DE102006015689A1 - Commissioning system/picking system`s material handling equipment controlling method, involves continuously detecting up-to-date condition images of pre-determined areas of material handling equipment with camera - Google Patents

Abstract

The method involves continuously detecting up-to-date condition images of pre-determined areas of a material handling equipment (20) with a camera (50) e.g. video camera, where the camera is perpendicularly arranged over the material handling equipment. The condition images are evaluated to determine an actual position of the material to be conveyed in the pre-determined area of a haulway. A comparison of target and actual values is performed for identifying the actual position. A control signal is generated based on the result of comparison of target and actual values. An independent claim is also included for a picking system with a material handling equipment.

Description

The The invention relates to a control system for conveyor systems, in particular for one Picking system, in the conveyed by means of a conveyor technology promoted become.

It is known to and picking systems automatically with a PLC (programmable logic Control) or by a computer-based unit to control. The Signals which trigger relevant state changes show, become conventional with light barriers or light sensors to a Steue tion, in particular to a warehouse management computer. The controller gives according to previously known Algorithms signals to actuators to suit the conveyor technology accordingly Taxes.

For example. With light barriers or light sensors, light-dark state changes take place detected. At accumulation roller conveyors is thus the arrival of a conveyed (Cardboard, container or other general cargo) detected a predetermined location, whereupon the drive of a allocated conveyor technology segment is stopped and the conveyor technology segment for example, exercises a stowing function. On similar Way scanners are activated, stoppers extended, Switches or conveyance transfers initiated.

in the Hereinafter, the term "conveyor technology" will be understood to mean a conveyor device, the moving of goods in demarcated operating areas, e.g. in a picking system, or generally guaranteed in a warehouse. Under the term materials handling becomes in a broader sense the process design during operation the conveyors be understood. conveyor Elements are, for example, conveyor belts, roller conveyors, Overhead conveyor, webbing Etc.

To picking articles are kept in so-called storage containers, can but also as Einzelstückgut be transported. The articles are carried out from the storage containers a picking person at a picking station in so-called order container given. The order containers be with the articles according to one Picking order. As soon as a order container is completely picked is, it is usually promoted to a so-called shipping station, to be delivered.

At the Use of light sensors and light barriers for the detection of conveyed goods, in particular of containers and general cargo, it is more common in the past come to problems. For example, it is not possible to detect with light barriers be, whether two containers directly behind one another, i. without a gap in between, transported become. For the photocell seems to have a single oblong conveyed promoted become. This is particularly problematic when using the light barrier an input and output device of the conveyor technology are controlled should. In this case it is not possible to transport both goods into the directing direction since there is no distinction between them can be.

Farther a photocell can not detect whether two conveyed goods transported side by side become. Here it can again cause problems in the control of Actuators of conveyor technology come, such as the above-mentioned input and output device.

Around To obtain a high throughput in the order picking is it required the goods to be transported with a relatively high average speed to move. However, the conveying speed depends et al from the dimensions and weight of the conveyed material. A towering one conveyed For example, it is not possible to steer around a bend as quickly as flat Conveyed. In particular, heavy goods are on Reason of their inertia more difficult slow down as lighter goods. Alles these factors must in the control of conveyor technology considered become.

One Another disadvantage of conventional light sensors and light barriers is that with them can not be detected to what kind or which type of conveyed goods it is about.

Further it is disadvantageous that light barriers and buttons are not always on positioned in the required places can be. For example, a positioning in overlapping areas or in the Range of points not possible.

One Another disadvantage is that a light barrier only information about the Condition of the conveyor system which prevails at the location of the light barrier itself. Local changes before or after the light barrier can not be seen with this. Consequently is a pre-planning control or a check of already executed control commands not possible with photocells.

It is therefore an object of the present invention to provide a device and a system for controlling a conveyor system, in particular in a picking system, which are improved over the known methods. In particular, the conveyor should be dynamically controlled with respect to the conveying speed. Advantageously, a dynamic storage function and a demand-based shutdown of such conveyor technology sections should be possible in de no material is stored to save energy.

These Task is solved with the objects, like she in the independent claims are defined.

According to one first embodiment Cameras are used to acquire up-to-date status pictures. In contrast to light switches or pushbuttons, the use of cameras makes this possible Capture larger areas the conveyor technology. Existing and non-existent distances between goods can be pre-determined be determined before the corresponding goods pass an actor. The speed lets based on this information about the upstream Better condition. The conveyor technology can be accelerated or decelerated, with different ones Speeds at different points through the use of conveyor technology segments, in particular motor-driven conveyor rollers.

