DE102022121308A1 - Method of operating a compressed air system, computer program, computer-readable medium, control arrangement, compressed air system and vehicle - Google Patents

Abstract

A method (100) for operating a compressed air system (1) of a vehicle (2) is disclosed. The compressed air system (1) comprises an air processing element (5'), an air compressor (3) configured to compress air through the air processing element (5') during operation, and a vent valve (7) located downstream of the air processing element (5') is arranged. The method (100) includes the step of controlling (120) the vent valve (7) between an open and a closed state based on data representing at least one of a past, a current and an imminent accumulation of matter in at least one component (3, 5, 5') of the compressed air system (1). The present disclosure further relates to a computer program, a computer-readable medium (200), a control arrangement (21), a compressed air system (1) for a vehicle (2) and a vehicle (2).

Description

TECHNICAL AREA

The present disclosure relates to a method of operating a compressed air system of a vehicle. The present disclosure further relates to a computer program, a computer-readable medium, a control arrangement for operating a compressed air system of a vehicle, a compressed air system for a vehicle, and a vehicle with a compressed air system.

BACKGROUND

Compressed air systems, also known as pneumatic systems, can be used in vehicles to power various systems and devices of the vehicle. Examples of this are braking systems, suspension systems, various types of pneumatic actuators for opening and closing doors, panels and the like.

Typically, a compressed air system includes an air compressor and an accumulator, where the air compressor is configured to compress air into the accumulator. The air compressor is usually operated in such a way that the pressure in the compressed air system is kept within a predetermined pressure range with an upper and a lower pressure limit.

Additionally, in many cases, a compressed air system includes an air processing unit that is configured to process the air compressed by the air compressor before the air is routed to various systems and/or the accumulator. The air processing unit may include one or more air dryer units configured to dry the air compressed by the air compressor.

A problem with automotive compressed air systems is the accumulation of matter in the components of the compressed air system. For example, under certain conditions, such as cold ambient temperatures, ice can form in compressed air system components such as the air compressor and air processing unit. The formation of ice can lead to malfunctions of the compressed air system and the equipment/systems operated with the compressed air system.

A known approach to addressing this problem is to activate the air compressor and run it continuously while regulating the air pressure in the compressed air system by opening a valve located between the air compressor and the air processing unit. This valve vents the pressure in the supply line to atmosphere. In this way, the air compressor can be operated to heat the compressed air system.

However, this approach has some problems and disadvantages. For example, only a limited amount of accumulated substances can be removed from the compressed air system with this approach. In addition, the build-up can stress the components of the compressed air system, particularly the air compressor of the compressed air system.

Additionally, in today's consumer market, it is generally advantageous for products, such as vehicles and related components, systems, and assemblies, to have conditions and/or characteristics that lend themselves to cost-effective manufacture and assembly.

SUMMARY

It is an object of the present invention to overcome or at least mitigate at least some of the problems and disadvantages noted above.

• - Steuern des Entlüftungsventils zwischen dem offenen und dem geschlossenen Zustand auf der Grundlage von Daten, die mindestens eine von einer vorangegangenen, einer laufenden und einer bevorstehenden Ansammlung von Stoffen in mindestens einer Komponente des Druckluftsystems anzeigen.

According to a first aspect of the invention, the object is achieved by a method for operating a compressed air system of a vehicle. The compressed air system includes an air processing element, an air compressor operatively configured to compress air through the air processing element, and a vent valve controllable between an open condition and a closed condition. The vent valve is configured to vent air from the compressed air system to atmosphere when commanded open. The vent valve is located downstream of the air processing element relative to a direction of air flow from the air compressor through the air processing element. The procedure includes the step:

• - controlling the vent valve between the open and closed states based on data indicative of at least one of a previous, an ongoing and an imminent accumulation of matter in at least one component of the compressed air system.

Because the vent valve is located downstream of the air processing element and the method includes the step of controlling the vent valve between the open and closed states based on the data, a method is provided that is capable of venting air from the compressed air system in a manner , which is less dependent on the operating status of the air compressor.

That is, a method is provided that allows air to be bled from the compressed air system by controlling the bleed valve in the open state and/or by maintaining the bleed valve in the open state even when the air compressor is in operation, without a Risk of damage or deterioration of the air compressor. This is because the air processing element may resist flow to the air compressor even when the vent valve is commanded open.

As a further result, a method is provided that offers more freedom in choosing the type of air compressor. In other words, the method enables the use of an air compressor that is more sensitive to unrestricted operation, such as a rotary compressor or the like.

In addition, because the method allows the vent valve to be controlled or maintained in the open state even when the compressor is running, a method is provided that provides the means for improved removal and/or prevention of matter in a larger portion of the compressed air system . Namely, studies have shown that water can accumulate in the air compressor, which can damage the air compressor and cause the compressed air system and the components/systems powered by the compressed air system to malfunction. By allowing the vent valve to be controlled or maintained in the open state even during operation of the air compressor, water and moisture within the air compressor can be efficiently removed.

By being able to control or maintain the bleed valve open even during operation of the air compressor, the air-handling element can be heated in an efficient manner, thereby removing and/or preventing the formation of ice in the air-handling element. In addition, the efficient heating of the air processing element creates the conditions for an efficient subsequent regeneration of the air processing element.

Accordingly, a method is provided that overcomes or at least mitigates at least some of the problems and disadvantages noted above. As a result, the above objective is achieved.

• - Steuern des Entlüftungsventils in den offenen Zustand, wenn die Daten mindestens eine von einer vorangegangenen, einer laufenden und einer bevorstehenden Ansammlung von Stoffen in der mindestens einen Komponente anzeigen.

Optionally, the method includes the following step:

• - controlling the vent valve to the open state when the data indicates at least one of a previous, an ongoing and an upcoming accumulation of matter in the at least one component.

This provides an efficient process capable of removing and/or preventing the formation of matter in a large part of the compressed air system.

• - Halten des Entlüftungsventils im offenen Zustand, bis der Luftdruck im Druckluftsystem unter den Schwellendruck fällt.

Optionally, the air compressor is configured to operate when an air pressure in the compressed air system is below a threshold pressure, and the method includes the step of:

• - Holding the vent valve in the open state until the air pressure in the compressed air system falls below the threshold pressure.

