Arrangement of a gantry lifting device and of a row of spaced-apart marking elements

Abstract

An arrangement of a gantry lifting device for handling containers, in particular ISO containers, having a sensor device for the navigation of the gantry lifting device and having a clearance profile which is formed such that the gantry lifting device can move across a container, and of a row of spaced-apart marking elements such that the gantry lifting device can be moved along the row of marking elements by means of raster navigation, where the row of marking elements can be read by the sensor device of the gantry lifting device. The sensor device, in an operating position, is arranged outside the clearance profile on the gantry lifting device so as, in the operating position, to read the row of marking elements for the navigation of the gantry lifting device, where the row of marking elements is arranged next to the clearance profile of the gantry lifting device.

Claims

1. A system for the navigation of a moveable gantry lift device over lanes in an automatically guided manner by grid navigation in order to change between two mutually crossing lanes or two adjacent parallel lanes by turning or by a lane change, said system comprising: a gantry lift device configured as a straddle carrier for handling containers, wherein the gantry lift device is moveable in an automatically guided manner by grid navigation, and wherein the gantry lift device has a clearance profile configured such that the gantry lift device can move across a container without collision; a row of marking elements for grid navigation spaced apart within a first lane for the gantry lift device; and a sensor apparatus disposed on the gantry lift device, wherein the sensor apparatus is operable to read the marking elements for navigation of the gantry lifting device; wherein the gantry lift device includes spaced apart running gear unit supports, and wherein the gantry lift device and the row of marking elements are arranged such that the gantry lift device can be moved within the first lane along the row of marking elements by grid navigation, and wherein the sensor apparatus in an operating position is arranged outside the clearance profile on the gantry lift device in order, in the operating position, to read the row of marking elements for navigation of the gantry lift device, and wherein the row of marking elements is located next to the clearance profile of the gantry lift device and underneath one of the running gear unit supports of the gantry lift device.

2. The system as claimed in claim 1, wherein the sensor apparatus comprises a first part having at least one sensor and comprises a second part having at least one sensor.

3. The system as claimed in claim 2, wherein the row of marking elements is located in relation to the gantry lift device underneath one of the running gear unit supports such that the row of marking elements can be read only by the sensor of the first part of the sensor apparatus, or only by the sensor of the second part of the sensor apparatus.

4. The system as claimed in claim 3, wherein the row of marking elements of the first lane is adjoined by a branching row of marking elements spaced apart within a second lane such that the gantry lift device can be moved by grid navigation along the branching row of marking elements, wherein the branching row of marking elements can be read only by the first part of the sensor apparatus or only by the second part of the sensor apparatus of the gantry lift device.

5. The system as claimed in claim 4, wherein after the gantry lift device has turned from the first lane to the second lane, the branching row of marking elements of the second lane are located in relation to the gantry lift device such that the branching row of marking elements can be read by the same or a different part of the sensor apparatus than that before the turn.

6. The system as claimed in claim 5, wherein the marking elements in at least one portion of either the first lane or the second lane for the gantry lift device are located, as seen in the direction of the longitudinal extensions of the first lane and second lane, only in a left half or only in a right half and no marking elements are located in the right half or the left half of the portion of the first lane or the second lane.

7. The system as claimed in claim 6, wherein the first lane and the second lane cross at a crossing region with the crossing region adjoining said at least one portion of either the first lane or the second lane, and wherein additional marking elements are provided in the crossing region in order to ensure that at least two marking elements can always be read by the sensor apparatus.

8. The system as claimed in claim 7, wherein a row of marking elements is located in both a left half and a right half of the crossing region as seen in the direction of the longitudinal extensions of both the first lane and the second lane.

9. The system as claimed in claim 8, wherein the row of marking elements of the first lane comprise a first row of marking elements, and wherein a second row of marking elements is spaced apart in the first lane with the second row of marking elements located such that the gantry lift device can be moved by grid navigation along the first row and second row of marking elements of the first lane, wherein one of the first row and second row of marking elements can be read by the first part of the sensor apparatus, and the other of the first row and second row of marking elements can be read by the second part of the sensor apparatus.

