WO1999044171A1

WO1999044171A1 - Storage system and robot and control unit for a storage system of this type

Info

Publication number: WO1999044171A1
Application number: PCT/DE1999/000522
Authority: WO
Inventors: Johannes Ponader
Original assignee: Johannes Ponader
Priority date: 1998-02-26
Filing date: 1999-02-26
Publication date: 1999-09-02
Also published as: AU3326499A

Abstract

The invention relates to a storage system with a means of orientation for a mobile robot (2), especially in a library, comprising the following: several storage locations for storing items, each item being provided with an identification marking (3); a sensor for detecting the identification markings attached to the items, said sensor being attached to the robot, and orientation markings (4) for the robot, said orientation markings being provided at the storage locations, having essentially the same appearance as the identification markings on the items, and bearing location information relating to the spatial position of the respective storage location. The sensor is connected to a control unit at the output end. Said control unit controls the movements of the robot according to the orientation markings detected by the sensor. The invention also relates to a method for operating a storage system, comprising the following steps: the robot travels to a first storage location within the storage system; the sensor with which the robot is provided successively detects the identification markings on the items located in the first storage location and establishes the respective item information; the robot's sensor detects the orientation marking provided in the first storage location and establishes the location information contained in said orientation marking, and according to the location information established, the position of the next storage location is determined and the robot independently travels to the same.

Description

STORAGE SYSTEM AND ROBOT AND CONTROL FOR SUCH A STORAGE SYSTEM

description

The invention relates to a storage system with an orientation option for a movable robot, in particular in a library, according to the preamble of claim 1 and a method for operating the storage system according to claim 10. Furthermore, the invention relates to a robot and a controller for such a storage system .

From the German published patent application DE 38 43 218 AI a modern high-bay warehouse for storage of data carriers is known, in the storage and removal of the stored data carriers is done automatically by a robot that can be moved on rails between the individual shelves and has a gripper to the data carriers to be stored or removed at the desired storage location.

The rail guidance of the robot in the high-bay warehouse advantageously enables a precise approach to predetermined storage locations within the high-bay warehouse, since the position of the robot is predetermined by the rail arrangement.

A disadvantage of such a high-bay warehouse, however, is the effort involved in installing the rail guide, which also requires a certain spatial arrangement of the individual shelves. Older warehouses with angled arrangements of the individual shelves can often not be equipped with such a robot system. In addition, the rails generally narrow the otherwise accessible area between the individual shelves and thereby limit the manual accessibility of the warehouse, which is particularly intolerable in libraries with public traffic.

The invention is therefore based on the object of creating an automated storage system which, without a separate rail arrangement, enables a robot to approach predetermined storage locations precisely in order to automatically store, remove or check inventory items. - 2 -

Starting from a known storage system according to the preamble of claim 1, this object is achieved by the characterizing features of claim 1 or - with regard to a corresponding working method - by the features of claim 10.

The invention encompasses the technical teaching of arranging orientation markings in a warehouse at the individual storage locations, the orientation markings and the identification markings affixed to the individual bearing articles being identical in terms of their external appearance and having only a different information content. The advantage of such a design of the orientation markings is that the pattern recognition of the robot then only has to recognize a single pattern, whereas the recognition of different patterns for identification markings and orientation markings would be considerably more complex.

The terms identification marking and orientation marking are to be understood here in general and in the following and are not restricted to the optical markings preferably used, which can be present, for example, in the form of stickers or labels. Rather, it is also possible to use electronic identification markings or orientation markings which consist, for example, of active or passive signal transmitters, the information content of which is detected by the robot on the radio path. In addition, other forms of identification markings or orientation markings can be used, which enable information to be read out.

According to the invention, the individual orientation markings each carry location information which, for example, can indicate the absolute position of the respective storage location within the storage system. Instead, the orientation markings can also be one

Bear location information, which reflects the relative location to the next storage location. For example, the location information could indicate that the next storage location is four meters to the left and two meters ahead. In this way, the individual orientation markings at the storage locations can define a course through the entire warehouse on which all storage locations are approached by the robot, for example in order to carry out an inventory of the inventory. This is particularly advantageous in libraries, since, for example, an automatic revision can be carried out at night without public traffic.