Thereby a method is provided by which the operation of the air compressor can be activated in a simple and controlled manner in order to efficiently clean and/or prevent the formation of material in a large part of the compressed air system.

• - Halten des Entlüftungsventils auch bei laufendem Luftkompressor im offenen Zustand.

Optionally, the method includes the following step:

• - Keeping the bleed valve open even when the air compressor is running.

Thereby a method is provided which has conditions for improved removal and/or prevention of substances in a larger part of the compressed air system, including the removal and/or prevention of water and moisture in the air compressor of the compressed air system.

Additionally, a method is provided that is capable of heating the air handling element in an efficient manner, whereby ice in the air handling element can be removed and/or prevented from forming. In addition, the efficient heating of the air processing element creates the conditions for an efficient subsequent regeneration of the air processing element.

Since the bleed valve is located downstream of the air processing element, the air processing element presents a flow resistance to the air compressor even when the bleed valve is in the open condition, as discussed above. This allows the air compressor to operate without risk of damage or wear and tear on the air compressor.

As a further result, a method is provided that offers more freedom in choosing the type of air compressor. In other words, the method enables the use of an air compressor that is more sensitive to unrestricted operation, such as a rotary compressor or the like.

Optionally, the data is indicative of the temperature of at least a portion of the compressed air system.

This allows the bleed valve to be accurately controlled between the open and closed states to provide efficient and reliable debris removal and/or debris build-up prevention in a large portion of the compressed air system.

• - Erhalten der Daten durch Erfassen der Temperatur von mindestens einem Teil des Druckluftsystems.

Optionally, the method includes the following step:

• - Obtaining the data by acquiring the temperature of at least part of the compressed air system.

In this way, accurate data indicative of at least one of a previous, ongoing, or forthcoming accumulation of matter can be easily obtained. Alternatively or additionally, the data can be obtained in other ways, for example by estimating/modeling the data and/or by obtaining the data from an external device such as a temperature sensor, a communication device or the like.

According to a second aspect of the invention, the object is achieved by a computer program that includes instructions that, when the program is executed by a computer, cause the computer to perform the method according to some embodiments of the present disclosure. As 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 described herein, a computer program is provided which has conditions for overcoming or at least mitigating at least some of the disadvantages mentioned above offers. As a result, the above objective is achieved.

According to a third aspect of the invention, the object is achieved by a computer-readable medium containing instructions that, when executed by a computer, cause the computer to perform the method according to some embodiments of the present disclosure. Because the computer-readable medium includes instructions that, when the program is executed by a computer, cause the computer to perform the method according to some embodiments described herein, a computer-readable medium is provided that includes conditions for overcoming or at least mitigating at least some of the above mentioned disadvantages. As a result, the above objective is achieved.

According to a fourth aspect of the invention, the object is achieved by a control arrangement for operating a compressed air system of a vehicle. The compressed air system includes an air processing element, an air compressor configured to compress air through the air processing element, and a vent valve controllable between an open state and a closed state. The vent valve is configured to vent air from the compressed air system to atmosphere when commanded open. The vent valve is located downstream of the air processing element relative to a direction of air flow from the air compressor through the air processing element. The control arrangement is configured to control the vent valve between the open and closed states based on data indicative of at least one of a past, a current, and a forthcoming buildup of matter in at least one component of the compressed air system.

Since the bleed valve is located downstream of the air processing element and the control arrangement is configured to control the bleed valve between the open and closed states based on the data, a control arrangement is provided that is capable of extracting air from the compressed air system in a drain way that is less dependent on the operating condition of the air compressor.

That is, a control arrangement is provided that allows air to be bled from the compressed air system by controlling the bleed valve open and/or maintaining the bleed valve open even when the air compressor is in operation, without damage or risk air compressor wear. This is because the air handling element presents a flow resistance to the air compressor when the vent valve is commanded open.

As a further result, a control arrangement is provided which offers more freedom in choosing the type of air compressor. In other words, the control arrangement enables use an air compressor that is more sensitive to unrestricted operation, such as B. a rotary compressor or the like.

Since the control arrangement makes it possible to control or maintain the vent valve in the open state even when the air compressor is in operation, a control arrangement is provided which sets the conditions for improved removal and/or avoidance of substances in a larger part of the Compressed air system offers. Studies have shown that water can accumulate inside the air compressor, which can damage the air compressor and cause the compressed air system and the components/systems powered by the compressed air system to malfunction. By controlling or maintaining the bleed valve open even during operation of the air compressor, water and moisture within the air compressor can be efficiently removed.

By allowing the vent valve to be controlled or maintained in the open state even during operation of the air compressor, the air processing element can be efficiently heated, thereby removing and/or preventing the formation of ice in the air processing element. In addition, the efficient heating of the air processing element creates the conditions for an efficient subsequent regeneration of the air processing element.

Accordingly, a control arrangement is provided that overcomes or at least mitigates at least some of the problems and disadvantages noted above. As a result, the above objective is achieved.

It becomes clear that the various described embodiments of the method can all be combined with the control arrangement described here. That is, the control arrangement according to the fourth aspect of the invention can be configured to carry out each 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 compressed air system for a vehicle. The compressed air system includes an air processing element, an air compressor configured to compress air through the air processing element, and a vent valve controllable between an open state and a closed state. The vent valve is configured to vent air from the compressed air system to atmosphere when commanded open. The vent valve is located downstream of the air processing element relative to a direction of air flow from the air compressor through the air processing element. The compressed air system includes a control arrangement configured to control the vent valve between the open and closed states based on data representing at least one of a past, a current, and an upcoming accumulation of matter in at least one Show compressed air system component.

Since the vent valve is located downstream of the air processing element and the control arrangement of the compressed air system is configured to control the vent valve between the open and closed states based on the data, a compressed air system is provided that is capable of air from the compressed air system in a manner that is less dependent on the operating condition of the air compressor of the compressed air system.

That is, a compressed air system is provided that allows air to be bled from the compressed air system by controlling the bleed valve open and/or by maintaining the bleed valve open even when the air compressor is operating, without damage or risking air compressor wear. This is because the air handling element presents a flow resistance to the air compressor when the vent valve is commanded open.

As a further result, a compressed air system is provided that offers more freedom in choosing the type of air compressor for the compressed air system. In other words, the compressed air system allows the use of an air compressor that is more sensitive to unrestricted operation, such as a rotary compressor or similar.

