EP4662074A1

EP4662074A1 - Method of operating an air suspension arrangement, computer program, computer-readable medium, control arrangement, and vehicle

Info

Publication number: EP4662074A1
Application number: EP24701531.6A
Authority: EP
Inventors: Robert Skaba
Original assignee: Scania CV AB
Current assignee: Traton AB
Priority date: 2023-02-06
Filing date: 2024-01-15
Publication date: 2025-12-17
Also published as: WO2024167449A1; SE546727C2; CN120418101A; SE2350109A1

Abstract

A method (100) of operating an air suspension arrangement (1) of a vehicle (2) is disclosed, wherein the vehicle (2) comprises a cargo unit (5) configured to accommodate cargo. The air suspension arrangement (1) comprises a number of air suspension members (6, 6') having a controllable pressure for adjusting a chassis height of a chassis (4) of the vehicle (2). The method (100) comprises the step of, upon receipt of a cargo unloading demand, lowering (120) the chassis height to a minimum chassis height position by reducing the pressure of a number of air suspension members (6, 6') to a set pressure level, wherein the set pressure level is adapted to cause the chassis (4) to assume a raised position when the cargo is unloaded from the cargo unit (5). The present disclosure further relates to a computer program, a computer-readable medium (200), a control arrangement (21), and a vehicle (2).

Description

Method of Operating an Air Suspension Arrangement, Computer Program, Computer-Readable Medium, Control Arrangement, and Vehicle

TECHNICAL FIELD

The present disclosure relates to a method of operating an air suspension arrangement of a vehicle. The present disclosure further relates to a computer program, a computer-readable medium, a control arrangement configured to operate an air suspension arrangement of a vehicle, and a vehicle comprising an air suspension arrangement.

BACKGROUND

Air suspension arrangements are used in some vehicles to adjust a chassis height of a chassis of the vehicle. Normally, an air suspension arrangement comprises an air compressor, a pressure reservoir, and a number of air suspension members, such as a number of suspension bellows, positioned between a wheel axle of the vehicle and a chassis of the vehicle. The air compressor is normally configured to compress air from the surroundings to the pressure reservoir, wherein the air suspension arrangement comprises a number of conduits fluidly connecting the pressure reservoir to the number of air suspension members. Moreover, air suspension arrangements of this type normally comprise a pneumatic control system comprising a number of control valves for regulating the pressure inside the number of air suspension members so as to adjust the chassis height of the chassis of the vehicle. In addition to the obtained adjustability of the chassis height of the chassis, the air inside the number of air suspension members can provide a spring effect upon relative movement between the chassis and the wheel axle.

The use of electric drive for vehicles provides many advantages, especially regarding local emissions. Such vehicles comprise one or more electric propulsion motors configured to provide motive power to the vehicle. These types of vehicles can be divided into the categories pure electric vehicles and hybrid electric vehicles. Pure electric vehicles, sometimes referred to as battery electric vehicles, only-electric vehicles, and all-electric vehicles, comprise a pure electric powertrain and comprise no internal combustion engine and therefore produce no emissions in the place where they are used.

A hybrid electric vehicle comprises two or more distinct types of power, such as an internal combustion engine and an electric propulsion system. The combination of an internal combustion engine and an electric propulsion system provides advantages with regard to energy efficiency, partly because of the poor energy efficiency of an internal combustion engine at lower power output levels. Moreover, some hybrid electric vehicles are capable of operating in pure electric drive when wanted, such as when driving in certain areas.

The electricity is usually stored in a number of battery packs each comprising a number of rechargeable battery cells. Some different types of battery cells are used, such as lithium-ion battery cells, lithium polymer battery cells, as well as other types of rechargeable battery cells. Energy can be less abundant in a pure electric vehicle as compared to a vehicle comprising an internal combustion engines due to a lower energy storage capacity of the batteries as compared to a fuel tank.

In cargo vehicles, such as dump trucks, an air suspension arrangement can be used to lower the chassis height of the chassis to a minimum chassis height position before unloading cargo from a cargo unit of the vehicle. The air suspension arrangement normally comprises a number of bump stops members arranged to limit movement of the chassis past the minimum chassis height position by an abutting contact between the bump stop members. By lowering the chassis height of the chassis to the minimum chassis height position, the stability of the vehicle can be improved during an unloading procedure of the cargo from the cargo unit. Moreover, damage to the number of air suspension members can be avoided. That is, as an example, if a dumper truck comprising a rear hinged cargo units rises the cargo unit and if the cargo slides off the cargo unit so fast that the number of air suspension members cannot be vented fast enough, the number of air suspension members may be damaged. Accordingly, by lowering the chassis height of the chassis to the minimum chassis height position via a reduction of the pressure of the number of air suspension members, such damage can be avoided.

For these reasons, it is an advantage if a chassis height of the chassis of the vehicle is lowered to the minimum chassis height position before unloading the cargo. However, when the cargo has been unloaded, the chassis height of the chassis must normally be raised again before driving off the vehicle. The process of raising the chassis height of the chassis to a driving chassis height position requires energy and takes time.

In vehicles comprising an internal combustion engine, the raising of the chassis height of the chassis adds to the fuel consumption of the vehicle and thus also the vehicle's environmental impact. Moreover, as mentioned, in at least partially electric vehicles, such as pure electric vehicles, energy can be less abundant than in vehicles comprising internal combustion engines. Therefore, it may also be desired to reduce the energy consumption for raising the chassis height of the chassis of an at least partially electric vehicle.

Moreover, in many commercial activities, for example in the mining industry, it may be desirable for economic reasons to reduce the time needed for raising the chassis height of the chassis after an unloading procedure of cargo. Furthermore, the time needed for raising the chassis height of the chassis after an unloading procedure of cargo may annoy some users.

SUMMARY

It is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a method of operating an air suspension arrangement of a vehicle, wherein the method is performed by a control arrangement, and wherein the vehicle comprises a chassis, a wheel axle comprising a number of wheels, the air suspension arrangement connecting the wheel axle to the chassis, and a cargo unit configured to accommodate cargo, wherein the wheel axle is configured to support at least part of the load of the cargo unit, and wherein the air suspension arrangement comprises a number of air suspension members having a controllable pressure for adjusting a chassis height of the chassis between raised positions and a minimum chassis height position, and bump stop members defining the minimum chassis height position by abutting contact between the bump stop members, and wherein the method comprises the step of, upon receipt of a cargo unloading demand: lowering the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to a set pressure level, wherein the set pressure level is adapted to cause the chassis to assume a raised position when the cargo is unloaded from the cargo unit.

