Method for dynamic automation using collaborative elements, and control system therefor

p0001The present invention relates to a method for dynamic automation with collaborative elements according to claim 1 and a guidance system for carrying out the method according to patent claim 18.

p0002The automation of industrial processes, especially of logistical processes, has the following characteristics:<ul><li>Special fully automatic systems: These are plants which perform certain processes fully automatically. The presence of persons is not foreseen in these facilities. The performance characteristics of these machines are given and can only be changed with a great deal of effort. Examples of such systems are high-rack storage, sorter and, in general, conveying systems.</li><li>Production lines: These largely correspond to the work organization of Ford. The production of products of industrial processes follows fixed, defined routes. These routes define fixed positions at which the individual work processes are executed. These operations can be carried out with the help of human beings or automatically by means of suitable equipment.</li></ul>

p0003Examples of this are the services of the following providers:<ul><li>Swisslog: (www.swisslog.com)</li><li>Siemens Dematic: Similar to Swisslog (www.siemensdematic.com/corp/en/index.php)</li><li>AFT: (www.aft.de)</li></ul>

p0004Another example of transport systems is HELPMATE^®, The Trackless Robotic Courier (http://www.helpmate.com/products/helpmate.asp). This transport system is able to distribute goods in environments in which people also work. The task of the robot in this case is to start the predetermined positions. The actual distribution of the goods is then taken by the people. Helpmate is not an actively controlling element of an industrial process, but is waiting passively at the approached position.

Disadvantages of known systems:

p0005The space occupied by automatic systems is only prepared for the automatic components. The presence of people is thus strongly hindered and in any case a disturbance of the system is caused thereby. Today's automatic systems provide defined zones where humans and machines can interact. These zones are static and it is in no case possible for persons and machines to move independently and autonomously at the same time. The space for driverless transport systems (FTS) is, for example, prepared in such a way that the carriageways are reserved for the movements of the FTS. Thus, the perception of obstacles of any kind (including the presence of a person) is processed as a disturbance. This proves to be disadvantageous because, as a rule, interruptions occur during the work processes, resp. Dead times.

p0006After <patcit id="pcit0001" dnum="JP10101222B"><text>JP 10101222</text></patcit> A method for a cost-optimized storage management is known in which a mobile robot is moved along a defined path at the part bearing. The worker meets the robot, on whose screen the instructions for loading the parts are shown. The charging process is supported by optical displays at the storage location and at the storage point on the robot.

p0007After <patcit id="pcit0002" dnum="US5825981A"><text>U.S. Patent No. 5,825,981</text></patcit> A robot system for a production line is known in which several robots are provided for performing a task. These robots are guided and monitored by a so-called 'software robot', a control system. The control data of the task is transmitted by the control system to at least one of the robots for the purpose of handling the task. The availability of several robots allows for efficient processing in case of failures of robots while avoiding dead times. An interaction with humans is not provided with this robot system.

p0008In the patent document <patcit id="pcit0003" dnum="EP0700841A"><text>EP0700,841</text></patcit> There is described a method for managing a storage system in which a plurality of mobile units communicate with a control center via a wireless communication link for receiving jobs for work to be performed. An ongoing location determination of the mobile units is carried out by means of a satellite navigation system (GPS). The respective use of the mobile units is thereby optimally controlled. An interaction with humans is likewise not provided with this procedure.

p0009The object of the present invention is to propose a method for a dynamic automation in which the disadvantages mentioned are omitted and which is distinguished by its efficiency. A further object is to specify a control system for carrying out the method.

p0010The object is achieved by a method according to patent claim 1 and by a control system according to claim 18.

p0011The method according to the invention is based on a collaboration between humans and machines, with the following characteristics:<ul><li>The workspace is accessible to both humans and mobile robots at any time;</li><li>The origin of products from industrial processes is the mobile robot, which navigates autonomously and freely in the work area;</li><li>The execution zone is determined dynamically. There, robots, the necessary resources for the execution as well as the people meet. People move autonomously;</li><li>The cooperation is initiated at the execution area by the mobile robot and the corresponding information is actively communicated by the robot in the local environment.</li></ul>