10. The system as claimed in claim 9, wherein the branching row of marking elements of the second lane comprises a first branching row of marking elements branching from the first row of marking elements of the first lane, and wherein a second branching row of marking elements spaced apart within the second lane is provided with the second branching row of marking elements adjoining the second row of marking elements of the first lane such that the gantry lift device can be moved by means of grid navigation along the first and second branching rows of marking elements, wherein one of the first and second branching rows of marking elements can be read by the first part of the sensor apparatus and the other of the first and second branching rows of marking elements can be read by the second part of the sensor apparatus.

11. The system as claimed in claim 2, wherein the row of marking elements of the first lane is adjoined by a branching row of marking elements spaced apart within a second lane such that the gantry lift device can be moved by grid navigation along the branching row of marking elements, wherein the branching row of marking elements can be read only by the first part of the sensor apparatus or only by the second part of the sensor apparatus of the gantry lift device.

12. The system as claimed in claim 11, wherein after the gantry lift device has turned from the first lane to the second lane, the branching row of marking elements of the second lane are located in relation to the gantry lift device such that the branching row of marking elements can be read by the same or a different part of the sensor apparatus than that before the turn.

13. The system as claimed in claim 1, wherein the marking elements in at least one portion of the first lane for the gantry lift device are located, as seen in the direction of the longitudinal extension of the first lane, only in a left half or only in a right half and no marking elements are located in the right half or the left half of the portion of the first lane.

14. The system as claimed in claim 4, wherein the first lane and the second lane cross at a crossing region with the crossing region adjoining said at least one portion of either the first lane or the second lane, and wherein additional marking elements are provided in the crossing region in order to ensure that at least two marking elements can always be read by the sensor apparatus.

15. The system as claimed in claim 14, wherein a row of marking elements is located in both a left half and a right half of the crossing region as seen in the direction of the longitudinal extensions of both the first lane and the second lane.

16. The system as claimed in claim 2, wherein the row of marking elements of the first lane comprise a first row of marking elements, and wherein a second row of marking elements is spaced apart in the first lane, with the second row of marking elements located such that the gantry lift device can be moved by grid navigation along the first row and second row of marking elements of the first lane, wherein one of the first row and second row of marking elements can be read by the first part of the sensor apparatus, and the other of the first row and second row of marking elements can be read by the second part of the sensor apparatus.

17. A system for the navigation of a moveable gantry lift device over lanes in an automatically guided manner by grid navigation in order to change between two mutually crossing lanes or two adjacent parallel lanes by turning or by a lane change, said system comprising: a gantry lift device configured as a straddle carrier for handling containers, wherein the gantry lift device is moveable in an automatically guided manner by grid navigation, and wherein the gantry lift device has a clearance profile configured such that the gantry lift device can move across a container; rows of marking elements spaced apart within respective parallel lanes extending in a first direction for the gantry lift device, wherein the lanes extending in the first direction comprise first lanes and the gantry lift device is configured for automatic guided movement within the first lanes; and a sensor apparatus disposed on the gantry lift device, wherein the sensor apparatus is operable to read the marking elements of the first lanes for navigation of the gantry lifting device; wherein the gantry lift device and the rows of marking elements of the first lanes are arranged such that the gantry lift device can be moved within the first lanes along the rows of marking elements by grid navigation, and wherein the sensor apparatus in an operating position is arranged outside the clearance profile on the gantry lift device in order, in the operating position, to read the rows of marking elements of the first lanes for navigation of the gantry lift device, and wherein the rows of marking elements of the first lanes are located next to the clearance profile of the gantry lift device.

18. The system as claimed in claim 17, further comprising: rows of marking elements spaced apart within respective parallel lanes extending in a second direction for the gantry lift device, wherein the lanes extending in the second direction comprise second lanes and the gantry lift device is configured for automatic guided movement within the second lanes; and wherein the rows of marking elements of the first lanes are adjoined by the rows of marking elements of the second lanes such that the gantry lift device can be moved by grid navigation along the rows of marking elements of the first lanes and the second lanes, and wherein the gantry lift device and the rows of marking elements of the second lanes are arranged such that the gantry lift device can be moved within the second lanes along the rows of marking elements by grid navigation, and wherein the sensor apparatus in an operating position is arranged outside the clearance profile on the gantry lift device in order, in the operating position, to read the rows of marking elements of the second lanes for navigation of the gantry lift device, and wherein the rows of marking elements of the second lanes are located next to the clearance profile of the gantry lift device.

