Uninterrupted operation of a driverless transport vehicle

Abstract

The invention relates to a continuously operating transport vehicle. The transport vehicle has several battery modules for power supply. A subset of the battery modules is sufficient to keep the transport vehicle in a switched-on operating state. The other battery modules can be replaced without switching off the transport vehicle. The power supply can then be switched to another subset of the battery modules in order to replace the remaining battery modules while the transport vehicle remains switched on. The productive availability of the transport vehicle is increased because it does not have to be switched off and on again to replace the battery modules, and because the charging of the battery modules takes place independently of the transport vehicle. If all battery modules are replaced at the same time, the subsequent service life of the transport vehicle is particularly long.

Description

Background of the invention

[0001] The invention relates to an operating method for a driverless transport vehicle with at least two interchangeable battery modules and to such a transport vehicle. The invention further relates to a system comprising such a transport vehicle.

[0002] Automated guided vehicles (AGVs) are used, among other things, in internal logistics for transporting various types of parts, such as semi-finished products, workpieces, finished parts, tools, and the like. These vehicles are generally designed to move autonomously, i.e., without operator intervention. Such vehicles are also referred to as autonomous moving robots (AMRs).

[0003] Typically, driverless transport vehicles are battery-electric powered. The batteries need to be charged regularly. This can be done via contact or inductive charging stations while the batteries remain in the transport vehicle. During such a charging process, the transport vehicles are stationary and cannot perform their normal tasks (downtime). This negatively impacts the efficiency of the transport vehicle itself and the facility in which it is used. In particular, continuous 24 / 7 operation of the facility with a single vehicle is conventionally not possible. The problem of downtime is exacerbated as soon as the vehicle has additional equipment that requires extra power, meaning that more frequent recharging is necessary with no change in battery capacity.While it is theoretically possible to install additional or larger batteries, this also increases the charging time, which further increases the downtime per recharge.

[0004] Often, additional transport vehicles cannot be used due to environmental conditions, such as narrow paths or space limitations, or they do not contribute to increased efficiency. Furthermore, the acquisition of additional transport vehicles involves corresponding costs.

[0005] Instead of recharging batteries, it is generally accepted practice to replace discharged batteries with fully charged ones. The batteries can then be recharged outside the transport vehicle and later reinstalled. This reduces the vehicle's downtime. Battery replacement can be performed manually or automatically.

[0006] If only one battery is used, the transport vehicle must either be powered by an additional voltage source to keep it switched on during the battery change, or it must be shut down beforehand and restarted after the battery change. This requires a significant amount of additional time.

[0007] US 2022 / 0212638 A1 describes an electric vehicle with a compartment for two batteries. The electric vehicle can be configured for autonomous driving. A discharged battery is replaced while the electric vehicle is in motion. For this purpose, a battery delivery vehicle drives autonomously or remotely underneath the electric vehicle while the electric vehicle is also moving. A lifting system in the battery delivery vehicle lifts a new battery into the electric vehicle when the battery delivery vehicle is vertically aligned below an available battery slot in the electric vehicle's compartment. The electric vehicle's power supply is then switched to the new battery, and the existing battery is lowered from the electric vehicle to the battery delivery vehicle.

[0008] This approach requires, firstly, that the electric vehicle has sufficient ground clearance so that the battery delivery vehicle can drive underneath it. Secondly, the operating environment must allow the battery delivery vehicle to operate alongside the electric vehicle. Furthermore, maintaining and operating the battery delivery vehicle involves corresponding costs. Object of the invention

[0009] One of the aims of the invention is to increase the availability of driverless transport vehicles in a rational manner. Description of the invention

[0010] This problem is solved according to the invention by an operating method according to claim 1, a transport vehicle according to claim 11 and a system according to claim 20. Operating method according to the invention

[0011] One aspect of the invention relates to an operating method for an automated guided vehicle (AGV). The AGV has at least two interchangeable battery modules. The AGV may have more than two battery modules. All battery modules are typically identical, particularly with regard to voltage and capacity. Each battery module has at least one battery. The batteries are typically rechargeable. The battery modules may also be referred to as accumulator modules, and the batteries may be referred to as accumulators. The battery modules are typically connected in parallel in the AGV.

[0012] In principle, one of the battery modules is sufficient to operate the transport vehicle (provided the battery module is adequately charged). The battery modules are individually replaceable. Therefore, they can be recharged outside the transport vehicle. This individual replaceability allows the battery modules to be removed from and inserted into the transport vehicle one after the other. With this sequential replacement, the transport vehicle can always be supplied with energy from one of the battery modules.

[0013] The transport vehicle is preferably a driverless transport vehicle according to the invention as described below. Particularly preferably, the transport vehicle is part of a system according to the invention as described below.

[0014] The transport vehicle generally has a transport area for receiving goods to be transported. The transport vehicle is designed to move between different destinations without direct human intervention, in particular to move the received goods from one location to another.

[0015] During operation, the transport vehicle moves autonomously to a battery exchange station. While moving, it is powered by energy from at least one of the battery modules. A final positioning movement of the transport vehicle can be performed externally, particularly by the battery exchange station. Preferably, the transport vehicle automatically assumes the position in which the battery modules are exchanged without any external intervention.

[0016] The battery modules are exchanged at the swapping station. The transport vehicle remains switched on throughout the entire swapping process and is supplied with energy from at least one of the battery modules. Keeping the transport vehicle switched on increases its availability, as it eliminates the time required for switching it off (shutting down) and on (starting up).

[0017] At the battery exchange station, the transport vehicle is initially powered by one of the battery modules. Simultaneously, a second battery module is removed from the vehicle and a charged module is inserted into it (in place of the second module). While the vehicle is powered by the first battery module, additional battery modules can be removed and replaced with charged ones. After the second battery module (and any further modules) has been replaced, the transport vehicle remains at the exchange station.