p0012The method and the associated control system are described below. Show it:<ul><li><figref idrefs="f0001">FIG</figref> Schematic representation of a work step</li><li><figref idrefs="f0002">FIG</figref> Schematic representation of the architecture of a dynamic automation <figref idrefs="f0003">FIG</figref> Transaction diagram of a flow of dynamic automation</li></ul>

p0013The core of the invention is a method which comprises collaborative elements, such as essentially humans, resp. Persons and mobile robots, as well as automata, who cooperate together in order to fulfill tasks and / or order processing as efficiently as possible. The basic principle is based on the fact that there is a division of labor between humans and mobile robots, whereby these two collaborative elements are autonomous in the workspace, resp. In space. Such a concept nowadays finds itself primarily in the cooperation between humans and partly also between machines, but not between man and machine. In the division of tasks between man and robot according to the invention, it is taken into account that each of these collaborative elements performs exactly that part of an operation which is most useful to the collaboration in terms of efficiency, flexibility, quality and performance.

p0014In the present invention, the following terms are defined:<ul><li>01. One <b>room</b> Is the work space in which dynamic automation is implemented.</li><li>02. One <b>collaborative element</b> Is a component of a work step. </li><li>03. One <b>Collaborative Element I. Type, KE (I)</b> Is a robot, usually designed as a transport system, which is mobile, autonomous and free to navigate. The robot is the place where a product of an order is created. In addition, the robot is able to transport static resources.</li><li>04. One <b>Collaborative Element II. Type, KE (II)</b> Is a person, or a person; The human being can move freely and autonomously in space. In this process he represents a mobile resource.</li><li>05. A <b>Collaborative Element III. Type, KE (III)</b> Is an automatic machine, or a machine, which is used for a working step and is generally not transportable, ie fixedly installed.</li><li>06. One <b>execution area</b> Is a zone of space in which collaborative elements meet to complete a work step.</li><li>07. One <b>Working step</b> Is the arrival of at least one collaborative element I. type and of at least one collaborative element II type and / or at least one collaborative element III. Type in an execution zone to handle an order position.</li><li>08. One <b>operation</b> Is the set of all work steps that are necessary to complete an order.</li><li>09. <b>communication media</b> Are the totality of the communication possibilities between KE (I), KE (II) and KE (III).</li><li>10. One <b>Partial product</b> Is the product of a work step.</li><li>11. One <b>product</b> Is a sum of partial products and the product of an order, whereby one order may also comprise several products.</li><li>12. One <b>current state</b> Of the collaborative system are the current locations of all KE (I) and KE (II), the status (free, occupied, disturbance, pause, etc.) Of all KE's, current inventory and location of all goods in the room and the execution of all known orders Order positions.</li><li>13. One <b>assignment</b> Describes a logical and logistic unit to be provided. The order is provided with an appointment (time, date): By which time the unit must be available. The job contains information about who has to receive this unit. The execution of an order produces a quantity of products.</li><li>14. One <b>Job location</b> Is part of an order and describes a step in the process of providing or producing a unit. It contains the information as to which resources are required to carry out the work step: goods and / or facilities. In the description of the order position, the result of this work step is precisely defined. A sequence number is assigned to each order item, which describes when a work step must be executed within an order: Which order items must be executed before the current order item; Which order positions must be carried out according to this order item; Which order positions can optionally be executed before or after this application position. The sequence numbers of all the order positions of an order thus form a mathematical order.</li><li>15. <b>Static resources</b> Are resources that are used when an order is executed and whose location in space determines the execution zone. They can be transported using KE (I), but not during the execution of a work step.</li><li>16. <b>Mobile resources</b> Are resources which move autonomously during the execution of an order or are transported by autonomous mobile robots. These resources are thus moved autonomously to the execution zone immediately before the execution of a working step.</li><li>17. <b>Fixed resources</b> Are resources which can not be transported (eg an injection robot, a bearing).</li><li>18. <b>Would</b> Is a resource that is consumed to execute a job location: After execution, this resource is not available for any further job.</li><li>19. <b>the furniture</b> Is a resource that is not consumed: After executing an order item, it is available for further orders (for example, a tool).</li><li>20. <b>Dynamic:</b> Each assignment takes place at the latest possible date or date, taking into account the current state of the collaborative system.</li></ul>

