METHOD FOR SENSING THE POSITION OF A MOBILE, EXCHANGEABLE LOAD CARRIER WHICH CAN BE TRANSPORTED VIA A UTILITY VEHICLE

Abstract

A method is for detecting the position of at least one mobile, interchangeable load carrier that is movable by a commercial vehicle, in a delimited detection area, in particular a depot, in which the at least one mobile, interchangeable load carrier is moved by vehicles. Accommodation operations and/or offloading events of the mobile, interchangeable load carrier in the detection area are determined by the vehicle as notification events, position data for identifying the position in the detection area are determined for the notification events, and position notification signals are formed by the commercial vehicle from the determined notification events and from the position data, and are transmitted to a communication center of the detection area via a wireless network. In the communication center, the current position data of the load carrier are determined from the received position notification signals and are stored in a memory and continuously updated.

Claims

1. A method for detecting a position of a mobile, interchangeable load carrier that is movable by a commercial vehicle in a delimited detection area in which the mobile, interchangeable load carrier is moved by the commercial vehicle, the method comprising: determining, by the commercial vehicle, at least one of an accommodation operation and an offloading operation of the at least one mobile, interchangeable load carrier in the detection area as a notification event; determining, by the commercial vehicle, position data for identifying the position of the notification event in the detection area; forming, by the commercial vehicle, a position notification signal from the determined notification event and the determined position data; transmitting the position notification signal to a communication center via a wireless network; determining, in the communication center, current position data of the mobile, interchangeable load carrier from the position notification signal, wherein the current position data is stored in a data memory and continuously updated.

2. The method of claim 1, wherein the mobile, interchangeable load carrier is a swap body for accommodation on the commercial vehicle, a semi-trailer for accommodation on the commercial vehicle configured as a semi-trailer tractor unit, a drawbar trailer for attachment to a commercial vehicle configured as a drawbar towing vehicle, a turntable drawbar for attachment to a commercial vehicle configured as a drawbar towing vehicle, or a container to be accommodated by a commercial vehicle configured as a container vehicle.

3. The method of claim 1, wherein the at least one of the accommodation operation and the offloading operation is a predetermined, defined operation carried out via technical coupling means.

4. The method of claim 1, wherein the load carrier is one of a plurality of load carriers and the commercial vehicle is one of a plurality of commercial vehicles provided in the detection area.

5. The method of claim 4, wherein the detection area is one of a depot having an external demarcation and at least one access road for the commercial vehicles, a rest stop, a building site, and a port area.

6. The method of claim 1, wherein via the commercial vehicle, the mobile, interchangeable load carrier is at least one of: delivered to the detection area, temporarily parked, moved on the delimited area, and transported away from the detection area by the commercial vehicle.

7. The method of claim 1, wherein the wireless network is a depot WLAN for protocol-based, non-open data transmission.

8. The method of claim 4, wherein the wireless network is a depot WLAN for protocol-based, non-open data transmission for only the plurality of mobile, interchangeable load carriers and the plurality of commercial vehicles.

9. The method of claim 1, wherein in order to determine the notification event, it is first determined from vehicle-internal data whether a standstill of the commercial vehicle exists, and if a standstill exists, it is determined from temporally successive measurement signals whether the notification event is an offloading operation or an accommodation operation, if a notification event is detected, a notification message is formed by an EBS control device of an electronic braking system of the commercial vehicle and is output to a telematics control unit of the commercial vehicle via a vehicle-internal data bus, the current position data are subsequently determined by the telematics control device, and, subsequently, the position notification signal is formed from the position data and the notification event and is transmitted to the communication center via the wireless network.

10. The method of claim 1, wherein the at least one of the offloading operation and the accommodation operation of the load carrier is determined by: recording of measurement signals of a pneumatic air suspension system of the commercial vehicle; determining from the measurement signals whether a change exists, said change being at least one of a temporal change in a lifting height of an air suspension device and a pressure change in air pressure in the air suspension device of the commercial vehicle exists; and, if at least one of the temporal change in the lifting height and the change in air pressure of the air suspension device is detected, deciding whether said change is to be evaluated as the at least one of the offloading operation and the accommodation operation, and if the at least one of the offloading operation and the accommodation operation is determined, subsequently forming the notification message

11. The method of claim 10, wherein the determination of whether the temporal change in lifting height exists is carried out via comparison of the measurement signals with pre-stored data and evaluation of a difference between the measurement signals and the pre-stored data.

