SE2151133A1

SE2151133A1 - Method of Operating a Compressed Air System, Computer Program, Computer-Readable Medium, Control Arrangement, Compressed Air System, and Vehicle

Info

Publication number: SE2151133A1
Application number: SE2151133A
Authority: SE
Inventors: Erik Bergenlid; Martin Fellke; Pawandeep Dhanoa; Richard Hellstrand
Original assignee: Scania Cv Ab
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2023-03-16
Also published as: DE102022121308A1; SE545395C2

Abstract

A method (100) of 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 venting valve (7) arranged downstream of the air processing element (5’). The method (100) comprises the step of controlling (120) the venting valve (7) between open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming 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

1 Method of Operating a Compressed Air System, Computer Program, Computer-Readable Medium, Control Arrangement, Compressed Air System, and Vehicle TECHNICAL FIELD 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 comprising a compressed air system.

BACKGROUND Compressed air systems, also known as pneumatic systems, can be used in vehicles for powering various systems and arrangements of the vehicle. Examples are brake systems, suspension systems, different types of pneumatic actuators for opening and closing doors, panels, and the like.

Normally, a compressed air system comprises an air compressor and a pressure reservoir wherein the air compressor is configured to compress air to the pressure reservoir. The air compressor is typically operated such that the pressure in the compressed air system is kept within a predetermined pressure range having an upper and a lower pressure limit.

Moreover, in many cases, a compressed air system comprises an air processing unit configured to process air compressed by the air compressor before the air is led to various systems and/or to the pressure reservoir. The air processing unit may comprise one or more air dryer units configured to dry air compressed by the air compressor.

A problem associated with compressed air systems of vehicles is accumulation of matter in components of the compressed air system. As an example, in some conditions, such as during cold ambient temperatures, ice may form in components of the compressed air system, such as in the air compressor and in the air processing unit. The formation of ice may cause malfunctions of the compressed air system and of arrangements/systems powered by the compressed air system.

A known approach to counter this problem is to activate and run the air compressor continuously while the air pressure in the compressed air system is regulated by opening a valve arranged between the air compressor and air processing unit. This valve exhausts the 2 pressure in the supply line to the atmosphere. ln this manner, the air compressor can be operated to heat the compressed air system.

However, this approach is associated with some problems and drawbacks. As an example, the approach provides a limited ability to remove accumulated matter from the compressed air system. Moreover, the approach may put strain on components of the compressed air system, especially the air compressor of the compressed air system.

Furthermore, generally, on today's consumer market, it is an advantage if products, such as vehicles and associated components, systems, and arrangements, have conditions and/or characteristics suitable for being manufactured and assembled in a cost-efficient manner.

SUMMARY lt 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 a compressed air system of a vehicle. The compressed air system comprises an air processing element, an air compressor configured to compress air through the air processing element during operation, and a venting valve controllable between an open state and a closed state. The venting valve is configured to vent air from the compressed air system to the surroundings when being controlled to the open state. The venting valve is arranged downstream of the air processing element as seen relative to an airflow direction from the air compressor through the air processing element. The method comprises the step of: - controlling the venting valve between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component of the compressed air system.

Since the venting valve is arranged downstream of the air processing element and since the method comprises the step of controlling the venting valve between the open and closed states based on the data, a method is provided capable of exhausting air from the compressed air system in a manner being less dependent on the operational status of the air COITIDFGSSOF.

That is, a method is provided allowing air to be exhausted from the compressed air system by controlling the venting valve to the open state, and/or by maintaining the venting valve in 3 the open state, also when the air Compressor is operating without risking damage or wear of the air compressor. This is because the air processing element can provide a flow resistance for the air compressor also when the venting valve is controlled to the open state.

As a further result thereof, a method is provided offering more freedom in the choice of type of air compressor. ln other words, the method is provided allowing the use of an air compressor being more sensitive to unrestricted operation, such as a rotary compressor, or the like.

Furthermore, since the method allows the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, a method is provided having conditions for an improved removal of, and/or prevention of, matter in a larger part of the compressed air system. That is, studies have shown that water may accumulate in the air compressor, which can damage the air compressor and can cause malfunctions of the compressed air system and of components/systems powered by the compressed air system. However, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, water and moisture in the air compressor can be removed in an efficient manner. ln addition, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, the air processing element can be heated in an efficient manner which can remove, and/or prevent formation of, ice in the air processing element. ln addition, the efficient heating of the air processing element provides conditions for an efficient subsequent regeneration of the air processing element.

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.

Optionally, the method comprises the step of: - controlling the venting valve to the open state if the data indicates at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component.

Thereby, an efficient method is provided capable of removing, and/or preventing formation of, matter in a large part of the compressed air system. 4 Optionally, the air Compressor is configured to operate when an air pressure in the compressed air system is below a threshold pressure, and wherein the method comprises the step of: - maintaining the venting valve in the open state until the air pressure in the compressed air system declines below the threshold pressure.