Since the method comprises the step of lowering the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to the set pressure level, the stability of the vehicle can be improved during an unloading procedure of the cargo from the cargo unit. Moreover, it can be ensured that damage to the number of air suspension members is avoided.

Furthermore, since the set pressure level is adapted to cause the chassis to assume the raised position when the cargo is unloaded from the cargo unit, a method is provided capable of raising the chassis height of the chassis to a raised position in a quick and energy-efficient manner. This is because the set pressure level of the number of air suspension members can provide an automatic increase of the chassis height of the chassis when the cargo is unloaded from the cargo unit.

Accordingly, as a further result, a method is provided capable of reducing the energy consumption of vehicles, such as reducing the fuel consumption of a vehicle comprising an internal combustion engine or reducing the consumption of electrical energy stored in a number of batteries of an at least partially electric vehicle. Accordingly, in this manner, the operational range of the vehicle can be increased, and the vehicle's environmental impact can be reduced.

Furthermore, since the set pressure level is adapted to cause the chassis to assume the raised position when the cargo is unloaded from the cargo unit, a method is provided capable of obtaining a significant reduction of the time needed for raising the chassis height of the chassis to a raised position. In other words, due to the features of the method, the vehicle is allowed to leave the scene faster which can be economically beneficial in many commercial activities.

Accordingly, a method is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

The feature that the set pressure level is adapted to cause the chassis to assume a raised position when the cargo is unloaded from the cargo unit can also be expressed as that the set pressure level is adapted to a pressure level at which the number of air suspension members causes the chassis to rise to a raised position when the weight of the cargo is removed from the cargo unit. The raised position of the chassis may also be referred to as a raised chassis height position of the chassis.

The cargo unloading demand may be received from an input device arranged in a driver environment of the vehicle and/or from a control device of the vehicle. The cargo unloading demand may be indicative of an impending or started unloading procedure of cargo from the cargo unit of the vehicle.

Optionally, the method comprises the step of: determining the set pressure level based on a load on the wheel axle obtained when no cargo is accommodated in the cargo unit and properties of the number of air suspension members.

Thereby, a method is provided having conditions for obtaining a raised position of the chassis in a more accurate manner when the cargo is unloaded from the cargo unit.

As is further explained herein, the properties of the number of air suspension members may comprise a characteristic of the number of air suspension member and/or a configuration of the number of air suspension members.

Optionally, the method comprises the step of: adapting the set pressure level to cause the chassis to assume a determined raised position when the cargo is unloaded from the cargo unit.

Thereby, a wanted raised position of the chassis can be obtained in an automatic manner when the cargo is unloaded from the cargo unit.

Optionally, the determined raised position corresponds to a determined driving chassis height position.

Thereby, a determined driving chassis height position can be obtained in an automatic manner when the cargo is unloaded from the cargo unit.

Optionally, the method comprises the steps of: inputting a current chassis height before lowering the chassis height to the minimum chassis height position, and determining the set pressure level based on the inputted chassis height.

Thereby, conditions are provided for obtaining a chassis height of the chassis at least substantially corresponding to the inputted chassis height in an automatic manner when the cargo is unloaded from the cargo unit.

Optionally, the method comprises the steps of: inputting a current pressure of the number of air suspension members before cargo is loaded into the cargo unit, and determining the set pressure level based on the inputted pressure. Thereby, a method is provided having conditions for obtaining a raised position of the chassis, such as a determined chassis height of the chassis, in a more accurate manner when the cargo is unloaded from the cargo unit.

According to a second aspect of the invention, the object is achieved by a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to some embodiments of the present disclosure. Since the computer program comprises instructions which, when the program is executed by a computer, cause the computer to carry out the method according to some embodiments, a computer program is provided which provides conditions for overcoming, or at least alleviating, at least some of the above-mentioned drawbacks. As a result, the above- mentioned object is achieved.

According to a third aspect of the invention, the object is achieved by a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to some embodiments of the present disclosure. Since the computer-readable medium comprises instructions which, when the program is executed by a computer, cause the computer to carry out the method according to some embodiments, a computer-readable medium is provided which provides conditions for overcoming, or at least alleviating, at least some of the above-mentioned drawbacks. As a result, the above- mentioned object is achieved.

According to a fourth aspect of the invention, the object is achieved by a control arrangement configured to operate an air suspension arrangement of a vehicle, wherein the vehicle comprises a chassis, a wheel axle comprising a number of wheels, the air suspension arrangement connecting the wheel axle to the chassis, and a cargo unit configured to accommodate cargo, wherein the wheel axle is configured to support at least part of the load of the cargo unit, and wherein the air suspension arrangement comprises a number of air suspension members having a controllable pressure for adjusting a chassis height of the chassis between raised positions and a minimum chassis height position, and bump stop members defining the minimum chassis height position by abutting contact between the bump stop members. The control arrangement is configured to, upon receipt of a cargo unloading demand: lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to a set pressure level, wherein the set pressure level is adapted to cause the chassis to assume a raised position when the cargo is unloaded from the cargo unit.

Since the control arrangement is configured to lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to the set pressure level, the stability of the vehicle can be improved during an unloading procedure of the cargo from the cargo unit. Moreover, it can be ensured that damage to the number of air suspension members is avoided.

Furthermore, since the set pressure level is adapted to cause the chassis to assume the raised position when the cargo is unloaded from the cargo unit, a control arrangement is provided capable of causing a rise of the chassis height of the chassis to a raised position in a quick and energy-efficient manner. This is because the set pressure level of the number of air suspension members can provide an automatic increase of the chassis height of the chassis when the cargo is unloaded from the cargo unit.

Accordingly, as a further result, a control arrangement is provided capable of reducing the energy consumption of vehicles, such as reducing the fuel consumption of a vehicle comprising an internal combustion engine or reducing the consumption of electrical energy stored in a number of batteries of an at least partially electric vehicle. In this manner, the operational range of the vehicle can be increased, and the vehicle's environmental impact can be reduced.