19. The system as claimed in claim 18, wherein the gantry lift device includes running gear unit supports, and wherein the sensor apparatus comprises a first part having at least one sensor on a first one of the running gear unit supports and wherein the sensor apparatus comprises a second part having at least one sensor on a second one of the running gear unit supports, with the first one of the running gear unit supports being spaced apart from the second one of the running gear unit supports, and wherein in each case the rows of marking elements of the first lanes and second lanes are located in relation to the gantry lift device underneath one of the running gear unit supports such that a respective one of the rows of marking elements can be read only by the sensor of the first part of the sensor apparatus, or only by the sensor of the second part of the sensor apparatus.

20. The system as claimed in claim 18, wherein each of the first lanes and second lanes include a left portion and a right portion as seen in the direction of the respective longitudinal extension of the first lanes and second lanes, and wherein rows of marking elements are disposed in one or both of the left portion and the right portion of the first lanes and second lanes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1a shows a gantry lift device in a system for the navigation of the gantry lift device in a first embodiment;

(2) FIG. 1b shows the gantry lift device of FIG. 1a in a system for the navigation of the gantry lift device in a second embodiment;

(3) FIG. 2 shows a view of the gantry lift device of FIGS. 1a and 1b from below;

(4) FIG. 3 shows a view of the system and the gantry lift device of FIGS. 1a and 1b from the side;

(5) FIG. 4a shows various positions of the gantry lift device in the system for the navigation of the gantry lift device according to the first embodiment in a plan view; and

(6) FIG. 4b shows the positions of the gantry lift device of FIG. 4a in the system for the navigation of the gantry lift device according to the second embodiment in a plan view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) FIG. 1a shows a schematic view of a first embodiment of a system for the navigation of a gantry lift device 1 in a container handling operation. The gantry lift device 1 incorporated into this system can be guided automatically by means of grid navigation in the above-defined sense and is operated and controlled accordingly in a driverless or unmanned manner. In this respect, driverless automated operation of a corresponding gantry lift device 1 can also be achieved when an accompanying driver is present but in this case does not actively intervene in the control of the gantry lift device 1.

(8) The gantry lift device 1 has two mutually parallel running gear unit supports 2 which are oriented in the longitudinal direction of the gantry lift device 1 and on which steerable wheels 3 are mounted. Since FIG. 1a illustrates by way of example a rear view of the gantry lift device 1 during travel straight-ahead in the travel direction F, only the rear wheels 3 can be seen and the front wheels 3 are concealed. The wheels 3, of which in each case two are arranged on one of the running gear unit supports 2, are provided with rubber tyres filled with air or gases, in the manner of pneumatic tyres, and can move thereon in a floor-bound but not rail-bound manner and are thus freely movable, wherein they run on a ground surface 4 of a container terminal, preferably in a port. Accordingly, the gantry lift devices 1 in the present case are to be distinguished from rail vehicles. The wheels 3 are disposed in a conventional manner in the corners of a notional rectangle. It is fundamentally also possible to provide more than four rubber-tired wheels 3 if this is required for technical reasons. This is then associated with an overall increase in the complexity of the gantry lift device 1 and therefore more complex technology must be employed in the area of the drive and steering. The drive of the gantry lift device 1 is typically diesel-electric, diesel-hydraulic or fully electric, in particular battery-electric, and accordingly comprises components such as e.g. a diesel engine and generator, batteries and/or hydraulic units. In order to form the spider leg-like gantry structure, a total of four gantry struts 5 extend from the running gear unit supports 2 in each case at the front and rear vertically upwards, said gantry struts forming, together with an attached machine platform 6 connecting the gantry struts 5, a gantry 7. Arranged on the machine platform 6 of the gantry 7 is a lifting device 9 for a container 8, to which lifting device a load picking-up means for the containers 8 which is defined as a spreader 10 is connected such that it can be lifted and lowered. For the purpose of picking up loads, the spreader 10 can be locked to the container 8 at its four corner fittings 11.