According to one another preferred embodiment a dynamic stowage function occurs by moving upstream to a Traffic jam located conveyor segments be operated so that the segments with a smaller and smaller Speed, the closer they are to the place of congestion.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

embodiments The invention are illustrated in the drawings and in the following description explained.

1 shows a schematic plan view of a picking system according to the present invention;

2 shows several conveyor segments when performing a dynamic stowage function;

3 shows a schematic block diagram of a warehouse management computer according to the present invention; and

4 shows a schematic flow diagram of the method according to the present invention.

In 1 is a picking system 10 shown according to the invention. The picking system 10 has a variety of order-picking modules, which can be extended by additional modules, which are not explicitly explained here. Similarly, some of the modules could be omitted. The attachment 10 according to the 1 thus represents only an exemplary embodiment, which is not limited to this specific form.

In the picking system 10 Storage containers and order containers are transported, hereinafter generally as a container 12 be designated. Filled containers 12 are in the 1 shown darkly. Empty containers 12 are in the 1 shown brightly. Furthermore, general cargo 14 promoted, which are indicated here schematically as circles. cargo 14 can also be in containers 12 be stored. The containers 12 be in container shelves 16 in a storage area 17 stored. In the upper part of the 1 are exemplified carousels that have a variety of storage bins for containers 12 which are arranged one above the other in several levels. The carousel 16 settles in the direction of an arrow 18 move. At the front of the carousel 16 is each a lift 19 provided that is height adjustable, allowing containers 12 can be taken from different levels or delivered to them. The lift 19 can have several load handling devices. With the help of the lift 19 are, as mentioned above, the container 12 from the front of the carousel 16 picked up and to a conveyor 20 delivered or from this for return to the carousel 16 added. The conveyor technology 20 may for example be implemented by a roller conveyor, as in an arrow 22 is indicated by way of example.

About the conveyor technology 20 , which is shown here as a self-contained loop, become the container 12 to pickers 24 transported to the respective picking stations 26 work. At the in 1 The picking system shown, the principle "goods-to-man" is realized 24 hardly has to be at the picking station 26 move. The articles to be picked are placed over the storage containers 12 to the picking person 24 transported.

The in 1 picking station shown 26 includes on one side of a picking process 27 in which the picking person 24 can move a variety of picking shafts ("pick-to-dead"), in the articles to be picked from the on the conveyor 20 to the picking station 26 delivered articles are picked. The picking shafts have an opening and closing mechanism at their lower vertical end. When opened, the articles thus picked into the shafts fall to one below the picking shafts centrally arranged anthology 30 or a webbing 30 , The on the tape 30 located articles become a delivery point 32 promoted. At the transfer point 32 be by means of another conveyor 34 , which may be, for example, another motorized roller conveyor or a belt conveyor, container 12 transported for receiving the article from the belt 30.

The picking person 24 However, it can also be used at the picking station 26 from the opposite side of the order picking shafts from order picking shelves 36 Article in container 12 Picking, by means of a separate or on the shelf 36 self-managed further conveyor technology 38 to get promoted. At the in 1 shown picking shelf can be a so-called. Passage shelf, which, relative to the picking station 26 , from behind via Zuführgasse 40 from a stacker crane (RBG) 42 equipped with, for example, europallets. The picker 24 Can then handle larger batches of items, for example, not in the picking shafts 24 fit, remove from the europallets and place them in containers 12 give. The containers 12 are then using the conveyor technology 38 either from the picking person 24 on the tape 30 provided by the conveyor technology 38 even on the tape 30 transported or transported to another location, such as to another picking station or directly to a shipping station.

The RBG 42 settles in the direction of an arrow 44 in Zuführgasse 40 method. To the flow racks 36 To load with pallets or other containers, the picking shelf opposite a pallet warehouse 46 be provided.

The conveyor technology 34 which also includes the transfer point already mentioned 32 is included in the exemplary annex 10 at the bottom of the 1 at an arrow 49 diverted. In this area is the conveyor technology 34 as an example divided into several segments S1-S5. Each of these elements is part of an accumulation conveyor line and is controlled by several separate cameras 50 supervised. Alternatively, fewer cameras can be used. Exemplary is also a single camera 52 shown, which can detect the entire longitudinal length of the accumulation conveyor line.

There are further cameras at other conveyor technology relevant points 54 to 62 arranged. Each of these cameras 50 to 62 monitors an assigned area 66 to 80 , The areas 66 to 80 lie in tax-technically relevant areas of the conveying techniques.