12. The method of claim 1, wherein the mobile, interchangeable, load carrier is a swap body; and, wherein the accommodation operation of the swap body is determined via the following steps: determining a current mass of a load from a pneumatic air suspension system; lowering or releasing a chassis of the commercial vehicle by at least one of detecting a control signal for chassis release and detecting level sinking; determining an engagement operation of a reverse gear from a gear shift signal or determining reverse travel from wheel speed signals; determining a raising of the chassis or a remaining at a predetermined chassis level over a measurement time period, from level adjustment control signals or level height measurement signals; subsequently determining at least one of an engagement of a forward gear from a gear shift signal and a forward travel from a wheel speed signal; subsequently determining a mass of the load or of the commercial vehicle having a load that is higher than an initially determined mass of the load or of the commercial vehicle without the load; and, wherein the accommodation operation is subsequently reported.

13. The method of claim 12, wherein the accommodation operation is subsequently reported as a notification message for subsequent formation of the position notification signal with current position data.

14. The method as claimed in claim 12, wherein the current position data are determined at least one of during or after the accommodation operation, when a gear shift signal is generated, and when a forward gear or reverse gear is engaged.

15. The method of claim 1, wherein the mobile, interchangeable load carrier is a swap body; and, wherein the offloading operation of the swap body is determined via the following steps: determining a current mass of a load from a pneumatic air suspension system; lowering or releasing a chassis of the commercial vehicle, by detecting at least one of a control signal for chassis release and a level lowering; determining an engagement operation of a forward gear from a gear shift signal or determining forward travel from wheel speed signals; determining a raising of the chassis or a remaining at the predetermined chassis level over a measurement time period, from level adjustment control signals or level height measurement signals; subsequently determining at least one of engagement of a forward gear from a gear shift signal and a forward travel from a wheel speed signal; determining a mass of the load that is lower than the initially determined mass of the load; wherein the offloading operation is subsequently reported.

16. The method of claim 13, wherein the determination of the total mass of the commercial vehicle with the swap body is performed after the chassis is raised or remains at the predetermined chassis level.

17. The method of claim 1, wherein the mobile, interchangeable load carrier is a trailer, wherein the trailer is a semi-trailer for accommodation on the commercial vehicle configured as a semi-trailer tractor unit or a drawbar trailer for attachment to the commercial vehicle configured as a drawbar towing vehicle, wherein for detecting the notification event of a coupling operation of the semi-trailer or drawbar trailer comprising its own trailer braking system, the following steps are provided: determining the establishment of a data link between an electronic braking system of the commercial vehicle and the trailer braking system of the trailer; determining a connection of a pneumatic trailer brake line to a brake line coupling of the commercial vehicle, and connecting a pneumatic trailer supply line to a pneumatic towing vehicle supply line coupling of the commercial vehicle; subsequently at least one of releasing a parking brake of the commercial vehicle and determining travel of the commercial vehicle by evaluating wheel speed signals; wherein the accommodation operation is subsequently reported.

18. The method of claim 17, wherein the connection of the pneumatic trailer brake line to the brake line coupling is determined by determining pressure signals in at least one of the commercial vehicle, a trailer vehicle, and the trailer.

19. The method of claim 1, wherein the determination of the offloading operation of a trailer vehicle is determined via the following steps: determining the engagement of a parking brake of the trailer; subsequently determining a disconnection of a pneumatic trailer brake line from a brake line coupling of the commercial vehicle, and disconnecting a pneumatic trailer supply line from a pneumatic towing vehicle supply line coupling of the commercial vehicle, and/or detecting an interruption of a data link between a towing vehicle electronic braking system and the trailer, wherein the offloading operation is subsequently reported.

20. The method of claim 4, wherein the method is also additionally carried out spatially beyond the detection area, and accommodation operations and offloading operations of the plurality of mobile, interchangeable load carriers are determined by the plurality of commercial vehicles as notification events, the position data for identifying the position in a global navigation satellite system are determined, the position notification signals are formed and transmitted to the communication center via a further wireless network wherein, in the communication center, the current position data of the at least one load carrier are determined from the received position notification signals and are stored and continuously updated in the data memory.

21. The method of claim 1, wherein, in the case that no wireless connection to the communication center can be established, the position data are recorded and stored, and after establishing a wireless connection, the stored position data are transmitted to the communication center.

