WO2013158015A1

WO2013158015A1 - Method and system for safe loading and unloading of motor vehicles

Info

Publication number: WO2013158015A1
Application number: PCT/SE2013/050345
Authority: WO
Inventors: Peter SIDÉN; Linus Bredberg
Original assignee: Scania Cv Ab
Priority date: 2012-04-19
Filing date: 2013-03-27
Publication date: 2013-10-24
Also published as: SE1250392A1; DE112013001525T5; DE112013001525B4

Abstract

The present invention relates to a method for safe loading and unloading of motor vehicles, comprising the step of using the vehicle's air suspension system to adjust the slope of the vehicle's load plane to a substantially horizontal position, which step of adjusting the slope of the load plane comprises the steps of using slope sensor means (210) to obtain (S1 ) information about the slope of the load plane and using the vehicle's air suspension system (220) to adjust (S2) the slope of the load plane to substantially horizontal positions on the basis of said information. The present invention relates also to a system for safe loading and unloading of motor vehicles. The present invention relates also to a motor vehicle. The present invention relates also to a computer programme and a computer programme product.

Description

METHOD AND SYSTEM FOR SAFE LOADING AND UNLOADING OF

MOTOR VEHICLES

TECHNICAL FIELD The invention relates to a method for safe loading and unloading of motor vehicles according to the preamble of claim 1. The invention relates also to a system for safe loading and unloading of motor vehicles according to the preamble of claim 8. It relates as well to a computer programme and a computer programme product.

BACKGROUND

In the loading and unloading of freight it is relevant that the load plane to be as horizontal as possible. If the load plane slopes when relatively heavy freight, e.g. in the form of a load pallet, is to be loaded or unloaded, there is risk of damage in that the pallet may well begin to slide, and its movement may be difficult to stop. Today's distribution vehicles are usually equipped with air suspension at least on the rear axle but often also on the front axle. This makes it possible for the driver to adjust the vehicle's slope relative to the horizontal plane. This is usually achieved by the driver stepping out of the vehicle, to make it easier for him/her to assess the slope of the load plane, and then using a remote control to manually adjust the individual levels of the respective axles.

Distribution rounds involving loading and unloading are often conducted to tight time schedules which result in the level adjustment of the vehicle's load plane being neglected. There is also risk of incorrect assessment of the level of the load plane. Even slight slopes may well cause heavy freight to begin to slide during hoisting.

US20080272562 refers to a system for adjusting the height and slope of a vehicle, said adjustment being conducted via a display to which information about the vehicle's height and/or slope is sent to serve as a basis for the driver to adjust the height and/or slope.

OBJECTS OF THE INVENTION One object of the present invention is to propose a method for safe loading and unloading of motor vehicles which makes it possible for them to be loaded and unloaded safely and efficiently.

One object of the present invention is to propose a system for safe loading and unloading of motor vehicles which makes it possible for them to be loaded and unloaded safely and efficiently.

SUMMARY OF THE INVENTION

These and other objects indicated by the description set out below are achieved by means of a method, a system, a motor vehicle, a computer programme and a computer programme product of the kind indicated in the introduction which further present the features indicated in the characterising parts of the attached independent claims 1 , 8, 15, 16 and 17. Preferred embodiments of the method and the system are defined in the attached dependent claims 2-7 and 9-14. The invention achieves the objects with a method for safe loading and unloading of motor vehicles, comprising the step of using the vehicle's air suspension system to adjust the slope of the vehicle's load plane to a substantially horizontal position, which step of adjusting the slope of the load plane comprises the steps of using slope sensor means to obtain information about the slope of the load plane and using the vehicle's air suspension system to adjust the slope of the load plane to substantially horizontal positions on the basis of said information. This makes efficient loading and unloading possible in that the slope of the load plane is thus relatively quickly adjusted to a substantially horizontal position with no need for the operator to make this assessment. It also makes safe loading and unloading possible in that the slope of the load plane is adjusted to a substantially horizontal position with no need for manual adjustment by an operator which might involve risk of incorrect slope assessment, and the fact that adjustments can take place relatively quickly with no manual involvement of an operator reduces the risk that the driver/operator might refrain from adjustment in order to save time. The risk of damage during loading and unloading is thus reduced.