Because the compressed air system provides the ability to control or maintain the vent valve open even during operation of the air compressor, a compressed air system is provided that meets the requirements for improved removal and/or avoidance of materials in a larger portion of the Compressed air system offers. Namely, studies have shown that water can accumulate inside the air compressor, which can damage the air compressor and cause malfunctions of the compressed air system and the components/systems powered by the compressed air system. By the vent valve also during operation of the air compressor in the can be controlled or maintained in an open state, water and moisture in the air compressor can be efficiently removed.

By being able to control or maintain the bleed valve open even during operation of the compressor, the air handling element can be efficiently heated, thereby removing and/or preventing the formation of ice in the air handling element. In addition, the efficient heating of the air processing element creates the conditions for an efficient subsequent regeneration of the air processing element of the compressed air system.

Accordingly, a compressed air system is provided that overcomes or at least mitigates at least some of the problems and disadvantages noted above. As a result, the above objective is achieved.

It goes without saying that the various described embodiments of the method can all be combined with the control arrangement described here. That is, the control arrangement of the compressed air system according to the fifth aspect of the invention can be configured to carry out each of the method steps of the method according to the first aspect of the invention.

Optionally, the compressed air system includes an air processing unit with the air processing element, wherein the vent valve is part of an outlet opening of the air processing unit. This creates the conditions for a compact and efficient compressed air system. In addition, a compressed air system is provided that has conditions and characteristics that are suitable for being manufactured and assembled in a cost-effective manner. This is because an outlet opening of the air processing unit, which can be used for other purposes in other types of compressed air systems, serves to vent the compressed air system to the atmosphere.

Optionally, the vent valve is an electronically controlled valve. This creates the conditions for accurate and reliable control of the bleed valve to efficiently remove and/or avoid matter in a larger portion of the compressed air system.

Optionally, the compressed air system includes an electric motor configured to drive the air compressor. This creates the conditions for the operation of the air compressor without the need for an internal combustion engine to be running. In this way, a compressed air system is provided that is able to achieve efficient removal and/or avoidance of matter in a larger portion of the compressed air system without the need for a running internal combustion engine.

Optionally, the air compressor is a rotary compressor. This provides a compressed air system that includes an efficient and reliable air compressor. Additionally, a compressed air system is provided that includes an air compressor that produces low noise levels during operation. In this way, the air compressor can also be operated in the absence of a running internal combustion engine without significantly increasing the noise level of a vehicle with the compressed air system.

A rotary compressor is a positive displacement compressor in which the compression of a fluid is achieved by at least one rotor, i. H. one or more rotating working elements, such as one or more screws or the like. A rotary compressor such as B. a screw compressor is sensitive to unrestricted operation, i. H. operation without significant back pressure at an outlet of the air compressor. One reason is that these types of compressors depend on a film of lubrication on one or more air compressor rotors. If the air compressor is operated with no back pressure at the outlet or with insufficient back pressure at the outlet, there is a risk that the film of lubricant will be removed from the one or more rotors. In this case, the lubricant can be carried with the airflow out of the compressor via the outlet of the air compressor. This can result in the one or more rotors being insufficiently lubricated, which can lead to wear and/or damage to the one or more rotors. In addition, the lubricant leaking from the air compressor can interfere with the operation of the compressed air system, for example, by plugging the air processing element or other parts or components of the compressed air system. In addition, the lubricant leaking from the air compressor can cause a reduction in the drying capacity of the air processing element.

However, since the bleed valve is located downstream of the air processing element as explained above, the air processing element represents a flow resistance for the air compressor even when the bleed valve is in the open state that the risk of damage or deterioration of the air compressor exists and without the threat of a subsequent malfunction of the compressed air system.

Optionally, the bleed valve is configured to restrictively bleed air from the compressed air system when open to create back pressure to the air compressor. This further ensures that the air compressor can also be operated when the vent valve is in the open state, without fear of damage or wear to the air compressor and subsequent malfunction of the compressed air system.

According to a sixth aspect of the invention, the objective is achieved by a vehicle having a compressed air system according to some embodiments of the present disclosure. Because the vehicle includes a compressed air system according to some embodiments, a vehicle having conditions for overcoming or at least mitigating at least some of the above disadvantages is provided. As a result, the above objective is achieved.

Optionally, the vehicle includes an electric traction motor configured to provide motive power to the vehicle. This provides a vehicle that offers the prerequisites for efficient, reliable and low-noise operation of the air compressor of the compressed air system of the bleed valve even in the absence of a running internal combustion engine.

Optionally, the vehicle includes at least one pneumatic actuator configured to use compressed air from the compressed air system as a power source. A vehicle is thereby provided that includes an efficient and reliable compressed air system for supplying one or more pneumatic actuators of the vehicle.

Optionally, the at least one pneumatic actuator is configured to move a component of the vehicle between at least two different positions. Thereby a vehicle is provided that includes an efficient and reliable compressed air system for operating one or more pneumatic actuators configured to move a component of the vehicle.

Other features and advantages of the present invention will become apparent from the appended claims and the detailed description that follows.

character list

• In 1 ein Fahrzeug gemäß einigen Ausführungsformen dargestellt ist,
• 2 schematisch einen Antriebsstrang und ein Druckluftsystem des in 1 dargestellten Fahrzeugs zeigt,
• 3 ein Verfahren zum Betreiben eines Druckluftsystems eines Fahrzeugs veranschaulicht, und
• 4 ein computerlesbares Medium zeigt.

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

• In 1 a vehicle is shown according to some embodiments,
• 2 schematically a drive train and a compressed air system of the in 1 vehicle shown shows
• 3 illustrates a method of operating a compressed air system of a vehicle, and
• 4 shows a computer-readable medium.

DETAILED DESCRIPTION

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

In 1 1 illustrates a vehicle 2 in accordance with some embodiments. According to the illustrated embodiments, the vehicle 2 is a truck, ie a heavy vehicle. According to further embodiments, the vehicle 2 described here may be another type of manned or unmanned vehicle for propulsion on land or water, e.g. B. a truck, a bus, a construction vehicle, a tractor, a car, a boat, a ship or the like.

The vehicle 2 includes a powertrain 10. The powertrain 10 is configured to provide motive power to the vehicle 2 via the wheels 17 of the vehicle 2, as further discussed herein.