22. A fleet management system for a delimited detection area for carrying out the method of claim 1, wherein the fleet management system comprises: a connection to at least one commercial vehicle; a plurality of load carriers that are movable by the at least one commercial vehicle in the delimited detection area; a communication center having a transceiver for a depot ne work for communication with the at least one commercial vehicle; said communication center including a data memory for storing current position data of the plurality of load carriers.

23. The fleet management system of claim 22, wherein the delimited detection area is a depot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The invention will now be described with reference to the drawings wherein:

[0044] FIG. 1 shows a depot with vehicle combinations and mobile, interchangeable transport units at various positions;

[0045] FIG. 2 shows various vehicle combinations and load carriers; and,

[0046] FIGS. 3 to 7 show flow diagrams of methods according to the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] A depot 1 shown in FIG. 1 constitutes an area that is spatially delimited by a boundary 1a, and that is accessible from the outside via an access road 1b. The depot 1 can be described by a two-dimensional position data system for uniquely identifying positions P1, P2, . . . Pi. Various vehicles 2 and mobile, interchangeable load carriers 3 are provided at the depot 1: Vehicles 2 shown in FIGS. 1 and 2 include for example a carrier vehicle 2a for a swap body 3a and, in FIG. 2, a semi-trailer tractor unit 2b for a semi-trailer 3b, as well as a towing vehicle 2c for a drawbar trailer 3c and a commercial vehicle 2d for accommodating a container 3d.

[0048] The swap body 3a, the semi-trailer 3b, the drawbar trailer 3c, and the container 3d thus constitute different mobile, interchangeable load carriers 3 that serve to transport cargo and that can be moved to various positions Pi at the depot 1. A vehicle 2 including one or several load carriers 3 forms a vehicle-transport combination 4.

[0049] At the depot 1, there are also several bulk material offloading points 5, for example for concrete and gravel as building materials, or for disposal, for example as building rubble offloading points. Finally, a communication center 8 is provided in or at the depot 1, which, according to this embodiment, is equipped with or connected to a WLAN transceiver unit 10, for forming a depot network 12 for wireless data transmission.

[0050] At the depot 1, there can additionally be driveways 14 or roads for the individual vehicles 2 or vehicle-transport combinations 4, but this is not necessary. Furthermore, buildings 15 are generally provided for example with loading and unloading stations, for example ramps, which are approached by the vehicle-transport combinations 4 to be loaded or unloaded.

[0051] The various positions Pi of at least the various load carriers 3, advantageously also of the various vehicles 2, at the depot 1, are stored in a constantly updated position file PD, which is advantageously connected to, that is, managed by, the communication center 8, for example in a memory unit 50 provided in the communication center 8. Here, the positions Pi can be stored for example according to a two-dimensional coordinate system, that is, as (xi, yi), as indicated in FIG. 1. To update the position data Pi, position notification signals PS are formed by the vehicles 2 for certain notification events M, respectively including the notification event M, that is, in particular an offloading operation Ma or an accommodation operation Mb, and furthermore the relevant position data Pi, that is, the position notification signals PS have at least the structure (Pi, M), wherein the notification event M may be formed for example as Ma_3d, that is, an offloading operation Ma of a container 3d.

[0052] Thus, a position notification signal PS is formed when a vehicle 2 accommodates a load carrier 3, that is, there is an accommodation operation Mb, and when the load carrier 3 is later offloaded at another position Pi. The last reported operation is thus stored in the PD position file.

[0053] The position notification signals PS are transmitted wirelessly from the respective vehicle 2, for example via the depot network 12 and the WLAN transceiver device 10, to the communication center 8, so that they are stored in the position file PD, that is, in particular previously stored data are updated. If such WLAN access does not exist or is not advantageous, a different wireless data transmission, for example via a mobile network, may also be used. The notification events M are advantageously dependent on the respective mobile, interchangeable load carrier 3. In principle, such notification events M are to be detected in which a current position Pi is changed, for example a load carrier 3 is moved away from its position or is emptied or loaded; thus, advantageously, a start time of an emptying or loading is reported, preferably also an end time. Furthermore, it is reported when the load carrier 3 is again parked in its new position Pi at the depot 1 after a trip with the respective vehicle 2.

[0054] Information from an ECAS (electronically controlled air suspension) system 23, that is, measurement signals S55 from the ECAS system 23, are used to detect a notification event M. Here, the time sequence of the change in lifting height Δh of an air suspension device 25 and/or a change in air pressure Δp of the air pressure P of the air suspension device 25, that is, an increase or a decrease in the air pressure P, is determined in order to detect a notification event. Thus, the parking/loading can be determined via the sequence of operations and/or via the pressure change in the ECAS system 23, or via both for plausibility checking.