Thereby, a method is provided capable of activating operation of the air compressor in a simple and controlled manner so as to remove, and/or prevent formation of, matter in a large part of the compressed air system in an efficient manner.

Optionally, the method comprises the step of: - maintaining the venting valve in the open state also when the air compressor is operating.

Thereby, a method is provided having conditions for an improved removal of, and/or prevention of, matter in a larger part of the compressed air system, including removal, and/or prevention of, water and moisture in the air compressor of the compressed air system. l\/loreover, a method is provided capable of heating the air processing element in an efficient manner which can remove, and/or prevent formation of, ice in the air processing element. ln addition, the efficient heating of the air processing element provides conditions for an efficient subsequent regeneration of the air processing element. l\/loreover, as explained above, because the venting valve is arranged downstream of the air processing element, the air processing element provides a flow resistance for the air compressor also when the venting valve is in the open state. Thereby, the air compressor can be operating without risking damage or wear of the air compressor.

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

Thereby, the venting valve can be controlled in an accurate manner between the open and closed states to obtain an efficient and reliable removal of matter, and/or prevention of formation of matter, in large part of the compressed air system.

Optionally, the method comprises the step of: - obtaining the data by sensing the temperature of at least one portion of the compressed air system.

Thereby, accurate data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter is obtained in a simple manner. As an alternative, or in addition, the data may be obtained in another manner, such as by an estimation/modelling of 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 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 described herein, 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 described herein, 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 for operating a compressed air system of a vehicle. The compressed air system comprises an air processing element, an air compressor configured to compress air through the air processing element, and a venting valve controllable between an open state and a closed state. The venting valve is configured to vent air from the compressed air system to the 6 surroundings when being controlled to the open state. The venting valve is arranged downstream of the air processing element as seen relative to an airflow direction from the air compressor through the air processing element. The control arrangement is configured to control the venting valve between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component of the compressed air system.

Since the venting valve is arranged downstream of the air processing element and since the control arrangement is configured to control the venting valve between the open and closed states based on the data, a control arrangement is provided capable of exhausting air from the compressed air system in a manner being less dependent on the operational status of the air compressor.

That is, a control arrangement is provided allowing air to be exhausted from the compressed air system by controlling the venting valve to the open state, and/or maintaining the venting valve in the open state, also when the air compressor is operating without risking damage or wear of the air compressor. This is because the air processing element provides a flow resistance for the air compressor when the venting valve is controlled to the open state.

As a further result thereof, a control arrangement is provided offering more freedom in the choice of type of air compressor. ln other words, the control arrangement is provided allowing the use of an air compressor being more sensitive to unrestricted operation, such as a rotary compressor, or the like.

Furthermore, since the control arrangement allows the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, a control arrangement is provided having conditions for an improved removal of, and/or prevention of, matter in a larger part of the compressed air system. That is, studies have shown that water may accumulate in the air compressor, which can damage the air compressor and can cause malfunctions of the compressed air system and of components/systems powered by the compressed air system. However, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, water and moisture in the air compressor can be removed in an efficient manner. ln addition, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, the air processing element can be heated in an efficient manner which can remove, and/or prevent formation of, ice in the air processing 7 element. ln addition, the efficient heating of the air processing element provides conditions for an efficient subsequent regeneration of the air processing element.

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. lt 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 compressed air system for a vehicle. The compressed air system comprises an air processing element, an air compressor configured to compress air through the air processing element, and a venting valve controllable between an open state and a closed state. The venting valve is configured to vent air from the compressed air system to the surroundings when being controlled to the open state. The venting valve is arranged downstream of the air processing element as seen relative to an airflow direction from the air compressor through the air processing element. The compressed air system comprises a control arrangement configured to control the venting valve between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component of the compressed air system.

Since the venting valve is arranged downstream of the air processing element and since the control arrangement of the compressed air system is configured to control the venting valve between the open and closed states based on the data, a compressed air system is provided capable of exhausting air from the compressed air system in a manner being less dependent on the operational status of the air compressor of the compressed air system.

That is, a compressed air system is provided allowing air to be exhausted from the compressed air system by a control of the venting valve to the open state, and/or by maintaining the venting valve in the open state, also when the air compressor is operating without risking damage or wear of the air compressor. This is because the air processing element provides a flow resistance for the air compressor when the venting valve is controlled to the open state. 8 As a further result thereof, a compressed air system is provided offering more freedom in the choice of type of air compressor for the compressed air system. ln other words, the compressed air system is provided allowing the use of an air compressor being more sensitive to unrestricted operation, such as a rotary compressor, or the like.