Furthermore, since the set pressure level is adapted to cause the chassis to assume the raised position when the cargo is unloaded from the cargo unit, a control arrangement is provided capable of reducing the time needed for raising the chassis height of the chassis to a raised position. In other words, due to the control performed by the control arrangement, the vehicle is allowed to leave the scene faster which can be economically beneficial in many commercial activities.

Accordingly, a control arrangement is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

It will be appreciated that the various embodiments described for the method are all combinable with the control arrangement as described herein. That is, the control arrangement according to the fourth aspect of the invention may be configured to perform any one of the method steps of the method according to the first aspect of the invention.

According to a fifth aspect of the invention, the object is achieved by a vehicle comprising a chassis, a wheel axle comprising a number of wheels, the air suspension arrangement connecting the wheel axle to the chassis, and a cargo unit configured to accommodate cargo, wherein the wheel axle is configured to support at least part of the load of the cargo unit, and wherein the air suspension arrangement comprises a number of air suspension members having a controllable pressure for adjusting a chassis height of the chassis between raised positions and a minimum chassis height position, and bump stop members defining the minimum chassis height position by abutting contact between the bump stop members, and wherein the vehicle comprises a control arrangement configured to, upon receipt of a cargo unloading demand: lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to a set pressure level, wherein the set pressure level is adapted to cause the chassis to assume a raised position when the cargo is unloaded from the cargo unit.

Since the control arrangement of the vehicle is configured to lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members to the set pressure level, the stability of the vehicle can be improved during an unloading procedure of the cargo from the cargo unit. Moreover, it can be ensured that damage to the number of air suspension members is avoided.

Furthermore, since the set pressure level is adapted to cause the chassis to assume the raised position when the cargo is unloaded from the cargo unit, a vehicle is provided in which the chassis height of the chassis can be raised to a raised position in a quick and energyefficient manner. This is because the set pressure level of the number of air suspension members can provide an automatic increase of the chassis height of the chassis when the cargo is unloaded from the cargo unit.

Accordingly, as a further result, a vehicle is provided having conditions for a reduced energy consumption. In this manner, the operational range of the vehicle can be increased, and the vehicle's environmental impact can be reduced.

Furthermore, since the set pressure level is adapted to cause the chassis of the vehicle to assume the raised position when the cargo is unloaded from the cargo unit, the time needed for raising the chassis height of the chassis to a raised position is reduced. In other words, the vehicle is allowed to leave the scene faster which can be economically beneficial in many commercial activities.

Accordingly, a vehicle is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the wheel axle is a rear wheel axle of the vehicle. Thereby, it can be ensured that the chassis height of the chassis can be raised to a raised position in a quick and energyefficient manner when the cargo is unloaded from the cargo unit.

Optionally, the cargo unit is hinged at a rear portion of the vehicle, and wherein the vehicle comprises a tilting mechanism controllable to tilt the cargo unit to a tilted position to unload cargo from the cargo unit. Due to the features of the control arrangement of the vehicle, the stability of the vehicle can be ensured upon tilting of the cargo unit. Moreover, it can be ensured that damage to the number of air suspension members is avoided. Furthermore, it can be ensured that the chassis height of the chassis is raised to a raised position in a quick and energy-efficient manner when the cargo slides off the cargo unit.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which:

Fig. 1 schematically illustrates a vehicle according to some embodiments,

Fig. 2 schematically illustrates the vehicle illustrated in Fig. 1 in which a cargo unit of the vehicle has been tilted to a tilted position relative to a chassis of the vehicle,

Fig. 3 schematically illustrates some parts of the vehicle illustrated in Fig. 1 and Fig. 2, such as a wheel axle, an air suspension arrangement, and a portion of the chassis of the vehicle, Fig. 4 schematically illustrates the parts illustrated in Fig. 3 in which a chassis height of the chassis has been lowered to a minimum chassis height position,

Fig. 5 schematically illustrates a method of operating of an air suspension arrangement of a vehicle, and Fig. 6 schematically illustrates a computer-readable medium.

DETAILED DESCRIPTION

Aspects of the present invention will now be described more fully. Like reference signs refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Fig. 1 schematically illustrates a vehicle 2 according to some embodiments. According to the illustrated embodiments, the vehicle 2 is a tipper truck, i.e. , a type of heavy vehicle, as well as a type of heavy commercial vehicle, comprising a cargo unit 5 being hinged around a pivot axis pA at a rear portion of the vehicle 2. The vehicle 2 according to the illustrated embodiments may also be referred to as a dump truck, a dumping truck, a dumper, or a tipper. According to further embodiments, the vehicle 2, as referred to herein, may be another type of heavy or lighter type of manned or unmanned vehicle for land-based propulsion such as a lorry, a construction vehicle, a tractor, or the like.

The vehicle 2 comprises a powertrain 20. The powertrain 20 comprises a transmission 14 and a power source 3. The power source 3 is configured to provide motive power to the vehicle 2 via the transmission 14. In more detail, the transmission 14 is configured to transmit power between the power source 3 and wheels w2 of the vehicle 2. The power source 3 of the vehicle 2 may comprise an internal combustion engine. As an alternative, or in addition, the power source 3 may comprise one or more electric machines. In other words, the powertrain 20 may comprise one or more electric machines in addition to an internal combustion engine for providing motive power to the vehicle 2. Thus, the powertrain 20 of the vehicle 2 may be a so-called hybrid electric powertrain or a fully electric powertrain.

In Fig. 1 , the vehicle 2 is illustrated as positioned in an intended use position on a surface 51 supporting the vehicle 2. As seen in Fig. 1 , wheels w1 , w2 of the vehicle 2 abut against the surface 51 when the vehicle 2 is positioned in the intended use position thereon. Moreover, in Fig. 1, a forward moving direction fd and a reverse moving direction rd are indicated. The reverse moving direction rd of the vehicle 2 is opposite to the forward moving direction fd of the vehicle 2.

