TECHNICAL FIELD

The present disclosure relates to a compression release brake arrangement for an engine. The present disclosure further relates to an engine comprising a compression release brake arrangement, a vehicle comprising an engine, a method of controlling a compression release brake arrangement, a computer program, a computer-readable medium, and a control arrangement for a compression release brake arrangement.

BACKGROUND

Internal combustion engines, such as four-stroke internal combustion engines, comprise one or more cylinders and a piston arranged in each cylinder. The pistons are connected to a crankshaft of the engine and are arranged to reciprocate within the cylinders upon rotation of the crankshaft. The engine usually further comprises one or more inlet valves and outlet valves as well as one or more fuel supply arrangements. The one or more inlet valves and outlet valves are controlled by a respective valve control arrangement usually comprising one or more camshafts rotatably connected to a crankshaft of the engine, via a belt, chain, gears, or similar. A four-stroke internal combustion engine completes four separate strokes while turning a crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The uppermost position of the piston in the cylinder is usually referred to as the top dead centre TDC, and the lowermost position of the piston in the cylinder is usually referred to as the bottom dead centre BDC.

The strokes are completed in the following order, inlet stroke, compression stroke, expansion stroke and exhaust stroke. During operation of a conventional four-stroke internal combustion engine, the inlet valve control arrangement controls inlet valves of a cylinder to an open state during the inlet stroke of a piston within the cylinder, to allow air, or a mixture of air and fuel, to enter the cylinder. During the compression stroke, all valves should be closed to allow compression of the air, or the mixture of the air and fuel, in the cylinder. If the engine is in a power producing state, fuel in the cylinder is ignited, usually towards the end of the compression stroke, for example by a spark plug or by compression heat in the cylinder. The combustion of fuel within the cylinder significantly increases pressure and temperature in the cylinder. The combustion of the fuel usually continues into a significant portion of the subsequent expansion stroke. The increased pressure and temperature in the cylinder obtained by the combustion is partially converted into mechanical work supplied to the crank shaft during the expansion stroke. Obviously, all valves should remain closed during the expansion stroke to allow the increased pressure and temperature to be converted into mechanical work. The expansion stroke is also usually referred to as the combustion stroke, since usually, the majority of the combustion takes place during the expansion stroke. In the subsequent exhaust stroke, the exhaust valve control arrangement controls exhaust valves of the cylinder to an open state to allow exhaust gases to be expelled out of the cylinder into an exhaust system.

During normal engine braking, occurring for example when a driver of a vehicle releases an accelerator pedal, the engine will continue to operate in the above described strokes, with the exception that, normally, no fuel is supplied to the engine during engine braking, and consequently, no combustion will take place during the end of the compression stroke or during the expansion stroke. In this condition, the engine will provide some braking torque due to internal friction and due to the pumping of air from the inlet to the exhaust, in the respective inlet stroke and exhaust stroke. As a piston travels upward during its compression stroke, the gases that are trapped in the cylinder are compressed. The compressed gases oppose the upward motion of the piston. However, almost all the energy stored in the compressed gases is returned to the crank shaft on the subsequent expansion stroke.

Thereby, during normal engine braking, the compression stroke together with the subsequent expansion stroke, will not contribute to a significant braking torque of the engine.

A compression release engine brake, sometimes referred to a Jake brake or Jacobs brake, is an engine braking mechanism used in some engines. Some compression release brake arrangements comprise a valve actuator assembly, which when activated, opens exhaust valves in the cylinders after the compression stroke, to release the compressed air trapped in the cylinders to the exhaust system. Thereby, the energy stored in the compressed gases during the compression stroke will not be returned to the crank shaft on the subsequent expansion stroke, which increases the braking torque of the engine. Some compression release engine brake arrangements comprise a hydraulic arrangement which actuates the valve actuator assembly by supplying a hydraulic pressure to the valve actuator assembly.