The term storage location is to be understood here and in the following generally and includes, for example, the shelves mentioned at the beginning in a high-bay warehouse or in a library. However, the invention is not limited to such rack storage, but also in others - 3 -

Storage systems can be used in which the stock items are stored in a different way at certain storage locations. Automated parking garages are to be mentioned here as examples, in which the parked motor vehicles are parked as storage items on parking spaces as storage locations. In addition, the storage system according to the invention can also be used at boat moorings in which the individual boats represent the storage items and are each located at specific berths which are to be understood as storage locations in the sense of the invention. Another application is the storage of bicycles in a bicycle rack, which is of interest, for example, when renting a bicycle. In the preferred embodiment of the invention, the robot has an internal power supply, for example in the form of a rechargeable battery, but a cable-based power supply is also conceivable, the power cable being rolled up or unrolled during the robot movement either by the robot or a stationary power supply unit can be.

Some design variants of the invention are given below:

Storage system with an orientation option for a movable robot, in particular in a library, with several storage locations for the storage of storage items, an identification mark being attached to each storage item, a sensor attached to the robot for detecting the identification markings attached to the storage items, with on orientation markings for the robot are attached to the storage locations, which have essentially the same appearance as the identification markings on the storage items and carry location information relating to the spatial position of the respective storage location, and the sensor on the output side being connected to a control unit which detects the robot movement as a function of controls the orientation marks detected by the sensor.

Such a storage system can also be characterized in that the orientation markings on the storage locations each reflect the absolute spatial position of the respective storage location within the storage system. A further development of this storage system is characterized in that the orientation markings attached to the storage locations each determine the relative position of the next storage location to be approached by the robot, so that the robot automatically travels from storage location to storage location on a predetermined course.

A basic further development of the storage system can consist of the sensor for detecting the orientation marks and the identification marks on the bearing - 4 -

is an optical sensor. As an alternative or in addition, it can be provided in this storage system that the identification markings are attached to the storage items in each case at the same height in order to simplify the identification. A further development of these variants can consist in that the optical axis of the optical sensor runs in the horizontal direction at the search height of the identification markings.

A general further development of the storage system can consist in the fact that the storage locations are in each case shelves, shelves or parking spaces within a shelf. It can further be provided that the optical axis of the optical sensor lies in a search plane, the vertical distance (h) between the search plane and the shelf being essentially equal to the height of the identification markings.

A further possible embodiment of the storage system according to the invention can consist in the robot having a mass memory in order to store the article information read out from the identification markings and / or the location information of the orientation markings for later evaluation.

In the method for operating a storage system, as was explained in particular above, the following steps are carried out: the robot moves to a first storage location within the storage system,

the identification marks of the stock items arranged in the first storage location are sequentially detected by the sensor of the robot and the respective item information is determined,

the orientation mark attached to the first storage location is detected by the sensor of the robot and the location information of the orientation mark is determined,

- Depending on the determined location information, the location of the next storage location is determined and approached automatically by the robot.

In a development of the method it is provided that the identification markings are detected optically by an optical sensor. As an alternative or in addition, the method can be characterized in that after the detection of an identification mark directly next to the identification mark already detected and at a predetermined height (h), an image pattern with a predetermined vertical (Δh) extent is detected and compared with a stored image pattern of an identification mark. Chen to determine whether a further identification mark or an orientation mark is arranged immediately next to the already detected identification mark. The latter method variant can be further developed in that the predetermined one Height (h) for the detection of the image pattern essentially corresponds to the height of an identification mark and the vertical extent (Δh) of the recorded image pattern is substantially less than the height of an identification mark. In a further development of this, if a further identification mark is not recognized, the horizontal position of the empty space can be stored in addition to the identification mark last recorded.

A general further development of the method according to the invention can consist in that, if a further identification marking is not recognized, the width of the empty space is stored immediately next to the identification marking last recorded, in order to enable a distinction to be made between a missing stock item and a thin stock item with an illegible identification mark.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Figure 1 is a library with several shelves and a course defined by several orientation markings for a robot and

FIG. 2 shows a schematic representation of a shelf board, each with an orientation mark on the shelf ends and with several books, each with a label as an identification mark.

The library shown schematically in Figure 1 essentially consists of several shelves 1 with books, the storage and removal of the individual books in a conventional manner being carried out manually by the individual users or the library staff, whereas the revision, i.e. the inventory is checked automatically outside the opening times of the library by a mobile robot 2, which is only shown schematically here.

The robot 2 is constructed in a conventional manner and has an electric motor-driven, wheel-supported undercarriage which enables the robot 2 to move independently within the library. The power supply is provided by a built-in battery, so that the robot 2 does not require a cable feed and can therefore move freely in the library. To perceive its surroundings, the robot 2 has an optical sensor which can be displaced in the vertical direction in order to be able to recognize the books on different shelves, the sensor for data evaluation being connected to a built-in computer.