[0055] FIG. 3 shows a flowchart of a method for detecting the position of a swap body 3a (swap container), including the following steps:

[0056] After the start in step St0, the current vehicle speed v2 is detected in step St1, for example via the CAN bus according to the speedometer speed, or from the ABS control unit as ABS reference speed, or directly from the wheel speeds n transmitted via the CAN bus. The vehicle speed v2 is compared with a limit vehicle speed v2tr; that is, if the vehicle speed falls below the limit vehicle speed v2tr, the vehicle 2 is assumed to be at a standstill 65. If this is the case, current measurement signals S55 of a change in lifting height Δh of the air suspension, that is, of one or several air cushions of the air-suspended axles of the vehicle 2, and/or a change Δp in the air pressure of the air suspension device 25, that is, of the pneumatic air cushions of the axles of the vehicle 2, are subsequently determined from the ELAS system 23 in accordance with the branch y1 in step St2. These changes can take place for example over a measurement period Δt of a few seconds in each case, that is, a difference quotient Δp/Δt or Δh/Δt of the measurements or, correspondingly, a time derivative dp/dt or dh/dt of the measurement signal, that is, of the pressure or level height, is thus determined in order to detect a change in lifting height Δh and/or a change in air pressure Δp.

[0057] In the subsequent decision step St3, the measured values Δh and Δp or Δh/Δt and Δp/Δt acquired in step St2 are then evaluated, that is, compared with limit values Δh_tr and Δp_tr, to distinguish them from noise. If the measured values are greater than these limit values and thus a change is detected, an offloading operation Ma or an accommodation operation Mb is subsequently detected in step St4 according to the branch y3, whereupon a notification message TM is output in step St5 to transmit a position notification signal PS from the vehicle 2 to the communication center 8 via the depot network 12. According to an embodiment, steps St1 to St5 can be carried out in the EBS control unit 20 of the vehicle 2.

[0058] Thus, in step St5, for example the EBS control device 20 outputs a notification message TM to another unit, preferably a telematics control device 22 of the vehicle 2, which then forms the position notification signal PS in steps St6 and St7.

[0059] For this purpose, the telematics control device 22 records a current GNSS position GNSS_2 in step St6,

[0060] in step St7, the telematics control device 22 forms the position notification signal PS with the entries (notification event M; position data Pi), and in step St8, the position notification signal PS thus formed is transmitted to the communication center 8 via the vehicle WLAN interface 24 and the wireless depot network 12 (WLAN or WiFi),

[0061] which then stores the position data Pi in a current position file PD, that is, constantly updates the position file PD, in step St9.

[0062] The position file PD can contain further information about the load and load carrier if the information has been entered for example in advance in the system, that is, in particular by the user/driver or automatically by recognition devices.

[0063] According to an alternative embodiment to this, the swap body can also be accommodated on a trailer, for example a drawbar trailer 3c; furthermore, another type of trailer already described may also be provided that includes a trailer EBS (TEBS), so that steps St1 to St5 or part of these steps can be carried out in a TEBS control device 21. Then, the TEBS control device 21, when performing these steps or part of these steps, can subsequently also form the position notification signal PS itself and generate the notification message TM in steps St6 and St7.

[0064] FIG. 4 shows the “accommodate swap body” operation in greater detail, including the following steps:

[0065] In step St4-1, information about the mass m and, if applicable, about the load, is extracted from the ECAS. In step St4-2, the chassis 40 is released via the ECAS 23, that is, compressed air is released by actuating the pneumatic air suspensions 25, thereby lowering the level.

[0066] In step St4-3, the reverse gear is then engaged, which can be determined via a corresponding gear selection sensor. Advantageously, the actual reverse motion is also determined in particular via the wheel speeds n and a gear selection signal GS that is available in the EBS and TEBS, wherein in principle, the reverse motion can also be determined from a transmission speed GD and the gear selection signal GS.

[0067] Thus, the vehicle 2a is moved beneath the swap body 3a, whereupon the chassis 40 is raised again in accordance with step St4-4 via corresponding actuation of the pneumatic air suspension device 25 via the ECAS 23, wherein it can be assumed as a further criterion that the chassis 40 also remains at this level h for a defined period of time, that is, the setting operation is terminated and is set for subsequent transport of the swap body 3a, that is, the swap body 3a has been raised as a result.

