DE9319564U1 - Loading location system based on a satellite navigation system - Google Patents

Description

Description

The invention relates to a cargo location determination system based on a satellite navigation system.

Up to now, it has often happened that parts, such as containers, left at loading areas cannot be found again or can only be found after lengthy searches because the driver of the loading vehicle either forgot to note the location of the part left or because he had mistakenly given the wrong location. Even in other storage or handling systems in which the goods to be loaded, especially general cargo, are either only temporarily stored or deposited for later use using crane-type loading units or track-guided or free-moving loading vehicles, precise location determination that is independent of human error sources is of great importance.

The invention is based on the technical problem of providing a system for automatically determining the location of loaded goods.

This problem is solved by a cargo location determination system, comprehensive

on a loading unit for the goods to be loaded, in particular loading vehicle:

a) a satellite navigation receiver for automatically determining a raw position value of a current position of the loading unit;

at an operations center:

b) a satellite navigation receiver for automatically determining a raw reference position value of a reference location whose exact geographical position is known as the reference position normal value ;

(c) a fault determination device for determining

a current position determination error by comparing the currently determined reference position raw value with the reference position normal value; and
at the operations center or at the loading unit:

d) a device for receiving raw position values transmitted by a forwarding unit of the loading unit or for receiving position determination errors transmitted by a forwarding unit of the operations centre;

e) a correction device for correcting raw position values determined at specific times with position determination errors of reference position raw values determined essentially at the same time; and

f) a device for storing the corrected position values or location information derived from the corrected position values.

The invention draws on existing satellite navigation systems, such as the US system GPS or the Russian system GLONASS. With the generally available civilian satellite navigation receivers, a current position can be determined with a relatively high inaccuracy of, for example, 100 m, whereby signal propagation times between at least three satellites and the receiving antenna of the satellite navigation receiver are evaluated mathematically. Due to the relatively high inaccuracy, the measurement results of the satellite navigation receiver, referred to in this context as raw position values, are not sufficient for further usable determination of the position of the respective goods being loaded. The raw position values are therefore corrected. For this purpose, a position determination error is determined in the operations center, essentially at the same time as the determination of the corresponding raw position value.

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in the loading vehicle. This position determination error is then used to correct the raw position value in the operations center or in the loading unit. This type of error correction is already known as the "satellite navigation system in differential mode". Accuracies of between 1 and 5 m can be achieved with this system. It is important that only the position of the goods being loaded is of interest, so that one could actually think of supplying the respective goods being loaded with the satellite navigation system. According to the invention, this effort is avoided by arranging the satellite navigation system not on the goods being loaded but on the loading unit for the goods being loaded, and by determining and passing on the current position of the loading unit when the goods are being unloaded as representative of the position of interest of the goods being loaded.

In order to obtain the most precise possible location determination of the goods being loaded during unloading, it is proposed that a receiving antenna of the satellite navigation receiver of the loading unit be arranged in the area of a loading device for the goods being loaded. If the satellite navigation receiver is a compact unit with an integrated antenna, this is installed entirely in the area of the loading device, in particular in the area of a lifting device or crane of the loading unit.

In a first embodiment of the invention, it is provided that the device for transmitting the determined raw position values or the position determination errors is formed by a transmitter, in particular a radio transmitter, and the device for receiving the raw position values or the position determination errors is formed by a receiver, in particular a radio receiver. This enables "real-time differential operation", i.e. the immediate evaluation of the raw position values determined by the loading unit by correction with the position determination error of the

determined reference position raw value. Since the data only needs to be transmitted in one direction, the data transfer is simplified.

When using loading vehicles with a relatively small radius of action, for example rotary or gantry cranes, it is possible to transmit the data online via a dedicated line. Independence from such dedicated lines is achieved if, in a further development of the invention, the device for transmitting the raw position values or the position determination errors is formed by a transmitter, in particular a radio transmitter, and the device for receiving the raw position values or the position determination errors is formed by a receiver, in particular a radio receiver.

In an alternative mode of operation, the raw position values are corrected at a later point in time, so that no "online" data transfer with the corresponding equipment outlay is required. For this purpose, the device for forwarding the determined raw position values comprises a data recording device for recording the raw position values and the respective measurement time on a data carrier, in particular a diskette, the device for receiving the raw position values comprises a data reader for the data carrier, and the error determination device is designed to continuously determine and store current position determination errors and the respective measurement time. Because the respective measurement time is also stored with the respective raw position value, a largely exact subsequent error correction can be carried out by correcting the respective raw position value with the position determination error that was determined at approximately the same measurement time. This procedure is also known as "post-processing differential operation". A standard hard disk can be used as a data storage device.