On the one hand, the sensor is used to detect the labels 3 attached to the spine of the individual books, which enable identification of the individual books and are shown by way of example in FIG.

On the other hand, the optical sensor also detects orientation markings OM, 4, which are attached to the individual shelves 1 at the ends of the rows of books and enable the robot 2 to be oriented within the library. Each of these orientation markings OM, 4 defines the relative spatial position of the next shelf, so that all orientation markings OM, 4 together define a course through the library, which is shown in FIG. 1 by the dashed intermediate positions of the robot 2 and the directional arrows running between them is shown.

The robot 2 is thus placed at the beginning of the automatic revision in such a way that the optical sensor detects the first orientation marking OM, 4, which is attached to the side of the row of books located on a specific shelf. The robot 2 then moves along the first shelf 1 and detects the labels 3 of the books on this shelf. At the end of the row of books, the robot 2 then encounters another orientation marking OM, 4, which defines the relative position of the next shelf to be approached, wherein the next shelf can be arranged at a different height on the same shelf or on a different shelf. The built-in computer uses this to calculate the control data for the chassis of the robot 2 and the vertical movement control of the sensor, whereupon the robot 2 then moves to the predetermined next rack position and there first searches for an orientation marking OM, 4 which defines the start of a new rack section. In addition, this orientation marker OM, 4 also serves to check whether the correct rack position has actually been approached. The robot 2 then travels along the shelf 1 in the manner described above and detects the labels 3 attached to the individual book spines in order to store the associated book data in the built-in computer for later data evaluation.

How the optical sensor of the robot 2 detects the individual labels 3 will now be described in detail with reference to FIG. It is assumed here that the robot 2 has already detected the orientation marker OM, 4 located at the beginning of a row of shelves and is now looking for the first label 3 to the right of the orientation marker OM, 4.

The optical sensor is now looking for the next label, which can be a book label 3 or an orientation mark OM, 4. However, he does not do this at any height, but only at a predetermined search height h above the shelf and in a vertical range Oh, the search height h being slightly less than the height of a label (book label 3 or orientation marker 4). This largely prevents misplacement of a label 3 on the spine from leading to error detections. If a label 3 is stuck on so deep, for example, that the lower edge of the label 3 already abuts the shelf, the upper end of the label 3 is still within the search range Oh. If, however, label 3 is placed too high on the spine of the book, the lower end of label 3 is usually still within the search range Oh. The search height h is communicated to the system by appropriate positioning of the orientation markings. It is important here that the optical axis of the sensor always runs parallel to the floor and in the plane of the search height, so that the search plane in the camera image is always in the center of the image regardless of the distance between the sensor and the shelf.

The computer built into the robot 2 then compares the almost linear pattern detected by the sensor with a predetermined pattern in order to determine whether a label 3 has been recognized. In this case there must be a white stripe which is interspersed with black spots, the black spots belonging to the black frame of the label 3 or the label printing. The computer then extends the vertical bandwidth 4h, whereby the label is also read out. The system then uses a database comparison of the read content to determine whether there is an identification mark for a book or an orientation mark. This offers the advantage that the distinction between identification markings (book labels) on the one hand and orientation markings on the other hand can be made by a simple text comparison. If it is a book label, the read content is saved for later data evaluation. If, on the other hand, it is an orientation marker, the robot extracts the information for the required movement processes from the orientation marker.

During the expansion of the vertical bandwidth 4h, the ascertained horizontal distance from the label found to the edge of the image can already be passed on to the control system, which then initiates a robot movement by this distance. This ensures that the new label is at the very edge of the sensor image and additional labels - 8th -

can move into the picture. When the label recognition is finally completed, the robot movement has already been carried out and the image recognition can search for the next label without waiting.

It is necessary to convert the distance information (number of image grid points) into metric information. For this purpose, the standardized and known label height or other standard values can be used as a reference. If it is found that the optical sensor is moving too far or too close to the shelf, the chassis also corrects it accordingly.

Furthermore, the distance information can be used to determine whether the associated book is immediately adjacent to the previous book or whether there is a space between these two books, which can either result from a book with an unrecognized label or from a gap.