In some compression release engine brake arrangements, the exhaust valves may be deactivated, so that they remain closed during the exhaust stroke. Usually, this is achieved by using a so called lost motion arrangement, which when actuated is arranged to not transfer motion caused by an exhaust cam lobe to the exhaust valve. The air in the cylinders will thereby be compressed also during the exhaust stroke. By using a valve actuator assembly opening exhaust valves near the end of the exhaust stroke, the compressed air trapped in the cylinders is released to the exhaust system. Thereby, the braking torque is almost doubled because compression and release events are performed in the compression stroke as well as in the exhaust stroke.

A compression release engine brake arrangement is a vital component of an engine, affects driveability of a vehicle, and affects functionality of other components a vehicle. If a compression release engine brake arrangement fails to activate braking, it will be noticed by a driver of the vehicle. If a compression release engine brake arrangement fails to deactivate braking, it may have consequences for other components of the engine. Further, if a compression release engine brake arrangement fails to deactivate braking, further travel with a vehicle will not possible because gases compressed during the compression stroke will be released from cylinders of the engine.

The malfunction of a compression release engine brake arrangement can for example be detected by monitoring variables such as engine pressures, engine speed, vehicle speed, and the like. Thus, a control unit may retrieve such variables, may calculate expected values, and may compare the retrieved variables with the expected variables, and may, based on such a comparison, or such comparisons, determine the function of the compression release brake arrangement. However, such a method is not very fast. Furthermore, such a method is not very reliable since the variables may also be affected by other factors than the functioning of the compression release brake arrangement.

SUMMARY

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

According to a first aspect of the invention, the object is achieved by a compression release brake arrangement for an engine. The arrangement comprises a control arrangement, and a valve actuator assembly configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder of the engine. The arrangement further comprises a first conduit arranged to connect the valve actuator assembly to a pressure source, and a first actuator valve configured to control flow in the first conduit. The arrangement further comprises a pressure sensor arranged to sense fluid pressure in a first portion of the first conduit between the valve actuator assembly and the first actuator valve. Further, the arrangement comprises a second valve configured to control flow in the first conduit. The control arrangement is configured to control the second valve to a closed state when the first actuator valve is controlled to a closed state and the sensed fluid pressure is above a predetermined threshold value.

Thereby, an arrangement is provided capable of detecting a malfunction of the compression release brake arrangement and capable of eliminating, or at least alleviating, the malfunction. For example, in case the first actuator valve is controlled to the closed state, but fails to close the connection between the pressure source and valve actuator assembly, for some reason, the valve actuator assembly would continue to perform compression release braking of the first cylinder. However, a pressure above the predetermined threshold value, caused a malfunction of the first actuator valve, or any component related to the functionality thereof, will be detected by the pressure sensor, and the control arrangement will as a result thereof, control the second valve to the closed state. When the second valve is in the closed state, the connection between the pressure source and the valve actuator assembly is closed. As a result, the valve actuator assembly is deactivated and the compression release braking of the first cylinder of the engine is cancelled. In this manner, the arrangement is capable of detecting the malfunction and capable of eliminating the malfunction. Thereby, a safer and more reliable compression release brake arrangement is provided.

Further, since the arrangement comprises the pressure sensor, and since the control arrangement is configured to control the second valve to a closed state when the first actuator valve is controlled to a closed state and the sensed fluid pressure is above a predetermined threshold value, an arrangement is provided capable of detecting the malfunction and capable of eliminating a malfunction within a short time-period. Thereby, a still safer and still more reliable compression release brake arrangement is provided, capable of reducing the risk of damage of other components of the engine.

Further, a compression release brake arrangement is provided capable of significantly reducing the risk of an unexpected stop of a vehicle caused by a malfunction of the compression release brake arrangement. As a further result thereof, a compression release brake arrangement is provided potentially improving driving safety of a vehicle hosting the compression release brake arrangement.

Accordingly, a compression release brake 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. Optionally, the arrangement comprises a first pressure reducer configured to reduce the pressure in the first portion of the first conduit when the first actuator valve is in the closed state. Thereby, deactivation of the valve actuator assembly, and cancelation of compression release braking, is further ensured when the first actuator valve is in the closed state.