Furthermore, since the compressed air system allows the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, a compressed air system is provided having conditions for an improved removal of, and/or prevention of, matter in a larger part of the compressed air system. That is, studies have shown that water may accumulate in the air compressor, which can damage the air compressor and can cause malfunctions of the compressed air system and of components/systems powered by the compressed air system. However, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, water and moisture in the air compressor can be removed in an efficient manner. ln addition, by allowing the venting valve to be controlled to, or maintained in, the open state also when the air compressor is operating, the air processing element can be heated in an efficient manner which can remove, and/or prevent formation of, ice in the air processing element. ln addition, the efficient heating of the air processing element provides conditions for an efficient subsequent regeneration of the air processing element of the compressed air system.

Accordingly, a compressed air system 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. lt 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 of the compressed air system according to the fifth 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.

Optionally, the compressed air system comprises an air processing unit comprising the air processing element, and wherein the venting valve form part of an outlet port of the air processing unit. Thereby, conditions are provided for a compact and efficient compressed air system. l\/loreover, a compressed air system is provided having conditions and characteristics suitable for being manufactured and assembled in a cost-efficient manner. 9 This is because an outlet port of the air processing unit, which can be used for other purposes in other types of compressed air systems, is used to vent air from the compressed air system to the surroundings.

Optionally, the venting valve is an electronically controlled valve. Thereby, conditions are provided for an accurate and reliable control of the venting valve for an efficient removal of, and/or prevention of, matter in a larger part of the compressed air system.

Optionally, the compressed air system comprises an electric motor configured to power the air compressor. Thereby, conditions are provided for operating the air compressor without the need for a running internal combustion engine. Thus, a compressed air system is provided capable of obtaining an efficient removal of, and/or prevention of, matter in a larger part of the compressed air system without the need for a running internal combustion engine.

Optionally, the air compressor is a rotary compressor. Thereby, a compressed air system is provided comprising an efficient and reliable air compressor. l\/loreover, a compressed air system is provided comprising an air compressor having conditions for generating low noise levels during operation. ln this manner, the air compressor can be operated also in the absence of a running combustion engine without significantly increasing the noise levels generated by a vehicle comprising the compressed air system.

A rotary compressor is a positive-displacement compressor in which compression of a fluid is performed by at least one rotor, i.e. one or more rotating working members, such as one or more screws, or the like. A rotary compressor, such as a rotary screw compressor, is sensitive to unrestricted operation, i.e. operation without a significant back pressure at an outlet of the air compressor. One reason for this is that these types of compressors are dependent on a lubrication film on one or more rotors of the air compressor. lf the air compressor is operated without a back pressure at the outlet or is operated with too low back pressure at the outlet, there is a risk that the lubricant film is removed from the one or more rotors. lf so, the lubricant may be transported out from the air compressor with the air stream via the outlet of the air compressor. As a result thereof, the one or more rotors may become insufficiently lubricated, which can cause wear and/or damage of the one or more rotors. l\/loreover, the lubricant transported out from the air compressor may disturb operation of the compressed air system, such as clogging the air processing element or other parts or components of the compressed air system. Furthermore, lubricant transported out from the air compressor may cause a reduction in a drying capacity of the air processing element.

However, as explained above, since the venting valve is arranged downstream of the air processing element, the air processing element provides a flow resistance for the air compressor also when the venting valve is in the open state. Thus, due to the features of the compressed air system, the air compressor can be operated also when the venting valve is in the open state without risking damage or wear of the air compressor and without risking a subsequent malfunction of the compressed air system.

Optionally, the venting valve is configured to vent air from the compressed air system in a restrictive manner when in the open state to generate a back pressure to the air compressor. Thereby, it is further ensured that the air compressor can be operated also when the venting valve is in the open state without risking damage or wear of the air compressor and without risking a subsequent malfunction of the compressed air system.

According to a sixth aspect of the invention, the object is achieved by a vehicle comprising a compressed air system according to some embodiments of the present disclosure. Since the vehicle comprises a compressed air system according to some embodiments, a vehicle is provided having conditions for overcoming, or at least alleviating, at least some of the above- mentioned drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the vehicle comprises an electric propulsion motor configured to provide motive power to the vehicle. Thereby, a vehicle is provided having conditions for an efficient, reliable, and silent operation of the air compressor of the compressed air system of the venting valve also in the absence of a running combustion engine.

Optionally, the vehicle comprises at least one pneumatic actuator configured to use compressed air from the compressed air system as a source of power. Thereby, a vehicle is provided comprising an efficient and reliable compressed air system for powering 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 comprising an efficient and reliable compressed air system for powering one or more pneumatic actuators configured to move a component of the vehicle.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description. 11 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 illustrates a vehicle according to some embodiments, Fig. 2 schematically illustrates a powertrain and a compressed air system of the vehicle illustrated in Fig. 1, Fig. 3 illustrates a method of operating a compressed air system of a vehicle, and Fig. 4 illustrates computer-readable medium.