p0015<figref idrefs="f0001">FIG</figref> 12 shows a schematic representation of a working step. A collaborative element I. Type KE (I), a mobile robot, is guided in a room 1, which is guided, controlled or ordered by means of a guidance system 2 into an execution zone 3. The control system 2 is generally located in the space 1 and is equipped with a bidirectional system for wireless transmission 6 of all information, instructions and feedback signals, which is indicated by an arrow. Advantageously, however, the guidance system can also be located on the KE (I), the mobile robot. In this case, transmission to the KE (I) can also take place at least partly by wire. The execution zone 3 is located in the space and is a region, or a zone of this space, in which collaborative elements meet in order to complete a working step or to fulfill the task set in the working step. Collaborative Element I. Type KE (I) can move freely and autonomously in space. Exceptions are exposed areas with obstacles, such as shelves, storage cabinets, barriers and the like, but also obstacles such as persons. 'Free' means that the KE (I) moves or navigates 'where it wants'; 'Autonomous' means that the KE (I) moves 'independently', as will be explained further below. Guided by the control system, the KE (I) moves towards the execution zone. Upon arrival in the execution zone or, advantageously, already in advance, eg, on the way to the execution zone, a collaborative element II. Type, KE (II), a human being, or KE (I) with instructions from and via the guidance system via communication media 4 A person is requested, who now goes into the execution zone, to receive further instructions after the arrival. As soon as KE (I) and KE (II) have arrived in the execution zone, KE (II) is instructed to carry out the part-generating step with the inclusion of static resources 5, which are needed in the execution of the working step. Such an instruction can be, for example, 'to put two packing screws into a shipping unit', the shipping unit being located on the KE (I), the mobile robot. The execution of this statement is monitored by KE (I). After an error-free processing, all the collaborative elements are released for further tasks. With this exemption, the work step is completed. The partial product of this work step is located on the KE (I) and has been formed on it. Thus the KE (I) is the point of origin of the partial product. The work step can also be a collaborative element III. Type, KE (III), an automatic machine, or a machine, which is also located in the execution zone. A KE (III) is generally not transportable, ie fixedly installed, eg labeling machine, winding machine, spraying robot.

p0016Since the human being and the mobile robots move autonomously, the method according to the invention presupposes the following requirements and / or preconditions:<ul><li>Space: People and mobile robots must be able to move safely in the same room. The room must be prepared so that<ul><li>The robots can independently navigate and orient themselves autonomously;</li><li>The robots can clearly identify humans as well as other robots;</li><li>The free movement of man is permitted at any time;</li><li>The robots are aware of the various locations of the people in the space at any time.</li></ul></li></ul>These tasks are all connected to the control system. Navigation: The autonomous mobile robots must be able to navigate in the space in such a way that the presence of people is taken into account and does not lead to disturbances, which can then be manually corrected by humans: the presence of a person can be for spatial reasons Stopping a mobile robot. As soon as the human being moves in such a way that the continuation is possible, the robot is able to resume its navigation autonomously. The mobile robot "hits" humans in the space to carry out a joint task or a working step with their help or collaboration. Therefore it is necessary that the robot can follow a certain person autonomously. Navigation must be designed in such a way that the mobile robot can avoid all obstacles, especially those who are currently not cooperating with the robot. The method according to the invention differs from known systems. Most vehicles which move in automatic systems either move on rails (shelf-operated units, hanging rails) or on fixed tracks. This applies to guideless transport systems (FTS) including Laser Guided AGV (Laser Guided Vehicles): the path is firmly defined in the corresponding software. The presence of obstacles leads to disturbances. Leaderless transport systems are not capable of following people autonomously.

p0017Communication: Collaboration between humans and robots takes place in space, rather than in a predefined, fixed location. The location of the collaboration (execution zone) is dynamically calculated based on the current state of the entire work process. Since persons can move independently of the robot, it is necessary that there is a suitable communication infrastructure between the robots and the persons. This supports the timely collision of the two collaborative elements (man / robot). After the interaction between the person and robot, an intensive communication or interaction takes place during the work step. The robot receives the necessary information from the robot to carry out the work step. On the other hand, the robot also monitors the work step and informs the person immediately if an error occurs during its execution. These two flows of communication are to be designed in such a way that they are as efficient and intuitive as possible for the human being, but the flow of information is at the same time also provided on time and with sufficient accuracy and security. This requirement requires that as many communication media as possible be used in parallel, such as speech, optical signals, acoustic signals, video, body language. Thus the method according to the invention is again different from known systems: these do not have the mentioned requirements for communication with humans. Main reason: The interaction between man and machine is in each case at locations in the room that are fixed relative to the machine.