Optionally, the control arrangement is configured to perform a function check of the arrangement by controlling the first actuator valve to an open state, changing the opening state of the second valve, and monitoring fluid pressure in the first portion of the first conduit. Thereby, a compression release brake arrangement is provided capable of performing a function check of components of the compression release brake arrangement, in a simple, reliable, and quick manner. As a further result thereof, a safer and still more reliable compression release brake arrangement is provided.

Optionally, the first actuator valve is connected to the pressure source via a second and a third portion, of the first conduit, and wherein the second portion of the first conduit connects the first actuator valve to the second valve. Thereby, a simple and reliable compression release brake arrangement is provided

Optionally, the arrangement comprises a second pressure reducer configured to reduce the pressure in the second portion of the first conduit when the second valve is in the closed state. Thereby, deactivation of the valve actuator assembly, and cancelation of compression release braking, is further ensured when the second valve is in the closed state.

Optionally, the arrangement further comprises a second valve actuator assembly configured to, when supplied with a fluid pressure, perform compression release braking of at least a second cylinder of the engine, a second conduit connecting the second valve actuator assembly to the second portion of the first conduit, and a second actuator valve configured to control flow in the second conduit. Accordingly, a compression release brake arrangement is provided capable of performing compression release braking of at least a second cylinder of the engine. Further, since the second valve actuator assembly is connected to the second portion of the first conduit, the second valve actuator assembly is deactivated and the compression release braking of the at least second cylinder is cancelled, when the second valve is controlled to a closed state. Thereby, a safer and still more reliable compression release brake arrangement is provided.

Optionally, the arrangement further comprises a second pressure sensor arranged to sense fluid pressure in a first portion of the second conduit between the second valve actuator assembly and the second actuator valve, and wherein the control arrangement is configured to control the second valve to the closed state when the second actuator valve is controlled to a closed state and the sensed fluid pressure in the first portion of the second conduit is above a predetermined threshold value. Thereby, an arrangement is provided capable of detecting a malfunction of the second actuator valve, or any component related to the functionality thereof, and capable of eliminating, or at least alleviating, the malfunction. For example, in case the second actuator valve is controlled to the closed state, but fails to close the connection between the pressure source and the second valve actuator assembly, for some reason, the second valve actuator assembly would continue to perform compression release braking of the first cylinder. However, a pressure above the predetermined threshold value, caused a malfunction of the second actuator valve, or any component related to the functionality thereof, will be detected by the second pressure sensor, and the control arrangement will as a result thereof, control the second valve to the closed state. When the second valve is in the closed state, the connection between the pressure source and the second valve actuator assembly is closed. As a result, the second valve actuator assembly is deactivated and the compression release braking of the at least second cylinder of the engine is cancelled. Thereby, a still safer and still more reliable compression release brake arrangement is provided.

Further, an arrangement is provided capable of detecting the malfunction and capable of eliminating a malfunction within a short time-period, thereby reducing the risk of damage of other components of the engine and potentially improving driving safety of a vehicle hosting the compression release brake arrangement.

According to a second aspect of the invention, the object is achieved by an engine comprising a compression release brake arrangement according to some embodiments, and at least a first cylinder, wherein the compression release brake arrangement is configured to perform compression release braking of the at least first cylinder of the engine.

Since the engine comprises the compression release brake arrangement, an engine is provided capable of detecting a malfunction of the compression release brake arrangement and capable of eliminating, or at least alleviating, the malfunction within a short time-period. Thereby, a safer and more reliable engine is provided, capable of reducing the risk of damage of other components of the engine.

Further, an engine is provided capable of significantly reducing the risk of an unexpected stop of a vehicle, hosting the engine, caused by a malfunction of the compression release brake arrangement of the engine. As a further result thereof, an engine is provided potentially improving driving safety of a vehicle hosting the engine.

Accordingly, an engine 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.

According to a third aspect of the invention, the object is achieved by a vehicle comprising an engine according to some embodiments.

Since the vehicle comprises the engine according to some embodiments, a vehicle is provided capable of detecting a malfunction of the compression release brake arrangement of the engine and capable of eliminating, or at least alleviating, the malfunction within a short time-period.