After the above-described traversing of the course defined by the individual orientation marking ranges OM, 4, the data of all labels 3 that were recorded during the revision are stored in the built-in computer. The stored data is then transferred to a central computer and compared with the library catalog, which shows the target inventory of the entire library. The central computer automatically creates a correction list that lists the entire shortage of the library and enables library staff to correct the book inventory. For this purpose, the library staff returns the books that have been misplaced to the right place and re-orders missing books if necessary.

The embodiment of the invention is not limited to the preferred exemplary embodiments specified above. Rather, a number of variants are conceivable which make use of the solution shown, even in the case of fundamentally different types.

In the following, further features and aspects of the invention are explained on the basis of representations of design variants.

In one aspect, the invention is an efficient orientation system for robots, in particular one for search and control robots in structured environments. - 9 -

The invention relates in particular to a process for the orientation of robots in rooms or places.

Mobile robots have to orient themselves in the room in which they move. This is usually done with the help of landmarks, radio transmitters or similarly designed landmarks. The tasks of such a robot are basically divided into two aspects:

1. The task of orientation in space

2. The real job of the robot

The invention simplifies the work of the robot by largely combining the two tasks into one work process. This is particularly useful, for example, for search and control robots. So far, these search robots have had to perform two tasks in parallel:

1. The task of orientation in space

2. The search or control task

The workload of these robots is to be reduced by combining the two tasks in one work process. This is achieved by a method with the features of claim I.

By giving the landmarks (e.g. landmarks) the same appearance as the objects to be searched for or controlled, the robot's task now is simply to search for these objects, regardless of whether they are moving search objects or the fixed orientation objects. If such an object is found, the recognition process is carried out, that is to say the characteristics of the object are recognized, and a simple and efficient comparison with an orientation point or landmark file then determines whether it is an object to be searched for or an orientation point. - 10 -

Another advantage of the system is that e.g. B. in the case of landmarks an inconspicuous and optically non-distracting or possibly even attractive from the design value is possible because the mark optically does not differ from the objects located in the room anyway.

The procedure is to be illustrated using the example of site revision in the reading rooms of a library:

The site revision in large libraries represents an important task, which has been carried out in a manual process up to now by comparing shelf to shelf with the current location catalog data. The first attempts at technical simplification can so far only be found in the fact that the personnel are equipped with portable computer systems and thus have easier access to the catalog.

This procedure is nevertheless complex and takes a lot of time. According to our research, for example, in the Regensburg University Library with a reading room inventory of 1.3 million books, such a catalog revision is only carried out every five years, sometimes even less frequently, depending on the available workforce. According to Mr. Library Director Dr. Eike Unger employed all 30 employees of the university library for about a year.

This infrequent implementation of the revision, combined with the fact that a number of titles are misadjusted in daily reading room traffic, on the one hand by mistake, but on the other hand on purpose - to a "reservation" that is only for one's own benefit, leads to the fact that Requested titles must be reordered, although it cannot be ruled out that they are in an unknown location in the library, only found by a systematic revision or by accident. In addition to the high personnel costs for the revision to be carried out at appropriate intervals, replacement costs are incurred because the overview of the current inventory cannot be obtained to a satisfactory extent.

The state of the art certainly has the ability to implement automated archiving and, theoretically, revision systems, such as those used in automated warehouses. Here, however, an adaptation of the working environment - 11 -

to the machine, be it rails of all kinds on which the system moves, or simply readable barcodes on the articles to be treated. To install such a system in a library would require extensive and expensive interventions in the spatial structure and the claim of a reading room as a meeting place between man and book, both with regard to the then necessary consideration of the technical environment as well as by an optical disadvantage disagree. Likewise, the system is then tied to the place of use set up for it. A library usually equipped with several reading rooms would have to buy and adapt such a system for each room again. Furthermore, equipping the entire reading room inventory of a large library with machine-readable codes would be extremely costly.

The invention makes it possible here to enable a simple system for catalog and location revision in libraries, which can be easily and inconspicuously adapted to the existing conditions in one or more reading rooms.

This object is achieved by a system with the features of claim I as follows. It is oriented in the room with the aid of a camera only on the basis of landmarks attached to the shelves, which prescribe a course - a programming that is specially adapted to the place of use is not necessary. This makes the system portable and can be easily used in all locations of a library. Due to the easy portability, a shared use of a system by several libraries is also conceivable (rental system).

The recognition of the books on the shelves is realized via an image recognition mechanism, which combines the acquisition of information for controlling the system by reading in the landmarks with reading the book identifications with the aid of a single text recognition process, saving time and computing effort. A control computer coordinates the mobile robot. The location data that this robot collects can be stored temporarily and can be automatically compared in a separate work step or immediately with the catalog data in electronic form using an appropriate program.