p0018In the process described so far, the collaborative elements form the basis for cooperation between humans and mobile robots. It was postulated that autonomously moving people meet with autonomously moving robots at specific locations and carry out a work step together. As soon as this joint work step has been completed, both the human being and the mobile robot are again available for other tasks. The human being can carry out a further work step, or a further job position of another work process or order, and the mobile robot Can prepare for a next step of the same work process.

p0019<figref idrefs="f0002">FIG</figref> 12 shows a schematic representation of the architecture of a dynamic automation. In general, the collaborative system consists of a set of collaborative elements, I., KE (I), ie of autonomous robots, and of a set of collaborative elements, II, type, KE (II) To run. Optionally, a set of collaborative elements III. Type, KE (III), ie automatons, or are or will be involved. All the collaborative elements are connected to the control system bidirectionally. The information flow is ensured between the KE (I) and KE (II) by means of the communication media. The following new tasks arise on the system level:<ul><li>Which work process must be carried out next by which robot;</li><li>Soft workstep, a person must perform next, ie, where is the person used, for what and when.</li></ul>

p0020The solution of these two tasks is carried out taking into account the performance maximization of the entire collaborative system (including the KE (III)) with the following criteria:<ul><li>Maximizing the number of operations that can be performed by the system per time unit;</li><li>Minimizes the throughput times of the individual work processes;</li><li>Uniform utilization of all persons involved.</li></ul>

p0021This results in coordination tasks between robots and people who are actively supported by technical devices, control systems and organizational measures.

Host system.

p0022The host system determines which jobs must be executed up to the latest time. The host system is responsible for ensuring that all necessary materials and resources are procured in good time and that the assigned or assigned orders can also be executed in a timely manner.

Control system.

p0023The control system determines the segmentation of the individual work processes. The control system coordinates all mobile robots, humans and automata (elements of the collaborative system), so that all work processes can be executed optimally. The control system knows the exact locations of the individual goods units in the room, as well as the locations of each person and robot. The control system also knows the current state of each machine. The control system determines which operation is assigned to which robot. The guidance system determines which are the next activities of the various persons, or each individual person.

KE (I), robots.

p0024The robot constantly communicates with the control system. On the one hand, in order to receive the information on the assigned work process, but on the other hand, in order to continue to report back to the control system the current advance of the assigned work processes. At the same time, the robot also continuously informs the control system of its condition and its location in the room.

KE (II), Human.

p0025The human being is equipped with communication devices, so that the communication between the human being and the control system takes place essentially uninterruptedly or continuously. The same communication devices are equipped in such a way that the location of each individual person can be determined continuously and continuously from the control system.

KE (III), Automat.

p0026Analogous to the robot, except for the location, since it can be fixed.

p0027<figref idrefs="f0003">FIG</figref> 12 shows a transaction diagram of a flow of dynamic automation. A first and a second working step AS1 and AS2 are represented in chronological succession on a time axis. On an ordinate are listed: The control system, a 1. KE (II), a 2. KE (II) and a KE (I). In the first operating step, commands 11, 12 are sent to KE (I) and KE (II) from the control system for movement into a first execution zone. Next, in the working step AS1, the information flow 13 necessary for executing the working step AS1 between KE (I) and 1. KE (II) takes place, the command system 14 executing the start of the command. Completion of the working step AS1 forms the monitoring by KE (I) with a feedback 15 to the control system. In the second working step, the commands 16, 17 are sent to KE (I) and KE (II) from the control system for movement into a second execution zone. Next, in the working step AS2, the information flow 18 necessary for executing the working step AS2 takes place between KE (I) and 2. KE (II), whereby the command system 19 executes the start. Completion of the working step AS2 forms the monitoring by KE (I) with a feedback to the control system (not shown).