[0068] According to step St4-5, the vehicle-transport combination 4 is then detected, which here thus constitutes a loaded vehicle 2, for example by engaging the forward gear and/or increasing the wheel speed n, since the loaded vehicle 2 can also start in reverse.

[0069] Thus, in step St4-5, if the conditions are met, the completion of the vehicle-transport combination 4 is detected.

[0070] According to step St4-6, information about the mass m of the cargo is then determined from the ECAS 23,

[0071] whereupon in step St4-7, the output of the notification message TM is then carried out according to step St5 of FIG. 3, that is, the notification message TM is output to the telematics control device 22, which then forms the position notification signal PS in steps St6 to St8 of FIG. 3 and outputs it to the communication center 8.

[0072] FIG. 5 shows a method corresponding to FIG. 4 for determining the “offload swap body” operation, including the following steps:

[0073] St5-1 to St5-2 corresponding to steps St4-1, St4-2 of FIG. 4;

[0074] Step St5-3 basically corresponds to St4-3, wherein, however, it is determined here whether the forward gear is engaged;

[0075] Step St5-4 corresponds to step St4-4;

[0076] Steps St5-6 and St5-7 correspond to the corresponding steps St4-6, St4-7 in FIG. 4.

[0077] Thus, the accommodation or loading of a swap body 3a can basically be detected by the fact that swap bodies 3a are removed backwards, since the vehicle 2a drives backwards beneath the swap body 3a and, correspondingly, conversely, after uncoupling or offloading the swap body 3a, the vehicle 2a drives away forwards beneath the swap body 3a.

[0078] FIG. 6 shows a flowchart of the detection of the “couple trailer/semi-trailer” operation:

[0079] In step St6-1, a data link 26 is established between the EBS control device 20 of the vehicle 2 and the TEBS control device 21 of the trailer 3b, 3c.

[0080] According to the above examples, trailers are in particular semi-trailers 3b, drawbar trailers 3c, and/or turntable trailers.

[0081] According to step St6-2, the brake supply line 127 of the trailer 3b, 3c is connected to the red coupling head 27 of the towing vehicle 2b, 2c;

[0082] furthermore, the brake control line 128 of the trailer 3b, 3c is connected to the yellow coupling head 28 of the towing vehicle 2b, 2c.

[0083] These pneumatic connections can be determined in step St6-2, for example by pressure sensors of the towing vehicle 2b, 2c and/or the trailer 3b, 3c.

[0084] Thus, the electrical and pneumatic connections are formed between both vehicles 2, 3. Subsequently, in step St6-3, it is checked whether the parking brake of the towing vehicle 2 and/or the trailer vehicle 3 is released. In addition or alternatively to this, it is checked whether a movement of the tractor-trailer combination 4 can already be determined by determining wheel speeds n of the towing vehicle 2 and/or the trailer vehicle 3, that is, n>0.

[0085] According to step St6-4, the notification message TM is again output from the EBS control device 10 to the telematics control device 22 below, as described above in steps St6, St7 in FIG. 3, in order to form a position notification signal PS, which thus contains, as a notification event, an accommodation event Mb that the trailer 3b, 3c has been withdrawn, that is, has been removed from its current stored position Pi.

[0086] Accordingly, the determination of the “uncouple trailer/semi-trailer” operation is described below with reference to FIG. 7.

[0087] In step St7-1, it is checked whether the parking brake 35 of the trailer 3b, 3c is engaged.

[0088] In step St7-2, it is determined whether the brake control line 128 of the trailer 3b, 3c has been decoupled or disconnected from the yellow coupling head 28 of the vehicle 2b, 2c and whether the supply line 127 of the trailer 3b, 3c has been decoupled or disconnected from the red coupling head 27 of the towing vehicle 2b, 2c.

[0089] Thus, the pneumatic connections are released. In contrast to the methods in FIG. 6, it may be provided that it is not checked whether the data link between the EBS control unit 20 and the TEBS control unit 21 has been changed, since the parked trailer 3c or semi-trailer 3b can in principle also continue to be connected to the towing vehicle 2 in terms of information technology while the pneumatic lines are disconnected.

[0090] Subsequently, in step St7-3, the notification message TM for parking the trailer 3b, 3c is output by the EBS control device 20, whereupon, again according to FIG. 3, the position notification signal PS is formed in steps St6, St7 and subsequently output in step St8.