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magnetic data storage, such as floppy disks or magnetic tape, or in the future possibly also an optical storage device, such as a writable CD-ROM. Error correction is preferably carried out in the operations center, so that the equipment and computing effort in the loading units can be kept to a minimum.

In both operating modes, the current position of the loading unit is only determined when the loading unit is currently in the position required for loading the goods. The determined position then corresponds to the position of the goods being loaded. The corresponding information is then saved so that the respective goods can be easily found later. An identification code for the goods being loaded is therefore also registered with the determined corrected raw position values. If a loading plan is specified and adhered to, the identification codes can be assigned to the corresponding corrected raw position values in the order of the loading plan. In order to have greater flexibility in planning when loading, it is advisable to provide a device on the loading unit for entering and/or automatically determining an identification code for the goods being loaded. The identification codes are transmitted to the operations center together with the raw position values or corrected position values by radio or data storage device. The identification code can be entered manually, for example. Automatic determination of the identification code requires more effort, but it eliminates any input errors. Such automatic devices for determining the identification code can be designed to read bar codes or to read alphanumeric characters using appropriate image recognition devices. In addition, the height positions of the goods being loaded can also be recorded to clearly determine the

respective loading goods locations.

The network of navigation satellites is becoming increasingly dense; independent systems are now available, namely GPS and GLONASS. To ensure error correction without any doubt, it is important that the raw position values and the raw reference position values are determined using the same satellites. To ensure this, it is proposed that the facilities for transmitting and receiving the raw position values should also be designed to transmit information that identifies the satellites used.

The invention is explained below using preferred embodiments based on the drawing. It shows:

Fig. 1 is a plan view of a container loading facility with loading vehicle and operations center equipped with a cargo location determination system according to the invention;

Fig. 2 is a rough schematic representation of the loading location determination system according to the invention with loading vehicle and operations center for the "real-time differential operation";

Fig. 3 is a rough schematic view of a loading vehicle;

Fig. 4 is a rough schematic representation corresponding to Fig. 2 for the "post-processing differential operation"; and

Fig. 5 is a rough schematic representation of a variant of the loading goods location determination system according to Fig. 2.

The invention is explained below using the example of a container loading system. However, a large number of other types of application are also possible in which an automatic, precise location determination of general cargo is important, whereby according to the invention the actual location determination is not carried out by a satellite navigation receiver arranged on the respective general cargo, but by a receiver provided only on the loading vehicle, and at the time of loading (setting down the cargo or possibly also picking up the cargo). This includes spacious shelf storage systems, especially high-bay storage systems.

The container loading facility shown schematically in Fig. 1 comprises a series of stacking places, for example three with the reference symbols 1OA, 1OB and IOC, each of which has one or more rows 11 of storage spaces for containers 12. The containers 12 are usually placed two on top of each other, as this corresponds to the lifting height of the usual loading vehicles (see Fig. 3). Higher stacks are also possible when cranes are used. In order to clearly identify the container being unloaded, a height position of the loaded goods (stack height) is required, which can be easily derived from the respective height of the loading gear (so-called spreader 14 in a container loading vehicle according to Fig. 3) when unloading or picking up the load.

The containers 12 of the stacking places 10 can, depending on the location of the container loading facility, be transported to and from the container loading area by truck and/or by rail and/or ship. In Fig. 1, top left, a port facility 15 with a ship 16 and containers 12' on the ship or containers 12'' on land is indicated, omitting a corresponding loading crane. Rail loading is symbolized by rails 18. Furthermore, one can see, in a highly simplified representation, two loading vehicles 20, which are used for the

Transport back and forth between the locations mentioned and also the loading and unloading of container semi-trailers (not shown). Finally, an operations center 22 is indicated in the center of the facility, but this can also be located outside the facility.

Both the operations center 22 and the loading vehicles 20 are each equipped with a satellite navigation receiver 26. These receive GPS time signals from satellites of a satellite navigation system, which they compare with a standard time of a system clock of the respective receiver 24 or 26, resulting in corresponding signal travel times between the satellite (symbolized in Fig. 2 with 28) and the respective receiver 24 or 26. From these travel times (usually from four satellites that can be received simultaneously), the respective receiver 24 or 26 calculates a current position. In the case of the satellite navigation receiver 24 of the operations center 22, this is a raw reference position value and in the case of the receiver 26 of the loading vehicle 20, it is a raw position value. The term "raw value" is used because the location determination is carried out solely on the basis of the evaluation of the satellite transit times with a relatively high degree of inaccuracy of, for example, ± 100 m, which is not sufficient for an operational location determination system, even for cargo the size of containers 12.