So are, for example, the cameras 50 and 52 in the fields of 66 or the area 68 that is relevant to the exercise of the storage function. The camera 54 with their assigned area 76 monitors, for example, a section of the conveyor system 34 , the transfer point 32 upstream upstream. The camera 56 with their assigned area 74 monitors the transfer point 32 itself. The camera 58 monitors the area 72 to determine whether conveyed or general cargo according to specification is properly oriented relative to the longitudinal axis of the conveyor itself. In the 1 is in the area 72 a container 12 arranged at an angle. With the help of the pictures of the camera 58 can this condition be recognized and, for example, in the area 70 by means of (lateral) sliders 71 correct. These correction operations can also be done with the help of the camera 60 be monitored. Correct orientation of the conveyed material is particularly important if the length of the conveyed material is longer than the width of the conveyor to prevent tilting of the conveyed in such areas of the conveyor, where it comes to changes in direction of the conveyor itself, such as in curves , However, even goods with smaller widths should always be aligned correctly.

In the fields of 78 and 80 the cameras 64 and 62 Be redirecting the conveyor technology 38 supervised. With the help of the pictures of the cameras 62 and 64 can input and Ausschleusvorrichtungen (here only exemplarily indicated by arrows) of the conveyor 38 be controlled. With the help of the camera 62 But it is not only the location of the deflection device that can be monitored, but also the entire length of the conveyor system 38 along the order picking shelf 36 , In this way, the utilization of this section of the conveyor technology can be 38 monitor and, if necessary, visualize. The same applies to the camera 64 monitored area 78 , The area 78 can be over the entire length of the anthology 30 extend.

Generally read all information of the cameras visually represent.

The cameras 50 to 64 submit their images to a higher-level warehouse management computer (LVR) 90 , These are the cameras 50 to 64 via connecting lines 102 eg with a data bus 100 , such as a PROFIBUS ^® , or via an Ethernet network, WLAN, USB or other fixed or wireless buses with the LVR 90 in connection. However, the cameras can also be directly connected to the LVR, as exemplified by a line 104 is indicated. Especially with locally difficult to access cameras, the signal transmission can also be wireless, as indicated by arrows 106 is indicated. Also, the conveyor segments S1 to S5 can be connected in this way with the warehouse management computer. Exemplary here is a connection via a line 108 shown.

In 2 is an accumulation roller conveyor 109 illustrated schematically. The accumulation roller conveyor 109 can be identical to the one in 1 be shown. It comprises here five segments S1 to S5. A main conveying direction runs in the 2 from left to right, as indicated by an arrow.

In the area of segment S5, a traffic jam has formed. This is done either by a camera assigned to this segment or by a higher-level camera (cf. 52 in 1 ) detected. The corresponding camera delivers an image to the LVR 90 which recognizes, by means of appropriate image processing software, that there are four containers in the area of the segment S5. In the in 2 shown example mean four containers 12 within one and the same conveyor segment a traffic jam. In order not to let more containers on this congestion, the LVR gives 90 Control commands to the upstream segments S1 to S4 to reduce their speed. Preferably, the speed of the individual segments S1 to S4 is set such that the closer the corresponding segment is to the congestion, the lower the speed.

Similarly, the LVR 90 turn off certain conveyor segments when it is determined on the basis of the images supplied by the cameras that the corresponding segments do not transport conveyed goods. However, if the transport of a conveyed material is detected by an upstream camera, the downstream conveying segments can be switched on again accordingly with a corresponding delay. In this way, a demand-driven control of the conveyor technology can be realized. The big advantage here is the saving of energy. Conveyor technology is therefore only operated if conveyed goods are actually located on the conveyor system.

By the previously explained Dynamic storage function makes it easier to avoid traffic jams. Vice versa can Traffic jams resolved faster be when downstream to congestion located conveyor segments again with an ever-increasing speed operated, the farther the segment downstream to the traffic jam is located.

By a use of the camera leaves So an actual state of the conditions on the conveyor determine not only the location of the camera itself, but also on entire conveyor technology areas extended. With the help of the cameras can be easily recognized be, for example, several goods directly transported one behind the other what a simple photocell due to lack of Distance between the conveyed goods not detected could be. The images generated by the cameras can also be visualized Use the utilization of the picking system. On This way, the utilization of an operator's facility can be visual entrusted with the task of the overall system to monitor. Also, that's the way a remote monitoring or remote maintenance given. It is understood that the cameras are not for monitoring the picking person himself should be used, but only for monitoring the Load status of the conveyor system.

