DE102012006163B4 - Storage system, in particular shelf storage, with load handling means, in particular storage and retrieval unit, for storing or retrieving objects and a method for operating a storage system - Google Patents

Abstract

Method for operating a storage system for the storage or retrieval of objects, with objects being stored in storage spaces of the storage system or removed from there, with storage spaces being arranged at different heights, with potential when removing an object from a storage space that is higher than another storage space Energy is converted into electrical energy, which is at least partially fed back into an alternating voltage network supplying the storage system, with price information for the electrical energy being taken into account during storage and retrieval by the respective storage location in which the object is to be stored or from which the object is to be relocated is determined depending on the price information and the object is moved during storage or retrieval on trajectories corresponding to the price information, each storage location being assigned an energy value, the energy value being that for storage is the amount of energy required or is the amount of energy that can be fed back in the event of outsourcing, with high storage spaces preferably being determined for storage at a price of electrical energy which is below a critical value, i.e. in particular the storage space marked with the highest energy value is determined for storage, and low storage spaces are determined when outsourcing, in particular for outsourcing the storage space marked with the lowest energy value for outsourcing is determined, with the amount of the storage space for outsourcing being selected to be high depending on the price, the amount increasing monotonously with the price level, in particular proportional to Price level, is selected, with the amount of storage space for storage being selected to be low depending on the price, the level being selected to decrease monotonically with the price level, in particular inversely proportional to the price level.

Description

The invention relates to a storage system, in particular a shelf storage facility, with load handling means, in particular a storage and retrieval unit, for storing or retrieving objects and a method for operating a storage system.

It is generally known that in storage systems it is important to put objects into and out of storage as quickly as possible. However, the energy consumption is high.

From the DE 10 2010 007 275 A1 a storage system with an energy store is known from which motor-operated drives can be supplied and energy-fed into the generator-operated drives.

From the DE 10 2006 043 299 A1 a regenerative storage system is known.

From the WO 2005 117 248 A1 a shelf storage system with energy feedback is known, with storage and retrieval units also working as a generator and being able to feed back electrical energy into the electrical supply circuit.

From the DE 10 2009 024 357 A1 a shelf storage system is known with an internal power supply device which feeds energy back into the power supply system.

The invention is therefore based on the object of protecting the environment by saving energy.

According to the invention, the object is achieved in the storage system according to the features specified in claim 7 and in the method according to the features specified in claim 1.

Important features of the invention in the storage system, in particular shelf storage, with load handling means, in particular storage and retrieval device, for storing or retrieving objects are that
whereby the objects from the load handling device can be stored in storage locations of the storage system or can be retrieved from there,
where storage spaces are arranged at different heights,
wherein the load handling device is connected to a controller, in particular in such a way that the load handling device can be controlled by the controller,
wherein the load handling device has at least one lifting drive which can be supplied from an AC voltage network,
where the energy generated when the lifting drive is operated as a generator can be at least partially fed back into the AC voltage network,
where price information can be fed to the controller via a data transmission channel, in particular from a computer of the system or company operating the AC voltage network,
wherein the controller has a storage location determining means, so that the storage locations for storing or retrieving the objects can be determined and / or the trajectories of the objects can be specified depending on the price information.

The advantage here is that the AC voltage network is balanced, that is, current fluctuations are reduced. Because the price is low when many and / or powerful power generation systems feed electrical energy into the AC voltage network, for example solar power plants during the day when the sky is not cloudy and / or wind power plants when the wind is strong enough. During this period of the low price, the storage system converts electrical energy at least partially into potential energy in the earth's gravitational field, in particular at least 80%. At high prices, i.e. when there is a shortage of energy, this potential energy is in turn made available as electrical energy.

The storage system also functions as an energy store to compensate, i.e. buffer, the fluctuations in the AC voltage.

In an advantageous embodiment, the objects are of the same type, that is to say in particular interchangeable. The advantage here is that when prices are high, an object can primarily be removed from the upper storage spaces, that is, removed from the storage system, and when prices are low, an object can be removed from the lower storage spaces. Correspondingly, the procedure is reversed for outsourcing. Since the same objects can be used interchangeably, the method according to the invention enables buffering of the network, this buffering being a secondary task of the storage system, since the main task of the storage system is the storage and retrieval of objects.

Not all objects have to be of the same type in order to achieve the advantage according to the invention. It is sufficient that several objects of one object type are of the same type. There are preferably two or more objects for each type of object. Objects of the same type are always understood below as objects of the same type.