The vehicle 2 in Fig. 1 is illustrated as comprising two wheel axles a1, a2 each comprising a number of wheels w1, w2. According to the illustrated embodiments, the wheels w1 of the wheel axle a1 constitutes front wheels of the vehicle 2. The wheels w1 of the wheel axle a1 may also be referred to as front wheels of the vehicle 2 and the wheel axle a1 may also be referred to as a front wheel axle of the vehicle 2. According to the illustrated embodiments, the wheels w1 of the wheel axle a1 are steered non-driven wheels. However, according to further embodiments, the wheels w1 of the wheel axle a1 may be driven wheels, i.e., may be driven to rotate by a power source 3 of the vehicle 2.

Moreover, according to the illustrated embodiments, the wheels w2 of the wheel axle a2 constitutes rear wheels of the vehicle 2. The wheels w2 of the wheel axle a2 may also be referred to as rear wheels of the vehicle 2 and the wheel axle a2 may also be referred to as a rear wheel axle of the vehicle 2. According to the illustrated embodiments, the wheels w2 of the wheel axle a2 are non-steered driven wheels. That is, according to the illustrated embodiments, the wheels w2 of the wheel axle a2 have a fixed rolling direction relative to a chassis 4 of the vehicle 2 and are arranged to be rotated by a power source 3 of the vehicle 2. However, according to further embodiments, the wheels w2 of the wheel axle a2 may be non-driven wheels. Moreover, according to some embodiments, the wheels w2 of the wheel axle a2 may be steered wheels, i.e., may be arranged such that the rolling direction thereof can be changed by a steering device relative to the chassis 4 of the vehicle 2.

According to further embodiments, the vehicle 2 may be provided with a different configuration of wheels w1, w2 and wheel axles a1 , a2 than depicted in Fig. 1. For example, the vehicle 2 may comprise two or more rear wheel axles, wherein each of the two or more rear wheel axles is configured to support at least part of the load of the cargo unit 5.

In Fig. 1 , the cargo unit 5 of the vehicle 2 is illustrated in a non-tilted position relative to the chassis 4 of the vehicle 2.

Fig. 2 schematically illustrates the vehicle 2 illustrated in Fig. 1 in which the cargo unit 5 has been tilted to a tilted position relative to the chassis. That is, as mentioned, according to the illustrated embodiments, the cargo unit 5 is hinged at the rear portion of the vehicle 2 around a pivot axis pA. In Fig. 1 and Fig. 2, the vehicle 2 is illustrated as seen along a viewing direction coinciding with the pivot axis pA of the cargo unit 5.

Moreover, as seen in Fig. 2, the vehicle 2 comprises a tilting mechanism 9. The tilting mechanism 9 is controllable to tilt the cargo unit 5 between the non-tilted position illustrated in Fig. 1 and the tilted position illustrated in Fig. 2. The tilting mechanism 9 may comprise a number of hydraulic or pneumatic actuators, such as rams, controllable to tilt the cargo unit 5 between the non-tilted position and the tilted position. According to the illustrated embodiments, the tilting mechanism 9 is controllable to tilt the cargo unit 5 from the non-tilted position illustrated in Fig. 1 to the tilted position illustrated in Fig. 2 to unload cargo from the cargo unit 5. That is, according to the illustrated embodiments, the cargo unit 5 is a type of open-box bed allowing cargo in the cargo unit 5 to be unloaded by sliding off the cargo unit 5 onto a ground surface behind the vehicle 2 when the cargo unit 5 is tilted to the tilted position. The cargo unit 5 may also be referred to as a bed, an open-box bed, a cargo body, a dump body, or the like.

As indicated in Fig. 1 and Fig. 2, the vehicle 2 comprises an air suspension arrangement 1. The air suspension arrangement 1 connects the wheel axle a2 to the chassis 4 of the vehicle 2.

Fig. 3 schematically illustrates some parts of the vehicle 2 illustrated in Fig. 1 and Fig. 2, such as the wheel axle a2, the air suspension arrangement 1, and a portion of the chassis 4 of the vehicle 2. In Fig. 3, the parts of the vehicle 2 are illustrated as seen in a direction coinciding with a forward moving direction fd of the vehicle 2 indicated in Fig. 1.

Below, simultaneous reference is made to Fig. 1 - Fig. 3, if not indicated otherwise. The air suspension arrangement 1 comprises a number of air suspension members 6, 6' positioned between the chassis 4 of the vehicle 2 and the wheel axle a2. In more detail, according to the illustrated embodiments, the number of air suspension members 6, 6' comprises two air suspension members 6, 6' arranged at a respective lateral side of the vehicle 2. The suspension members 6, 6' may also be referred to as air suspension members, suspension bellows, air suspension bellows, or the like.

Moreover, the air suspension arrangement 1 comprises an air supply system 24. The air supply system 24 may also be referred to as a pneumatic control system. As is further explained below, the air supply system 24 is controllable to adjust the pressure of the number of air suspension members 6, 6'. The air supply system 24 comprises a pressure reservoir and an air compressor configured to compress air from the surroundings to the pressure reservoir. The air compressor and the pressure reservoir are not illustrated in Fig. 1 - Fig. 4 for reasons of brevity and clarity.

The air compressor of the air supply system 24 may be powered by an electric motor. As an alternative, or in addition, the air compressor of the air supply system 24 may be powered by the power source 3 of the vehicle 2. The air supply system 24 further comprises a number of conduits 10 fluidly connecting the pressure reservoir to the number of air suspension members 6, 6’. Moreover, the air supply system 24 comprises a number of control valves for regulating the pressure inside the number of air suspension members 6, 6’. The air suspension arrangement 1 and the air supply system 24 may together be referred to as an air suspension system.

As indicated in Fig. 3, the vehicle 2 comprises a control arrangement 21. The control arrangement 21 is operably connected to the air supply system 24 and is configured to control operation thereof. The control arrangement 21 may be comprised in the air supply system 24 and/or in an air suspension system comprising the air suspension arrangement 1 and the air supply system 24. The features, functions, and advantages of the control arrangement 21 are further explained below.