Further, a vehicle is provided capable of significantly reducing the risk of an unexpected stop of a vehicle, caused by a malfunction of the compression release brake arrangement of the engine. As a further result thereof, a vehicle is provided with potentially improved driving safety.

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

According to a fourth aspect of the invention, the object is achieved by a method of controlling a compression release brake arrangement for an engine, wherein the

arrangement comprises:

a valve actuator assembly configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder of the engine, a first conduit arranged to connect the valve actuator assembly to a pressure source,

a first actuator valve configured to control flow in the first conduit, a pressure sensor arranged to sense fluid pressure in a first portion of the first conduit between the valve actuator assembly and the first actuator valve, and a second valve configured to control flow in the first conduit,

and wherein the method comprises:

controlling the first actuator valve to a closed state, sensing fluid pressure in the first portion of the first conduit, and controlling the second valve to a closed state in case the sensed fluid pressure is above a predetermined threshold value.

Since the method comprises the step of controlling the first actuator valve to a closed state and sensing fluid pressure in the first portion of the first conduit, a method is provided capable of detecting a malfunction of the first actuator valve, or any component related to the functionality thereof, in a quick, safe and reliable manner. Furthermore, since the method comprises the step of controlling the second valve to a closed state in case the sensed fluid pressure is above a predetermined threshold value, a method is provided capable of eliminating, or at least alleviating, the malfunction in a quick, safe and reliable manner.

Thereby, a method is provided improving safety and reliability of a compression release brake arrangement. As a further result thereof, a method is provided capable of reducing the risk of damage of components of the engine, capable of reducing the risk of an unexpected stop of a vehicle, caused by a malfunction of the compression release brake arrangement, and capable of potentially improving driving safety of a vehicle hosting the engine.

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 further comprises:

performing a function check of the arrangement by:

controlling the first actuator valve to an open state,

changing the opening state of the second valve, and

monitoring fluid pressure in the first portion of the first conduit.

Thereby, a method is provided capable of performing a function check of components of the compression release brake arrangement, in a simple, reliable, and quick manner. As a further result thereof, a method is provided further improving safety and reliability of a compression release brake arrangement.

Optionally, the arrangement comprises:

a second valve actuator assembly configured to, when supplied with a fluid pressure, perform compression release braking of at least a second cylinder of the engine, a second conduit connecting the second valve actuator assembly to the second portion of the first conduit,

a second actuator valve configured to control flow in the second conduit, and a second pressure sensor arranged to sense fluid pressure in a first portion of the second conduit between the second valve actuator assembly and the second actuator valve,

and wherein the method further comprises:

controlling the second actuator valve to a closed state,

sensing fluid pressure in the first portion of the second conduit, and controlling the second valve to the closed state in case the sensed fluid pressure in the first portion of the second conduit is above a predetermined threshold value.

Since the method comprises the step of controlling the second actuator valve to a closed state and sensing fluid pressure in the first portion of the second conduit, a method is provided capable of detecting a malfunction of the second actuator valve, or any component related to the functionality thereof, in a quick, safe and reliable manner. Furthermore, since the method comprises the step of controlling the second valve to a closed state in case the sensed fluid pressure in the first portion of the second conduit is above a predetermined threshold value, a method is provided capable of eliminating, or at least alleviating, the malfunction in a quick, safe and reliable manner.

According to a fifth 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.

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

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

According to a seventh aspect of the invention, the object is achieved by a control arrangement for a compression release brake arrangement of an engine, wherein the compression release brake arrangement comprises:

a valve actuator assembly configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder of the engine, a first conduit arranged to connect the valve actuator assembly to a pressure source,

a first actuator valve configured to control flow in the first conduit, a pressure sensor arranged to sense fluid pressure in a first portion of the first conduit between the valve actuator assembly and the first actuator valve, and a second valve configured to control flow in the first conduit,

and wherein the control arrangement is configured to:

control the first actuator valve to a closed state,

monitor fluid pressure in the first portion of the first conduit, and

control the second valve to a closed state in case the monitored fluid pressure is above a predetermined threshold value.