[0018] The transport vehicle is then supplied with energy from another battery module at the exchange station, in particular the previously used charged battery module. During this process, the first battery module is removed from the transport vehicle and another charged battery module is inserted (in place of the first battery module). Even while the transport vehicle is being supplied with energy from the other battery module, additional battery modules can be removed from the transport vehicle and replaced with a charged battery module.

[0019] Replacing at least two battery modules allows the transport vehicle to operate productively for a longer period than would be the case if only one battery module were replaced. Preferably, all battery modules of the transport vehicle are replaced during each visit to the exchange station, while one of the battery modules in the transport vehicle keeps it switched on and operating.

[0020] The removed battery modules are typically recharged at the exchange station. The charged battery modules are typically removed from the exchange station after they have been recharged there.

[0021] After the battery modules have been replaced, the transport vehicle automatically moves away from the exchange station. The exchange station is then available to other transport vehicles. The transport vehicle can then resume its original task. A large energy reserve is available after several, preferably all, of the transport vehicle's battery modules have been replaced with fully charged ones.

[0022] The battery modules can, in principle, be replaced manually. This reduces the equipment required and increases flexibility, for example, when different types of transport vehicles are used or different types of exchange stations are available.

[0023] Preferably, the changeover is automated. This can increase the speed and reliability of the process. Furthermore, safety requirements are easier to meet when working on the powered-up transport vehicle if no people are interacting with it.

[0024] It may be envisaged that a handling robot, in particular a six-axis robot, removes the battery modules from the transport vehicle and inserts them into the transport vehicle. Handling robots are flexibly programmable and capable of moving the battery modules precisely. Six-axis robots are characterized by their particularly high degree of flexibility.

[0025] In one configuration, the handling robot is carried along by the transport vehicle. Under normal operating conditions, the handling robot can be used for loading and / or unloading the transport vehicle. Using this handling robot reduces the effort required for automated battery module replacement by utilizing the existing handling robot for this additional function. This essentially requires only additional programming.

[0026] The handling robot can be powered (during the changeover process) by the currently active battery module of the transport vehicle. If a separate power source for the transported handling robot is not required, the payload of the transport vehicle can be increased.

[0027] Alternatively, an additional battery module could be provided for the handling robot. This could simplify the installation of the handling robot on the transport vehicle.

[0028] In another variant, the handling robot is stationary at the exchange station. This is particularly advantageous if further handling operations are to take place in the vicinity of the exchange station, for example, if a production machine is located adjacent to it. The handling robot can then both exchange the battery modules and load the production machine.

[0029] Advantageously, the handling robot is designed to move parts (transported goods), particularly workpieces, into and / or remove them from the transport area of ​​the transport vehicle before and / or after changing the battery modules. The handling robot thus performs a dual function: process automation and battery module changing. This reduces the hardware costs for operating the transport vehicle within the relevant plant, such as a production facility. Typically, the battery modules are not changed with every loading or unloading operation, but only after a large number of transport cycles.

[0030] During the changeover process, the transport vehicle can monitor the handling robot's work area. This can be achieved using a sensor array on the transport vehicle, such as a laser scanner. Monitoring the work area allows for checks to see if objects are entering it. While it is possible to have the entire work area covered by the sensor array, it is not essential. Under typical operating conditions, monitoring often requires capturing a two-dimensional, closed boundary of the work area, particularly near the floor on which the transport vehicle can move.

[0031] If the transport vehicle detects an intrusion into the work area, it interrupts the changeover process. To do this, the transport vehicle can stop the handling robot.

[0032] When the transport vehicle is moving, it can monitor its surroundings, especially its path, using the same sensor array. If obstacles are detected in the environment, the transport vehicle can be stopped.

[0033] To safeguard the exchange process, an existing sensor array already present on the transport vehicle is advantageously used. Additional safety measures, such as an enclosure or separate hardware for monitoring the work area, are unnecessary. Furthermore, if the handling robot is transported by the vehicle, secure communication between the two is already established, eliminating the need for any further setup. Monitoring the handling robot's work area by the transport vehicle takes advantage of the fact that the vehicle remains switched on during the exchange process, allowing its sensor array to be used.

[0034] The battery exchange station can be located at a production machine. This reduces the distance required to travel to the exchange station, thus minimizing the downtime lost by the transport vehicle per exchange. It is possible to schedule the battery exchange to coincide with the loading and / or unloading of parts. Furthermore, if the production machine or transport vehicle is already equipped with a suitable handling robot, the battery modules can be exchanged automatically without any additional hardware.

[0035] An operating method in which the same handling robot, whether stationary or transported by the transport vehicle, both exchanges battery modules and moves parts between the transport vehicle and a facility of a production plant, in particular a production machine, is considered an invention in its own right, irrespective of the exchange of the battery modules while the transport vehicle is switched on.

[0036] It can be implemented that the contact resistance between each battery module and a corresponding connection on the transport vehicle is measured, and a warning is issued if the contact resistance exceeds a predefined limit. This allows for the detection of contact wear due to repeated replacement processes.

[0037] Each battery module can have a replaceable battery adapter for connecting to the transport vehicle. Wear-prone contact processes (plugging in and unplugging) during battery changes therefore occur at the battery adapters. If their connections wear out before a battery in a particular module reaches the end of its service life, the battery adapters can be replaced easily and cost-effectively. The battery adapters can be screwed and / or snapped into the housing of the respective battery module.

[0038] It is particularly preferred that a battery adapter of one of the battery modules be replaced, especially after the battery module has undergone a predefined number of insertion cycles and / or if the contact resistance between the battery module and a connection of the transport vehicle exceeds a predefined limit. This prevents disruptions in the energy transfer from the respective battery module to the transport vehicle.