In one embodiment of the method, said slope sensor means comprise accelerometer means. Effective obtaining of information about the slope of the vehicle's load plane for said adjustment is thus made possible.

In one embodiment of the method, said accelerometer means are part of the vehicle's normal accelerometer configuration. In one variant, the vehicle's normal accelerometer configuration comprises its normal accelerometer configuration for its anti-skid system and/or for its clutch actuator, i.e. the vehicle's automatic gearchange means. Existing means are thus utilised, which means that the method may be applied cost-effectively and without requiring any further installations.

In one embodiment of the method, said slope sensor means comprise pressure sensor means of the vehicle's air suspension system. Effective obtaining of information about the slope of the vehicle's load plane for said adjustment is thus made possible. Means of the existing air suspension system are further utilised for this purpose, with the result that the method may be applied cost-efficiently and without requiring any further installations. In one embodiment of the method, said slope sensor means comprise pendulum means. Effective obtaining of information about the slope of the vehicle's load plane for said adjustment is thus made possible.

In one embodiment of the method, the slope of the load plane is adjusted both in the vehicle's longitudinal direction and transversely thereto by using forward and/or rear air suspension means, and/or right and/or left air suspension means, of the vehicle's air suspension system. Optimisation of the adjustment according to desired use of air suspension means is thus made possible.

In one embodiment of the method, said adjustment involves an iteration procedure, enabling optimised adjustment and correction for any deviations from horizontal positions.

The invention achieves the objects with a system for safe loading and unloading of motor vehicles, comprising means for using the vehicle's air suspension system to adjust the slope of the load plane to a substantially horizontal position, which means for adjusting the slope of the load plane comprise means for using slope sensor means to obtain information about the slope of the load plane and means for using the vehicle's air suspension system to adjust the slope of the load plane to substantially horizontal positions on the basis of said information. This makes efficient loading and unloading possible in that the slope of the load plane is thus relatively quickly adjusted to a substantially horizontal position with no need for the operator to make this assessment. It also makes safe loading and unloading possible in that the slope of the load plane is adjusted to a substantially horizontal position with no need for manual adjustment by an operator which might involve risk of incorrect slope assessment, and the fact that adjustments can take place relatively quickly with no manual involvement of an operator reduces the risk that the driver/operator might refrain from adjustment in order to save time. The risk of damage during loading and unloading is thus reduced. In one embodiment of the system, said slope sensor means comprise accelerometer means. Effective obtaining of information about the slope of the load plane for said adjustment is thus made possible.

In one embodiment of the system, said accelerometer means are part of the vehicle's normal accelerometer configuration. In one variant, the vehicle's normal accelerometer configuration comprises its normal accelerometer configuration for the vehicle's anti-skid system and/or for its clutch actuator, i.e. its automatic gearchange means. Existing means are thus utilised, which means that the method may be applied cost-effectively and without requiring any further installations.

In one embodiment of the system, said slope sensor means comprise pressure sensor means of the vehicle's air suspension system. Effective obtaining of information about the slope of the vehicle's load plane for said adjustment is thus made possible. Means of the existing air suspension system are further utilised for this purpose, with the result that the method may be applied cost-effectively and without requiring any further installations.

In one embodiment of the system, said slope sensor means comprise pendulum means. Effective obtaining of information about the slope of the vehicle's load plane for said adjustment is thus made possible.

In one embodiment of the system, the slope of the load plane is adapted to being adjusted both in the vehicle's longitudinal direction and transversely thereto by using forward and/or rear air suspension means, and/or right and/or left air suspension means, of the vehicle's air suspension system. Optimisation of the adjustment according to desired use of air suspension means is thus made possible.