(9) As illustrated by way of example in FIG. 1a, the gantry lift device 1 can move within a first lane 13a defined on the ground 4 and in this case can be guided automatically according to the principle of grid navigation. As part of this procedure, the precise vehicle positions and orientations on the ground 4 of the container terminal and in particular within the first lane 13a are determined continuously. For this purpose, the first lane 13a is allocated two rows of marking elements 16 (see also FIG. 4a) which are located within the first lane 13a in the region of the ground 4. As seen in the direction of the longitudinal extension of the lane 13a, the first lane 13a has two halves. In the portion 17 illustrated in FIG. 1a (see also FIG. 4a) of the lane 13a, each of these halves is allocated one of the two rows of marking elements 16. Both rows extend preferably in parallel with one another. However, by reason of the view selected in FIG. 1a, only one marking element 16 of each row can be seen. Preferably, the two rows are spaced apart from one another such that in each case a row of marking elements 16 is located under each running gear unit support 2 or its vertical projection surface, in order to be able to be read by the sensor apparatus 12 of the gantry lift device 1.

(10) FIG. 1b shows the gantry lift device of FIG. 1a in a second embodiment of the system for the navigation of the gantry lift device 1. The second embodiment illustrated in FIG. 1b differs from the first embodiment essentially in that only one row of marking elements 16 is provided in the first lane 13a at least in the portion 17 (see also FIG. 4b). In contrast to the first embodiment, one of the two rows of marking elements 16 of the first embodiment has been omitted, as illustrated in FIG. 1b. In FIG. 1b, a row of marking elements 16 is located by way of example in the portion 17 only in the left half of the lane 13a, whereas the right half of the lane 13a in the portion 17 is free of marking elements 16. In this case, the respective row of marking elements 16 is located underneath one of the two travel supports 2, in particular underneath the vertical projection thereof onto the ground 4. Accordingly, no marking elements 16 are located underneath the other one of the two travel supports 2. Alternatively, the allocation of the row of marking elements 16 within the lane 13a can also be reversed so that marking elements 16 are located only in the right half of the portion 17 of the lane 13a. For the remainder, the statements provided in respect of FIG. 1a also apply accordingly to FIG. 1b.

(11) The marking elements 16 each comprise a transponder, in particular a passive transponder, or a magnet. In this case, the marking elements 16 can be embedded into the ground 4 and in particular can be located completely under a surface of the ground 4, on which the wheels 3 of the gantry lift device 1 run. The gantry lift device 1 is guided automatically along the row of marking elements 16, in that the marking elements 16 can be read by a sensor apparatus 12 of the gantry lift device 1 and the read information, as measurement signals, can influence the automatic navigation of the gantry lift device 1. For this purpose, the coordinates of the corresponding marking element 16 are stored as information in each marking element 16 and are made available to be read. The reading can also detect decoding of the information if said information is stored in encoded form in the marking elements 16 or is made available to be read.

(12) In order to be able to determine the position and orientation of the gantry lift device 1, two mutually spaced-apart marking elements 16 are always read by the sensor apparatus 12. As a result, the position and orientation of the gantry lift device 1 can be determined both relative to the corresponding marking elements 16 and also thereby within the container terminal or the corresponding lane 13a, 13b and can be used for the automatically guided navigation. In principle, the sensor apparatus 12 can be designed in one piece and can comprise only one sensor which is then designed accordingly such that two marking elements 16 can be read by the sensor at the same time. Continuous determination of the vehicle position and orientation is thus even possible if a sensor of the sensor apparatus 12 is provided only in the region of a single vehicle side or the running gear unit support 2 at that location. This is also possible if the system according to the second embodiment has portions 17 having only one row of marking elements 16. Alternatively, simpler sensors can be also be used for the sensor apparatus 12, which sensors cannot read a plurality of marking elements 16 at the same time but instead can always read only one marking element 16 at a time. In this case, the sensor apparatus 12 has at least two such simple sensors. The dimensions of the sensor or sensors of the sensor apparatus 12 and the distances between the marking elements 16 are to be adapted to one another accordingly. Since more precise position and location determination of the gantry lift device 1 is possible with a greater distance between the marking elements 16, the simpler sensors can have smaller dimensions and can be mounted on the gantry lift device 1 at the required distance. As a result, the sensor apparatus 12 can also be accommodated overall in smaller receiving spaces. Moreover, the space between the sensors can be used for accommodating other components and a further distance between the marking elements 16 and thus a reduction in the total number of required marking elements 16 can be achieved.