[0039] The battery module may include an electronic unit. In particular, the electronic unit may be located within the battery adapter. The electronic unit may, for example, control an enable pin of the battery module. Alternatively or additionally, the electronic unit may prevent current flow to and / or from the battery module, for example by controlling a corresponding switching component, such as a contactor, a MOSFET, or the like. Transport vehicle according to the invention

[0040] The present invention also encompasses a driverless transport vehicle with at least two interchangeable battery modules. The transport vehicle may have more than two battery modules. All battery modules are typically identical, particularly with regard to voltage and capacity. Each battery module comprises at least one battery. The batteries are typically rechargeable. The battery modules may also be referred to as accumulator modules.

[0041] The transport vehicle is designed to selectively interrupt the power supply from any one of the battery modules, allowing that battery module to be replaced, while a power supply from another battery module keeps the transport vehicle switched on. The transport vehicle can be operated in the manner described above according to the invention.

[0042] The transport vehicle is preferably equipped to automatically seek out a battery swap station when the charge level of any of its battery modules falls below a predefined threshold. This threshold can specify, in particular, a minimum charge level (e.g., a minimum voltage) for each individual battery module. The charge level threshold can be adaptively predefined with regard to upcoming transport tasks. This ensures that the transport vehicle always has a sufficient energy reserve available.

[0043] The threshold can define the latest possible time at which the transport vehicle visits the battery swap station. A pre-threshold for the state of charge of the battery modules can be predefined; if the state of charge falls below this threshold, the vehicle must visit the swap station for a battery module swap, provided the transport vehicle is in close proximity to the swap station and / or has no urgent transport tasks to perform.

[0044] The transport vehicle can be configured to maintain a minimum charge level in at least one of the battery modules, preferably in all battery modules. This battery module(s) allows the transport vehicle to remain switched on (in operation) while the at least one other battery module is being replaced.

[0045] A handling robot, particularly a six-axis robot, can be attached to the transport vehicle. The handling robot can be used both for loading and / or unloading the transport vehicle with parts, as well as for replacing the battery modules. This increases the operating time of the handling robot.

[0046] The transport vehicle can have a sensor arrangement, in particular comprising a laser scanner, for monitoring its surroundings, especially its travel path, and the working area of ​​the handling robot. The transport vehicle is preferably configured to stop or maneuver around an obstacle in its surroundings, especially its travel path, if it detects such an obstacle while traveling using the sensor arrangement. The transport vehicle is also preferably configured to stop the handling robot, in particular to interrupt a battery module exchange process being carried out by the handling robot, if the transport vehicle detects an intrusion into the working area using the sensor arrangement. This prevents hazards to persons caused by the handling robot. The same sensor arrangement thus enables the safety of both battery exchange processes and the vehicle's operation.

[0047] Preferably, each battery module has a replaceable battery adapter for connecting to the transport vehicle. Wear-prone contact processes (plugging in and unplugging) during battery changes thus occur at the battery adapters. If their connections wear out before at least one battery in a given battery module has reached the end of its service life, the battery adapters can be replaced easily and cost-effectively. The battery adapters can be screwed to the housing of the respective battery module. Alternatively or additionally, the battery adapters can be snapped into place on the housing of the respective battery module.

[0048] A transport vehicle with battery modules, each having an interchangeable battery adapter, is also considered a separate invention, irrespective of the interchangeability of the battery modules when the transport vehicle is switched on.

[0049] Each battery adapter can have a first plug connector for connection to a fixed terminal on the battery module housing. The battery adapter can also have a second plug connector for connection to a terminal on the transport vehicle or the exchange station, in particular a receiving adapter on the transport vehicle or a charging adapter on the exchange station.

[0050] The transport vehicle can have at least one replaceable adapter for connecting the battery modules. Wear-prone contact operations (plugging in and unplugging) during battery changes thus occur at this adapter. If its contacts wear out before the transport vehicle reaches the end of its service life, the adapter can be replaced easily and cost-effectively. The adapter is complementary to the battery adapter (if present) or a fixed connection (if no battery adapter is present) of the battery modules.

[0051] A separate mounting adapter can be provided for each battery module on the transport vehicle. Alternatively, a single mounting adapter can be provided to connect multiple, in particular all, battery modules to the transport vehicle.

[0052] Each battery module can have one master battery and at least one slave battery. Alternatively or additionally, each battery module can have its own battery management system. These configurations facilitate the interruption of the power supply from the respective battery module to the transport vehicle for battery replacement.

[0053] The transport vehicle can have a CAN bus for controlling the battery modules. This allows the operator to select which battery module powers the transport vehicle during regular operation and when changing battery modules.

[0054] In one embodiment, the transport vehicle can have at least one battery compartment for receiving at least one of the battery modules. Preferably, the battery compartment is closable with a cover. The cover can be part of a transport compartment of the transport vehicle.

[0055] Preferably, a common battery compartment, in particular with a common cover, is provided for all battery modules. Alternatively, a separate battery compartment with its own cover or a common cover for all battery compartments can be provided for each battery module.

[0056] The battery modules can be arranged upright in an upwardly open, particularly vertical, battery compartment; the cover is then typically located on the top of the transport vehicle. Top-loading battery modules reduce the space required at the exchange station.

[0057] The battery modules can be arranged horizontally in a laterally open, particularly horizontal, battery compartment; the cover is then typically located on one side of the transport vehicle. In this way, a particularly stable upper transport area for receiving cargo can be created.

[0058] In another embodiment, the transport vehicle has at least one battery drawer for receiving at least one of the battery modules. The battery drawer can, in particular, include a pull-out mechanism for guiding at least one battery module received in the drawer. Pulling out the battery drawer improves access to the battery modules for replacement. Electrical connections, in particular at least one receiving adapter of the transport vehicle, can be integrated into the battery drawer. In this way, the battery modules can supply the transport vehicle with energy even when the battery drawer is pulled out.

[0059] Preferably, a common battery drawer is provided for all battery modules. The battery modules can be arranged upright in the common battery drawer.