The chassis height of the chassis 4 of the vehicle 2 can be changed by changing the pressure of the number of air suspension members 6, 6'. In Fig. 3, the chassis 4 of the vehicle 2 is illustrated in a raised position. As can be seen in Fig. 2, according to the illustrated embodiments, the wheel axle a2 is configured to support at significant part of the load of the cargo unit 5. Since the number of air suspension members 6, 6' of the air suspension arrangement 1 connects the wheel axle a2 to the chassis 4, the number of air suspension members 6, 6' also supports a significant part of the load of the cargo unit 5 when the chassis 4 of the vehicle 2 is in the raised position.

Fig. 4 illustrates the parts illustrated in Fig. 3 in which the chassis height of the chassis 4 has been lowered to a minimum chassis height position. The chassis height of the chassis 4 has been lowered to the minimum chassis height position by lowering the pressure inside the number of air suspension members 6, 6'.

As illustrated in Fig. 3 and Fig. 4, the air suspension arrangement 1 comprises bump stop members 8, 8’. The bump stop members 8, 8’ are configured to prevent further movement of the chassis 4 past the minimum chassis height position. In more detail, the bump stop members 8, 8’ comprise a first set of bump stop members 8 connected to the chassis 4 of the vehicle 2 and a second set of bump stop members 8’ connected to the wheel axle a2, wherein the bump stop members 8, 8’ are configured to prevent further movement of the chassis 4 past the minimum chassis height position by an abutting contact between the first set of bump stop members 8 and the second set of bump stop members 8’. In Fig. 3 and Fig. 4, the bump stop members 8, 8’ are illustrated as positioned inside a respective air suspension member 6, 6'. However, the bump stop members 8, 8’ may be arranged outside of the number of air suspension members 6, 6', such as in front of, behind, or at a side of an air suspension member 6, 6' as seen relative to a forward moving direction fd of the vehicle 2.

As understood from the above, the bump stop members 8, 8’ define the minimum chassis height position by abutting contact between the bump stop members 8, 8’. The bump stop members 8, 8’, as referred to herein, may also be referred to as a number of bump stop members 8, 8’. Each of the bump stop members 8, 8’ may be formed by a resilient material, such as rubber or a rubber-like material.

The bump stop members 8, 8’ may be arranged such that at least part of the load of the cargo unit 5 is transferred from the number of air suspension members 6, 6' to the bump stop members 8, 8’ when the chassis height of the chassis 4 is lowered to the minimum chassis height position. Moreover, the bump stop members 8, 8’ may be arranged such that substantially the full load from the cargo unit 5 on the number of air suspension members 6, 6' is transferred from the number of air suspension members 6, 6' to the bump stop members 8, 8’ when the pressure inside the number of air suspension members 6, 6' is lowered to an ambient pressure level. The cargo unit 5 has been omitted in Fig. 3 and Fig. 4 for reasons of brevity and clarity. However, as can be seen in Fig. 1 and Fig. 2, the cargo unit 5 is attached to the chassis 4 of the vehicle 2. In more detail, according to the illustrated embodiments, the cargo unit 5 is hinged at a rear portion of the chassis 4 of the vehicle 2.

As seen when comparing Fig. 3 and Fig. 4, the relative distance d1 , d2 between the chassis 4 and a rotation axis r2 of the wheels w2 of the wheel axle a2 is changed when the pressure inside number of air suspension members 6, 6' is changed. In this manner, the relative distance between the chassis 4 of the vehicle 2 and a surface 51 currently supporting the vehicle 2 is also changed when the pressure inside number of air suspension members 6, 6' is changed. Likewise, since the cargo unit 5 is attached to the chassis 4 of the vehicle 2, the relative distance between the cargo unit 5 and the surface 51 currently supporting the vehicle 2 is also changed when the pressure inside number of air suspension members 6, 6' is changed.

In other words, as understood from the above described, the number of air suspension members 6, 6’ has a controllable pressure for adjusting a chassis height of the chassis 4 between raised positions and a minimum chassis height position. According to embodiments herein, the control arrangement 21 is configured to, upon receipt of a cargo unloading demand, lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members 6, 6’ to a set pressure level, wherein the set pressure level is adapted to cause the chassis 4 to assume a raised position when the cargo is unloaded from the cargo unit 5.

In this manner, as is further explained herein, the chassis height of the chassis 4 can be raised to a raised position in a quick and energy-efficient manner. Moreover, since the control arrangement 21 is configured to lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members 6, 6' to the set pressure level, the stability of the vehicle 2 can be improved during an unloading procedure of the cargo from the cargo unit 5. Moreover, it can be ensured that damage to the number of air suspension members 6, 6' is avoided.

The control arrangement 21 may be operably connected to a control device and may be configured to receive the cargo unloading demand therefrom. The control device may for example be arranged in a driver environment 55 of the vehicle 2. The driver environment 55 of the vehicle 2 is schematically illustrated in Fig. 1 and Fig. 2. As an alternative, or in addition, the control arrangement 21 may be operably connected to another type of control device and may be configured to receive the cargo unloading demand therefrom, such as for example a control device arranged on the vehicle 2 at a location outside of the driver environment, and/or a control device in the form of a separate unit, such as a separate handheld unit.

Any of such control devices may comprise an input unit, wherein the control device is configured to generate the cargo unloading demand upon actuation of the input unit. The input unit may for example comprise a button, a lever, a touch sensitive screen, or the like.

Moreover, any of such control devices may be implemented in a control device or control unit for controlling operation of the tilting mechanism 9. According to such embodiments, the control device may be configured to generate the cargo unloading demand when the control device or control unit is operated for moving the cargo unit 5 from the non-tilted position illustrated in Fig. 1 towards the tilted position illustrated in Fig. 2.

The control arrangement 21 may thus be configured to receive the cargo unloading demand and may in response to a receipt of the cargo unloading demand lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members 6, 6’ to the set pressure level. As mentioned, the set pressure level is adapted to cause the chassis 4 to assume a raised position when the cargo is unloaded from the cargo unit 5. The feature that the set pressure level is adapted to cause the chassis 4 to assume a raised position when the cargo is unloaded from the cargo unit 5 can also be expressed as that the set pressure level is adapted to a pressure level at which the number of air suspension members 6, 6’ causes the chassis 4 to rise to a raised position when the weight of the cargo is removed from the cargo unit 5.