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

Fig. 1 illustrates a vehicle 2 according to some embodiments. According to the illustrated embodiments, the vehicle 2 is a truck, i.e. a heavy vehicle. According to further embodiments, the vehicle 2, as referred to herein, may be another type of manned or unmanned vehicle for land or water-based propulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, a boat, a ship, or the like.

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

Fig. 2 schematically illustrates the powertrain 10 and a compressed air system 1 of the vehicle 2 illustrated in Fig. 1. Below, simultaneous reference is made to Fig. 1 and Fig. 2, if not indicated otherwise.

According to the illustrated embodiments, the powertrain 10 comprises an electric propulsion motor 8. The electric propulsion motor 8 is configured to provide motive power to the vehicle 2 via wheels 17 of the vehicle 2. The electric propulsion motor 8 may also be referred to as an electric propulsion machine, or the like. According to the illustrated embodiments, the powertrain 10 is a pure electric powertrain and comprise no internal combustion engine. According to further embodiments, the powertrain 10, as referred to herein, may be a so called hybrid electric powertrain comprising an internal combustion engine in addition to the electric propulsion motor 8 for providing motive power to the vehicle 2. Moreover, according 12 to some embodiments of the present disclosure, the powertrain 10 of the vehicle 2, as referred to herein, may comprise an internal combustion engine and may lack an electric propulsion motor. ln Fig. 2, the powertrain 10 is illustrated as comprising one electric propulsion motor 8. However, the powertrain 10 may comprise more than one electric propulsion motor 8. According to the illustrated embodiments, the powertrain 10 comprises a transmission 19. The transmission 19 is configured to transmit power between the electric propulsion motor 8 and one or more wheels 17 of the vehicle 2.

The powertrain 10 comprises a battery 9. According to the illustrated embodiments, the battery 9 is a propulsion battery configured to supply electricity to the electric propulsion motor 8 during operation of the vehicle 2. The battery 9 may comprise a number of battery cells, such as lithium-ion battery cells, lithium polymer batteries cells, or nickel-metal hydride battery cells.

The electric propulsion motor 8 comprises a rotor 22 and a stator 24. The electric propulsion motor 8 is capable of converting electrical energy into mechanical energy in the form of rotation of the rotor 22. l\/loreover, the electric propulsion motor 8 may be capable of converting mechanical energy in the form of rotation of the rotor 22 into electrical energy which for example can be stored in the battery 9. ln this manner the electric propulsion motor 8 may provide regenerative braking of the vehicle 2.

According to the illustrated embodiments, the powertrain 10 comprises a power module 23. The power module 23 is configured to control the amount of electricity supplied from the battery to the electric propulsion motor 8. One of the stator 24 and the rotor 22 may comprise a number of permanent magnets and the other of the stator 24 and the rotor 22 may comprise wire windings. An alternating electric current passed through the wire windings by 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 electric current passed through the wire windings is alternated in a manner following the rotation of the rotor 22. ln this manner, a continuous torque can be applied to the rotor 22 during rotation thereof.

As indicated above, the vehicle 2 comprises a compressed air system 1. The compressed air system 1 comprises 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 13 illustrated embodiments, the compressed air system 1 comprises an air processing unit 5, wherein the air processing element 5' is comprised in the air processing unit 5. Moreover, according to the illustrated embodiments, the air processing element 5' of the air processing unit 5 is configured to dry, i.e. dehumidify, air compressed by the air compressor 3. The air processing element 5', as 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 a pressure reservoir 12. According to the illustrated embodiments, the pressure reservoir 12 is a type of pressure accumulator tank configured to hold pressurized air. The pressure reservoir 12 may also be referred to as a pressure tank, a pressure accumulator tank, or the like. The pressure reservoir 12 comprises a pressure relief valve 35. The pressure relief valve 35 is configured to open to the surroundings when the pressure in the pressure reservoir 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 to the pressure reservoir 12 via the air processing element 5' of the air processing unit 5.

According to the illustrated embodiments, the compressed air system 1 comprises an electric motor 6 configured to power the air compressor 3. ln other words, according to the illustrated embodiments, the air compressor 3 is an electrically driven air compressor 3. However, according to further embodiments, the air compressor 3 of the compressed air system 1 may be driven in another manner, such as mechanically, hydraulically, or the like.

The vehicle 2 may comprise at least one pneumatic actuator 11 configured to use compressed air from the compressed air system 1 as a source of power. Moreover, 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 comprises pneumatic brakes 26. ln more detail, according to the illustrated embodiments, the vehicle 2 comprises 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 rotation of a wheel 17 of the vehicle 2, and a disengaged position, in which the brake pad is moved to a position in which braking of the wheel 17 is cancelled.