[0060] Alternatively, a separate battery drawer can be provided for each battery module. The battery modules can be arranged horizontally in their respective battery drawers.

[0061] In principle, at least one battery module could be placed in a battery drawer and at least one battery module could be placed in a battery compartment. Inventive transport system

[0062] The present invention also encompasses a system comprising a transport vehicle according to the invention as described above and a battery exchange station with at least two, preferably at least three, charging stations, each for one battery module. At the exchange station, the largely discharged battery modules from the transport vehicle can be exchanged for charged battery modules. The discharged battery modules can be recharged at the charging stations. They are then available for use in the transport vehicle or another transport vehicle.

[0063] The battery exchange station typically holds at least as many battery modules as are installed in the transport vehicle. If the charging station has at least one more charging slot than there are battery modules in the transport vehicle, a battery module removed from the transport vehicle can always be moved directly to an available charging slot for charging. The battery modules do not need to be moved to intermediate storage areas but can be exchanged directly between the charging slots and the transport vehicle.

[0064] The battery swapping station can have a replaceable charging adapter for connecting the battery modules. Wear-prone contact processes (plugging in and unplugging) during battery swapping therefore occur at the charging adapters. If their connections wear out before the battery swapping station reaches the end of its service life, the charging adapters can be replaced easily and cost-effectively.

[0065] Each charging point can be equipped with a separate charging adapter. Alternatively, a single charging adapter can be used for multiple, or even all, charging points. The charging adapter complements the battery adapter or a fixed connection for the battery modules. The charging adapter and a receiving adapter for the transport vehicle can be identical in design.

[0066] The system may include a manufacturing machine. The transport vehicle can pick up parts (goods), especially workpieces, from the manufacturing machine and / or bring them to the manufacturing machine.

[0067] Preferably, the exchange station and the production machine are located adjacent to each other. Changing the battery modules can be accomplished without additional travel distances or with minimal additional travel distances for the transport vehicle if the transport vehicle is already accessing the production machine to fulfill its transport task. Particularly preferably, the exchange station and the production machine are located directly adjacent to each other, so that a handling robot can move both the battery modules between the transport vehicle and the exchange station and components between the transport vehicle and the production machine. The handling robot can be attached to the transport vehicle or stationary at the exchange station and the production machine.

[0068] Further features and advantages of the invention will become apparent from the description, the claims, and the drawings. According to the invention, the features mentioned above and those further elaborated can each be used individually or in any suitable combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather serve as examples for illustrating the invention. Detailed description of the invention and drawing

[0069] The invention is illustrated in the drawing and described using exemplary embodiments. Fig. Figure 1 shows a system according to the invention with a driverless transport vehicle according to the invention during the exchange of battery modules at an exchange station next to a production machine, in a schematic diagram; Fig. Figure 2 shows a battery module with a master battery, a slave battery and a battery adapter as well as a corresponding mounting adapter for a transport vehicle, in a schematic diagram; Fig. Figure 3 shows a battery module with a battery adapter arranged on a housing, in a schematic perspective view; Fig. Figure 4 shows a schematic flowchart of an operating method according to the invention for a driverless transport vehicle; Fig. Figure 5 shows a schematic flowchart of optional process steps for functional testing on the transport vehicle within the framework of the operating procedure according to the invention; Fig. Figure 6 shows a schematic flowchart of optional process steps for functional testing at a changeover station within the framework of the operating method according to the invention; Fig. Figure 7 shows a driverless transport vehicle according to the invention with an upwardly open battery compartment and with a handling robot carried on the transport vehicle, in a schematic perspective view; Fig. Figure 8a shows a driverless transport vehicle according to the invention with a laterally open battery compartment and with a handling robot carried on the transport vehicle, in a schematic perspective view; Fig. 8b shows the transport vehicle of Fig. 8a in a schematic, partially cutaway side view; Fig. Figure 9 shows a driverless transport vehicle according to the invention with a battery drawer in which several battery modules are arranged upright and with a handling robot carried on the transport vehicle, in a schematic perspective view; Fig. Figure 10 shows a driverless transport vehicle according to the invention with several battery drawers, in each of which a battery module is arranged lying down, in a schematic diagram.

[0070] Fig. Figure 1 shows a production plant 10. Workpieces 16 are machined on a production machine 12, in the illustrated embodiment a machine tool with a tool 14. The production plant 10 can include further production machines and, for example, storage facilities (not shown in detail). A handling robot 18 is provided to load the production machine 12. In this embodiment, the handling robot 18 is arranged stationary at the production machine 12. The handling robot 18 can, for example, be a six-axis robot, wherein in Fig. 1 Some articulated arms of the six-axis robot are indicated.

[0071] An automated guided vehicle (AGV) 20 is used to transport parts, for example, workpieces 16 and / or tools 14. The AGV 20 has electrically driven wheels 22, at least some of which are steerable or omnidirectionally rotatable. Several battery modules 24a, 24b (collectively referred to as 24) are arranged in the AGV 20 to supply power. The battery modules 24 are connected to a controller 28 via a CAN bus 26. The controller 28 controls the wheels 22, enabling the AGV 20 to move to its respective destination without external intervention. The controller 28 can also selectively allow or disable the power supply to individual battery modules 24a, 24b. For this purpose, the controller 28 can be connected to a battery management system 30. Fig. 2, the battery modules 24 communicate.

[0072] In the illustrated embodiment, the battery management system 30 is arranged in a battery adapter 32 (in Fig. 1 hatched with diagonal lines). The battery adapter 32 is attached to a housing 34 (in Fig. 1 checkered hatched) of the battery module 24, for example screwed to the housing 34. In Fig. Figure 3 shows an example of a battery module 24 with a battery adapter 32 attached to the housing 34.