(13) In the case of the gantry lift device 1 which can be used for navigation in both embodiments of the system, the sensor apparatus 12 comprises four sensors which can each read one marking element 16. Two of the total of four sensors are arranged spaced apart from one another at the front and rear on the left first running gear unit support 2 between the associated wheels 3 and form a first part 12a of the sensor apparatus 12 (see also FIGS. 2, 3, 4a and 4b). In the same manner, two sensors are arranged on the right second running gear unit support 2 and form a second part 12b of the sensor apparatus 12. It is thus arranged on each vehicle side of the gantry lift device 1 of one of the parts 12a or 12b of the sensor apparatus 12. FIGS. 1a and 1b illustrate the respective rear sensor of the two parts 12a, 12b in broken lines. The parts 12a, 12b can also each comprise only one sensor which can read two marking elements 16 at the same time.

(14) FIGS. 1a and 1b illustrate a clearance profile 15 of the gantry lift device 1 in each case with a broken line, said clearance profile being formed underneath the gantry lift device 1 and being dimensioned at least large enough that the gantry lift device 1—perpendicular to the drawing plane—can travel across at least one container 8 in order to pass, pick up or set down the container 8. The clearance profile 15 thus encloses at least the clear space underneath the gantry lift device 21 which is required for travelling over at least one container 8 without collision. In this case, the clearance profile 15 extends between the two running gear unit supports 2 at least over one container width plus a certain tolerance. The clearance profile 15 thus corresponds at least to the outer contour of a container 8, which is set down on the ground 4, plus the desired tolerance. If the gantry lift device 1 is designed e.g. as a 1-over-3 device, the clearance profile 15 is dimensioned correspondingly higher. Accordingly, the container 8 is arranged, both in the loading operation when picking up and setting down the container 8 and also in the travel operation when transporting the picked-up container 8, within the clearance profile 15 and passes therethrough. In the present case, the clearance profile 15 is not to be understood to be the outer contour of the gantry lift device 1.

(15) The sensor apparatus 12 is arranged on the gantry lift device 1 or its running gear unit supports 2 such that the sensor apparatus 12 in its operating position is arranged outside the clearance profile 15 and thus does not enter therein while the gantry lift device 1 is being automatically guided by means of grid navigation. This applies both during travel operation and also during loading operation and equally during empty travel without a picked-up container 8. In this case, the container 8 suspended from the spreader 10 can also be suspended in the clearance profile 15 lower than in FIG. 1a, in particular to as far as underneath the sensor apparatus 12 because this is arranged outside the clearance profile 15 and as a result a collision with the container 8 can be precluded.

(16) FIG. 2 shows a view of the gantry lift device 1 of FIGS. 1a and 1b from below. The figure shows the arrangement of the two parts 12a, 12b or the associated and mutually spaced-apart sensors on corresponding undersides of the running gear unit supports 2. The sensors or their flat housings extend horizontally or in parallel with the ground 4 (see also FIGS. 1a, 1b and 3) and in this case preferably have a rectangular base surface which extends with its longitudinal extension in the travel direction F of the gantry lift device 1. In this case, the sensor apparatus 12 extends, as also schematically illustrated in FIGS. 1a and 1b, in the direction of the clearance profile 15 and terminates flush with the corresponding running gear unit support 2 so that both the running gear unit supports 2 and the sensor apparatus 12 are adjacent to the clearance profile 15 and delimit same. Alternatively, the sensor apparatus 12 can also extend beyond the respective running gear unit support 2 so that the clearance profile 15 does not extend as far as the two running gear unit supports 2, but instead extends only as far as the sensor apparatus 12, is adjacent thereto and is delimited thereby. It is also feasible for the sensor apparatus 12 to protrude outwards beyond the corresponding running gear unit support 2. It is likewise feasible for the sensor apparatus 12 to extend at least partially within a vertical projection surface of the respective running gear unit support 2, without being located adjacent to the projection surface. The sensor apparatus 12 does not have to extend over the entire width between the running gear unit supports 2, but instead can be formed to be correspondingly narrower and more space-saving by reason of the described design and arrangement and optionally flush fit underneath the running gear unit supports 2. By reason of the above-described arrangement and design of the sensor apparatus 12 in its operating position, the clearance profile 15 is not adversely affected for lifting, lowering, setting-down and picking-up as well as travelling over containers 8.