In an advantageous embodiment, the storage location determination means has a memory in which the storage locations occupied by the respective stored objects are noted. The advantage here is that so-called chaotic storage can be carried out, which is always known in the memory is which object is stored in which storage location.

In an advantageous embodiment, the data transmission channel is at least partially covered by the Internet. The advantage here is that no additional lines or radio data transmission channels have to be set up, but the existing infrastructure can also be used.

In an advantageous embodiment, the lifting drive has a matrix converter or a converter capable of feedback. The advantage here is that inexpensive components can be used.

Important features of the method for operating a storage system for storing or retrieving objects are that objects are stored in or retrieved from storage locations in the storage system,
where storage spaces are arranged at different heights,
where when an object is removed from a storage space that is higher than another storage space, potential energy is converted into electrical energy, which is at least partially fed back into an AC voltage network supplying the storage system,
whereby a price information of the electrical energy is taken into account during storage and retrieval,
in that the respective storage location in which the object is to be stored or from which the object is to be removed is determined depending on the price information and the object is moved on trajectories corresponding to the price information when it is stored or removed from storage.
The advantage here is that electrical energy can be temporarily stored as mechanical energy, in particular potential energy, in the storage system and in this way the network can be buffered by using the price information as the input variable.

Ultimately, the price information corresponds to the current electrical energy fed into the AC voltage network by energy producers.

In an advantageous embodiment, an energy value is assigned to each storage location, in particular the energy value being the amount of energy required for storage or the amount of energy that can be fed back during removal. The advantage here is that each storage location thus has a value which identifies it, in particular which clearly identifies it. Thus, the prioritization of the storage locations during storage and retrieval can be carried out very easily. Because at high prices, the unoccupied storage space with the lowest energy value is stored for storage; at low prices, the unoccupied storage space with the highest energy value is stored for storage; at high prices, the occupied storage space with the highest energy value is removed for storage, and at low prices outsourced from the occupied storage space with the lowest energy value for outsourcing.

In an advantageous embodiment, if the price of electrical energy is below a critical value, high storage spaces are preferably determined for storage, i.e. in particular the storage space marked with the highest energy value is determined for storage, and low storage spaces are determined during removal, in particular, the storage space marked with the lowest energy value for removal is determined for removal. The advantage here is that by specifying the critical value, that is to say the threshold value, a high price can be easily distinguished from a low price.

In an advantageous embodiment, if the price of electrical energy is above a critical value, preferably low storage spaces are determined for storage, i.e. in particular the storage space marked with the lowest energy value for storage is determined for storage, and high storage spaces are used when retrieving determined, in particular the storage location marked with the highest energy value for removal is determined for removal. The advantage here is that by specifying the critical value, that is to say the threshold value, a high price can be easily distinguished from a low price.
In an advantageous embodiment, in the time-critical state of the storage system, the price information is not taken into account, that is, the fastest possible storage or retrieval is carried out. The advantage here is that the method according to the invention does not slow down the operating speed in a time-critical state.

In an advantageous embodiment, the price information to be expected in the future is estimated and it is taken into account when determining the storage spaces to be used in the future,
in particular taking into account a solar forecast, wind forecast or weather forecast,
in particular by means of a neural network. The advantage here is that forward planning is possible.

In an advantageous embodiment, storage is faster in the time-critical state than in the non-time-critical state.

In an advantageous embodiment, that storage location is determined for storage whose energy difference value is proportional to the price difference between the current price and the critical value, the energy difference value being determined as the difference between the energy value of the storage space and the average value of the energy values determined for all occupied or unoccupied storage spaces in the storage system. In particular, that storage location is determined for outsourcing, the energy difference value of which is proportional to the price difference between the critical value and the current price, the energy difference value being determined as the difference between the energy value of the storage location and the average value of the energy values determined for all occupied or unoccupied storage locations in the storage system. The advantage here is that a correspondingly higher or lower storage location is selected to the extent that the price increases.

• Die Erfindung bezieht sich auf ein Regallager, in welchem Objekte einlagerbar und auslagerbar sind. Hierzu weist das Regallager verschieden hoch angeordnete Lagerplätze auf.

The invention will now be explained in more detail with reference to the figures:

• The invention relates to a shelf storage facility in which objects can be stored and retrieved. For this purpose, the rack warehouse has storage spaces arranged at different heights.