2 shows schematically the drive train 10 and a compressed air system 1 of FIG 1 illustrated vehicle 2. In the following, unless otherwise stated, at the same time 1 and 2 referenced.

According to the illustrated embodiments, the powertrain 10 includes an electric drive motor 8 . The electric drive motor 8 is configured to provide motive power to the vehicle 2 via the wheels 17 of the vehicle 2 . The electric drive motor 8 can also be referred to as an electric drive machine or the like the. According to the illustrated embodiments, the powertrain 10 is a purely electric powertrain and does not include an internal combustion engine. According to further embodiments, the drive train 10 , as described herein, can be a so-called hybrid electric drive, which comprises an internal combustion engine in addition to the electric drive motor 8 in order to drive the vehicle 2 . Additionally, in accordance with some embodiments of the present disclosure, the powertrain 10 of the vehicle 2 described herein may include an internal combustion engine and may not include an electric traction motor.

In 2 the drive train 10 is shown with an electric drive motor 8 . However, the drive train 10 can also include more than one electric drive motor 8 . According to the illustrated embodiments, the powertrain 10 includes a transmission 19 . The transmission 19 is configured to transmit power between the electric traction motor 8 and one or more wheels 17 of the vehicle 2 .

The powertrain 10 includes a battery 9 . According to the illustrated embodiments, the battery 9 is a traction battery configured to power the electric traction motor 8 during operation of the vehicle 2 . The battery 9 can consist of a number of battery cells, such as. B. lithium-ion battery cells, lithium-polymer battery cells or nickel-metal hydride battery cells.

The electric drive motor 8 comprises a rotor 22 and a stator 24. The electric drive motor 8 is able to convert electrical energy into mechanical energy in the form of a rotation of the rotor 22. In addition, the electric drive motor 8 can be able to convert mechanical energy in the form of the rotation of the rotor 22 into electrical energy, which can be stored in the battery 9, for example. In this way, the electric drive motor 8 can ensure regenerative braking of the vehicle 2 .

According to the illustrated embodiments, the powertrain 10 includes a power module 23. The power module 23 is configured to control the amount of current supplied to the electric traction motor 8 by the battery. The stator 24 or rotor 22 may include a number of permanent magnets and the other of the stator 24 and rotor 22 may include wire windings. An alternating electrical current passed through the wire windings from the power module 23 causes a torque to be applied to the rotor 22 due to the magnetic interaction between the wire windings and the permanent magnets. During operation of the powertrain 10, the electrical current conducted through the wire windings is alternated in a manner that follows the rotation of the rotor 22. In this manner, a continuous torque can be applied to the rotor 22 as it rotates.

As mentioned above, the vehicle 2 includes a compressed air system 1. The compressed air system 1 includes an air processing element 5' and an air compressor 3 configured to compress air through the air processing element 5' during operation. According to the illustrated embodiments, the compressed air system 1 comprises an air processing unit 5 , the air processing element 5 ′ being contained in the air processing unit 5 . According to the illustrated embodiments, the air processing element 5' of the air processing unit 5 is further designed to dry, i.e. to dehumidify, the air compressed by the air compressor 3. The air processing element 5' referred to herein may be a replaceable element, such as a replaceable moisture absorbing cartridge or the like.

According to the illustrated embodiments, the compressed air system 1 comprises an accumulator 12. According to the illustrated embodiments, the accumulator 12 is a type of accumulator tank designed to hold compressed air. The pressure accumulator 12 can also be referred to as a pressure tank, pressure storage container or the like. The accumulator 12 includes a pressure relief valve 35. The pressure relief valve 35 is configured to open to atmosphere when the pressure in the accumulator 12 reaches a predetermined pressure. According to the illustrated embodiments, the compressed air system 1 comprises an air filter unit 25, wherein the air compressor 3 is configured to compress/pump air from the air filter unit 25 via the air processing element 5' of the air processing unit 5 into the accumulator 12.

According to the illustrated embodiments, the compressed air system 1 includes an electric motor 6 configured to drive the air compressor 3 . In other words, according to the illustrated embodiments, the air compressor 3 is an electrically driven air compressor 3. According to further embodiments, however, the air compressor 3 of the compressed air system 1 can also be driven in other ways, e.g. B. mechanical, hydraulic or the like.

The vehicle 2 may include at least one pneumatic actuator 11 configured to receive compressed air from the compressed air system tem 1 uses as an energy source. Additionally, the at least one pneumatic actuator 11 may be configured to move a component 13 of the vehicle 2 between at least two different positions. According to the illustrated embodiments, the vehicle 2 includes pneumatic brakes 26. More specifically, according to the illustrated embodiments, the vehicle 2 includes a pneumatic actuator 11 configured to move a component 13 in the form of a brake pad between an engaged position in which the brake pad brakes the rotation of a wheel 17 of the vehicle 2, and moves to a disengaged position in which the brake pad is moved to a position in which braking of the wheel 17 is released.

Alternatively or additionally, the vehicle 2 may include one or more other types of pneumatic actuators 16, each of which may be configured to move one or more other types of components of the vehicle 2 between different positions, using compressed air from the compressed air system 1 as a power source is used. By way of example only, such pneumatic actuators 16 may include a pneumatic actuator of a suspension system of the vehicle 2, a pneumatic actuator for opening and closing doors, panels, and the like of the vehicle 2. The pneumatic actuators 11, 16 are arranged downstream of the air processing element 5' of the air processing unit 5. In other words, the air processing element 5' of the air processing unit 5 is configured to process the air compressed by the air compressor 3 before the air is routed to the pneumatic actuators 11,16.

The compressed air system 1 also includes a vent valve 7. According to the illustrated embodiments, the vent valve 7 is an electronically controlled vent valve. The vent valve 7 can be controlled between an open state and a closed state. The vent valve 7 is configured such that, when open, it releases air from the compressed air system 1 to the environment. The vent valve 7 is arranged downstream of the air processing element 5' relative to a direction of air flow from the air compressor 3 through the air processing element 5'. In other words, the vent valve 7 is located after the air processing element 5' relative to the air flow direction from the air compressor 3 through the air processing element 5'.