(17) Each sensor of the sensor apparatus 12 has an antenna and/or a magnetic field sensor in order to be able to read the marking elements 16 located in a positionally fixed manner, as soon as the corresponding marking elements 16 are located in the detection region of the sensor apparatus 12 by reason of the movement of the gantry lift device 1. The detection region typically includes a vertical projection surface underneath the sensor apparatus 12 or its sensors, wherein typically a reading distance is to be maintained between the sensors and the marking elements 16, which distance can be e.g. about 10 to 40 cm. For this purpose, the sensors of the sensor apparatus 12 are arranged on the gantry lift device 1 accordingly just about in a region close above the ground 4 or the marking elements 16 provided at that location.

(18) FIGS. 4a and 4b each show one of the two embodiments of the system for the navigation of gantry lift devices 1 and, in this connection, different positions or arrangements of the gantry lift device 1 in a plan view. The figures illustrate in each case a plurality of first lanes 13a which are arranged next to one another and extend in parallel with one another, and a plurality of second lanes 13b which are likewise arranged in parallel with one another and next to one another and cross the first lanes 13a in each case in a crossing region 14.

(19) In FIG. 4a, each lane 13a, 13b is allocated two rows of marking elements 16, as already described above with reference to FIG. 1a. As a result, the illustrated gantry lift device 1, at least during travel straight-ahead in the corresponding lanes 13a, 13b, e.g. in the positions A, C and E illustrated by way of example, can read with each part 12a, 12b of the sensor apparatus 12 the corresponding marking elements 16 because the gantry lift device 1 is always positioned at that location with both running gear unit supports 2 and the associated sensors over the marking elements 16.

(20) In contrast, in FIG. 4b, each lane 13a, 13b is allocated only a single row of marking elements 16, as already described above with reference to FIG. 1b. This applies at least to the illustrated portions 17 and with the exception of the crossing regions 14. As a result, the illustrated gantry lift device 1, at least during travel straight-ahead in the portions 17 of the corresponding lanes 13a, 13b, e.g. in the positions A, C and E illustrated by way of example, can read with only one of the two parts 12a, 12b of the sensor apparatus 12 the corresponding marking elements 16. Therefore, marking elements 16 are read at least in the portions 17 only in the region of a vehicle side or a running gear unit support 2 by the sensor apparatus 12 at that location. For this purpose, the gantry lift device 1 at this location is located accordingly within the corresponding lane 13a or 13b in relation to the corresponding row of marking elements 16, in particular with one of the two running gear unit supports 2 and the associated sensors above the corresponding row of marking elements 16. Therefore, it is possible that, at the container terminal, considerably fewer marking elements 16 are required in order to be able to navigate with a corresponding gantry lift device 1 automatically according to the principle of grid navigation. The number of marking elements 16, in particular in the portions 17, can be halved in comparison with the first embodiment, in which for each lane 13a, 13b two parallel rows of marking elements 16 are located at least in the portions 17.

(21) It is apparent that, in both embodiments, those marking elements 16 which are read by the sensor apparatus 12 are never located underneath the clearance profile 15, but instead are always located adjacent thereto and in particular underneath at least one of the running gear unit supports 2. In both embodiments, the gantry lift device 1 is located, at least in the portions 17, completely within the corresponding lane 13a or 13b.

(22) Possible travel routes which can be travelled by the gantry lift device 1 both in the system of the first and also the second embodiment in an automatically guided manner by means of grid navigation will be described by way of example hereinafter.