The objects are transported from a floor level to their storage location by means of a storage and retrieval unit, the floor level being understood to mean the height of the storage and retrieval area, i.e. the area of the rack storage area where the objects are picked up or released by the storage and retrieval unit. The higher the storage space, the greater the potential energy that must be supplied to the object in order to store it. For this purpose, the storage and retrieval unit has one or more electromotive drives. When an object is removed from storage, it is transported from a high storage area to the ground level, whereby electrical energy can be generated by means of the regenerative drives and can be fed back into the electrical supply network.

For this purpose, the drives have a regenerative drive. For example, a matrix converter is provided in the drive that feeds an electric motor or the drive has a converter with a DC voltage intermediate circuit, from which an inverter stage of the converter is fed, which feeds a three-phase motor, with an inverter stage being connected between the supply network and the intermediate circuit in such a way that Energy generated by the motor as a generator can be fed into the supply network from the intermediate circuit and the inverter stage acts as a rectifier in motor operation.

In all of the aforementioned designs, an electric motor can be fed on the AC voltage supply network, in particular a three-phase network, so that an object can be conveyed upwards against gravity by means of a lifting mechanism of the storage and retrieval unit. In generator operation, energy can be fed back into the supply network by lowering the object in the gravitational direction.

The drives of the storage and retrieval unit are connected to a controller, which is a central controller of the shelf storage system or is connected to such a controller.

The central control of the rack warehouse now specifies the storage location to which the incoming object is to be transported. The central control also specifies which stored object is to be removed next.

The central control is connected with a data transmission line, in particular the Internet, to the computer of the electricity supply company which operates the supply network or provides the electrical energy via the network.

Information about the currently valid price of electrical energy is transmitted at time intervals. In this way, the weather-dependent and therefore short-term increased supply from solar energy or wind energy is taken into account. Because when there is little cloud cover, a high supply of solar energy is provided and when wind occurs a high supply of wind energy.

If the price is low as a result of a high supply of electrical energy, the objects to be stored are stored at the highest possible storage locations. However, if the price is high as a result of a low supply of electrical energy, the objects to be stored are stored in the lowest possible storage locations. In addition, when prices are high, storage is carried out at the latest possible time. If the shelf warehouse has a buffer store for objects at the goods receipt, i.e. several objects can be stored in a queue, this buffer store is used to the maximum. Conversely, when prices are low, the buffer storage tank is emptied as quickly as possible.

The objects to be outsourced are also prioritized in such a way that when prices are high, the highest objects are outsourced first and as quickly as possible. At low prices, however, the lower ones are outsourced.

To distinguish between high and low prices, a critical value is defined; if it is exceeded, a price is considered high and if it is undershot, a price is considered low.

The invention has particularly great advantages when many objects of the same type are stored. For example, each of the similar objects is a pallet with detergent packs. Due to long-term operation, i.e. storage and retrieval of the objects, such objects are stored in high and low storage positions in the rack warehouse. In the case of outsourcing, a corresponding outsourcing according to the invention is thus made possible depending on the electricity price, that is to say the lower-lying ones at low electricity prices and the higher-lying ones at high electricity costs.

To determine the storage locations that can be used for storage or retrieval, each storage location is assigned an energy value that is typical for storage or retrieval.

It can also be taken into account that the transport route in the horizontal direction also requires energy. So when the storage and retrieval unit picks up the objects at a pick-up position, it must then follow a horizontal path, in particular quasi from front to back, and a vertical path, in particular quasi from bottom to top, for storage. The energy expenditure required for this therefore adds up. During the outsourcing process, energy can be obtained through the vertical downward movement, but the horizontal movement also requires energy. In the case of shelf stores that are sufficiently short in the horizontal direction, however, a net energy gain is made possible, so that energy can be fed back into the supply network.

When storing, the shelf storage is also filled from front to back, if possible, in order to reduce the horizontal effort.

In a further exemplary embodiment according to the invention, the above-described method according to the invention is only carried out when there is no time-critical state of the shelf storage. Such a state is considered to be when the number of objects waiting for storage in a starting time interval, in particular 30 minutes, is greater than the number of objects that can be stored in the shelf storage by the storage and retrieval unit in this time interval. In this case, the fastest possible storage will be carried out. In particular, the warehouse is filled from front to back and from bottom to top, i.e. without taking the current price into account.