Since the control arrangement is configured to control the first actuator valve to a closed state, and monitor fluid pressure in the first portion of the first conduit, a control arrangement is provided capable of detecting a malfunction of the first actuator valve, or any component related to the functionality thereof, in a quick, safe and reliable manner. Furthermore, since the control arrangement is configured to control the second valve to a closed state in case the monitored fluid pressure is above a predetermined threshold value, a control

arrangement is provided capable of eliminating, or at least alleviating, the malfunction in a quick, safe and reliable manner.

Thereby, a control arrangement is provided improving safety and reliability of a compression release brake arrangement. As a further result thereof, a control arrangement is provided capable of reducing the risk of damage of components of the engine, capable of reducing the risk of an unexpected stop of a vehicle, caused by a malfunction of the compression release brake arrangement, and capable of potentially improving driving safety of a vehicle hosting the control arrangement.

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.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

Fig. 1 schematically illustrates a compression release brake arrangement, according to some embodiments,

Fig. 2 schematically illustrates a compression release brake arrangement, according to some further embodiments,

Fig. 3 schematically illustrates an engine, according to some embodiments,

Fig. 4 illustrates a vehicle, according to some embodiments,

Fig. 5 illustrates a method of controlling a compression release brake arrangement, and Fig. 6 illustrates computer-readable medium, according to some embodiments.

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 schematically illustrates a compression release brake arrangement 1 , according to some embodiments. The compression release brake arrangement 1 is configured to selectively perform compression release braking of an engine. The compression release brake arrangement 1 comprises a valve actuator assembly 7 configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder 8’ of the engine. In Fig. 1 , the first cylinder 8’ is schematically illustrated as a dashed box. The valve actuator assembly 7 comprises a compression release brake valve 2 and a valve actuator 4. The valve actuator 4 comprises a portion of a camshaft 6 comprising a cam lobe 6’ and a hydraulic component 10 comprising a fluid chamber 10’. The camshaft 6 is configured to rotate upon rotation of a crankshaft of the engine.

For the reason of brevity and/or clarity, the compression release brake arrangement 1 is in some places herein referred to as“the arrangement 1”. The arrangement 1 comprises a first conduit 9 connecting the compression release brake valve 2 of the valve actuator assembly 7 to a pressure source 1 1 . The pressure source 1 1 may comprise a hydraulic component connected to an engine oil circuit of the engine. The engine oil circuit of an engine is pressurized, during operation of the engine, due to pumping action of a lubricant pump of an engine. The pressure of oil in an engine oil circuit can for example be within the range of 2 - 8 bars.

The arrangement 1 further comprises a first actuator valve 13 configured to control flow in the first conduit 9. Further, the arrangement 1 comprises a control arrangement 5 configured to control the first actuator valve 13. When the control arrangement 5 controls the first actuator valve 13 to an open state, an open connection is provided between the pressure source 1 1 and the compression release brake valve 2 of the valve actuator assembly 7. Thereby, the compression release brake valve 2 is subjected to a fluid pressure via the first conduit 9. As a result, the fluid chamber 10’ of the hydraulic component 10 is filled with fluid, e.g., engine oil. Accordingly, when the compression release brake valve 2 is subjected to a fluid pressure it allows transport of fluid into the fluid chamber 10’. In addition, when the compression release brake valve 2 is subjected to a fluid pressure, it also hiders transport of fluid out of the fluid chamber 10’. As a result, when the cam lobe 6’ abuts against the hydraulic component 10, an exhaust valve 12 of the engine is opened. This because the motion of the cam lobe 6’ can be transferred to an opening motion of the exhaust valve 12. The camshaft 6 and the cam lobe 6’ are provided such that the opening occurs towards the end of a compression stroke of the first cylinder 8’. As a result, gases compressed during the compression stroke are released from the first cylinder 8’. Thus, the control arrangement 5 can activate the valve actuator assembly 7 to perform compression release braking of the first cylinder 8’ of the engine, simply by controlling the first actuator valve 13 to an open state.