In the following, a cargo unloading procedure is explained with reference to Fig. 1 - Fig. 4. In Fig. 1 , the vehicle 2 can be said to have been stopped with cargo in the cargo unit 5. As mentioned, the cargo unit 5 is illustrated in a non-tilted position in Fig. 1. Since the vehicle 2 has been driven to the location illustrated in Fig. 1, the chassis height of the chassis 4 can be assumed to be at a raised position, as is illustrated in Fig. 3. The cargo in the cargo unit 5 may for example comprise loose material, such as gravel, soil, or the like.

When an operator of the vehicle 2, or a control system of the vehicle 2, determines that the cargo in the cargo unit 5 is to be unloaded, a cargo unloading demand may be sent to the control arrangement 21. Upon receipt of the cargo unloading demand, the control arrangement 21 initiates a lowering of the chassis height from the raised position illustrated in Fig. 3 to the minimum chassis height position illustrated in Fig. 4 by reducing the pressure of the number of air suspension members 6, 6’ to the set pressure level.

The pressure of the number of air suspension members 6, 6' may be reduced from a current pressure to the set pressure level by venting air from the number of air suspension members 6, 6'. The venting of the air from the number of air suspension members 6, 6' may be initiated by controlling a number of valves of the air supply system 24. The venting of the air from the number of air suspension members 6, 6' may be stopped when the pressure of the number of air suspension members 6, 6' reaches the set pressure level.

In this procedure, the chassis height of the chassis 4 is thus lowered from a raised position as illustrated in Fig. 3 to the minimum chassis height position as illustrated in Fig. 4. As mentioned, in the minimum chassis height position, an abutting contact is obtained between the bump stop members 8, 8’. In this manner, the stability of the vehicle 2 can be ensured in the unloading procedure of cargo from the cargo unit 5 and damage to the number of air suspension members 6, 6' can be avoided. The tilting of the cargo unit 5 from the non-tilted position illustrated in Fig. 1 towards the tilted position illustrated in Fig. 2 may be initiated when the chassis height of the chassis 4 has reached the minimum chassis height position. As an alternative, tilting of the cargo unit 5 from the non-tilted position towards the tilted position may be initiated when initiating the lowering of the chassis height of the chassis 4, and/or upon receipt of the cargo unloading demand.

When the cargo unit 5 has reached a certain angle relative to a local gravity vector, the cargo starts to slide off the cargo unit 5. In this process, the weight of the cargo is transferred such that the load on the wheel axle a2 increases. However, since an abutting contact is obtained between the bump stop members 8, 8’ when the chassis 4 is in the minimum chassis height position, damage to the number of air suspension members 6, 6' can be avoided.

The load on the wheel axle a2 starts to decrease when a first certain amount of the cargo has been transported out of the cargo unit 5. Moreover, since the pressure of the number of air suspension members 6, 6’ has been reduced to the set pressure level, the chassis height of the chassis 4 starts to rise from the minimum chassis height position illustrated in Fig. 4 towards a raised position as illustrated in Fig. 3, when a second certain amount of cargo has been transported out of the cargo unit 5. When all cargo has been transported out of the cargo unit 5, the chassis 4 will assume the raised position illustrated in Fig. 3.

Accordingly, in this manner, an automatic increase of the chassis height of the chassis 4 is obtained when the cargo is unloaded from the cargo unit 5. This is because the set pressure level in the number of air suspension members 6, 6' ensures that the chassis 4 springs back to the raised position when the cargo is unloaded from the cargo unit 5, i.e. , when the weight of the cargo is removed from the cargo unit 5. In other words, the set pressure level in the number of air suspension members 6, 6' ensures that the number of air suspension members 6, 6' lifts the chassis 4 to the raised position when the cargo is unloaded from the cargo unit 5.

Thereby, the use of the air compressor of the air supply system 24 can be reduced which reduces the energy consumption of the vehicle 2. Moreover, a significant decrease is obtained of the time needed for raising the chassis height of the chassis 4 from the minimum chassis height position to a raised position. Thereby, the vehicle 2 can be driven from the location earlier than would be the case otherwise which can provide economic benefits in some commercial activities. As understood from the above, the feature that the pressure of the number of air suspension members 6, 6’ is reduced to the set pressure level means that some of the pressure of the number of air suspension members 6, 6’ is kept at a pressure level above ambient pressure.

According to some embodiments, the control arrangement 21 is configured to determine the set pressure level based on a load on the wheel axle a2 obtained when no cargo is accommodated in the cargo unit 5 and properties of the number of air suspension members 6, 6’. The properties of the number of air suspension members 6, 6’ may comprise a characteristic of the number of air suspension member 6, 6’ and/or a configuration of the number of air suspension members 6, 6’. The control arrangement 21 may determine the set pressure level using a model of the number of air suspension members 6, 6', and/or a model of the vehicle 2, indicating a movement characteristic of the chassis 4 at various pressure levels of the number of air suspension members 6, 6' and at various loads applied onto the cargo unit 5 of the vehicle 2.

According to some embodiments, the control arrangement 21 may be configured to adapt the set pressure level to cause the chassis 4 to assume a determined raised position when the cargo is unloaded from the cargo unit 5. The determined raised position may correspond to a determined driving chassis height position. As an alternative, or in addition, the determined raised position may correspond to an inputted chassis height position, wherein vehicle 2 allows the input of a wanted chassis height position, for example via a control device according to the above described.

Moreover, according to some embodiments, the control arrangement 21 may be configured to input a current chassis height before lowering the chassis height to the minimum chassis height position and may be configured to determine the set pressure level based on the inputted chassis height. According to such embodiments, the control arrangement 21 can cause a rise of the chassis height of the chassis 4 to a raised chassis height position at least substantially corresponding to the chassis height before lowering the chassis height to the minimum chassis height position in an automatic manner when the cargo is unloaded from the cargo unit 5.

Furthermore, according to some embodiments, the control arrangement 21 may be configured to input a current pressure of the number of air suspension members 6, 6’ before cargo is loaded into the cargo unit 5 and may be configured to determine the set pressure level based on the inputted pressure. In this manner, the control arrangement 21 can obtain a raised position of the chassis, such as a determined chassis height of the chassis, in a more accurate manner when the cargo is unloaded from the cargo unit 5.