In the 1 the procedure is shown using a flow chart. After an order for storage or retrieval has been received, it is first checked whether the status of the system is time-critical or not. In the case of a time-critical state, the standard sequence shown last is used. In the other case, the price is first determined and, depending on this, the respective object is stored in the upper or lower half of the shelf storage or retrieved from the upper or lower half. Alternatively, according to the energy value assigned to each storage location, the storage in the storage location with the highest energy value is carried out at low prices and, in the case of high prices, storage in the storage location with the lowest energy value. Accordingly, the removal of objects from low storage locations at high prices is preferred and the removal of objects from high storage locations at low prices. This prioritization is preferably carried out according to the energy value assigned to each storage location.

In a further exemplary embodiment according to the invention, the course of the price over time is additionally estimated on the basis of a weather forecast, in particular by using a neural network. In this way, storage and retrieval can be prioritized in advance.

List of reference symbols

EVU

Electricity utilities

NT

Low price tariff, low price

HT

High price tariff, high price

Claims (11)

Method for operating a storage system for the storage or retrieval of objects, with objects being stored in storage spaces of the storage system or removed from there, with storage spaces being arranged at different heights, with potential when removing an object from a storage space that is higher than another storage space Energy is converted into electrical energy, which is at least partially fed back into an alternating voltage network supplying the storage system, with price information for the electrical energy being taken into account during storage and retrieval by determining the respective storage location in which the object is to be stored or from which the object is to be outsourced is determined depending on the price information and the object is moved during storage or removal on trajectories that are dependent on the price information, each storage location being assigned an energy value, the energy value being that for the input is the amount of energy required or is the amount of energy that can be fed back when outsourcing, with a price of electrical energy that is below a critical value, preferably high storage spaces are determined for storage, in particular the storage space marked with the highest energy value is determined for storage, and low storage spaces are determined during removal, in particular for removal the storage space marked with the lowest energy value for outsourcing is determined, the amount of the storage space for outsourcing being selected to be high depending on the price, the amount being selected monotonically with the price level, in particular proportional to the price level, the amount depending on the price of the storage space for storage is chosen to be low, the height is chosen to decrease monotonically with the price level, in particular inversely proportional to the price level. Procedure according to Claim 1 , characterized in that at a price of the electrical energy which is above a critical value, preferably low storage locations are determined for storage, in particular for storage the storage location marked with the lowest energy value for storage is determined, and high storage locations are determined when retrieving are determined, in particular for retrieval, the storage space marked with the highest energy value for retrieval. Method according to at least one of the preceding claims, characterized in that in the time-critical state of the storage system the price information is not taken into account, that is to say the fastest possible storage or retrieval is carried out. Method according to at least one of the preceding claims, characterized in that the price information to be expected in the future is estimated and is taken into account when determining the storage spaces to be used in the future, in particular taking into account a solar forecast, wind forecast or weather forecast, in particular by means of a neural network. Method according to at least one of the preceding claims, characterized in that that storage location is determined for storage, the energy difference value of which is proportional to the price difference between the current price and the critical value, the energy difference value being the difference between the energy value of the storage location and all of the occupied or unoccupied storage locations of the storage system determined average value of the energy values. Method according to at least one of the preceding claims, characterized in that that storage location is determined for retrieval, the energy difference value of which is proportional to the price difference between the critical value and the current price, the energy difference value being the difference between the energy value of the storage location and all of the occupied or unoccupied storage locations of the storage system determined average value of the energy values. Storage system, in particular shelf storage, for carrying out a method according to one of the preceding claims, with load handling means, in particular storage and retrieval units, for storing or retrieving objects, the objects being able to be stored or retrieved from the load handling means in storage locations of the storage system, with storage locations being arranged at different heights The load handling device is connected to a controller, in particular so that the load handling device can be controlled by the controller, wherein the load handling device has at least one lifting drive that can be supplied from an AC voltage network, with energy generated when the lifting drive is operated as a generator at least partially into the AC voltage network can be fed back, characterized in that price information can be fed to the controller via a data transmission channel, in particular from a computer of the system or company operating the AC voltage network, whereby ei the controller has a storage location determining means, so that depending on the price information, the storage locations for storing or retrieving the objects can be determined and / or the trajectories of the objects can be specified, in particular where the height and / or height of the respective storage location is selected an energy value relevant to storage or retrieval is taken into account. Storage system according to Claim 7 , characterized in that the objects are of the same type, in particular thus interchangeable. Storage system according to one of the Claims 7 to 8th , characterized in that the storage location determining means has a memory in which the storage locations occupied by the respective stored objects are noted. Storage system according to one of the Claims 7 to 9 , characterized in that the Data transmission channel is at least partially covered by the Internet. Storage system according to one of the Claims 7 to 10 , characterized in that the lifting drive has a matrix converter or a regenerative converter.

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