In order to deactivate the valve actuator assembly 7, the control arrangement 5 is configured to close the first actuator valve 13. When the first actuator valve 13 closes, a first pressure reducer 17’ reduces the pressure in a first portion 9’ of the first conduit 9, between the first actuator valve 13 and the compression release brake valve 2 of the valve actuator assembly 7. Thereby, the compression release brake valve 2 is subjected to a reduced fluid pressure in the first conduit 9. The compression release brake valve 2 is configured to allow fluid transport out of the fluid chamber 10’ of the hydraulic component 10 when subjected to a reduced fluid pressure in the first conduit 9. Thereby, no motion is transferred from the cam lobe 6’ to the exhaust valve 12 when the cam lobe 6’ abuts against the hydraulic component 10, because fluid can flow out of the fluid chamber 10’ when a portion of the fluid component 10 is displaced by the cam lobe 6’. As a result, the exhaust valve 12 will remain closed towards the end of a compression stroke of the first cylinder 8’. Thus, the control

arrangement 5 can deactivate the valve actuator assembly 7, to cancel the compression release braking of the first cylinder 8’ of the engine, simply by controlling the first actuator valve 13 to a closed state.

The first pressure reducer 17’ may be configured to reduce the pressure in the first portion 9’ of the first conduit 9 to a pressure below the opening pressure of the compression release brake valve 2 by opening a connection between the first portion 9’ and a portion of a hydraulic arrangement having a low pressure level, such as a tank or an inlet of a pump. According to the illustrated embodiments, the first pressure reducer 17’ is arranged at the first actuator valve 13. As an alternative, or in addition, the compression release brake valve 2 of the valve actuator assembly 7 may comprise a pressure reducer configured to reduce the pressure in the first portion 9’ of the first conduit 9, when the first actuator valve 13 is in a closed state.

The arrangement 1 further comprises a pressure sensor 15 arranged to sense fluid pressure in the first portion 9’ of the first conduit 9 between the valve actuator assembly 7 and the first actuator valve 13. Further, the arrangement 1 comprises a second valve 16 configured to control flow in the first conduit 9. The control arrangement 5 is configured to control the second valve 16 to a closed state when the first actuator valve 13 is controlled to a closed state and the sensed fluid pressure is above a predetermined threshold value. The predetermined threshold value may be set to a value below an opening pressure of the compression release brake valve 2.

Thereby, an arrangement 1 is provided capable of detecting a malfunction of the

compression release brake arrangement 1 and capable of eliminating the malfunction. For example, in case the first actuator valve 13 is controlled to the closed state, but fails to close the connection between the pressure source 1 1 and the compression release brake valve 2, the valve actuator assembly 7 would continue to perform compression release braking of the first cylinder 8’. Flowever, a pressure above the predetermined threshold value, caused by the malfunction of the first actuator valve 13, or any component related to the functionality thereof, will be detected by the pressure sensor 15, and the control arrangement 5 will as a result thereof, control the second valve 16 to the closed state. When the second valve 16 is in the closed state, the connection between the pressure source 1 1 and the compression release brake valve 2 is closed. As a result, the valve actuator assembly 7 is deactivated and the compression release braking of the first cylinder 8’ of the engine is cancelled.

Further, since the arrangement 1 comprises the pressure sensor 15, and since the control arrangement 5 is configured to control the second valve 16 to a closed state when the first actuator valve 13 is controlled to a closed state and the sensed fluid pressure is above a predetermined threshold value, an arrangement 1 is provided capable of detecting the malfunction, and capable of eliminating a malfunction, within a short time-period. According to the illustrated embodiments, the arrangement 1 comprises a second pressure reducer 17” configured to reduce the pressure in the second portion 9” of the first conduit 9 when the second valve 16 is in the closed state. The second pressure reducer 17” may be configured to reduce the pressure in the second portion 9” of the first conduit 9 to a pressure below the opening pressure of the compression release brake valve 2 by opening a connection between the second portion 9” and a portion of a hydraulic arrangement having a low pressure level, such as a tank or an inlet of a pump.