As an alternative, or in addition, the vehicle 2 may comprise one or more other types of pneumatic actuators 16 which each may be configured to move one or more other types of components of the vehicle 2 between different positions using compressed air from the 14 compressed air system 1 as a source of power. Purely as examples, such pneumatic actuators 16 may comprise 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. ln other words, the air processing element 5' of the air processing unit 5 is configured to process air compressed by the air compressor 3 before the air is led to the pneumatic actuators 11, 16.

The compressed air system 1 further comprises a venting valve 7. According to the illustrated embodiments, the venting valve 7 is an electronically controlled venting valve. The venting valve 7 is controllable between an open state and a closed state. The venting valve 7 is configured to vent air from the compressed air system 1 to the surroundings when being controlled to the open state. The venting valve 7 is arranged downstream of the air processing element 5' as seen relative to an airflow direction from the air compressor 3 through the air processing element 5'. ln other words, the venting valve 7 is arranged after the air processing element 5' seen relative to the airflow direction from the air compressor 3 through the air processing element 5'.

The compressed air system 1 comprises a control arrangement 21 configured to operate at least part of the compressed air system 1. The control arrangement 21 is operably connected to the venting valve 7. According to embodiments herein, the control arrangement 21 is configured to control the venting valve 7 between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component 3, 5, 5' of the compressed air system 1. ln this manner, an efficient and reliable removal of matter, and/or prevention of formation of matter, can be provided in large part of the compressed air system 1, as is further explained herein.

According to some embodiments, the control arrangement 21 is configured to control the venting valve 7 to the open state if the data indicates at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component 3, 5, 5' of the compressed air system 1. The preceding, ongoing, and/or upcoming accumulation of matter in the at least one component 3, 5, 5' may for example comprise formation of ice 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 component of the compressed air system 1. As another example, the preceding, ongoing and/or upcoming accumulation of matter in the at least one component 3, 5, 5' may for example comprise formation of water 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 one portion 59 of the compressed air system 1. ln other words, the data may be indicative of a temperature of at least one portion 59 of the compressed air system 1. ln more detail, according to the illustrated embodiments, the compressed air system 1 comprises a temperature sensor 18 configured to sense a current temperature of a portion 59 of the compressed air system 1, wherein the control arrangement 21 is operably connected to the temperature sensor 18 and is configured to obtain the data therefrom. ln this manner, the control arrangement 21 can obtain data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component 3, 5, 5' in a simple, efficient, and reliable manner. According to the illustrated embodiments, the portion 59 of the compressed air system 1 is a portion of the air processing unit 5. However, according to further embodiments, the temperature sensor 18 may be configured to sense the temperature of another portion of the compressed air system 1, another portion of the powertrain 10, and/or another portion of the vehicle 2 comprising the compressed air system 1.

Furthermore, according to some embodiments, the control arrangement 21 may obtain data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component 3, 5, 5' from another type of device than a temperature sensor. As an example, the control arrangement 21 may obtain the data from an external device, such as an external sender. The obtained data may be indicative of a current or upcoming ambient temperature, an estimated current or upcoming ambient temperature, or the like, which also can give an indication of the temperature of at least one portion of the compressed air system 1. As a further alternative, or in addition, the data may be obtained by estimating or modelling the data. The data may be estimated/modelled using input such as calendar data, position data, historic accumulation data, historic data of temperatures, and the like.

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. As seen in Fig. 2, according to the illustrated embodiments, the compressed air system 1 comprises a pressure sensor 14 configured to sense a current air pressure in the compressed air system 1. According to the illustrated embodiments, the pressure sensor 14 is arranged in the pressure reservoir 12 and is thus configured to sense a current pressure in the pressure reservoir 12. 16 According to further embodiments, the pressure sensor 14 may be arranged at a different portion of the compressed air system 1. According to the illustrated embodiments, the control arrangement 21 is operably connected to the pressure sensor 14 and is configured to receive pressure data therefrom. I\/|oreover, according to the illustrated embodiments, the control arrangement 21 is configured to activate 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, as referred to herein may also be referred to as a first threshold pressure. Furthermore, the control arrangement 21 is configured to deactivate operation of the air compressor 3 when the sensed current air pressure in the compressed air system 1 rises above a second threshold pressure. ln this manner, the control arrangement 21 may utilize data from the pressure sensor 14 in the control of the electric motor 3 to obtain a pressure in the compressed air system 1 within a predetermined pressure range. The second threshold pressure, i.e. 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, such as a control arrangement arranged in the air compressor 3 being configured to activate operation of the air compressor 3, for example when 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 maintain the venting valve 7 in the open state until the air pressure in the compressed air system 1 declines below the threshold pressure. Thereby, operation of the air compressor is triggered in a controlled manner so as to remove, and/or prevent formation of, matter in compressed air system 1 as is further explained herein. Furthermore, according to some embodiments, the control arrangement 21 is configured to maintain the venting valve 7 in the open state also when the air compressor 3 is operating. ln prior art solutions, such operation would risk damaging the air compressor 3. However, since the venting valve 7 is arranged downstream of the air processing element 5', the air processing element 5' provides a flow resistance for the air compressor 3 allowing the air compressor 3 to operate also when the venting valve 7 is in the open state without risking damage or wear of the air compressor 3.