To correct the raw position values of the receiver 2 6, the receiver 24 of the operations center 22 is used, which is located at a geodetically precisely measured location. The receiver 24 continuously determines its own position (= raw reference position values), the respective measurement time and the respective satellites of the satellite navigation system used. By comparing the respective current raw reference position values with the geodetic location (= normal reference position value), an error determination device 3 0 determines a current position.

determination error. This is used in a correction device 3 2 for the corresponding correction of raw position values, which are transmitted to the operations center 22 essentially at the same time as they are determined in the respective loading vehicle 20 (real-time differential operation according to Fig. 2) or at a suitable later time (post-processing differential operation according to Fig. 4). Since the position determination errors generally fluctuate relatively strongly over time, care must be taken to ensure that the correction of a raw position value is carried out by a position determination error whose underlying reference position raw value was determined essentially at the same time as the raw position value (i.e. that the signal propagation time measurements of the two receivers 24 and 25 must take place essentially at the same time).

The error determination device 30, symbolically indicated as a block in Fig. 2, and the correction device 32 can be implemented in a computer unit 34 in terms of hardware or software. The computer unit 34 also houses a unit 36 for storing the corrected raw position values (= position values) or location information for the containers 12, which are derived from the position values. Coordinates, e.g. grid squares, which are specific to the respective loading facility can be used for this purpose.

In order that the current raw position values determined by the satellite navigation receiver 26 on the loading vehicle correspond as accurately as possible to the respective container position during unloading or loading and, in particular, are independent of the current orientation of the loading vehicle 20, the receiver 26 is mounted exactly above the center of the container 12 on a drive motor unit 38 according to Fig. 3, which drives the pulley 40 for raising and lowering the container 12.

In the embodiment of Fig. 2, the receiver 26 is connected to a data transmitter 41, which in the schematic representation according to Fig. 3 is located on the roof of a driver's cabin 42. This data transmitter communicates with a corresponding data receiver 43 in the operations center 22. The data receiver 43 is in turn connected to the computing unit 34.

As soon as the loading vehicle 20 has brought a container 12 to a designated stacking location in the designated final position, the receiver 26 is activated and a raw position value is determined. This activation can either be carried out manually by the driver in the driver's cab 42 or automatically, for example triggered by the spreader 14 as soon as it releases the connection to the container 12.

The determined raw position value is forwarded to the operations center 22 via the data transmitter 41. At least one further piece of information is expediently transmitted, namely an identification code of the unloaded container 12. This code number can be entered manually or, if a corresponding device with pattern recognition properties is used, also determined automatically. In Fig. 3, such a device is symbolically indicated and designated 44. It is connected to the data transmitter 41 via a dashed line 46, just as the receiver 2 6 is connected to the data transmitter 41 via a line 48. Furthermore, a height position sensor 3 9 for the respective container stacking position is indicated at the upper end of the pulley, which is connected to the data transmitter 41 via a line 4 9.

Further information that can be forwarded via the data transmitter 41 to the data receiver 43 is information that determines the satellites used for the transit time measurement and, if necessary, the respective measuring device.

Time to ensure a correction with the simultaneous positioning error.

In the "post-processing differential operation" shown in simplified form in Fig. 4, the error correction takes place at a later point in time, so that the effort of constant data transmission, in particular by radio, can be dispensed with. The data transmitter 41 is replaced by a data recording device 41' and the data receiver 43 by a data reader 43'. The data carrier can be a conventional data carrier, such as magnetic tape or, as shown, a data diskette 45. As Fig. 3 indicates, the data recording device 41' is conveniently located in the driver's cab 42. The rest of the system structure is unchanged.

After placing a container 12, the receiver 26 is activated and the corresponding raw position value is determined and stored in an internal data memory and/or on the data disk 45. At the same time, the measurement time is stored as well as the identification code for the current container 12. In addition, information can be stored about the satellites used in the determined system as well as about the stack height of the placed container.

At a later point in time, for example at the end of a work shift, the diskette 45 containing all the data is fed to the data reader 41' of the operations center 22 to read the data into the computing unit 34. The computing unit 34 also stores the position determination errors determined at short intervals during the day by the error determination device 30 with the respective measurement times. The raw position values are then corrected with the appropriate simultaneous position determination errors. The corrected values are then placed in a grid square and the corresponding

The corresponding grid square information for the individual container locations is saved.

Fig. 5 shows a variant of the embodiment according to Fig. 2. Components that correspond in function to those in Fig. 2 are provided with the same reference numbers, each increased by 100. The essential difference is that the error correction does not take place in the operations center 122, but on the respective loading vehicle 120.