In one embodiment of the system, said means for adjusting the slope of the vehicle's load plane are configured to iteratively effect said adjustment, enabling optimised adjustment and correction of any deviations from horizontal positions. DESCRIPTION OF DRAWINGS

The present invention will be better understood by reading the detailed description set out below in conjunction with the attached drawings, in which the same reference notations are used for similar items throughout the various views, and Fig. 1 schematically illustrates a motor vehicle according to an embodiment of the present invention.

Fig. 2 schematically illustrates a plan view of the motor vehicle 1 in Fig. 1 , showing its chassis and air suspension system, Fig. 3 schematically illustrates a system for safe loading and unloading of motor vehicles according to an embodiment of the present invention,

Figs. 4a-c schematically illustrate the vehicle in Fig. 1 at various slopes and in loading and unloading states,

Fig. 5 is a schematic block diagram of a method for safe loading and unloading of motor vehicles according to an embodiment of the present invention, and

Fig. 6 schematically illustrates a computer according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The term "link" refers herein to a communication link which may be a physical connection such as an opto-electronic communication line, or a non-physical connection such as a wireless connection, e.g. a radio link or microwave link.

Fig. 1 illustrates schematically a motor vehicle 1 intended to form part of a vehicle train according to an embodiment of the present invention. The vehicle here exemplified is a heavy vehicle in the form of a truck, e.g. a distribution vehicle for loading and unloading. It may alternatively be any suitable vehicle, e.g. a bus or a car. The vehicle is provided with a system I according to the present invention. Fig. 2 is a schematic plan view of the motor vehicle 1 in Fig. 1 , showing its frame and air suspension system. The vehicle comprises a frame 2, 3, a forward axle X1 with opposite front wheels RF, LF, and a powered rear axle X2 with opposite tractive wheels RD, LD.

The vehicle further comprises a air suspension system comprising air suspension means B1 , B2, B3, B4. Said air suspension means comprise a first air suspension means B1 situated on the right side close to the forward axle X1 , and a second air suspension means B2 situated on the left side close to the forward axle X1.

Said air suspension means further comprise a third air suspension means B3 situated on the right side close to the powered rear axle X2, and a fourth air suspension means B4 situated on the left side close to the powered rear axle X2.

The respective air suspension means are situated between the vehicle frame 2, 3 and the respective axles, making it possible for the vehicle to be raised and lowered by regulation of air in the air suspension means.

The air suspension system further comprises an air valve configuration 100 which is connected to said air suspension means B1 , B2, B3, B4 and adapted to regulating the air pressure in the respective air suspension means B1 , B2, B3, B4.

The vehicle further comprises an air pressure source configuration 110 to supply the air valve configuration 100 with air.

The air valve configuration 100 comprises in one embodiment undepicted air valve units comprising valve means with an air intake connected to a compressed air source, a venting outlet and a supply outlet, and valve means each adapted to regulating the air pressure in their respective air suspension means.

Each air suspension means B1 , B2, B3, B4 is provided with a pressure sensor means adapted to monitoring the air pressure in the respective air suspension means. Said air suspension means take in one variant the form of bellows units or comprise bellows units.

In one variant, said first and second air suspension means are pressure- connected in such a way that raising and lowering of the forward axle X1 is effected, and said third and fourth air suspension means are connected in such a way that raising and lowering of the powered rear axle X2 is effected. This variant thus makes it possible to raise and lower the rear and front of the vehicle.

In one variant, said first, second, third and fourth air suspension means are separate units so that raising and lowering by means of respective air suspension means can take place individually, i.e. for respective wheels. This variant enables raising and lowering sideways, raising and lowering longitudinally and combinations thereof. Air suspension means of conventional distribution vehicles for loading and unloading are commonly arranged in this way.

Fig. 3 schematically illustrates a system I for safe loading and unloading of motor vehicles according to an embodiment of the present invention.