Furthermore, since the venting valve 7 can be controlled to, or maintained in, the open state also when the air compressor 3 is operating, an improved removal of, and/or prevention of, matter in a larger part of the compressed air system 1 can be provided. That is, studies have shown that water may accumulate in the air compressor 3, which can damage the air 17 Compressor 3 and can cause malfunction of the of the compressed air system 1 and/or malfunction of components/systems powered by the compressed air system 1. However, by allowing the venting valve 7 to be controlled to, or maintained in, the open state also when the air compressor 3 is operating, water and moisture in the air compressor 3 can be removed in an efficient manner. ln addition, by allowing the venting valve 7 to be controlled to, or maintained in, the open state also when the air compressor 3 is operating, the air processing element 5' can be heated in an efficient manner which can remove, and/or prevent formation of, ice in the air processing element 5". ln addition, the efficient heating of the air processing element 5' provides conditions for an efficient subsequent regeneration of the air processing element 5".

The compressed air system 1 comprises a purge valve 55. According to the illustrated embodiments, the purge valve 55 is arranged on the air processing unit 5 at a position upstream of the air processing element 5' as seen relative to an airflow direction from the air compressor 3 through the air processing element 5". According to further embodiments, the compressed air system 1 may comprise a purge valve arranged at another position/location of the compressed air system, such as 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 arrangement 21 is operably connected to the purge valve 55 and is configured to control the purge valve 55 between an open and a closed state. The purge valve 55 is configured to vent air from the compressed air system 1 when being controlled to the open state. The control arrangement is configured to perform a regeneration of the air processing element 5' of the air processing unit 5 by controlling the purge valve 55 to the open state. According to embodiments herein, the control arrangement 21 is configured to control the purge valve 55 to the open state during stand still periods of the air compressor 3. The control arrangement 21 may ensure that the air compressor 3 does not operate by deactivating the air compressor 3.

When the purge valve 55 is controlled to the open state, compressed air is flowing from the pressure reservoir 12 backwards through the air processing element 5' of the air processing unit 5 and out from the compressed air system 1 via the purge valve 55, i.e. is flowing through the air processing element 5' in a direction opposite to the flow direction of air obtained when the air compressor 3 is compressing/pumping air through the air processing element 5". ln this manner, the air processing element 5' is regenerated and matter, such as water and moisture, is removed from the air processing element 5' in an efficient manner. By 18 regenerating the air processing element 5', the service life of the air processing element 5', and the available time before a replacement of the air processing element 5' is needed, can be significantly increased.

According to some embodiments, the air compressor 3 is a rotary compressor, such as a rotary screw compressor. A rotary compressor is a positive-displacement compressor in which compression of a fluid is performed by at least one rotor, i.e. one or more rotating working members, such as one or more screws, or the like. A rotary compressor lacks a reciprocating piston, connecting rod, and crank mechanism of a reciprocating compressor.

A rotary compressor is an efficient means of compressing air. Furthermore, a rotary compressor is normally able to generate less noise and vibration during operating than a reciprocating compressor. ln addition, a rotary compressor normally has a less varying, i.e. more constant, driving torque than a reciprocating compressor making it more suitable to be powered by an electric motor than a reciprocating compressor.

However, a rotary compressor, such as a rotary screw compressor, is more sensitive to unrestricted operation, i.e. operation without significant back pressure at an outlet of the air compressor 3 as compared to a reciprocating compressor. One reason is that rotary compressors are dependent on a lubrication film on one or more rotors. lf the air compressor is operated without a back pressure at the outlet or is operated with too low back pressure at the outlet, there is a risk that the lubricant film is removed from the one or more rotors. lf so, the lubricant may be transported out from the air compressor 3 together with the air stream via the outlet of the air compressor 3. As a result thereof, the one or more rotors may become insufficiently lubricated, which can cause wear and/or damage of the one or more rotors. l\/loreover, lubricant transported out from the air compressor 3 may cause a malfunction of the compressed air system 1, 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. Furthermore, lubricant transported out from the air compressor 3 may cause a reduction in a drying capacity of the air processing element 5'.

However, as explained above, since the venting valve 7 is arranged downstream of the air processing element 5', the air processing element 5' provides a flow resistance for the air compressor 3. Thus, due to the features of the compressed air system 1, the air compressor 3 can be operated also when the venting valve 7 is in the open state without risking damage or wear of the air compressor 3 and without risking a subsequent malfunction of the 19 compressed air system 1 also in embodiments in which the air Compressor 3 is a rotary COmpfeSSOf, SUCh EIS a l'Otal'y SCFGW COmpfeSSOf.