[0073] In the housing 34 of a respective battery module 24, two batteries are arranged, namely a master battery 36 and a slave battery 38, compare Fig. 2. An internal connection 40 electrically connects the batteries 36 and 38 to the battery adapter 32. The internal connection 40 can be formed with pins and sockets. The batteries 36 and 38 are connected to the battery adapter 32 via an external plug connector 42. On the one hand, the connection contacts of the plug connector 42 serve for power transmission. On the other hand, at least one connection contact can serve to connect the battery management system 30 to the controller 28. The battery management system 30 can be connected via control lines to both the batteries 36 and 38 and to switches 43 (e.g., relays) for enabling or interrupting power transmission. The switches 43 are located in the battery adapter 32. Alternatively or additionally, switches could be provided in the housing 34 (not shown in detail).

[0074] In the transport vehicle 20, an interchangeable mounting adapter 44 is provided for each battery module 24, compare Fig. 1. Each receiving adapter 44 is connected to the control unit 28 via the CAN bus 26 for power and signal transmission. The receiving adapters 44 each have a connector 46 corresponding to the external plug connector 42 of the battery modules 24 (see figure). Fig. 2.

[0075] In the operation of production plant 10, compare Fig. 1. The transport vehicle transports 20 parts, such as tools 14 and / or workpieces 16, between different facilities of the production plant 10; see step 102 in Fig. 4. In particular, the transport vehicle can deliver 20 parts to and from production plant 12.

[0076] The energy supply of the battery modules 24 of the transport vehicle 20 is gradually depleted. The state of charge of the battery modules 24 is checked regularly; see step 104. At the latest when the state of charge of all battery modules 24 of the transport vehicle 20 falls below a predefined limit, the transport vehicle 20 automatically moves to a battery exchange station 50 in step 106; see step 104. Fig. 1. The limit value is set such that the operation of the transport vehicle 20 can still be maintained for a certain period of time. In the exemplary embodiment of Fig. In the first instance, the exchange station 50 is located directly adjacent to the production machine 12. This makes it possible, on the one hand, to combine accessing the exchange station 50 with a transport operation to or from the production machine 12. On the other hand, due to the directly adjacent arrangement of the production machine 12 and the exchange station 50, the handling robot 18 is able to both move parts between the transport vehicle 20 and the production machine 12 and exchange battery modules 24 between the transport vehicle 20 and the exchange station 50.

[0077] The exchange station 50 has several charging stations 52 for battery modules 24. The exchange station 50 holds at least as many charged battery modules 24', 24'' as are used in the transport vehicle 20. Typically, the battery modules 24', 24'' are located at the charging stations 52 where they were previously charged.

[0078] The exchange station has more charging points 52 than the transport vehicle has 20 battery modules 24. At one of the charging points 52 (the right charging point 52 in Fig. 1) There is no battery module present, so this charging slot 52 is free.

[0079] Each of the charging positions 52 is equipped with an interchangeable charging adapter 54. The charging adapters 54 are connected to a power grid 56 via power electronics (not shown). The charging adapters 54 can be identical in construction to the receiving adapters 44.

[0080] To replace the battery modules 24, the power supply of the transport vehicle 20 is switched to the first battery module 24a in step 108. The controller 28 interrupts the power supply from the second battery module 24b; its battery management system 30 can then disconnect the master and slave batteries 36 and 38 from the external connector 42. The transport vehicle 20 remains switched on during this process and is supplied with electrical energy by the first battery module 24a.

[0081] Then, in step 110, the second battery module 24b is removed from the transport vehicle 20 and taken to the available charging station 52. There, the battery adapter 32 is connected to the charging adapter 54. The battery module 24b is recharged.

[0082] After the transfer of battery module 24b from transport vehicle 20 to exchange station 50, the charged battery module 24' is inserted into transport vehicle 20, see step 112.

[0083] If the transport vehicle 20 has more than two battery modules, these additional battery modules can also be exchanged for charged battery modules, while the first battery module 24a keeps the transport vehicle 20 switched on.

[0084] After the second battery module 24b (and any further battery modules) has been replaced, the power supply of the transport vehicle 20 is switched to the newly installed, charged battery module 24' in step 114. For this purpose, the controller 28 enables the power supply from battery module 24', possibly with the assistance of its battery management system 30. In addition, the controller 28 interrupts the power supply from the first battery module 24a; its battery management system 30 can then disconnect the master and slave batteries 36 and 38 from the external connector 42. The transport vehicle 20 remains switched on during this time and is supplied with electrical energy by the previously installed battery module 24'.

[0085] Then, in step 116, the first battery module 24a is removed from the transport vehicle 20 and moved to the now free charging station 52. There, the battery adapter 32 is connected to the charging adapter 54. The battery module 24a is recharged.

[0086] After the transfer of battery module 24a from transport vehicle 20 to the exchange station 50, the additional charged battery module 24'' is inserted into transport vehicle 20, see step 118. The controller 28 can release the power supply from the additional charged battery module 24'', possibly with the assistance of its battery management system 30.

[0087] The handling of the battery modules 24 in steps 110, 112, 116 and 118 is carried out using the handling robot 18.

[0088] The battery modules 24a, 24b, 24', 24'' are preferably all identical in construction.

[0089] After all battery modules 24 have been replaced, the transport vehicle 20 moves away from the exchange station 50 in a single step 120. It is understood that parts can be exchanged between the transport vehicle and the production machine 12 before, during, or after the battery module 24 replacement. However, it is also possible that only the battery modules 24 are replaced at the exchange station 50.

[0090] When changing the battery modules 24, their external plug connections 42 are connected to or disconnected from the connectors 46 of the receiving adapters 44 and charging adapters 54. This can lead to mechanical wear of the contacts of the adapters 32, 44, 54. To avoid malfunctions, as described in the Fig. 5 and Fig. The procedure shown in section 6 should be followed.