[0091] Thus, in each case, the operation of moving a trailer 3b, 3c, that is, removing it from the current position Pi, and then moving and parking the trailer 3b, 3c at the new position Pi, can be automatically detected and transmitted to the communication center 8.

[0092] The communication center 8 can basically note if a trailer 3 has been removed from the current position Pi according to the available data, but no parking operation has been determined yet; such trailers 3 can be identified with a data suffix in this case. On the one hand, trailers 3 currently being transported at the depot 1 can be identified, in particular directly by entering them on a map; furthermore, trailers 3 located outside the depot can also be detected, wherein GNSS coordinates can be transmitted here.

[0093] Furthermore, it is also possible that the communication center 8 manages existing parking spaces, and thus also notes the vacancy of a parking space; thus, upon request of a towing vehicle 2, it can be communicated where there is a vacant parking space.

[0094] If a wireless connection to the communication center 8 cannot be established, it may be provided that the position data Pi is recorded and stored in a memory 66, and after a wireless connection is established, the stored position data. Pi is then transmitted to the communication center 8, whereupon the stored data can then be deleted.

[0095] Furthermore, according to the present disclosure, it may be provided that a position file is also transmitted when the telematics unit is shut down and/or switched off.

[0096] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE CHARACTERS (PART OF THE DESCRIPTION)

[0097] 1 Detection area, in particular depot [0098] 1a External demarcation [0099] 1b Access road [0100] 2 Vehicles, for example: [0101] 2a Carrier vehicle for a swap body 3a, [0102] 2b Tractor unit of a semi-trailer truck 4 or [0103] 2c Towing vehicle of drawbar combination 4 [0104] 2d Commercial vehicle for accommodating a transport container [0105] 3 Mobile, interchangeable load carrier [0106] 3a Swap body [0107] 3b Semi-trailer [0108] 3c Drawbar trailer [0109] 3d Transport container, for example construction waste container [0110] 3e ISO container or overseas container, as examples of transport containers. [0111] 4 Vehicle-transport combination, consisting of a vehicle 2 and a mobile, interchangeable load carrier 3 [0112] 5 Bulk material offloading point [0113] 8 Communication center [0114] 10 Transceiver unit of the wireless network, in particular WLAN [0115] 12 Depot network, for example WLAN [0116] 14 Driveways at depot 1 [0117] 15 Building [0118] 20 EBS control unit of the commercial vehicle 2 [0119] 21 TEBS control unit of the trailer 3 [0120] 22 Telematics control unit of the commercial vehicle 2 [0121] 23 ECAS system [0122] 24 Vehicle-WLAN interface of the commercial vehicle 2 [0123] 25 Air suspension system, level control system of the commercial vehicle 2 [0124] 26 Data link between the EBS control unit 20 of the vehicle 2 and the TEBS control unit 21 of the trailer 3b, 3c [0125] 27 Red coupling head of the towing vehicle 2b, 2c, [0126] 28 Yellow coupling head of the towing vehicle 2b, 2c [0127] 40 Chassis of the commercial vehicle 2 [0128] 50 Data memory [0129] 55 ECAS system [0130] 60 Fleet management system [0131] 65 Standstill of the commercial vehicle 1, that is, in particular v=0 [0132] 127 Brake supply line of the trailer 3b, 3c, for connection to the red coupling head 27 of the towing vehicle 2b, 2c [0133] 128 Brake control line of the trailer 3b, 3c, for connection to the yellow coupling head 28 of the towing vehicle 2b, 2c [0134] M Notification event [0135] Ma Offloading operation, offloading or uncoupling a load carrier 3 [0136] Mb Accommodation operation, accommodation or coupling of a load carrier 3 [0137] Pi Position data, Pi=(xi, yi) [0138] PD Position file [0139] PS Position notification signal, PS=(notification event M; position data Pi), [0140] S55 Measurement signals of the ECAS system 55 [0141] TM Notification message [0142] Δh Change in lifting height, change in level of the trolley 40 [0143] Δp Change in air pressure in the air suspension system [0144] Δt Measurement period [0145] 134 Control signal for chassis release [0146] 135 Forward gear [0147] 136 Reverse gear [0148] 137 Gear shift signal [0149] 138 Chassis level [0150] 139 Level adjustment control signals [0151] 140 Load [0152] 142 Parking brake