The image recognition: - 12 -

An image recognition module is required to recognize the books, which locates the book labels in the camera image with the least possible computing effort and reads out the signatures. The way it works is described as follows:

The first label should already be found and deciphered. It is somewhere in the camera image, the other books are on the right. The algorithm now searches to the right of the label found at a predetermined standard height for the next label. He makes use of an important and not entirely trivial finding: albeit the labels

"With regard to the height at which they are attached to the spine of the book, they are often very different, but a certain height can be determined at which the label is almost certainly encountered: the measure sought corresponds approximately to the height a standard label, measured from the shelf along the spine. An extremely deeply glued label just reaches this height, and a very highly glued label just sets

15 there.

At this height, the image recognition program is now looking for the next label in a certain vertical range, which it presents as a white stripe, possibly interspersed with black spots (which belong to the letters on the label) (see Fig. 1, 1. ). 0 Of course, a certain tolerance against color deviations and noise effects must be taken into account. If it thinks it has found the next label, it extends the examination area up and down (2.) and at the same time finds the letters of the signature, which serves as an assurance that this is actually a label 25. The illustrations of the letters, if found, are passed on to simple text recognition. Then it continues the search to the right.

However, at the moment when the examination begins to expand up and down, the image recognition module already passes on information to the control module: the

30 Distance between the new and the old label, which can only be expressed for the first time in the number of pixels that lie between the left edge of the two labels in the camera image.

This information can be obtained with knowledge of the distance to the spines in

35 an absolute distance information can be converted. This lens-book distance information can either: - 13 -

* using a distance measuring sensor or

* based on standardized sizes in the camera image (standard height or width of a label;

5 standard size of a letter, fixed distance shelf level - camera center plane) can be recognized.

The control module can then move the robot accordingly, so that

10 Now the new label is in the place of the old one in the picture.

At the same time, the image recognition module with text recognition has time to decrypt the new label using the previous image and to store the information found (the book ID) in the memory, if it was a label at all. If it has reached the edge of the image, it can now read a new camera image and look for the next label.

An important measure here is that the lens center of the camera is set up exactly at the search height for the labels described above at the beginning of a shelf.

20 Then, and only then, this height ideally also remains at the same height (in the middle) in the camera image, regardless of the distance from the camera to the shelf (or also at what angle to the shelf, because also an angle of the camera direction - The direction of the shelf not equal to 90 ° basically only results in an increase in the distance and a 25 "thinning" of the labels at the same time). The height of an object in the camera image can be ideally expressed, as already indicated above, with a first degree function on the distance; the slope corresponds to the difference in height between the object and the center of the lens; if it is zero, the function remains constant.

30 There is still the task of implementing an error correction that carries out the distance corrections that are determined to be necessary while the shelf is being moved by a skillful control of the robot without disturbing the reading of the book labels. If the robot turns a small curve, it must still be able to determine how far it is

"- in the direction of the image, in the sense of the request from the image recognition module," move forward x mm "really moved. Elementary geometrical considerations can, however, come to an approximate useful result, which is certainly preferable - 14 -

is set high than too low, because then the robot travels too short rather than too far. If necessary, the program reads a label twice, which can easily be rejected. The possibly "wasted" computing time has to be accepted in view of the risk of missing a book.

The system is now sufficiently tolerant of deviations in the implementation of the required movements by the driving mechanics; Only a deviation of more than one label width in the course of a book width could disturb the algorithm.

Beginning and end of the robot journey - the markings and the guidance system

But how does the robot find the first label; and how does he know that the shelf is over?

Certainly, the robot cannot move freely in the natural world without orientation aids

Move space. The effort that an independent recognition of its environment entails without any adaptation to the "needs" of the robot does not appear to be justified compared to a one-time simple identification. However, it should be emphasized that it is precisely the simplicity of this labeling that makes the system superior and distinguishes it fundamentally from space-based variants in the form of automated archiving and storage systems. If it is cleverly done, there is no need to file a map of the surroundings in electronic form, the production of which is basically a lot more complicated than the labeling of the room.