[0091] According to Fig. 5 can be inserted into the transport vehicle 20 after inserting a battery module 24, compare step 202 (corresponding to steps 112 and 118 from Fig. 3) In step 204, the contact resistance between the battery adapter 32 of the respective battery module 24 and the associated receiving adapter 44 in the transport vehicle 20 is measured. Alternatively or additionally, in step 205, the mating cycles of the respective battery adapter 32 and the respective receiving adapter 44 can be counted. The total number of mating cycles can be stored in the battery management system 30 and / or the controller 28.

[0092] If the contact resistance and / or the total number of mating cycles exceed a predefined limit, a corresponding notification is issued in step 206, for example, displayed on the transport vehicle 20 and / or transmitted to a central control system of the production plant 10. The battery adapter 32 and / or the receiving adapter 44 are then replaced (see steps 208 and 210). This can occur immediately after the notification is issued, particularly if excessive contact resistance has been measured. Alternatively, a suitable point in the production process can be awaited, especially if a certain number of mating cycles has been exceeded.

[0093] Similarly, after inserting a battery module 24 into a charging station 52 of the exchange station 50, see step 302 in Fig. 6 (corresponding to steps 110 and 116 from Fig. 3) can be proceeded. In step 304, the contact resistance between the battery adapter 32 of the respective battery module 24 and the associated charging adapter 54 of the swap station 50 can be measured. Alternatively or additionally, in step 305, the mating cycles of the respective battery adapter 32 and the respective charging adapter 54 can be counted. The total number of mating cycles can be stored in the battery management system 30 and / or a control unit of the swap station 50.

[0094] If the contact resistance and / or the total number of mating cycles exceed a predefined limit, a corresponding notification is issued in step 306, for example, displayed at the exchange station 50 and / or transmitted to a central control system of the production plant 10. The battery adapter 32 and / or the charging adapter 54 are then replaced (see steps 308 and 310). This can occur immediately after the notification is issued, particularly if excessive contact resistance has been measured. Alternatively, a suitable point in the production process can be awaited, especially if a certain number of mating cycles has been exceeded.

[0095] Fig. Figure 7 shows another driverless transport vehicle 60. A handling robot 62, here a six-axis robot, is attached to the transport vehicle 60. The handling robot 62 is thus carried by the transport vehicle 60. The handling robot 62 is supplied with energy by the battery modules 24, which enable the drive of the transport vehicle 60. In this embodiment, the transport vehicle 60 has three battery modules 24a, 24b, 24c, which are collectively designated 24. It is understood that at least three charged battery modules are kept ready for exchange at a corresponding exchange station 50, wherein the exchange station 50 preferably has one free charging position 52, i.e., at least four charging positions 52.

[0096] The portable handling robot 62 can – like the stationary handling robot 18 – Fig. 1 - Move parts between a production machine 12 and a transport area 64 of the transport vehicle 60. The transport area 64 is designed as a support surface on the upper side of the transport vehicle 60. Furthermore, the accompanying handling robot 62 – like the stationary handling robot 18 – can exchange battery modules 24 between the transport vehicle 60 and the exchange station 50.

[0097] In Fig. Figure 7 shows how the handling robot 62 inserts a battery module 24a into a battery compartment 66 of the transport vehicle 60. During this process, the transport vehicle 60, including the handling robot 62, is powered by one of the other battery modules 24b, 24c located in the battery compartment 66. The successive replacement of the battery modules 24a-24c in the transport vehicle 60 is carried out as described above. Specifically, battery modules 24b, 24c can be replaced while battery module 24a powers the transport vehicle 60 and the handling robot 62. The power supply for replacing battery module 24a can be provided by one of the battery modules 24b, 24c, or by both battery modules 24b, 24c together.

[0098] At the in Fig. In the embodiment of the transport vehicle 60 shown in Figure 7, the battery compartment 66 is open at the top. The battery modules 24 are arranged vertically in the battery compartment 66. A cover 68 for closing the battery compartment 66 is part of the transport area 64 when closed. The handling robot 60 can be configured to open and close the cover 68. Alternatively, a motorized drive for the cover 64 can be provided, which can also be powered by the currently active battery module 24 (not shown in detail).

[0099] In Fig. Figure 7 also shows a sensor arrangement 69 of the transport vehicle 60. The sensor arrangement 69 here includes, by way of example, two laser scanners 69a, which are arranged at opposite corners of the transport vehicle 60 (in Fig. (7) only one of the laser scanners 69a is visible; the other is obscured. Alternatively or additionally, the sensor arrangement 69 can include further sensors, e.g., proximity sensors, in particular ultrasonic proximity sensors. The transport vehicle 60 uses the sensor arrangement 69 to monitor its surroundings. During operation, obstacles in its path can be detected. Depending on the situation, the transport vehicle 60 can either avoid the obstacle or stop. When changing battery modules 24 and handling parts such as workpieces 16 or tools 14, the transport vehicle 60 monitors a work area of ​​the handling robot 62 using the sensor arrangement 69. If there is an intrusion into the work area, for example, if a person approaches the transport vehicle 60 with the handling robot 62 too closely, the transport vehicle 60 stops the movement of the handling robot 62.In addition, the transport vehicle 60 can issue a warning, for example acoustically and / or visually.

[0100] The Fig. 8a and Fig. Figure 8b shows a modification of transport vehicle 60 from Fig. 7. Here too, the transport area 64 is formed on the upper side of the transport vehicle 60. In this embodiment, a battery compartment 66 is open on the side and can be closed by a cover 68, which is designed in the manner of a door. The battery modules 24 are held horizontally in the battery compartment 66 at a certain angle of inclination (for example, less than 20°) relative to a strictly horizontal orientation; see in particular the figure below. Fig. 8b.