The system I comprises an electronic control unit 200 for said improvement of safety when driving a motor vehicle. The system I further comprises slope sensor means 210 to obtain information about the slope of the vehicle's load plane.

In one variant, said slope sensor means 210 comprise accelerometer means 212. In one variant said accelerometer means forms part of the vehicle's normal accelerometer configuration for its anti-skid system and/or its normal accelerometer configuration for clutch actuator. Said accelerometer means is configured to read the vehicle's slope with a given assumption about gravitational constant.

In one variant, said slope sensor means 210 comprise pressure sensor means 214 of the vehicle's air suspension system. Said pressure sensor means comprise pressure sensor means situated in each air suspension means. Said pressure sensor means are adapted to monitoring pressures close to the respective vehicle axles/wheels, i.e. the pressure in each air suspension means of the air suspension system.

Using means with which the vehicle is already provided, e.g. accelerometer means 212 and/or pressure sensor means 214 of the air suspension system, achieves cost-effectiveness in that no further installations or upgrades of the vehicle are required to obtain information about the slope of its load plane.

In one variant, said slope sensor means 210 comprise pendulum means 2 6 adapted to monitoring the angle of the slope of the vehicle's load plane relative to the horizontal plane.

The system I further comprises said air suspension system 220 comprising air suspension means, e.g. air suspension means B1 , B2, B3, B4 as in Fig. 2, for adjusting the slope of the vehicle's load plane to substantially horizontal positions. The air suspension means of the air suspension system may take any suitable form, e.g. depending on whether the vehicle is equipped with bogies and/or further axles where there is a plurality of air suspension means, e.g. a further two.

Said air suspension system 220 is also configured in one variant for adjustment of the height of the vehicle's load plane relative to a reference point such as the ground under the vehicle or a loading ramp. Said air suspension system comprises in one variant an air valve configuration 100 in accordance with Fig. 2.

Said air suspension system 220 comprises accordingly in one variant said pressure sensor means 214. The system I further comprises an operating means 230 to activate said adjustment of the slope of the vehicle's load plane to substantially horizontal positions. Said operating means is preferably situated close to the driver's location to provide him/her with easy access before said adjustment. It takes in one variant the form of a push-button, a rotary means or equivalent for activating said adjustment. The electronic control unit 200 is signal-connected to said slope sensor means 210 in order to obtain information about the slope of the vehicle's load plane via a link 10a which enables it to receive from said means 210 a signal which represents vehicle slope data for the slope of the vehicle's load plane. The electronic control unit 200 is signal-connected to said accelerometer means 212 in order to obtain information about the slope of the vehicle's load plane via a link 12 which enables it to receive from said means 212 a signal which represents acceleration data for longitudinal acceleration.

The electronic control unit 200 is signal-connected to said pressure sensor means 214 in order to obtain information about pressures of air suspension means of the vehicle's air suspension system 220, for determination of the slope of the vehicle's load plane, via a link 14 which enables it to receive from said means 214 a signal which represents air suspension means pressure data.

The electronic control unit 200 is signal-connected to said pendulum means 216 in order to obtain information about the slope of the vehicle's load plane via a link 16 which enables it to receive from said means 216 a signal which represents angle data for the slope of the load plane.

The electronic control unit 200 is signal-connected to said operating means 230 for activation of adjustment of the slope of the vehicle's load plane, via a link 30 which enables it to receive from said means 230 a signal which represents activation data for activation of adjustment of the slope of the load plane.

The electronic control unit 200 is signal-connected to said air suspension system 220 for adjustment of the slope of the vehicle's load plane, via a link 20a which enables it to send to said system 220 a signal which represents adjustment data for adjustment of the slope of the load plane. Said adjustment data comprise height data for height adjustment of respective air suspension means. The electronic control unit 200 is signal-connected to said air suspension system 220 via a link 20b which enables it to receive from said system 220 a signal which represents height data for current heights of respective air suspension means.