Moreover, in embodiments in which the air compressor 3 is a rotary compressor and in which the vehicle 2 comprising the compressed air system 1 is an at least partially electrically driven vehicle 2, the air compressor 3 can be powered in an efficient, reliable, and silent manner, for example using electricity from a battery 9 of the vehicle 2, also in the absence of a running internal combustion engine.

According to some embodiments, the venting valve 7 is configured to vent air from the compressed air system 1 in a restrictive manner to generate a back pressure to the air compressor 3 when the venting valve 7 is in the open state. ln this manner, it is further ensured that the air compressor can be operated also when the venting valve 7 is in the open state without risking damage or wear of the air compressor 3 and without risking a subsequent malfunction of the compressed air system 1. This is because the restrictive ventilation of the venting valve 7 can ensure a 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 operation of the air compressor 3. The venting valve 7 may be configured to vent air from the compressed air system 1 in a restrictive manner to generate a back pressure to the air compressor 3 by providing a smaller effective cross-sectional area when in the open state 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 venting valve 7 provides an effective cross-sectional area when in the open state being less than 50%, or less than 25%, of an effective cross-sectional area of the supply line 49.

According to the illustrated embodiments, the supply line 49 is connected to an inlet port 50 of the air processing unit 5. Moreover, as seen in Fig. 2, the air processing unit 5 comprises a number of outlet ports 51 - 54. ln the illustrated example embodiments, one outlet port 51 is fluidly connected to the pressure reservoir 12 and two outlet ports 52, 53 are each fluidly connected to a respective pneumatic actuator 11, 16. l\/loreover, as seen in Fig. 2, according to the illustrated embodiments, the venting valve 7 form part of an outlet port 54 of the air processing unit 5. When the air processing unit 5 is comprised in a compressed air system comprising a mechanically driven air compressor, the outlet port 54 can be used as an output 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 port 54 is not needed for outputting a pneumatic control signal. Thus, by using the outlet port 54 of the air processing unit 5 for venting air from the compressed air system 1, a compact compressed air system 1 is provided having conditions and characteristics suitable for being manufactured and assembled in a cost-efficient manner.

Fig. 3 illustrates a method 100 of operating a compressed air system of a vehicle. The compressed air system may be a compressed air system 1 according to the embodiments illustrated in Fig. 2. I\/|oreover, the vehicle may be a vehicle 2 according to the embodiments illustrated in Fig. 1. Therefore, below, simultaneous reference is made to Fig. 1 - Fig. 3, if not indicated othen/vise. The method 100 is a method of 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 venting valve 7 controllable between an open state and a closed state. The venting valve 7 is configured to vent air from the compressed air system 1 to the surroundings when being controlled to the open state. The venting valve 7 is arranged downstream of the air processing element 5' as seen relative to an airflow direction from the air compressor 3 through the air processing element 5". The method 100 comprises the step of: - controlling 120 the venting valve 7 between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component 3, 5, 5' of the compressed air system 1.

As illustrated in Fig. 3, the method may comprise the step of: - obtaining 110 data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component 3, 5, 5' of the compressed air system 1.

The step of obtaining 110 the data is preferably performed prior to, or simultaneously as, the step of controlling 120 the venting valve 7 between the open and closed states. The step of obtaining 110 the data may comprise a step of retrieving the data from a device of the compressed air system 1 or from an external device or system. As an alternative, or in addition, the step of obtaining 110 the data may comprise a step of estimating or modelling the data.

As illustrated in Fig. 3, the method 100 may comprise the step of: - controlling 122 the venting valve 7 to the open state if the data indicates at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component 3, 5, 5". 21 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 threshoid pressure, and wherein the method 100 may comprise the step of: - maintaining 124 the venting valve 7 in the open state until the air pressure in the compressed air system 1 declines below the threshold pressure.

I\/|oreover, as is illustrated in Fig. 3, the method 100 may comprise the step of: - maintaining 126 the venting valve 7 in the open state also when the air compressor 3 is operating.

According to some embodiments, the data is indicative of a temperature of at least one portion 59 of the compressed air system 1.

Furthermore, as is illustrated in Fig. 3, the step of obtaining 110 the data may comprise the step of: - obtaining 112 the data by sensing the temperature of at least one portion 59 of the compressed air system 1.

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 110, 112, 120, 122, 124, and 126 of the method 100.

Fig. 4 illustrates 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.

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.

The control arrangement 21, as referred to herein, may be comprised in the vehicle 2 and may be 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, in order to perform the method 100 illustrated in Fig. 3. One skilled in the art will appreciate that the method 100 of operating a compressed 22 air system 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 110, 112, 120, 122, 124, and 126 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. ROIVI (Read-Only l\/lemory), PROIVI (Programmable Read-Only Memory), EPROIVI (Erasable PROIVI), EEPROIVI (Electrically Erasable PROIVI), etc. in different embodiments.