Fig. 5 illustrates a method 100 of operating of an air suspension arrangement of a vehicle. The air suspension arrangement and the vehicle may be an air suspension arrangement 1 of a vehicle 2 explained with reference to Fig. 1 - Fig. 4. Therefore, below, simultaneous reference is made to Fig. 1 - Fig. 5, if not indicated otherwise.

The method 100 is a method of operating of an air suspension arrangement 1 of a vehicle 2, wherein the method 100 is performed by a control arrangement 21, and wherein the vehicle 2 comprises a chassis 4, a wheel axle a2 comprising a number of wheels w2, the air suspension arrangement 1 connecting the wheel axle a2 to the chassis 4, and a cargo unit 5 configured to accommodate cargo, wherein the wheel axle a2 is configured to support at least part of the load of the cargo unit 5, and wherein the air suspension arrangement 1 comprises a number of air suspension members 6, 6’ having a controllable pressure for adjusting a chassis height of the chassis 4 between raised positions and a minimum chassis height position, and bump stop members 8, 8’ defining the minimum chassis height position by abutting contact between the bump stop members 8, 8’. The method 100 comprises the step of, upon receipt of a cargo unloading demand: lowering 120 the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members 6, 6’ to a set pressure level, wherein the set pressure level is adapted to cause the chassis 4 to assume a raised position when the cargo is unloaded from the cargo unit 5.

As indicated in Fig. 5, the method may comprise the steps of: receiving 107 a cargo unloading demand, and performing 121 the step of lowering 120 the chassis height to the minimum chassis height position in response to the receipt of the cargo unloading demand.

Moreover, as illustrated in Fig. 5, the method 100 may comprises the step of: determining 110 the set pressure level based on a load on the wheel axle a2 obtained when no cargo is accommodated in the cargo unit 5 and properties of the number of air suspension members 6, 6’.

The step of determining 110 the set pressure level may be performed prior to the step of lowering 120 the chassis height to the minimum chassis height position. Furthermore, as illustrated in Fig. 5, the method 100 may comprises the step of: adapting 112 the set pressure level to cause the chassis 4 to assume a determined raised position when the cargo is unloaded from the cargo unit 5.

The step of adapting 112 the set pressure level may be performed prior to the step of lowering 120 the chassis height to the minimum chassis height position.

According to some embodiments, the determined raised position corresponds to a determined driving chassis height position.

Moreover, as illustrated in Fig. 5, the method 100 may comprise the steps of: inputting 103 a current chassis height before lowering the chassis height to the minimum chassis height position, and determining 114 the set pressure level based on the inputted chassis height.

Obviously, the step of inputting 103 the current chassis height is performed prior to the step of lowering 120 the chassis height to the minimum chassis height position. Moreover, the step of determining 114 the set pressure level may be performed prior to the step of lowering 120 the chassis height to the minimum chassis height position.

Furthermore, as illustrated in Fig. 5, the method 100 may comprise the steps of: inputting 105 a current pressure of the number of air suspension members 6, 6’ before cargo is loaded into the cargo unit 5, and determining 116 the set pressure level based on the inputted pressure.

Obviously, the step of inputting 105 a current pressure of the number of air suspension members 6, 6’ is performed prior to the step of lowering 120 the chassis height to the minimum chassis height position. Moreover, the step of determining 116 the set pressure level may be performed prior to the step of lowering 120 the chassis height to the minimum chassis height position.

As understood from the above, according to some embodiments, the set pressure level may be determined based on at least one of the inputted chassis height, the inputted pressure, and a load on the wheel axle a2 obtained when no cargo is accommodated in the cargo unit 5 and properties of the number of air suspension members 6, 6’. In other words, according to some embodiments, the steps of determining 110, 114, 116 the set pressure level described herein may be combined into one step of determining the set pressure level based on two or more of the inputted chassis height, the inputted pressure, and a load on the wheel axle a2 obtained when no cargo is accommodated in the cargo unit 5 and properties of the number of air suspension members 6, 6’

It will be appreciated that the various embodiments described for the method 100 are all combinable with the control arrangement 21 as described herein. That is, the control arrangement 21 may be configured to perform any one of the method steps 103, 105, 107, 110, 112, 114, 116, 120, and 121 of the method 100.

Fig. 6 illustrates a computer-readable medium 200 comprising instructions which, when executed by a computer, cause the computer to carry out the method 100 according to some embodiments of the present disclosure. According to some embodiments, the computer- readable medium 200 comprises a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method 100 according to some embodiments.

One skilled in the art will appreciate that the method 100 of operating of an air suspension arrangement 1 of a vehicle 2 may be implemented by programmed instructions. These programmed instructions are typically constituted by a computer program, which, when it is executed in the control arrangement 21, ensures that the control arrangement 21 carries out the desired control, such as the method steps 103, 105, 107, 110, 112, 114, 116, 120, and 121 described herein. The computer program is usually part of a computer program product 200 which comprises a suitable digital storage medium on which the computer program is stored.

The control arrangement 21 may comprise a calculation unit which may take the form of substantially any suitable type of processor circuit or microcomputer, e.g., a circuit for digital signal processing (digital signal processor, DSP), a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression “calculation unit” may represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The control arrangement 21 may further comprise a memory unit, wherein the calculation unit may be connected to the memory unit, which may provide the calculation unit with, for example, stored program code and/or stored data which the calculation unit may need to enable it to do calculations. The calculation unit may also be adapted to store partial or final results of calculations in the memory unit. The memory unit may comprise a physical device utilised to store data or programs, i.e. , sequences of instructions, on a temporary or permanent basis. According to some embodiments, the memory unit may comprise integrated circuits comprising silicon-based transistors. The memory unit may comprise e.g., a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g., ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments.

The control arrangement 21 is connected to components of the vehicle 2, such as to components of the air suspension arrangement 1 and components of the air supply system 24, for receiving and/or sending input and output signals. These input and output signals may comprise waveforms, pulses, or other attributes which the input signal receiving devices can detect as information and which can be converted to signals processable by the control arrangement 21. These signals may then be supplied to the calculation unit. One or more output signal sending devices may be arranged to convert calculation results from the calculation unit to output signals for conveying to other parts of the vehicle's control system and/or the component or components for which the signals are intended. Each of the connections to the respective components of the vehicle 2 for receiving and sending input and output signals may take the form of one or more from among a cable, a data bus, e.g., a CAN (controller area network) bus, a MOST (media orientated systems transport) bus or some other bus configuration, or a wireless connection.

