearing shell ring 10 Clamping set 11 Spring-loaded fixing 12 Sheath tube 13 Planetary gear 14 Axle 15 Ball bearing 16 Generator 17 Energy storage 18 Evaluation electronics 19 Occupancy sensor 20 Microcontroller 21 Transmitter unit 22 Antenna 23 Receiver 24 Computer system 25 Base support

Claims

Sensor roller for conveying and storage equipment for transporting unit loads, which are equipped with a plurality of rotatably mounted rollers for supporting and transporting a unit load placed on them, wherein the sensor roller (1) has at least one sensor which sends a signal when it detects a unit load that has accumulated on the sensor roller (1), wherein the sensor roller (1) has, in addition to the sensor, current-generating elements and a transmitter as components arranged within the roller body of the sensor roller (1), characterized in that the transmitted signal is coded and has its own unique identifier, which is linked to a defined position of the sensor roller (1) in the conveying and storage equipment during installation, and that the sensor roller is provided with an internal energy storage device (17).for receiving the energy generated by a rotation of the sensor roller (1) and supplying it to the consumers of the sensor roller (1) as required, wherein electronics are provided for evaluating the current generation and information derived therefrom regarding the direction of rotation, rotational speed, etc. of the sensor roller (1). Sensor roller according to claim 1, characterized in that the current-generating elements are designed as an “electrical” generating unit that converts the rotation of the sensor roller body rotation into current. Sensor roller according to claim 1 or 2, characterized in that the transmitter is designed as a unidirectional or bidirectional radio device for generating a radio signal, which can be uniquely assigned to a specific sensor roller (1) and can be transmitted multiple times, via the determined roller information, which is triggered by the rotational movement or the rolling over or the stopping of goods on the sensor roller (1) and transmitted to at least one receiver. Sensor roller according to one of the preceding claims, characterized in that it is further provided at least with capacitive or pressure or deformation measuring sensors to increase the information content of the detection. Sensor roller according to claim 4, characterized in that the sensor for pressure measurement is designed as a strain gauge arranged in the axial region of the sensor roller (1), which detects a change in weight applied via a mechanical deformation of the axial region. Sensor roller according to claim 4, characterized in that the sensor for pressure measurement is designed as a piezoelectric sensor which detects a change in weight applied to it via its mechanical deformation. Sensor roller according to claim 4, characterized in that the sensor for pressure measurement is designed as a force sensing resistor which detects a change in weight applied to it via its mechanical deformation. Sensor roller according to claim 4, characterized in that the capacitive sensor is designed as an element for detecting a change in the capacitive field between a metallic casing tube of the sensor roller (1) and the frame of the conveying and storage equipment, wherein an internally installed electronics establishes a connection to the metallic casing of the sensor roller (1) and to the metallic frame. Sensor roller according to one of the preceding claims, characterized in that the coded signal further provides information on standstill or movement, direction of rotation, rotational speed and number of revolutions of the sensor roller (1) and thus on the path of the goods and / or instead of the movement information, by means of an additional occupancy sensor, provides a signal about the presence of a stationary goods. Sensor roller according to one of the preceding claims, characterized in that it is designed as a supporting sensor roller (1) corresponding to the other conveyor rollers of the conveying and storage equipment, the construction dimensions and design of the fastening device being essentially identical in construction and variably positionable with the other conveyor rollers. Sensor roll according to one of the preceding claims, characterized in that the energy generating element, the sensor(s), the signal sending element and the electronics for evaluation are combined as an integral unit in a cartridge for arrangement within a roll casing of the sensor roll (1). Conveyor and storage equipment for the transport of unit loads, comprising at least one sensor roller (1) according to one of the preceding claims. Conveyor and storage equipment according to claim 12, characterized in that the plane on which the sensor roller (1) touches the pallet is arranged slightly elevated relative to the conveying surface formed by the support rollers for the transmission of frictional forces. Conveyor and storage equipment according to claim 12, characterized in that the at least one sensor roller (1) has a slightly larger diameter compared to the surrounding conveyor rollers. Conveyor and storage equipment according to claim 12, 13 or 14, characterized in that at least one stationary receiving unit is provided for receiving the signal emitted by the at least one sensor roller (1) and for forwarding it to a data processing system.

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