(23) In a starting position A, the gantry lift device is located in portion 17 of one of the first lanes 13a. Proceeding therefrom, the gantry lift device 1 can travel straight-ahead along the longitudinal extension of the first lane 13a. The gantry lift device 1 can also turn via a position B to the left into one of the transversely extending second lanes 13b adjoining the first lane 13a. After turning, the gantry lift device 1 is located in the portion 17 of the corresponding second lane 13b in a position C in which travel straight-ahead can likewise be performed. Alternatively, the gantry lift device 1 can also turn via a position D to the right into one of the transversely extending second lanes 13b adjoining the first lane 13a. After turning, the gantry lift device 1 is then located in the corresponding second lane 13b in a position E in which travel straight-ahead can likewise be performed.

(24) For the purpose of automatically guided turning by means of grid navigation, according to the first embodiment in FIG. 4a, the two rows of marking elements 16 provided in the first lane 13a are adjoined by two rows of spaced-apart marking elements 16 which branch to the left and right respectively and which are allocated to the respective second lane 13b in the same manner as the two rows of the first lane 13a. According to the second embodiment in FIG. 4b, only one row of marking elements 16 branching to the left and right respectively is provided at least in the portions 17. The row of marking elements 16 which, as seen in the illustrated travel direction F of the gantry lift device 1, branches to the left is located, as seen in this direction, likewise in the left half of the second lane 13a. The row of marking elements 16 which, as seen in the illustrated travel direction of the gantry lift device 1, branches to the right is located, as seen in this direction, in the right half of the second lane 13a. Alternatively, however, in the case of the second embodiment an inverted arrangement of the rows of marking elements 16 in each case in the respective other half of the corresponding lane 13a, 13b would also be feasible.

(25) The arrangement shown in FIG. 4b ensures that, when the gantry lift device 1 is moved within the first lane 13a, in particular during travel straight-ahead in the portion 17, only the row of marking elements 16 located in the region underneath the left first running gear unit support 2 is read because no marking elements 16 are located in the region underneath the right second running gear unit support 2. Accordingly, a marking element 16 is indicated in each case underneath the two sensors of the first part 12a of the sensor apparatus 12. In contrast, the two sensors of the second part 12b of the sensor apparatus 12 are designated by an X because no marking elements 16 can be detected and read in the corresponding position A. This also applies to travel in a first turning direction, when turning left during travel from position A to position C via position B in the present example illustrated in FIG. 4b.

(26) When the gantry lift device 1 is moved in a second turning direction, when turning to the right in the present example likewise illustrated in FIG. 4b, the side of the gantry lift device 1 on which the sensor apparatus 12 reads the marking elements 16 changes from left to right. The change is effected during travel from position A to position E via position D when turning in the region of the position D in the respective crossing region 14. In this case, as illustrated in FIG. 4b, a marking element 16 can also be read for a short period of time in the region of each running gear unit support 2, i.e. by both parts 12a and 12b. This also applies to the first embodiment in FIG. 4a. In both embodiments shown in FIG. 4a and FIG. 4b, additional marking elements 16 can also be located in the corresponding crossing region 14 in order to ensure that two marking elements 16 can always be read at the same time. At the latest when travel around a bend during turning ends and the gantry lift device 1 is oriented accordingly in the second lane 13b, in the case of the second embodiment in FIG. 4b only the row of marking elements 16 located in the region underneath the right running gear unit support 2 is still read by means of the second part 12b of the sensor apparatus located at that point. Then, no more marking elements 16 are read on the left side. This is continued during onward travel, which follows after turning, as travel straight-ahead in the example position E.

(27) If the gantry lift device 1 travels along one of the first lanes 13a without turning into one of the second lanes 13b, the side on which the marking elements 16 are read remains. This applies in the case of the present arrangement even when there is a change in lane between two adjacent parallel lanes 13a or 13b. When there is a change in the travel direction F of the gantry lift device 1 in the opposite direction, the same marking elements 16 are then read by the same sensors. However, these sensors are then located, as seen in the new opposite travel direction F, on the other vehicle side of the gantry lift device 1 than before the change in direction.

(28) Of course, in contrast to the linear illustration in FIGS. 4a and 4b, the lanes 13a and 13b and the respectively allocated rows of marking elements 16 can also have curved progressions both in the portions 17 and in the crossing regions 14.