The control arrangement 21 is connected to components of the compressed air system 1 and/or the vehicle 2 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 23 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 may take the form of one or more from among a cable, a data bus, e.g. a CAN (controller area network) bus, a l\/IOST (media orientated systems transport) bus or some other bus configuration, or a wireless connection. ln 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 of the type here concerned are therefore often provided with significantly more control arrangements than depicted in Fig. 2, 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 110, 112, 120, 122, 124, and 126 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 ROIVI disc, as is illustrated in Fig. 4, or a ROIVI (read-only memory), a PROIVI (programable read-only memory), an EPROIVI (erasable PROIVI), a flash memory, an EEPROIVI (electrically erasable PROIVI), 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.

The compressed air system 1, as referred to herein, may also be referred to as a pneumatic system.

The wording upstream and downstream, as used herein, relates to the relative positions of objects in relation to an intended flow direction of fluid in the system or circuit referred to. As an example, the feature that a first object is arranged upstream of a second object in a circuit 24 means that the first object is arranged before the second object seen relative to the intended flow direction of fluid through the circuit. As another example, the feature that a first object is arranged downstream of a second object in a circuit means that the first object is arranged after the second object seen relative to the intended flow direction of fluid through the circuit. lt is to be understood that the foregoing is iliustrative 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 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 venting valve (7) controllable between an open state and a closed state, the venting valve (7) being configured to vent air from the compressed air system (1) to the surroundings when being controlled to the open state, wherein the venting valve (7) is arranged downstream of the air processing element (5”) as seen relative to an airflow direction from the air compressor (3) through the air processing element (5'), and wherein the method (100) comprises the step of: - controlling (120) the venting valve (7) between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component (3, 5, 5') of the compressed air system (1). The method (100) according to claim 1, wherein the method (100) comprises the step of: - controlling (122) the venting valve (7) to the open state if the data indicates at least one of a preceding, an ongoing, and an upcoming accumulation of matter in the at least one component (3, 5, 5”). The 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 step of: - maintaining (124) the venting valve (7) in the open state until the air pressure in the compressed air system (1) declines below the threshold pressure. The method (100) according to any one of the preceding claims, wherein the method (100) comprises the step of: - maintaining (126) the venting valve (7) in the open state also when the air compressor (3) is operating. The method (100) according to any one of the preceding claims, wherein the data is indicative of a temperature of at least one portion (59) of the compressed air system (1).The method (100) according to any one of the preceding claims, wherein the method (100) comprises the step of: - obtaining (112) the data by sensing the temperature of at least one portion (59) of the compressed air system (1 ). 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 - A computer-readabie 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 - A 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 compress air through the air processing element (5”), and - a venting valve (7) controllable between an open state and a closed state, the venting valve (7) being configured to vent air from the compressed air system (1) to the surroundings when being controlled to the open state, wherein the venting valve (7) is arranged downstream of the air processing element (5') as seen relative to an airflow direction from the air compressor (3) through the air processing element (5'), and wherein the control arrangement (21) is configured to control the venting valve (7) between the open and closed states based on data indicative of at least one of a preceding, an ongoing, and an upcoming accumulation of matter in at least one component (3, 5, 5”) of the compressed air system (1). A 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 venting valve (7) controllable between an open state and a closed state, the venting valve (7) being configured to vent air from the compressed air system (1) to the surroundings when being controlled to the open state,wherein the venting valve (7) is arranged downstream of the air processing element (5”) as seen relative to an airflow direction from the air compressor (3) through the air processing element (5'), and and wherein the compressed air system (1) comprises a control arrangement (21) according to claim The compressed air system (1) according to claim 10, wherein the compressed air system (1) comprises an air processing unit (5) comprising the air processing element (5”), and wherein the venting valve (7) form part of an outlet port (54) of the air processing unit (5). The compressed air system (1) according to claim 10 or 11, wherein the venting valve (7) is an electronically controlled valve. The compressed air system (1) according to any one of the claims 10 - 12, wherein the compressed air system (1) comprises an electric motor (6) configured to power the air compressor (3). The compressed air system (1) according to any one of the claims 10 - 13, wherein the air compressor (3) is a rotary compressor. The compressed air system (1) according to any one of the claims 10 - 14, wherein the venting valve (7) is configured to vent air from the compressed air system (1) in a restrictive manner when in the open state to generate a back pressure to the air compressor (3). A vehicle (2) comprising a compressed air system (1) according to any one of the claims 10 - The vehicle (2) according to claim 16, wherein the vehicle (2) comprises an electric propulsion motor (8) configured to provide motive power to the vehicle (2).