The compressed air system 1 includes a control arrangement 21 which is set up to operate at least part of the compressed air system 1 . The control arrangement 21 is operationally connected to the vent valve 7 . According to the embodiments described herein, the control arrangement 21 is configured to control the vent valve 7 between the open and closed states based on data representing at least one of a previous, an ongoing and an upcoming accumulation of substances in at least one component 3, 5, 5' of the compressed air system 1. In this way, efficient and reliable removal of matter and/or prevention of the formation of matter in a large part of the compressed air system 1 can be provided, as will be explained further herein.

According to some embodiments, the control arrangement 21 is configured in such a way that it controls the vent valve 7 in the open state when the data shows at least one of a previous, an ongoing and an upcoming accumulation of substances in the at least one component 3, 5, 5' of the Show compressed air system 1. The previous, ongoing and/or forthcoming accumulation of substances in the at least one component 3, 5, 5' can, for example, result in ice formation in a component of the compressed air system 1, such as in the air processing unit 5, the air processing element 5' or in another part or a other components of the compressed air system 1 include. As a further example, the previous, ongoing and/or forthcoming accumulation of substances in the at least one component 3, 5, 5' can include, for example, water formation in the air compressor 3 of the compressed air system 1 or in another part or component of the compressed air system 1.

According to some embodiments, the control arrangement 21 is configured to obtain the data by sensing the temperature of at least a portion 59 of the compressed air system 1 . In other words, the data can be indicative of a temperature of the at least a portion 59 of the compressed air system 1 . More precisely, according to the illustrated embodiments, the compressed air system 1 comprises a temperature sensor 18 which is configured to detect a current temperature of a part 59 of the compressed air system 1, the control arrangement 21 being operatively connected to the temperature sensor 18 and being configured to receive the data from to get this. In this way, the control arrangement 21 can easily, efficiently and reliably obtain data indicative of at least one of a previous, a current and an impending accumulation of substances in the at least one component 3, 5, 5'. According to the illustrated embodiments, the part 59 of the compressed air system 1 is a Part of the air processing unit 5. However, according to further embodiments, the temperature sensor 18 may be configured to sense the temperature of another part of the compressed air system 1, another part of the powertrain 10 and/or another part of the vehicle 2 with the compressed air system 1.

Furthermore, according to some embodiments, the control arrangement 21 can receive data indicative of one of a previous, a current and an upcoming accumulation of substances in the at least one component 3, 5, 5' from a different type of device than a temperature sensor. For example, the control arrangement 21 can receive the data from an external device, such as an external transmitter. The data obtained can give an indication of a current or upcoming ambient temperature, an estimated current or upcoming ambient temperature or the like, which can also give an indication of the temperature of at least a part of the compressed air system 1 . As a further alternative or in addition, the data can be obtained by estimating or modeling the data. The data can be estimated/modeled using inputs such as calendar data, position data, historical accumulation data, historical temperature data, and the like.

According to some embodiments, the air compressor 3 is configured to operate when the air pressure in the compressed air system 1 is below a threshold pressure. As in 2 As can be seen, the compressed air system 1 according to the illustrated embodiments comprises a pressure sensor 14 which is configured to detect a current air pressure in the compressed air system 1 . According to the illustrated embodiments, the pressure sensor 14 is arranged in the pressure accumulator 12 and is thus designed to detect a current pressure in the pressure accumulator 12 . According to further embodiments, the pressure sensor 14 can be arranged on a different section of the compressed air system 1 . According to the illustrated embodiments, the control arrangement 21 is operationally connected to the pressure sensor 14 and configured to receive pressure data therefrom. Furthermore, according to the illustrated embodiments, the control arrangement 21 is configured to activate the operation of the air compressor 3 when the sensed current air pressure in the compressed air system 1 falls below the threshold pressure. The threshold pressure mentioned here can also be referred to as the first threshold pressure. In addition, the control arrangement 21 is configured to disable operation of the air compressor 3 when the sensed current air pressure in the compressed air system 1 rises above a second threshold pressure. In this way, the control arrangement 21 can use the data from the pressure sensor 14 to control the electric motor 3 in order to obtain a pressure in the compressed air system 1 within a predetermined pressure range. The second threshold pressure, ie the upper limit of the predetermined pressure range, may be lower than the predetermined pressure at which the pressure relief valve 35 is configured to open.

According to further embodiments, the operation of the air compressor 3 may be controlled by another type of device or control arrangement, for example a control arrangement arranged in the air compressor 3 and configured to activate the operation of the air compressor 3 when, for example, the air pressure at an outlet of the air compressor 3 falls below the threshold pressure.

According to some embodiments, the control arrangement 21 is configured to keep the vent valve 7 in the open state until the air pressure in the compressed air system 1 falls below the threshold pressure. This initiates the operation of the air compressor in a controlled manner to remove matter in the compressed air system 1 and/or prevent the formation of matter, as further explained herein. According to some embodiments, the control assembly 21 is also configured to keep the vent valve 7 open even when the air compressor 3 is operating. With prior art solutions, such an operation would entail the risk of damaging the air compressor 3 . However, since the vent valve 7 is located downstream of the air processing element 5', the air processing element 5' provides a flow resistance for the air compressor 3, so that the air compressor 3 can be operated even when the vent valve 7 is in the open state, without a Damage or wear of the air compressor 3 threatens.

In addition, since the vent valve 7 can be controlled or maintained in the open state even during operation of the air compressor 3, improved removal and/or prevention of matter in a larger portion of the compressed air system 1 can be achieved. That is, studies have shown that water can accumulate in the air compressor 3, which can damage the air compressor 3 and cause the compressed air system 1 to malfunction and/or the components/systems supplied by the compressed air system 1 to malfunction.

However, by the vent valve 7 during operation of the air compressor 3 in the can be controlled or maintained in the open state, water and moisture in the air compressor 3 can be efficiently removed.

By being able to control or maintain the vent valve 7 in the open state even during the operation of the air compressor 3, the air processing element 5' can be heated in an efficient manner, whereby ice in the air processing element 5' can be removed and/or its formation can be prevented. In addition, the efficient heating of the air processing element 5' creates the conditions for an efficient subsequent regeneration of the air processing element 5'.

The compressed air system 1 comprises a bleed valve 55. According to the illustrated embodiments, the bleed valve 55 is arranged on the air processing unit 5 at a position upstream of the air processing element 5', relative to an air flow direction from the air compressor 3 seen through the air processing element 5'. According to further embodiments, the compressed air system 1 can comprise a vent valve arranged at another position/location of the compressed air system, for example at a supply line 49 of the compressed air system 1 arranged between the air compressor 3 and the air processing unit 5 .