Determination of the location of the static resources in space.

p0028The control system determines the locations of all static resources in the room due to fractions, predictions or pre-registration of orders. The locations and the quantity of the individual resources are defined as a weighted, non-linear combination of the following criteria:<ul><li>Optimization of the routes which the persons have to travel to reach the different execution zones;</li><li>Optimize the paths the remaining mobile resources need to travel to reach the execution zones;</li><li>Reducing the refilling of the goods used during the execution of the relevant orders;</li><li>Reduction of collision probability of all mobile robots;</li><li>Increasing execution parallelism: If the same product is distributed at several locations, all orders that require this product can be executed in parallel.</li></ul>The location of the static resources is calculated dynamically and constantly: If a location becomes vacant, its re-allocation is recalculated according to the above criteria plus the current state of the collaborative system.

p0029The location of the static resources is recalculated at the beginning of a planning period.

Dynamic allocation (scheduling).

p0030The assignment or loading of the orders to the mobile robots takes place dynamically. The selection of the next order is determined by:<ul><li>Order sequence: This is determined on the basis of the latest possible execution date included in the order;</li><li>Dependency on other orders if the execution of other orders is a prerequisite for the execution of an order;</li><li>Availability of the resources necessary for the order; </li><li>Location of robots relative to the necessary, fixed resources.</li></ul>

p0031This determines which product of the order has to be provided or produced on which mobile robot. This determines the amount of order positions which must be carried out in order to provide the product. The order of execution of the order position is not yet determined at this time.

Dynamic determination of the next job position.

p0032The determination as to which job location must be carried out is as follows:<ul><li>After allocation or loading of a product on a mobile robot;</li><li>Immediately after an order position has been executed or completed.</li></ul>

p0033The quantity of possible order items for a product is determined by the sequence numbers of the order items still to be executed. The selection from this set is subject to the following criteria:<ul><li>Current availability of mobile and static resources;</li><li>Minimize the paths that the mobile resources need to travel (due to current locations). If the required, fixed resource is available in different locations, the implementation zone is also set (read 'static resource') using this criterion;</li><li>Uniform utilization of persons;</li><li>Uniform utilization of all resources; All KE (I) and KE (III).</li></ul>

Arrival of all mobile resources in the execution zone.

p0034The control system is responsible for the timely arrival of all mobile resources in the execution area. To enable this, the next job location and its execution zone are prepared during the execution of the current job location, but have not yet been definitively defined. In this way, the available free (order-free) mobile resources are directed to the "in preparation" execution zone. The same criteria are used when preparing the next order item. The following basic rule applies: The current state of all required resources is not considered, but the probable state at the time of execution. As soon as a prepared, mobile resource becomes free, it is immediately led to the "in preparation" execution zone.

p0035An exemplary embodiment for dynamic automation in the warehouse logistics is described below. In order to simplify the presentation (ie, it is not to be understood), the description is limited to a logistics process, namely to picking.

Picking with collaborative elements.

p0036The definitions for a logistical environment are translated below. It means:<ol><li>1. One <b>assignment</b> In the picking corresponds to a shipping order. This is provided with a delivery date and a delivery address.</li><li>2. The <b>Job location</b> Of a shipping order, which goods and which properties must be delivered in which quantity. In this case, the work step includes packaging the goods so that they are prepared for shipping. Job locations can have a sequence number. This describes the logic for the stacking of the goods: heavy goods are first picked.</li><li>3. <b>Static resources</b> Are in this case goods which are stored in fixed resources.</li><li>4. <b>Mobile resources</b> Are mobile robots.</li><li>5. <b>Fixed resources</b> Are shelves, storage places, labeling stations, high rack storage etc. </li><li>6. <b>Would</b> Are the products to be picked.</li><li>7. <b>Furnishings:</b> Is rarely used in this process. Examples of these are: pricing machines.</li><li>8th. <b>product</b> Is the shipping unit.</li></ol>

Determination of the storage location of the goods in the picking warehouse.

p0037The storage location of the goods in the warehouse is determined by means of invoices, forecasts and pre-declarations of dispatch orders. The same product can also be stored in several locations. The place of storage and the quantity of goods to be stored shall be determined by a non-linear combination of the following criteria:<ul><li>Uniform distribution of future picking processes in the entire room;</li><li>Reduction of refilling during picking;</li><li>Parallelism: goods that are often used is distributed to several storage locations.</li></ul>

p0038The storage locations are determined dynamically, even during picking and refilling.