As a sign, there are code labels that are located at the beginning and end of a shelf or a row of books and do not contain a signature, but a route information. Both the book signatures and the direction information are stored polymorphically in the same "container", the standard label. This has the decisive advantage that there is no need to test whether the shelf has ended at the time of the computationally intensive image recognition; The marking labels are initially handled by the system like a signature label. If the label text is decoded, a simple string comparison leads to the recognition of the direction information. Such information would be e.g. For example: "UP 50 as" further 50 cm higher "-" DOWN 30 "as" further 30 cm lower "- ON 200" as "further 200 cm right" - "TURN 180" as "rotation 180 °". Instead of a complex image recognition process for orientation, a simple text comparison is used. - 15 -

At the target positions of these movement instructions, as well as at the beginning of the work route, which can be set at each of these target positions, by the way, there is a special label that is easily recognizable in the picture. This z. B. color-coded label can then be located in the picture and is the starting point for another movement or a new series of books. It is at the standard average height described above and can contain a sign indicating the direction of work (left or right). Length information or the like about the book material to be processed is also conceivable as error-avoiding redundancy information.

10

Ultimately, the reading room is laid out in a "parcours" in which the robot is described in the form of small "traffic signs" from shelf to shelf.

15 The trouble-free movement in the room

But how is it now ensured that the robot does not bump anywhere and does not damage itself or anything else?

20th

First, it may be necessary to make it clear that the robot is not designed to drive around between users in a busy reading room. It should be used at times when the reading rooms are not open to the public and at most the library staff are present.

25

Collisions with the inventory or the walls must also be prevented. To do this, the robot must be warned of the obstacle before it can become dangerous. For this purpose, the camera is attached to the robot so that it looks a little ahead of the robot when working. A marking label at the end of the shelf or, if necessary, if there is no more space

30 is right on the obstacle with the meaning: "Warning!" and a path information does the rest: The robot can turn or turn at a sufficient distance.

Incidentally, it is assumed that before a shelf always enough space for loading - _<- movements of the robot. If this should not be the case, this must also be identified with a warning code. - 16 -

A special case not to be forgotten is the arrangement of two shelves at right angles to each other. A marker should also be provided here, which informs the robot of this fact and causes it to rotate in good time.

Inadequate labeling (specific problems and their solution)

Quite often there is not even enough space on the back of a book to hold the label in its narrow form with the label tilted by 90 °. Then the system is unable to recognize the signature. However, he can use the information if he at least recognizes that this is a book whose signature he cannot read. The clever positioning of a light source carried along can make it easier to recognize such a book through the shadow in the narrow column between two book spines.

However, this information that a book was found at all is very important and can save the staff a lot of work. The stored information will be compared later with the electronic catalog of the library. If the system recognizes that between two recognized books there are one or more volumes whose signatures cannot be recognized, it at least stores this information with the remaining data. If a comparison with the catalog data reveals that the number of books found should really be exactly between the two volumes identified, it can be assumed with a high degree of certainty that the correct books are located here; a manual check is not necessary. If, however, a comparison is found that either more or fewer books are found in the catalog than found, an error can be reported for this area, which is then corrected by the library staff.

If a book is missing, or if a book is set incorrectly at this point, the comparison program raises the alarm and thus initiates a check or correction. The revision system only recognizes this error if a book is missing at this point and another is incorrectly set at the same time. However, if you rule out courage in connection with a good knowledge of the system, this case is very unlikely. - 17 -

Fortunately, if someone who knows this weakness of the system actually uses this fact to swap two or more books for their advantage (knowledge advantage), this is fortunately a point of attack:

When a user searches for this book, there is someone else who stands in his place. If the two books were merely interchanged, which in most cases should be the result of such a deliberate or inadvertently caused disruption, the title found at the location of the book sought leads immediately to the location of the missing work. Even if the ring was exchanged, it can be released again in this way. Only if a book is inserted instead of a lost or stolen book can the exchange no longer be traced backwards, the book must be replaced. This case is one of the extremely rare curiosities in library life.

Fortunately, the cost of replacing a thin book is usually relatively low, and these are just such books; Books that are at least 1 cm thick offer enough space for proper and relatively machine-readable labeling.

The comparison with the catalog - evaluation of the data

After the work is done, the robot is in the reading room with a full mass storage. A removable disk system is available as a storage medium, in which the entire data of a revision tour can be transferred to a mainframe computer in one hand, which then compares it with the electronic library catalog.

It is important here that the catalog is available in an electronic 1: 1 representation based on the locations, which is not always a matter of course. If this form of the catalog does not exist, it must be generated from the systematic catalog that is now probably available in electronic form at every major library before the revision system is used for the first time.