The electronic control unit 200 is signal-connected to said slope sensor means 210 via a link 10b which enables it to send to said means 210 a signal which represents slope sensor means activation data for activation of obtaining of information about the slope of the vehicle's load plane.

The electronic control unit 200 is adapted to processing said activation data from the operating means 230 for said activation. In one variant said slope sensor means 210 are thus activated, whereupon the electronic control unit 200 receives and processes vehicle slope data from said means 210. In an alternative variant, the electronic control unit 200 is adapted to responding to receiving said activation data by processing said vehicle slope data and using them as a basis for sending adjustment data to said air suspension system 220 for adjustment of the slope of the vehicle's load plane.

The electronic control unit 200 is adapted, when the slope sensor means 210 is activated, to processing said vehicle slope data, taking account of vehicle- specific parameters comprising distances from a notional midpoint to the respective axles and thereby determining height data for said adjustment.

The electronic control unit 200 is in one variant adapted to processing said acceleration data in order to determine slope angles and to using said slope angles relative to the horizontal plane and said vehicle-specific parameters as a basis for determining height positions of the respective air suspension means relative to the horizontal plane.

The electronic control unit 200 is in one variant adapted to processing said pressure data in order to determine slope angles and to using said slope angles relative to the horizontal plane and said vehicle-specific parameters as a basis for determining height positions of the respective air suspension means relative to the horizontal plane. The electronic control unit 200 is in one variant adapted to processing said angle data for slope angles relative to the horizontal plane and said vehicle- specific parameters to determine height positions of the respective air suspension means relative to the horizontal plane.

In this case, air suspension means of the air suspension system 220 are adapted to adjusting the height on the basis of said adjustment data in the form of height data pertaining to air suspension means or, alternatively, pressure data for air pressures in air suspension means. Said adjustment data correspond to a certain change in the height of respective air suspension means.

When the vehicle is stationary on an upgrade, as in Figs. 4a-b, said air suspension means may in one variant be subjected to maximum lowering at the front, i.e. maximum lowering of the forward air suspension means, or maximum raising at the rear, i.e. maximum raising of the rear air suspension means. In such situations, an advantage of raising the rear as little as possible is that it minimises the upward and downward hoisting of loading hatches.

When the vehicle is stationary on an upgrade, as in Figs. 4a-b, said air suspension means may in one variant be subjected to a certain amount of lowering at the front, i.e. lowering the forward air suspension means to a certain extent, and to a certain amount of raising at the rear, i.e. raising the rear air suspension means to a certain extent.

In one embodiment of the system I, the slope of the vehicle's load plane is arranged to be adjustable both in the vehicle's longitudinal direction and transversely thereto by using forward and/or rear air suspension means and/or right and/or left air suspension means of the vehicle's air suspension system. Substantial slopes may require maximum lowering at the front and maximum lowering at the rear.

In one embodiment, said slope sensor means 210 are configured, during adjustment of the slope of the vehicle's load plane to a substantially horizontal position, to continuously receive information about the slope of the vehicle's load plane and send vehicle slope data to the electronic control unit 200 for processing, to which the control unit responds by continuously sending adjustment data to the air suspension system 220 for adjustment. In this case said adjustment is effected by an iteration procedure in order to achieve a substantially horizontal position of the vehicle's load plane. The adjustment in this variant is consequently arranged to be effected by iteration.

In one embodiment, said electronic control unit 200 is configured, during adjustment of the slope of the vehicle's load plane to a substantially horizontal position, to continuously receive information about current heights of said air suspension means from the air suspension system 220 for processing, and to respond thereto by continuously sending adjustment data to the air suspension system for height adjustment of said air suspension means. In this case said adjustment is effected by an iteration procedure in order to achieve a substantially horizontal position of the vehicle's load plane. The adjustment in this variant is consequently arranged to be effected by iteration.