[0101] In Fig. Figure 8b shows that the two laser scanners 69a of the sensor arrangement 69 are arranged at diagonally opposite corners of the transport vehicle 60. At the level of the laser scanners 69a, an outer shell of the transport vehicle 60 has a circumferential recess 69b; see also Figure 8b. Fig. 8a, into which the laser scanners 69a are inserted. Due to their recessed position behind the outer contour, the laser scanners 69a are protected from damage and contamination. Simultaneously, the channel-like recess 69b provides each of the laser scanners 69a with a 270° field of view, which includes a ground-parallel plane at the level of the laser scanners 69a and the recess 69b. Thus, the entire ground-level environment of the transport vehicle 60 can be monitored with both laser scanners 69a. If an object from outside the footprint of the transport vehicle 60 were to approach it, this object would be detected by the laser scanners 69a of the sensor arrangement 60. In particular, the object is detected before it enters the working area of ​​the handling robot 62. The handling robot 62 can then be stopped to prevent collisions with the intruding object.

[0102] If, due to the operating conditions of the transport vehicle 60, monitoring of the working area of ​​the handling robot 62 for objects penetrating from above is desired, at least one sensor could be arranged on the top of the transport vehicle 60. Fig. Figure 8a shows two 3D cameras 69c as examples. One or more 3D cameras 69c could be used instead of or in addition to the laser scanners 69a. 3D cameras 69c can also be used to monitor the route of the transport vehicle 60.

[0103] The in Fig. The further transport vehicle 60 shown in Figure 9 largely corresponds to the transport vehicle 60 from the Fig. 8a, Fig. 8b. The battery modules 24 are arranged here upright in a common battery drawer 70. The battery modules 24 can each be individually removed upwards from the open battery drawer 70 by the accompanying handling robot 62 or inserted into the battery drawer 70 from above.

[0104] The handling robot 60 can be configured to open and close the battery drawer 70. Alternatively, a motorized drive for the battery drawer 70 can be provided, which can also be powered by the currently active battery module 24 (not shown in detail).

[0105] Fig. Figure 10 shows a transport vehicle 20 similar to that of Fig. 1, wherein three battery modules 24a-24c are provided. The battery modules 24 are each guided horizontally by a pull-out mechanism 72. A battery drawer 74 for the horizontal storage of one of the battery modules 24 can be provided on each pull-out mechanism 72.

[0106] It goes without saying that the transport vehicle 20 of Fig. 10 or the transport vehicle 20 from Fig. 1 like the transport vehicles 60 of the Fig. 7 to 9 can each be equipped with a handling robot 62. For automated battery module replacement 24, a handling robot 18 is then not required at the replacement station 50.

[0107] Accordingly, 60 of the transport vehicles can be selected from the Fig. 7 to 9, the accompanying handling robot 62 is omitted if either the battery modules 24 are changed manually or a handling robot 18 is present at the changing station 50.

[0108] In summary, a first aspect of the invention relates to a continuously operating transport vehicle. The transport vehicle has several battery modules for power supply. A subset of the battery modules is sufficient to keep the transport vehicle in a switched-on operating state. The other battery modules can be replaced without switching off the transport vehicle. The power supply can then be switched to another subset of the battery modules to replace the remaining battery modules while the transport vehicle remains switched on. The productive availability of the transport vehicle is increased because it does not have to be switched off and on again to replace the battery modules, and because the charging of the battery modules takes place independently of the transport vehicle. If all battery modules are replaced at the same time, the subsequent service life of the transport vehicle is particularly long.

[0109] A second aspect of the invention relates to the replacement of battery modules of an automated guided vehicle (AGV) by a handling robot, in particular a handling robot carried by the AGV, which is also used for loading and unloading the AGV. If the handling robot has its own power supply, the AGV can be switched off during the battery replacement. Preferably, the AGV remains switched on during the battery replacement, and the handling robot is powered by other battery modules of the AGV while it replaces individual battery modules.

[0110] A third aspect concerns a driverless transport vehicle with at least one replaceable battery module, preferably several. The battery module itself has a replaceable battery adapter. Electrical contact between the transport vehicle and a charging device for recharging the battery module is made at the battery adapter, in particular via a plug connector on the battery adapter. An electrical plug contact can also be provided between the battery adapter and the battery module. The battery adapter remains connected to the battery module for a majority of operating and charging cycles. Should the contacts on the battery adapter become worn after several operating and charging cycles, the battery adapter can be easily replaced. The service life of the external contacts, which are subject to mechanical wear, therefore does not limit the service life of the battery module. Reference symbol list 10 production plant 12 manufacturing machines 14 tools 16 workpieces 18; 62 Handling robots 20; 60 Transport vehicle 22 wheels 24, 24a, 24b, 24c, 24', 24'' battery module 26 CAN bus 28 Control 30 Battery Management System 32 battery adapters 34 cases 36 Master Battery 38 Slave batteries 40 internal connection 42 external plug connector 43 switches 44 Mounting adapters 46 connectors 50 exchange stations 52 charging points 54 charging adapters 56 Power grid 64 Transport area 66 Battery compartment 68 lids 69 Sensor arrangement 69a Laser scanner 69b In-depth study 69c 3D camera 70 Shared battery drawer 72 Extension mechanism 74 Individual battery drawer 102 Transporting parts 104 Check charge level Visit exchange station 106 108 Switch to power supply via first battery module 110 Remove the second battery module from the transport vehicle and take it to the exchange station. 112 Insert charged battery module into transport vehicle 114 Switch to power supply via second battery module 116 Remove the first battery module from the transport vehicle and take it to the exchange station. 118 Insert another charged battery module into the transport vehicle 120 Exit exchange station 202 Plug battery module into transport vehicle 204 Measure the contact resistance to the transport vehicle 205 mating cycles count 206 notes issued 208 Replacing battery adapters Replace 210 recording adapter Insert the 302 battery module into the exchange station. 304 Measure the contact resistance to the exchange station 305 mating cycles count 306 Note issued 308 Replacing battery adapters 310 Replacing charging adapters QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2022 / 0212638 A1

[0007]