The Cameras can both over the conveyor technology as well as laterally to the conveyor technology to be ordered. A lateral arrangement allows a height of the conveyed To determine piece goods. This information is particularly relevant when very high Transported goods become. High goods tend at high conveying speeds to fall over. The conveying speed can thus also in dependence from the geometric height of the conveyed goods become.

In 3 is a schematic block diagram of the LVR 90 of the 1 and 2 shown. The LVR 90 includes a database 10 in which algorithms for image processing, conveyor technology control and the like are stored. Furthermore, the LVR includes 90 a CPU 112 , a variety of interfaces 114 (eg USB), with connections 115 to communicate with the various actuators and the cameras are connectable. The LVR 90 can also use special image processing modules 116 and target-actual comparison module 118 (in the form of software or hardware).

In 4 the method according to the present invention is shown schematically in the form of a flow chart. In a first process step 120 Timing status displays of the conveyor technology are recorded. In a further process step 130 the image processing takes place. Subsequently, in one step 140 a target-actual comparison is performed. For this purpose, the captured images are compared with previously calculated or read states, which should optimally prevail in the picking system. If the comparison of the desired state with the actual state shows that there are no deviations between the two, the step becomes 120 Returned or appropriate control signals are issued to downstream actuators, the further (pre-planned) transport of goods through the order picking 10 regulate. If there are deviations between the actual state and the desired state, other actuators can be actuated to correct this deviation.

A great advantage of the invention is the fact that large areas of the conveyor technology a easily and quickly monitored. In particular, in the case of errors, it can be determined in advance how best to react to them. Material can be correctly positioned again. Conveyed goods can be separated. The storage function can be designed dynamically. Material can be recorded and documented according to type and number. A check of the processing of order picking is possible. For example, color design of the picking these can also be distinguished and directed to their destination. Containers may be provided with appropriate codes that can be read by the cameras to control downstream actuators to direct the respective containers to predetermined destinations (storage rack, order picking station, shipping station, etc.). It is understood that not only cameras, such as video cameras, can be used, which work in the visible range. Also, cameras for detecting other wavelengths can be used.

Claims (10)

Method for controlling a conveyor system ( 20 . 34 . 38 ) of a picking system ( 10 ), a conveyed goods ( 12 . 14 ) at a predetermined time in a main conveying direction to a predetermined location, comprising the steps of: - continuously acquiring current state images of predetermined areas of the conveyor with a camera ( 50 - 62 ), in particular with a video camera, which is preferably arranged vertically above the conveyor system; - Evaluating a state image to determine an actual position of the conveyed in the predetermined range of the conveyor line; - Performing a target-actual comparison for the actual position; Generating a control signal based on the target / actual comparison result, and outputting the control signal to an actuator, in particular to an input / output device, a scanner, a stopper, a diverter, a slide, a speed-controlled conveyor segment or a stowage station. The method of claim 1, further comprising: to save from acquired state images, desired-actual comparison results and / or Control signals for logging. The method of claim 1 or 2, wherein for performing the Target-actual comparison pre-calculated or read-in target positions become. Method according to one of the preceding claims, wherein is determined during evaluation, whether the conveyed relative to the main conveying direction properly aligned, and where, if the conveyed is not aligned properly is, the control signal output to at least one adjusting device is to the conveyed goods to align properly. Method according to one of the preceding claims, wherein during evaluation, it is determined whether several items are transported in direct succession, to be able to separate them. Method according to claim 5, wherein the control signal, if it has been determined that several items are transported in direct succession, to spend at least one stowage space to at least one of Temporarily stop the conveyed goods, so that at least the first conveyed has a distance to a subsequent conveyed him. The method of claim 6, wherein in the evaluation geometric lengths of the conveyed goods be around these lengths control accordingly many accumulation bins to be able to. Method according to one of claims 1 to 7, wherein the of The camera covered the area of conveyor technology in several segments is divided, each with different speeds are controllable, so that each segment at a speed which is the lower, the closer the segment is relative to a Fördergutstau is arranged. Method according to one of the preceding claims, wherein is determined during evaluation, whether several items next to each other relative to the main conveying direction promoted be to control if necessary slide such that the transported side by side Organized goods arranged one behind the other become. Picking system with a conveyor system, at least one actuator and a control unit ( 80 ) adapted to perform the method according to any one of claims 1 to 9.