In one embodiment, said system is adapted to vehicle-specific parameters such as distances between the vehicle's axles, positions/locations of the vehicle's air suspension means etc. In this case, suitable adjustment for the specific vehicle is tested on the basis of information from said slope sensor means. Such vehicle-specific adaptation results in more exact adjustment of the load plane by the air suspension system during loading and unloading of a thus adapted vehicle.

The regulating strategies according to the iteration procedure and the vehicle-specific adaptation may with advantage be combined.

In one variant, the slope sensor means is an integral part of a further electronic control unit, e.g. the vehicle's brake system or automatic gearchange system, in which control unit certain processing of data from the slope sensor means might take place. In one variant, the air suspension system is an integral part of a further electronic control unit, in which certain processing of data from the air suspension means might take place. In such cases, communication between the electronic control unit 200 and these control units would be for said adjustment of the slope of the vehicle's load plane. Alternatively, these control units might communicate directly with one another for said adjustment of the slope of the load plane.

Figs. 4a-c illustrate schematically the vehicle 1 in Fig. 1 at various gradients of the road/ground G and in loading and unloading positions.

Fig. 4a illustrates schematically the vehicle 1 on an upgrade at an angle a1 before loading/unloading.

Fig. 4b illustrates schematically the vehicle 1 on the upgrade in Fig. 4a after adjustment by means of the system I according to the present invention, with the load hatch 5 lowered. Fig. 4c illustrates schematically the vehicle 1 close to a loading ramp L in a situation where the vehicle is stationary on a slight downgrade at an angle a2 and the slope of the vehicle's load plane has been adjusted by means of the system I according to the present invention.

Fig. 5 is a schematic block diagram of a method for safe loading and unloading of motor vehicles according to an embodiment of the present invention.

In one embodiment, the method for safe loading and unloading of motor vehicles comprises a first step S1 in which information about the slope of the vehicle's load plane is obtained by using slope sensor means. In one embodiment, the method for safe loading and unloading of motor vehicles comprises a second step S2 in which the vehicle's air suspension system is used to adjust the slope of the load plane to substantially horizontal positions on the basis of said information. Figure 6 is a diagram of one version of a device 500. The control unit 200 described with reference to Figure 3 may in one version comprise the device 500. The device 500 comprises a non-volatile memory 520, a data processing unit 510 and a read/write memory 550. The non-volatile memory has a first memory element 530 in which a computer programme, e.g. an operating system, is stored for controlling the function of the device 500. The device 500 further comprises a bus controller, a serial communication port, I/O means, an A/D converter, a time and date input and transfer unit, an event counter and an interruption controller (not depicted). The non-volatile memory has also a second memory element 540.

A proposed computer programme P comprises routines for safe loading and unloading of motor vehicles according to the innovative method. The programme comprises routines for using slope sensor means to obtain information about the slope of the vehicle's load plane. It comprises routines for using the vehicle's air suspension system to adjust the slope of the load plane to substantially horizontal positions on the basis of said information. The programme P may be stored in an executable form or in compressed form in a memory 560 and/or in a read/write memory 550. Where the data processing unit 510 is described as performing a certain function, it means that it conducts a certain part of the programme stored in the memory 560, or a certain part of the programme stored in the read/write memory 550. The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is intended to communicate with the data processing unit via a data bus 511. The read/write memory 550 is adapted to communicating with the data processing unit via a data bus 514. The links associated for example with the control unit 200 may be connected to the data port. When data are received on the data port 599, they are stored temporarily in the second memory element 540. When input data received have been temporarily stored, the data processing unit 510 is prepared to conduct code execution as described above. The signals received on the data port may be used by the device 500 to obtain via slope sensor means information about the slope of the vehicle's load plane. The signals received on the data port may be used by the device 500 to employ the vehicle's air suspension system to adjust the slope of the load plane to substantially horizontal positions on the basis of said information.

Parts of the methods herein described may be conducted by the device 500 by means of the data processing unit 510 which runs the programme stored in the memory 560 or the read/write memory 550. When the device 500 runs the programme, methods herein described are executed.