The control assembly 21 is operatively connected to the vent valve 55 and is configured to control the vent valve 55 between an open and a closed state. The vent valve 55 is configured to vent air from the compressed air system 1 when commanded open. The control arrangement is configured to perform regeneration of the air processing element 5' of the air processing unit 5 by controlling the vent valve 55 to the open state. According to the present embodiments, the control assembly 21 is configured to control the vent valve 55 to the open state during downtimes of the air compressor 3 . The control arrangement 21 can ensure that the air compressor 3 is not in operation by switching off the air compressor 3 .

When the vent valve 55 is controlled in the open state, compressed air from the accumulator 12 flows backwards through the air processing element 5' of the air processing unit 5 and out of the compressed air system 1 via the vent valve 55, i.e. it flows through the air processing element 5' in a direction corresponding to the direction of flow of the air obtained when the air compressor 3 compresses/pumps air through the air processing element 5'. In this way, the air processing element 5' is regenerated and substances such as water and moisture are efficiently removed from the air processing element 5'. By regenerating the air processing element 5', the service life of the air processing element 5' and the time available before the air processing element 5' needs to be replaced can be significantly increased.

In some embodiments, the air compressor 3 is a rotary compressor, e.g. B. a rotary screw compressor. A rotary compressor is a positive displacement compressor in which the compression of a fluid is achieved by at least one rotor, i. H. one or more rotating working elements, such as B. one or more screws or the like takes place. A rotary compressor lacks the reciprocating piston, connecting rod, and crank mechanism of a reciprocating compressor.

A rotary compressor is an efficient means of compressing air. Also, a rotary compressor typically generates less noise and vibration during operation than a reciprocating compressor. Also, a rotary compressor usually has a less fluctuating, i. H. More constant driving torque than a piston compressor, making it more suitable for being driven by an electric motor than a piston compressor.

A rotary compressor such as A screw compressor, however, is more sensitive to unrestrained operation, ie operation without significant back pressure at an outlet of the air compressor 3, compared to a reciprocating compressor. One reason for this is that rotary compressors depend on a lubricating film on one or more rotors. If the air compressor is operated with no back pressure at the outlet or with insufficient back pressure at the outlet, there is a risk that the film of lubricant will be removed from the one or more rotors. In this case, the lubricant can be transported out of the air compressor 3 via the outlet of the air compressor 3 together with the air flow. This can result in the one or more rotors being insufficiently lubricated, which can lead to wear and/or damage to the one or more rotors. In addition, lubricant leaking from the air compressor 3 may cause the compressed air system 1 to malfunction, for example by clogging components of the compressed air system 1 such as the air processing element 5' or other parts or components of the compressed air system 1. In addition, from the air compressor 3 escaping lubricant can reduce the Effect drying performance of the air processing element 5'.

However, since the vent valve 7, as explained above, is arranged downstream of the air processing element 5', the air processing element 5' represents a flow resistance for the air compressor 3. Thus, due to the characteristics of the compressed air system 1, the air compressor 3 can also be operated in the open state of the vent valve 7 without risk of damage or wear and tear of the air compressor 3 and without risk of subsequent malfunction of the compressed air system 1, even in embodiments where the air compressor 3 is a rotary compressor, such as a rotary compressor. B. a rotary screw compressor is.

In embodiments in which the air compressor 3 is a rotary compressor and in which the vehicle 2 with the compressed air system 1 is an at least partially electrically powered vehicle 2, the air compressor 3 can also be efficiently, reliably and quietly powered in the absence of a running internal combustion engine, for example with power from a battery 9 of the vehicle 2.

According to some embodiments, the bleed valve 7 is configured to restrictively bleed air from the compressed air system 1 to create a back pressure to the air compressor 3 when the bleed valve 7 is in the open state. In this way it is further ensured that the air compressor can also be operated when the vent valve 7 is in the open state, without there being any risk of damage or wear and tear to the air compressor 3 and subsequent malfunction of the compressed air system 1 . This is because the restrictive ventilation of the ventilation valve 7 can ensure sufficient back pressure in the supply line 49 of the compressed air system 1 arranged between the air compressor 3 and the air processing unit 5 during the operation of the air compressor 3 . The bleed valve 7 may be configured to restrictively bleed air from the compressed air system 1 to create back pressure to the air compressor 3 by having a smaller effective cross-sectional area when open than an effective cross-sectional area of the supply line 49 between the air compressor 3 and the Air processing unit 5. According to some embodiments, the vent valve 7 has an effective cross-sectional area that is less than 50% or less than 25% of an effective cross-sectional area of the supply line 49 in the open state.

According to the illustrated embodiments, the supply line 49 is connected to an inlet opening 50 of the air processing unit 5 . As in 2 As can be seen, the air processing unit 5 also comprises a plurality of outlet ports 51-54. In the illustrated embodiments, one outlet port 51 is connected to the accumulator 12 and two outlet ports 52, 53 are connected to a pneumatic actuator 11, 16, respectively. As in 2 As can be seen, the vent valve 7 according to the illustrated embodiments is also part of an outlet port 54 of the air processing unit 5. If the air processing unit 5 is included in a compressed air system with a mechanically driven air compressor, the outlet port 54 can be used as an outlet port for a pneumatic control signal. However, since the compressed air system 1 according to the illustrated embodiments comprises an electrically driven air processing unit 5, the outlet opening 54 is not required for the output of a pneumatic control signal. By using the outlet opening 54 of the air processing unit 5 for venting the compressed air system 1, a compact compressed air system 1 is thus provided which has conditions and properties which are suitable for cost-effective manufacture and assembly.

• - Steuern 120 des Entlüftungsventils 7 zwischen dem offenen und dem geschlossenen Zustand auf der Grundlage von Daten, die auf mindestens eine von einer vorangegangenen, einer laufenden und einer bevorstehenden Ansammlung von Stoffen in mindestens einer Komponente 3, 5, 5' des Druckluftsystems 1 hinweisen.