The work of the evaluation program: - 18 -

The work of this evaluation program basically consists of only comparative work and will not be described further here. If the program detects that a book is on the shelf too much or a book is missing, it records this fact in a comparison log. With undetected signatures of books, but which could be interpreted as a book, the procedure is as described in the section above, i.e. H. an error is only reported if the number of unrecognized books deviates from the target number, or if a large number of books within a shelf or directly in succession has not been recognized. However, if the robot was unable to find a book, an entry is also made in the comparison log for the library staff to use to check whether it was a robot recognition error or an actually missing book.

Problems

15

In some special cases, the system may not recognize a book for some reason, not because of a more or less accidental failure (due to the incidence of light, a bad video image, due to the location on the shelf), but in principle not. From time to time there are handwritten additions, printed letters or simply dirt on the signatures. The recognition program can also have problems with books with a white spine if it cannot clearly lift the label off the spine. Such books should, if they are categorized as not recognized the first time the system is run, be given new, clearly legible labels; 25 For white books, a dark border around the label helps.

"Double labels"

In theory, it is also possible for the image recognition to label two labels directly next to one another

30 other relatively thin books as a label. If one gives the recognition program a certain intelligence related to the signature system of the respective library, so that it recognizes irregularities in the composition of the signature, such recognition errors can be avoided here. Otherwise the comparison program detects an error and thus initiates a check. - 19 -

A final, almost exhilarating source of error, which should be mentioned here and which triggers an error in the program, shows the clear inferiority of the machine to humans in actually very simple things: a book placed upside down is of course saved as not recognized and can then be used by library staff be turned around. It differs from a thin book on which no label can be attached, precisely in that there should actually be a label on the back; the recognition program saves such books as "with a missing label"; the comparison program records this message in its log.

The power supply

A further consideration is the power supply to the robot due to a possible reduction in the profitability of the system. If the use of such robot systems is to be worthwhile, they should work independently for as long as possible. H. can work without being operated by an employee. At least 12-14 hours (overnight) maintenance-free operation would be a desirable period of use, provided there are no irregularities. In addition to a supply via batteries, the possibility of an external power supply is also conceivable.

Here you will first think of a cable that connects the robot to the power supply unit. The cable can be rolled up or rolled out either by the robot or the stationary unit. Three basic directions of movement are conceivable: the robot moves away from the power supply and, over time, has to pull an ever longer cable behind it; he describes a circle, or he starts his work with rolled out cable and stands cleanly next to the supply unit in the morning. Theoretically, the last option would even allow the robot to be controlled via the designed cable.

In the same way it would of course be possible to set up a power supply coming from the ceiling in suitable rooms; this is primarily intended for larger reading rooms, where the shelves are arranged around an open space in the middle.

Another conceivable method would be replacement batteries positioned in the room at certain points or at a central charging station, which the robot can pick up independently. - 20 -

With the camera and its flexible control, however, the robot would have ideal conditions for this process.

Finally, cyclical work is also conceivable, in which the robot always returns to the central unit for charging and simultaneous data processing when its energy supply is running low.

Other variants in construction

In the context of the discussion about energy supply that has just taken place, the idea also arises of reducing the structures on the moving robot and placing them in a central location for this purpose. In particular, the computer, even one of the heaviest parts with a lightweight design, could already find a place outside the robot, already firmly networked with the library catalog.

However, this also removes the possibility of independent control from the robot; the commands, like the video data, must be transmitted by cable or by radio. With today's possibilities of technology, this solution is obvious. The movable unit then only has to carry the camera on a movable tripod and the transmitting and receiving unit. The energy requirement drops and in return the maintenance-free working time increases.

Another technical addition to the system is a device for removing and re-inserting the books. The robot, which is directly connected to the library catalog by radio, can remove incorrectly positioned books or pull them out a little, so that they can be easily recognized, removed and correctly set the next day. Furthermore, in the case of very thin books, he could get hold of the signature or the barcode of the loan system, which is often attached to the front page. For this purpose, two grippers, which insert themselves into the optically or mechanically localized gap between two books, would clamp them with mutual pressure and pull them towards themselves.

Some preferred and advantageous embodiments of the invention are given below: - 21 -

An automated and autonomous revision system for book entry with the aid of image recognition and a computer-aided, flexible car control can be characterized in that it is oriented in the room using a control system that is similar in appearance to that of the book labels, that it reads its command data optically independently, like the signature data, that the information acquisition for control and signature recognition is combined in an optimized image recognition process and it finally provides the data for an automated catalog comparison.