The operations center 122 in turn houses the satellite navigation receiver 124, which receives the GPS time signal from the satellite 128 and forwards it to the error determination device 130 within the computing unit 134. The error determination device 130 determines the current position determination error by comparing the respective reference position raw value with the geodetic reference position normal value. The current position determination error is transmitted together with further information, in particular the measurement time and the satellite configuration used, to the respective data receiver 141 of the loading vehicle 120 using a data transmitter 143 (radio transmitter). The data receiver 141 in turn forwards this data to a computing unit 150. This simultaneously receives the current receiver position from the satellite navigation receiver 126, which corresponds to the position of the cargo that has just been unloaded (or picked up). In the correction device 132 within the computing unit 150, these raw position values are then corrected using the current position determination errors. The position values thus obtained are stored in the unit 136 together with other characteristic data such as, in particular, the identification code number of the load and the stack height. The stored data can be retrieved at a later point in time, for example after the end of the shift, using a data recording device connected to the computing unit 150.

device 152 onto a portable data carrier, in particular diskette 154, for further use, in particular within the operations center 122, the
is provided with a corresponding data reader 156. However, under certain circumstances, a transmission
The data can be transmitted wirelessly, although this involves greater effort.

The methods described above can, as mentioned, be carried out with an automatic reading and identification system
for container numbers or the like. Thus
it is possible to check each individual loading object
to be found again later reliably and independently of human error.

Claims (11)

Expectations 1. A cargo location system based on a satellite navigation system, comprising: on a loading unit for the goods to be loaded, in particular a loading vehicle (20;120): a) a satellite navigation receiver (26; 126) for automatically determining a raw position value of a current position of the loading unit; at an operations center: b) a satellite navigation receiver (24; 124) for automatically determining a reference position raw value of a reference location whose exact geographical position is known as a reference position normal value; c) an error determination device (30; 130) for determining a current position determination error by comparing the currently determined reference position raw value with the reference position normal value; and at the operations center (22) or at the loading unit (120): d) a device (43;141) for receiving from a transfer unit (41) of the loading unit (20) transmitted raw position values or to receive position determination errors transmitted by a forwarding unit (143) of the operations center (122); e) a correction device (32,-132) for correcting raw position values determined at specific times with position determination errors of reference position raw values determined essentially at the same time; and f) a device (36;13 6) for storing the 16 .' I corrected position values or location information derived from the corrected position values. 2. Loading goods location determination system according to claim 1, characterized in that a receiving antenna of the satellite navigation receiver {26) of the loading unit is arranged in the region of a loading device for the loading goods. 3. Loading goods location determination system according to claim 2, characterized in that the receiving antenna is arranged in the area of a hoist or crane of the loading unit. 4. Loading goods location determination system according to one of the preceding claims, characterized in that the device for forwarding and the device for receiving the raw position values or the position determination errors are designed for transmission immediately after they have been determined to the correction device. 5. Loading goods location determination system according to claim 4, characterized in that the device for transmitting the raw position values or the position determination errors is formed by a transmitter (41; 143), in particular a radio transmitter, and the device for receiving the raw position values or the position determination errors is formed by a receiver (43, -141), in particular a radio receiver. 6. Cargo location determination system according to one of the preceding claims, characterized, that the device provided on the loading unit (120) (136) for storing the corrected position values is connected to a data recording device (152) for recording on a portable data storage device, in particular a diskette (154), and that the operations center (122) is provided with a data reader (156) for the data carrier, 7. Cargo location determination system according to one of claims 1 to 3, characterized in that the device for forwarding the determined raw position values comprises a data recording device (41') for recording the raw position values and the respective measurement time on a portable data carrier, in particular a diskette, that the device for receiving the raw position values comprises a data reading device (43') for the data carrier, and that the error determination device (30) is designed for continuously determining and storing current position determination errors and the respective measurement time (Fig. 4). 8. Cargo location determination system according to one of the preceding claims, characterized in that a device (44) for entering and/or automatically determining an identification code for the goods being loaded is provided on the loading unit. 9. Cargo location determination system according to one of the preceding claims, characterized in that the devices for transmitting and receiving the raw position values or the position determination errors are also designed to transmit the measurement time at which the respective raw position value was determined. 10. Cargo location determination system according to one of the preceding claims, characterized in that the devices for transmitting and receiving the raw position values or the position determination errors are also designed to transmit information which determines the satellites of the satellite navigation system used in each case. 11. Cargo location determination system according to one of the preceding claims, characterized, that a device (39) for inputting and/or automatically determining a height position of the goods being loaded is provided on the loading unit (20).