In the embodiments illustrated, the vehicle 2 comprises a control arrangement 21 but might alternatively be implemented wholly or partly in two or more control arrangements or two or more control units.

Control systems in modern vehicles generally comprise a communication bus system consisting of one or more communication buses for connecting a number of electronic control units (ECUs), or controllers, to various components on board the vehicle. Such a control system may comprise a large number of control units and taking care of a specific function may be shared between two or more of them. Vehicles and air suspension arrangements of the type here concerned are therefore often provided with significantly more control arrangements than depicted in Fig. 3 and Fig. 4, as one skilled in the art will surely appreciate.

The computer program product 200 may be provided for instance in the form of a data carrier carrying computer program code for performing at least some of the method steps 103, 105, 107, 110, 112, 114, 116, 120, and 121 according to some embodiments when being loaded into one or more calculation units of the control arrangement 21. The data carrier may be, e.g. a CD ROM disc, as is illustrated in Fig. 6, or a ROM (read-only memory), a PROM (programable read-only memory), an EPROM (erasable PROM), a flash memory, an EEPROM (electrically erasable PROM), a hard disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer program product may furthermore be provided as computer program code on a server and may be downloaded to the control arrangement 21 remotely, e.g., over an Internet or an intranet connection, or via other wired or wireless communication systems.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended independent claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended independent claims.

As used herein, the term "comprising" or "comprises" is open-ended, and includes one or more stated features, elements, steps, components, or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof.

Claims

1. A method (100) of operating an air suspension arrangement (1) of a vehicle (2), wherein the method (100) is performed by a control arrangement (21), and wherein the vehicle (2) comprises: a chassis (4), a wheel axle (a2) comprising a number of wheels (w2),

- the air suspension arrangement (1) connecting the wheel axle (a2) to the chassis (4), and a cargo unit (5) configured to accommodate cargo, wherein the wheel axle (a2) is configured to support at least part of the load of the cargo unit (5), and wherein the air suspension arrangement (1) comprises: a number of air suspension members (6, 6’) having a controllable pressure for adjusting a chassis height of the chassis (4) between raised positions and a minimum chassis height position, and bump stop members (8, 8’) defining the minimum chassis height position by abutting contact between the bump stop members (8, 8’), and wherein the method (100) comprises the step of, upon receipt of a cargo unloading demand: lowering (120) the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members (6, 6’) to a set pressure level, wherein the set pressure level is adapted to cause the chassis (4) to assume a raised position when the cargo is unloaded from the cargo unit (5).

2. The method (100) according to claim 1, wherein the method (100) comprises the step of: determining (110) the set pressure level based on a load on the wheel axle (a2) obtained when no cargo is accommodated in the cargo unit (5) and properties of the number of air suspension members (6, 6’).

3. The method (100) according to claim 1 or 2, wherein the method (100) comprises the step of: adapting (112) the set pressure level to cause the chassis (4) to assume a determined raised position when the cargo is unloaded from the cargo unit (5).

4. The method (100) according to claim 3, wherein the determined raised position corresponds to a determined driving chassis height position.

5. The method (100) according to any one of the preceding claims, wherein the method (100) comprises the steps of: inputting (103) a current chassis height before lowering the chassis height to the minimum chassis height position, and determining (114) the set pressure level based on the inputted chassis height.

6. The method (100) according to any one of the preceding claims, wherein the method (100) comprises the steps of: inputting (105) a current pressure of the number of air suspension members (6, 6’) before cargo is loaded into the cargo unit (5), and determining (116) the set pressure level based on the inputted pressure.

7. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method (100) according to any one of the claims 1 - 6.

8. A computer-readable medium (200) comprising instructions which, when executed by a computer, cause the computer to carry out the method (100) according to any one of the claims 1 - 6.

9. A control arrangement (21) configured to operate an air suspension arrangement (1) of a vehicle (2), wherein the vehicle (2) comprises: a chassis (4), a wheel axle (a2) comprising a number of wheels (w2), the air suspension arrangement (1) connecting the wheel axle (a2) to the chassis (4), and a cargo unit (5) configured to accommodate cargo, wherein the wheel axle (a2) is configured to support at least part of the load of the cargo unit (5), and wherein the air suspension arrangement (1) comprises: a number of air suspension members (6, 6’) having a controllable pressure for adjusting a chassis height of the chassis (4) between raised positions and a minimum chassis height position, and bump stop members (8, 8’) defining the minimum chassis height position by abutting contact between the bump stop members (8, 8’), and wherein the control arrangement (21) is configured to, upon receipt of a cargo unloading demand: lower the chassis height to the minimum chassis height position by reducing the pressure of the number of air suspension members (6, 6’) to a set pressure level, wherein the set pressure level is adapted to cause the chassis (4) to assume a raised position when the cargo is unloaded from the cargo unit (5).

10. A vehicle (2) comprising: a chassis (4), a wheel axle (a2) comprising a number of wheels (w2), the air suspension arrangement (1) connecting the wheel axle (a2) to the chassis (4), and a cargo unit (5) configured to accommodate cargo, wherein the wheel axle (a2) is configured to support at least part of the load of the cargo unit (5), and wherein the air suspension arrangement (1) comprises: a number of air suspension members (6, 6’) having a controllable pressure for adjusting a chassis height of the chassis (4) between raised positions and a minimum chassis height position, and bump stop members (8, 8’) defining the minimum chassis height position by abutting contact between the bump stop members (8, 8’), and wherein the vehicle (2) comprises a control arrangement (21) according to claim 9.

11. The vehicle (2) according to claim 10, wherein the wheel axle (a2) is a rear wheel axle of the vehicle (2).

12. The vehicle (2) according to claim 10 or 11, wherein the cargo unit (5) is hinged at a rear portion of the vehicle (2), and wherein the vehicle (2) comprises a tilting mechanism (9) controllable to tilt the cargo unit (5) to a tilted position to unload cargo from the cargo unit (5).