Such a system can be further developed in that the device is equipped with an external power supply via a cable that is unrolled and / or unrolled either by the robot or by a fixed station located in the room.

Alternatively or additionally, it can be provided in such a system that individual components are located at a fixed station in the room and the communication of these components with the movable system part is realized via cable and / or radio.

Another embodiment variant of the system according to the invention provides that additional guidance information is obtained from the rolled-out cable.

It is also possible with the system according to the invention that the device can accommodate spare accumulators that are positioned independently in the room, or that it can independently return to a charging station.

Another embodiment of the system is characterized in that it has a device for removing and re-inserting the books.

Another possibility is that the system recognizes the books with a contactless electronic, electromagnetic or other recognition system.

Claims

- 22 patent claims

1. Storage system with an orientation option for a movable robot (2), in particular in a library, with a plurality of storage locations (1) for the storage of storage items, an identification mark (3) being attached to each storage item, one attached to the robot (2) Sensor for detecting the identification markings (3) attached to the stock items, characterized in that orientation markings (OM, 4) for the robot (2) are attached to the storage locations (1) which have essentially the same appearance as the identification markings (3) the storage items and the spatial position of each. Bear location information (1) and that the sensor is connected on the output side to a control unit which controls the robot movement depending on the orientation markings (OM, 4) detected by the sensor.

2. Storage system according to claim 1, characterized in that the orientation markings (OM, 4) attached to the storage locations (1) each reflect the absolute spatial position of the respective storage location (1) within the storage system.

3. Storage system according to claim 2, characterized in that the orientation markings (OM, 4) attached to the storage locations (1) each determine the relative position of the next storage location (1) to be approached by the robot (2), so that the robot (2 ) automatically travels from storage location to storage location on a specified course.

4. Storage system according to one of the preceding claims, characterized in that the sensor for detecting the orientation marks (OM, 4) and the identification marks (3) on the bearing articles is an optical sensor.

5. Storage system according to one of the preceding claims, characterized in that the identification markings (3) are attached to the storage items in each case at the same height in order to simplify the detection. - 23 -

6. Storage system according to claim 4 and claim 5, characterized in that the optical axis of the optical sensor extends in the horizontal direction in the search height of the identification markings (3).

7. Storage system according to one of the preceding claims, characterized in that the storage locations are in each case shelves, shelves or parking spaces within a shelf.

8. Storage system according to claim 7, characterized in that the optical axis of the optical sensor lies in a search plane, the vertical distance (h) between the search plane and the shelf being substantially equal to the height of the identification markings.

9. Storage system according to one of the preceding claims, characterized in that the robot (2) has a mass memory in order to store the identification markings (3) read article information and / or the location information of the orientation markings for later evaluation.

10. Method for operating a storage system according to one of the preceding claims, with the following steps: a robot (2) approaches a first storage location (1) within the storage system,

- The identification marks (3) of the stock items arranged in the first storage location (1) are successively detected by the sensor of the robot (2) and the respective item information is determined,

- The orientation mark (OM, 4) attached to the first storage location (1) is detected by the sensor of the robot (2) and the location information of the orientation mark (OM, 4) is determined,

- Depending on the determined location information, the location of the next storage location (1) is determined and automatically approached by the robot (2).

11. The method according to claim 10, characterized in that the detection of the identification marks (OM, 3, 4) is carried out optically by an optical sensor.

12. The method according to claim 10 or 11, characterized in that after the detection of an identification mark (3) immediately next to the already detected identification mark (3) and at a predetermined height (h) an image pattern with a predetermined vertical (Δh) extension detected and compared with a stored image pattern of an identification mark (3) to determine whether immediately - 24 -

in addition to the identification mark already detected, a further identification mark or an orientation mark is arranged.

13. The method according to claim 12, characterized in that the predetermined height (h) for the detection of the image pattern substantially corresponds to the height of an identification mark (3) and the vertical extent (Δh) of the recorded image pattern is substantially less than the height of an identification mark (3).

14. The method according to claim 13, characterized in that, if a further identification mark (3) is not recognized, the horizontal position of the empty space is stored in addition to the identification mark (3) last recorded.

15. The method according to any one of claims 10 to 12, characterized in that in the event of a non-detection of a further identification mark (3) immediately next to the last detected identification mark (3), the width of the empty space is stored in order to distinguish between a missing stock item and a thin one To enable stock items with illegible identification marks.