The vehicle described above in relation to Fig. 2 has a front axle X1 and a powered axle X2, but the invention is applicable on any suitable vehicles which have for example a front axle, a rear axle and a tag axle with two or four wheel drive; two front axles, a powered axle and a tag axle; or vehicles with further axles, e.g. ten or twelve, one or more of them being powered.

The above description of the preferred embodiments of the present invention is provided for illustrative and descriptive purposes. It is not intended to be exhaustive nor to restrict the invention to the variants described. Many modifications and variations will obviously suggest themselves to one skilled in the art. The embodiments have been chosen and described in order best to explain the principles of the invention and their practical applications and thus make it possible for one skilled in the art to understand the invention for different embodiments and with the various modifications appropriate to the intended use.

Claims

1. A method for safe loading and unloading of motor vehicles, comprising the step of using the vehicle's air suspension system to adjust the slope of the vehicle's load plane to a substantially horizontal position, characterised in that the step of adjusting the slope of the load plane comprises the steps of using slope sensor means (210) to obtain (S1 ) information about the slope of the load plane and using the vehicle's air suspension system (220) to adjust (S2) the slope of the load plane to substantially horizontal positions on the basis of said information.

2. A method according to claim 1 , in which said slope sensor means (210) comprise accelerometer means.

3. A method according to claim 2, in which said accelerometer means is part of the vehicle's normal accelerometer configuration.

4. A method according to claim 1 , in which said slope sensor means (210) comprise pressure sensor means belonging to the vehicle's air suspension system.

5. A method according to claim 1 , in which said slope sensor means (210) comprise pendulum means.

6. A method according to any one of claims 1-5, in which the slope of the load plane both in the vehicle's longitudinal direction and transversely thereto is adjusted by using forward and/or rear air suspension means (B1 , B2, B3, B4) belonging to the vehicle's air suspension system (220) and/or right and/or left air suspension means (B1 , B2, B3, B4) belonging to the vehicle's air suspension system (220).

7. A method according to any one of claims 1-6, in which said adjustment comprises an iteration procedure.

8. A system (I) for safe loading and unloading of motor vehicles, comprising means for using the vehicle's air suspension system (220) to adjust the slope of the load plane to a substantially horizontal position, characterised in that said means for adjusting the slope of the load plane comprise means (200) for using slope sensor means (210) to obtain information about the slope of the load plane, and means (200) for using the vehicle's air suspension system (220) to adjust the slope of the load plane to substantially horizontal positions on the basis of said information.

9. A system according to claim 8, in which said slope sensor means (210) comprise accelerometer means.

10. A system according to claim 9, in which said accelerometer means is part of the vehicle's normal accelerometer configuration.

11. A system according to claim 8, in which said slope sensor means (210) comprise pressure sensor means belonging to the vehicle's air suspension system.

12. A system according to claim 8, in which said slope sensor means (210) comprise pendulum means.

13. A system according to any one of claims 8-12, in which the slope of the load plane of the vehicle (1 ) both in the vehicle's longitudinal direction and transversely thereto is arranged to be adjustable by using forward and/or rear air suspension means (B1 , B2, B3, B4) belonging to the vehicle's air suspension system (220) and/or right and/or left air suspension means (B1 , B2, B3, B4) belonging to the vehicle's air suspension system (220).

14. A system according to any one of claims 8-13, in which said means (200, 220) for adjusting the slope of the vehicle's load plane are configured to iteratively effect said adjustment.

15. A motor vehicle (1 ) provided with a system (I) according to claims 8-14.

16. A computer programme (P) for safe loading and unloading of motor vehicles, which programme (P) comprises programme code which, when run by an electronic control unit (200) or another computer (500) connected to the electronic control unit (200), enables the electronic control unit (200) to perform steps according to claims 1-7.

17. A computer programme product comprising a digital storage medium which stores the computer programme according to claim 16.