Dynamic assignment (scheduling).

p0039The allocation and / or the loading of the orders on the mobile robots takes place dynamically. The selection of the next order is determined by:<ul><li>The order of the orders: This is determined by the delivery dates, which are contained in the order resp. Related priorities;</li><li>The availability of the goods in the order warehouse, which are necessary for the order;</li><li>The location of the robots relative to the necessary fixed resources.</li></ul>

p0040This step is used to determine which shipping unit of the order has to be prepared or produced on which mobile robot. This determines the amount of order positions which must be executed in order to produce the shipping unit. The sequence of execution is not yet determined at this time.

p0041With packing pattern logic, it is possible to determine the quantity of the dispatch unit of an order in advance: This means that all dispatch units of an order can be assigned or loaded in parallel.

Dynamic determination of the next job position.

p0042Which order location must be executed is defined as follows:<ul><li>After assignment (loading) of a shipping unit on a mobile robot;</li><li>Immediately after an order location has been executed.</li></ul>

p0043The set of possible order positions for a shipping unit is determined by the sequence of the order items still to be picked.

p0044The selection from this set is subject to the following criteria:<ul><li>Current availability of persons and goods;</li><li>Minimize the distances that the required persons and the mobile robots have to cover (due to the corresponding current locations). If the required product is available at different locations, it is also determined by using this criterion where picking is carried out;</li><li>Uniform utilization of persons;</li><li>Uniform utilization of all resources.</li></ul>

Arrival of the necessary mobile resources at the picking location.

p0045The system is responsible both for the timely meeting (at the picking location) of the mobile robot with the shipping unit as well as with the person who has to pick up the goods. In order to enable this, the next order item and its goods (picking location) are prepared during the execution of the current location, but have not yet been definitively defined. It is checked whether the person who is picking the current location is also suitable for the next order position, on the basis of the following criteria:<ul><li>Shortest path relative to all pending job positions: The same person performs the next job of this job only if this causes the shortest displacement of the person;</li><li>Waiting times of other persons: If there are persons who wait very long for a work, or for a working process, then these persons are first taken.</li></ul>

p0046This is used to direct the free persons present to the "in preparation" pick-up location. The same criteria are used when preparing the next order item.

p0047The following basic rule applies: The current state of all required resources is not considered, but the probable state at the time of execution. As soon as a prepared mobile resource becomes available, this is immediately led to the "in preparation" execution zone.

Organizational restrictions.

p0048This process can be restricted by meaningful, organizational measures. These may be necessary in order to make the work organization understandable to the persons involved. Further measures can be introduced on the basis of the specific, recurring, topological properties of the work area (here the warehouse).

Picking zone.

p0049As a rule, a person works in a defined storage zone. This zone is defined by the topology of the camp: A person usually works in a few campsites (ducts between shelves) and leaves this zone only if the picking processes in the warehouse are very uneven due to mis-planning.

Formation of trains of mobile robots.

p0050It is assumed that the mobile robots move in one gear only in one direction of travel. The direction of travel to be traveled is determined exactly when a first robot actually arrives at an empty gear, which is not occupied by robots. This direction of travel remains fixed as long as there is still a mobile robot in the lagging. Each further robot now applies this 'occupied' gear with a predetermined direction of travel, resulting in the formation of a train of two or more mobile robots. It is assumed, that mobile robots can not overtake in a Lagergang. This assumption is based on known, widespread storage topologies.

p0051Since a bearing normally has long bearing lengths, the trains of mobile robots are formed automatically. The application of the above-defined algorithm for determining the next activity of a person can have the following expressions, resp. Features:<ul><li>If a train has formed in a bearing train, the person always moves in the opposite direction of travel (to the robot);</li><li>As soon as a person has finished a location on a robot, it moves to the next robot waiting for picking;</li><li>If the first robot is waiting for another picking at the same location, the person simply stops;</li><li>The person executes the next order item.</li></ul>

p0052Assuming that two adjacent bearing lengths are served by two different persons, and that the direction of travel of the robot in one of these bearing positions is opposite to the direction of travel of the robot in the other bearing passage, a traveling carousel, a so-called "collaborative picking carousel" :<ul><li>For example, the robots move clockwise;</li><li>The two persons move counterclockwise.</li></ul>

p0053If more than two people are needed in these storage areas, they can be clamped into the carousel at any time.