Claims

[1] Operating method for a driverless transport vehicle (20; 60) with at least two interchangeable battery modules (24, 24a-24c, 24', 24''), wherein the transport vehicle (20; 60) moves automatically to an exchange station (50) at which the battery modules (24, 24a-24c, 24', 24'') are exchanged, wherein the transport vehicle (20; 60) remains switched on during the entire exchange process and is supplied with energy from at least one of the battery modules (24, 24a-24c, 24', 24''), where at the exchange station (50) - the transport vehicle (20; 60) is initially supplied with energy from a first of the battery modules (24a) and during this time a second of the battery modules (24b, 24c) is removed from the transport vehicle (20; 60) and a charged battery module (24') is inserted into the transport vehicle (20; 60), - the transport vehicle (20; 60) is then supplied with energy from another battery module, in particular the previously inserted charged battery module (24') and during this time the first battery module (24a) is removed from the transport vehicle (20; 60) and another charged battery module (24'') is inserted into the transport vehicle (20; 60), and wherein the transport vehicle (20; 60) moves away automatically from the exchange station (50) after the battery modules (24, 24a-24c, 24', 24'') have been changed. [2] Method according to claim 1, wherein a handling robot (18; 62), in particular a six-axis robot, removes the battery modules (24, 24a-24c, 24', 24'') from the transport vehicle (20; 60) and inserts them into the transport vehicle (20; 60). [3] Method according to claim 2, wherein the handling robot (62) is carried by the transport vehicle (60). [4] Method according to claim 3, wherein the handling robot (62) is supplied with energy by the respective active battery module (24, 24a-24c, 24', 24'') of the transport vehicle (60). [5] Method according to claim 2, wherein the handling robot (18) is arranged stationary at the exchange station (50). [6] Method according to any one of claims 2 to 5, wherein the transport vehicle (60) monitors a working area of ​​the handling robot (62) during the changeover process, in particular with a laser scanner, and wherein the transport vehicle (60) interrupts the changeover process when it detects an intrusion into the working area. [7] Method according to any one of claims 2 to 6, wherein the handling robot (18; 62) places parts, in particular workpieces (16), into a transport area (64) of the transport vehicle (20; 60) and / or removes them from the transport area (64) of the transport vehicle (20; 60) before and / or after changing the battery modules (24, 24a-24c, 24', 24''). [8] Method according to one of the preceding claims, wherein the changeover station (50) is arranged on a production machine (12). [9] Method according to one of the preceding claims, wherein a respective contact resistance between one of the battery modules (24, 24a-24c, 24', 24'') and a respective connection of the transport vehicle (20; 60) is measured, and wherein a notification is issued when the contact resistance exceeds a predefined limit value. [10] Method according to one of the preceding claims, wherein a battery adapter (32) of one of the battery modules (24, 24a-24c, 24', 24'') is replaced, in particular after the battery module (24, 24a-24c, 24', 24'') has undergone a predefined number of insertion cycles and / or when the contact resistance between the battery module (24, 24a-24c, 24', 24'') and a connection of the transport vehicle (20; 60) exceeds a predefined limit. [11] Driverless transport vehicle (20; 60) with at least two interchangeable battery modules (24, 24a-24c, 24', 24''), wherein the transport vehicle (20; 60) is configured to selectively interrupt the power supply from any of the battery modules (24, 24a-24c, 24', 24'') so that this battery module (24, 24a-24c, 24', 24'') can be replaced, while a power supply from another battery module (24, 24a-24c, 24', 24'') keeps the transport vehicle (20; 60) in a switched-on state, preferably wherein the transport vehicle (20; 60) is equipped to automatically seek out a battery exchange station (50) when the charge level of each of its battery modules (24, 24a-24c, 24', 24'') falls below a predefined limit. [12] Transport vehicle (60) according to claim 11, further comprising a handling robot (62) attached to the transport vehicle (60), in particular a six-axis robot. [13] Transport vehicle (20; 60) according to claim 11 or 12, wherein the battery modules (24, 24a-24c, 24', 24'') each have an interchangeable battery adapter (32) for contacting the transport vehicle (20; 60). [14] Transport vehicle (20; 60) according to one of claims 11 to 13, wherein the transport vehicle (20; 60) has at least one interchangeable receiving adapter (44) for contacting the battery modules (24, 24a-24c, 24', 24''). [15] Transport vehicle (20; 60) according to one of claims 11 to 14, wherein each battery module (24, 24a-24c, 24', 24'') comprises a master battery (36) and at least one slave battery (38). [16] Transport vehicle (20; 60) according to one of claims 11 to 15, wherein each battery module (24, 24a-24c, 24', 24'') has its own battery management system (30). [17] Transport vehicle (20; 60) according to one of claims 11 to 16, wherein the transport vehicle (20; 60) has a CAN bus (26) for controlling the battery modules (24, 24a-24c, 24', 24''). [18] Transport vehicle (20; 60) according to one of claims 11 to 17, wherein the transport vehicle (20; 60) has at least one battery compartment (66) for receiving at least one of the battery modules (24, 24a-24c, 24', 24''), wherein the battery compartment (66) is preferably closable with a cover (68). [19] Transport vehicle (20; 60) according to one of claims 11 to 18, wherein the transport vehicle (20; 60) has at least one battery drawer (70; 74) for receiving at least one of the battery modules (24, 24a-24c, 24', 24''). [20] System comprising a transport vehicle (20; 60) according to one of claims 11 to 19 and a swap station (50) with at least two, preferably at least three, charging places (52) for one battery module each (24, 24a-24c, 24', 24''). [21] System according to claim 20, wherein the exchange station (50) has an interchangeable charging adapter (54) for contacting the battery modules (24, 24a-24c, 24', 24''). [22] System according to claim 20 or 21, further comprising a manufacturing machine (12), wherein the changeover station (50) and the manufacturing machine (12) are adjacent to each other.

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