3 FIG. 1 shows a method 100 for operating a compressed air system of a vehicle. The compressed air system can be a compressed air system 1 according to in 2 be illustrated embodiments. Furthermore, the vehicle can be a vehicle 2 in accordance with 1 illustrated embodiments act. Therefore, in the following at the same time 1 - 3 Referenced unless otherwise noted. Method 100 is a method of operating a compressed air system 1 of a vehicle 2, the compressed air system 1 having an air processing element 5', an air compressor 3 configured to compress air through the air processing element 5' during operation, and a vent valve 7 that is controllable between an open state and a closed state. The vent valve 7 is configured to vent air from the compressed air system 1 to atmosphere when commanded open. The vent valve 7 is arranged downstream of the air processing element 5' relative to a direction of air flow from the air compressor 3 through the air processing element 5'. The method 100 includes the step:

• - Controlling 120 the vent valve 7 between the open and the closed state on the basis of data relating to at least one of a previous, a current and an upcoming accumulation Development of substances in at least one component 3, 5, 5 'of the compressed air system 1 indicate.

• - Erhalten von 110 Daten, die auf mindestens eine von einer vorangegangenen, einer laufenden und einer bevorstehenden Ansammlung von Stoffen in mindestens einer Komponente 3, 5, 5' des Druckluftsystems 1 hinweisen.

As in 3 illustrated, the procedure may include the following step:

• - Obtaining 110 data indicative of at least one of a previous, a current and a forthcoming accumulation of substances in at least one component 3, 5, 5' of the compressed air system 1.

The step of obtaining 110 the data is preferably performed before or at the same time as the step of controlling 120 the vent valve 7 between the open and the closed state. The step of obtaining 110 the data may include a step of retrieving the data from a device of the compressed air system 1 or from an external device or system. Alternatively or additionally, the step of obtaining 110 the data may include a step of estimating or modeling the data.

• - Steuern 122 des Entlüftungsventils 7 in den offenen Zustand, wenn die Daten mindestens eine von einer vorangegangenen, einer laufenden oder einer bevorstehenden Ansammlung von Stoffen in dem mindestens einen Bauteil 3, 5, 5' anzeigen.

As in 3 As illustrated, the method 100 may include the following step:

• - Controlling 122 the vent valve 7 in the open state if the data indicate at least one of a previous, an ongoing or an imminent accumulation of substances in the at least one component 3, 5, 5'.

• - Halten 124 das Entlüftungsventil 7 im offenen Zustand, bis der Luftdruck im Druckluftsystem 1 unter den Schwellendruck sinkt.

According to some embodiments, the air compressor 3 is configured to operate when an air pressure in the compressed air system 1 is below a threshold pressure, and the method 100 may include the following step:

• - Maintain 124 the vent valve 7 in the open state until the air pressure in the compressed air system 1 falls below the threshold pressure.

• - Halten 126 das Entlüftungsventil 7 auch bei Betrieb des Luftkompressors 3 im offenen Zustand.

In addition, the method 100, as in 3 illustrated, include the following step:

• - Keep 126 the vent valve 7 in the open state even when the air compressor 3 is in operation.

In some embodiments, the data provides information about the temperature of at least a part 59 of the compressed air system 1.

• - Erhalten der Daten 112 durch Erfassen der Temperatur von mindestens einem Teil 59 des Druckluftsystems 1.

As in 3 As illustrated, the step of obtaining 110 data may also include the step of:

• - obtaining the data 112 by detecting the temperature of at least a part 59 of the compressed air system 1.

It becomes clear that the various embodiments that have been described for the method 100 can all be combined with the control arrangement 21 described here. That is, the control arrangement 21 can be configured to carry out any of the method steps 110 , 112 , 120 , 122 , 124 and 126 of the method 100 .

4 1 shows a computer-readable medium 200 that includes instructions that, when executed by a computer, cause the computer to perform method 100, according to some embodiments.

According to some embodiments, the computer-readable medium 200 includes a computer program having instructions that, when the program is executed by a computer, cause the computer to perform the method 100 according to some embodiments.

The control assembly 21 described herein may be included in the vehicle 2 and connected to one or more components of the vehicle 2, such as one or more components of the powertrain 10 of the vehicle 2 and/or one or more components of the compressed air system 1 of the vehicle 2, to this in 3 to carry out the method 100 shown. Those skilled in the art will understand that the method 100 for operating a compressed air system 1 of a vehicle 2 can be implemented through programmed instructions. These programmed instructions are typically formed by a computer program which, when executed in the control arrangement 21, causes the control arrangement 21 to carry out the desired control, such as method steps 110, 112, 120, 122, 124 and 126 described herein . The computer program is typically part of a computer program product 200, which includes a suitable digital storage medium on which the computer program is stored.

The control arrangement 21 may comprise a computing unit which may essentially take the form of any suitable type of processor circuit or microcomputer, e.g. B. a digital signal processing circuit (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 can interpret and execute instructions . The term "processing unit" as used herein can represent a processing circuit that includes a plurality of processing circuits, such as. B. one, some or all of the above.

The control arrangement 21 can also include a storage unit, wherein the processing unit can be connected to the storage unit, which can supply the processing unit, for example, with stored program code and/or stored data that the processing unit needs in order to be able to carry out calculations. The computing unit can also be suitable for storing partial or final results of calculations in the memory unit. The storage unit may comprise a physical device used for temporary or permanent storage of data or programs, ie sequences of instructions. According to some embodiments, the memory unit may include integrated circuits with silicon-based transistors. The storage unit can e.g. B. a memory card, a flash memory, a USB memory, a hard drive or other similar volatile or non-volatile memory device for storing data such. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in various embodiments.

The control arrangement 21 is connected to components of the compressed air system 1 and/or the vehicle 2 in order to receive and/or send input and output signals. These input and output signals can be waveforms, pulses or other attributes which can be recognized as information by the input signal receivers and converted into signals which can be processed by the control arrangement 21 . These signals can then be fed to the computing unit. One or more output signal transmission devices may be arranged to convert the calculation results of the computing unit into output signals which are forwarded to other parts of the vehicle control system and/or the component or components for which the signals are intended. Each of the connections to the respective components of the compressed air system 1 and/or the vehicle 2 for receiving and sending input and output signals can take the form of one or more cables, a data bus, e.g. a CAN (Controller Area Network) bus, a MOST (Media Orientated Systems Transport) bus or other bus configuration, or a wireless connection.

In the illustrated embodiments, the vehicle 2 includes a control arrangement 21, but can also be fully or partially equipped with two or more control arrangements or two or more control units.

Control systems in modern vehicles typically include a communication bus system consisting of one or more communication buses to connect a number of electronic control units (ECUs) or controllers to various components on board the vehicle. Such a control system may include a large number of controllers and the execution of a particular function may be shared between two or more of them. Vehicles of the type considered here are therefore often equipped with significantly more control arrangements than in 2 presented as a person skilled in the art would surely appreciate.

The computer program product 200 can be provided, for example, in the form of a data carrier that carries the computer program code for carrying out at least some of the method steps 110, 112, 120, 122, 124 and 126 according to some embodiments when it is loaded into one or more computing units of the control arrangement 21. The data carrier can be a CD-ROM, for example, as shown in 4 or a ROM (read-only memory), a PROM (programmable read-only memory), an EPROM (erasable PROM), a flash memory, an EEPROM (electrically erasable PROM), a hard disk, a memory Stick, optical storage medium, magnetic storage medium, or other suitable medium, such as disk or tape, that can contain machine-readable data in a non-transitory manner. The computer program product can also be provided as computer program code on a server and remotely, e.g. B. via an Internet or intranet connection or via other wired or wireless communication systems, are downloaded to the control arrangement 21.

The compressed air system 1 described here can also be referred to as a pneumatic system.

As used herein, the terms "upstream" and "downstream" refer to the relative positions of objects with respect to an intended direction of flow of fluid in the system or circuit in question. For example, the feature that a first object is located upstream of a second object in a circuit means that the first object is located in front of the second object relative to the intended direction of flow of fluid through the circuit. Another example: the feature that a first object is located downstream of a second object in a circuit means that the first object is located after the second object with respect to the intended flow direction of the fluid through the circuit.

It should be understood that the foregoing illustrates various embodiments and that the invention is defined solely by the appended independent claims. Those skilled in the art will recognize that the exemplary embodiments can be modified and that various features of the exemplary embodiments can 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 "comprising" is open-ended and includes one or more specified features, elements, steps, components, or functions, but includes the presence or addition of one or more other features, elements, steps, components , functions or groups do not assume this.

Claims (17)

Method (100) for operating a compressed air system (1) of a vehicle (2), the compressed air system (1) comprising: - an air processing element (5'), - an air compressor (3) configured to compress air through the air processing element (5') during operation, and - a bleed valve (7) controllable between an open and a closed state, the bleed valve (7) being configured to bleed air from the compressed air system (1) to atmosphere when controlled to the open state, wherein the vent valve (7) is arranged downstream of the air processing element (5') as seen with respect to an air flow direction from the air compressor (3) through the air processing element (5'), and the method (100) comprising the step of: - controlling (120) the vent valve (7) between the open and the closed state on the basis of data representing at least one of a previous, an ongoing and an upcoming accumulation of substances in at least one component (3, 5, 5') of the compressed air system (1 ). Method (100) according to claim 1 , wherein the method (100) comprises the following step: - Controlling (122) the vent valve (7) in the open state when the data at least one of a previous, a current and an upcoming accumulation of substances in the at least one component ( 3, 5, 5'). Method (100) according to claim 1 or 2 , wherein the air compressor (3) is configured to operate when an air pressure in the compressed air system (1) is below a threshold pressure, and wherein the method (100) comprises the following step: - holding (124) the vent valve (7) in the open state until the air pressure in the compressed air system (1) falls below the threshold pressure. Method (100) according to any one of the preceding claims, wherein the method (100) comprises the following step: - Keeping (126) the vent valve (7) open even when the air compressor (3) is in operation. A method (100) as claimed in any preceding claim, wherein the data is indicative of a temperature of at least a portion (59) of the compressed air system (1). Method (100) according to any one of the preceding claims, wherein the method (100) comprises the following step: - Obtaining (112) the data by detecting the temperature of at least a part (59) of the compressed air system (1). Computer program with instructions which, when the program is executed by a computer, cause the computer to perform the method (100) according to any one of Claims 1 until 6 to execute. A computer-readable medium (200) having instructions which, when executed by a computer, cause the computer to carry out the method (100) according to any one of Claims 1 until 6 to execute. Control arrangement (21) for operating a compressed air system (1) of a vehicle (2), the compressed air system (1) comprising: - an air processing element (5'), - an air compressor (3) configured to force air through the air processing element ( 5') to compress, and - a vent valve (7) controllable between an open and a closed state, the vent valve (7) being configured to vent air from the compressed air system (1) to the atmosphere when it is controlled to the open state, wherein the vent valve (7) is arranged downstream of the air processing element (5'), seen with respect to an air flow direction from the air compressor (3) through the air processing element (5'), and wherein the control arrangement (21) is configured is to the vent valve (7) between the open and to control the closed condition on the basis of data indicative of at least one of a previous, an ongoing and an impending accumulation of substances in at least one component (3, 5, 5') of the compressed air system (1). Compressed air system (1) for a vehicle (2), the compressed air system (1) comprising: - an air processing element (5'), - an air compressor (3) configured to compress air through the air processing element (5'), and - a vent valve (7) controllable between an open and a closed condition, the vent valve (7) being configured to vent air from the compressed air system (1) to atmosphere when controlled to the open condition , wherein the vent valve (7) is arranged downstream of the air processing element (5'), seen in relation to an air flow direction from the air compressor (3) through the air processing element (5'), and wherein the compressed air system (1) has a control arrangement (21). claim 9 includes. Compressed air system (1) after claim 10 wherein the compressed air system (1) comprises an air processing unit (5) comprising the air processing element (5'), and wherein the vent valve (7) forms part of an outlet opening (54) of the air processing unit (5). Compressed air system (1) after claim 10 or 11 , wherein the vent valve (7) is an electronically controlled valve. Compressed air system (1) according to one of Claims 10 until 12 wherein the compressed air system (1) comprises an electric motor (6) configured to drive the air compressor (3). Compressed air system (1) according to one of Claims 10 until 13 , wherein the air compressor (3) is a rotary compressor. Compressed air system (1) according to one of Claims 10 until 14 wherein the vent valve (7) is configured to restrictively vent air from the compressed air system (1) when open to create a back pressure to the air compressor (3). Vehicle (2) with a compressed air system (1) according to one of Claims 10 until 15 . Vehicle (2) after Claim 16 wherein the vehicle (2) comprises an electric traction motor (8) configured to provide motive power to the vehicle (2).

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