The control arrangement 5 may be configured to perform a function check of the

arrangement 1 by controlling the first actuator valve 13 to an open state, changing the opening state of the second valve 16, and monitoring fluid pressure in the first portion 9’ of the first conduit 9.

Thus, according to such embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the first actuator valve 13 to an open state, controlling the opening state of the second valve 16 from a closed state to an open state, and monitoring fluid pressure in the first portion 9’ of the first conduit 9. If the fluid pressure in the first portion 9’ rises, the components 5, 13, 15, and 16 can be determined to work as intended. If no rise in fluid pressure in the first portion 9’ can be monitored, or if a lower pressure than expected is monitored in the first portion 9’, one or more of the components 5, 13, 15, and 16 can be determined to not work as intended.

Further, according to these embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the first actuator valve 13 to an open state, controlling the opening state of the second valve 16 from an open state to a closed state, and monitoring fluid pressure in the first portion 9’ of the first conduit 9. If a reduction in fluid pressure in the first portion 9’ is monitored, the components 5, 13, 15, and 16 can be determined to work as intended. If no reduction in fluid pressure in the first portion 9’ can be monitored, or if a lower reduction in fluid pressure than expected is monitored in the first portion 9’, one or more of the components 5, 13, 15, and 16 can be determined to not work as intended.

According to the embodiments illustrated in Fig. 1 , the first actuator valve 13 is connected to the pressure source 1 1 via a second and a third portion 9”, 9’” of the first conduit 9, and the second portion 9” of the first conduit 9 connects the first actuator valve 13 to the second valve 16. That is, according to the illustrated embodiments, the second valve 16 is arranged prior to the first actuator valve 13 in an intended flow direction in the first conduit 9, and the first and second actuator valves 13, 16 are arranged in series in the first conduit 9. The second valve 16 may comprise the same type, or a similar type, of valve as the first actuator valve 13.

Further, according to further embodiments, the second valve 16 may be arranged after the first actuator valve 13 in an intended flow direction in the first conduit 9. Thus, according to such embodiments, the second valve 16 is connected to the pressure source 1 1 via the second and the third portion 9”, 9’” of the first conduit 9, and the second portion 9” of the first conduit 9 connects the second valve 16 to first actuator valve 13. Accordingly, as compared to the illustrated embodiments, the second valve 16 and first actuator valve 13 can be said to have changed place with each other in the first conduit 9. Further, in such embodiments, the pressure sensor 15 and the first portion 9’ of the first conduit 9 is arranged between the second valve 16 and the compression release brake valve 2 of the valve actuator assembly 7. Also, in such embodiments, the control arrangement 5 may be configured to perform a function check of the arrangement 1 by controlling the first actuator valve 13 to an open state, changing the opening state of the second valve 16, and monitoring fluid pressure in the first portion 9’ of the first conduit 9.

Thus, in embodiments where the second valve 16 is arranged after the first actuator valve 13 in an intended flow direction in the first conduit 9, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the first actuator valve 13 to an open state, controlling the opening state of the second valve 16 from a closed state to an open state, and monitoring fluid pressure in the first portion 9’ of the first conduit 9. If the fluid pressure in the first portion 9’ rises, the components 5, 13, 15, and 16 can be determined to work as intended. If no rise in fluid pressure in the first portion 9’ can be monitored, or if a lower pressure than expected is monitored in the first portion 9’, one or more of the components 5, 13, 15, and 16 can be determined to not work as intended. Further, in embodiments where the second valve 16 is arranged after the first actuator valve 13 in an intended flow direction in the first conduit 9, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the first actuator valve 13 to an open state, controlling the opening state of the second valve 16 from an open state to a closed state, and monitoring fluid pressure in the first portion 9’ of the first conduit 9. If a reduction in fluid pressure in the first portion 9’ is monitored, the components 5, 13, 15, and 16 can be determined to work as intended. If no reduction in fluid pressure in the first portion 9’ can be monitored, or if a lower reduction in fluid pressure than expected is monitored in the first portion 9’, one or more of the components 5, 13, 15, and 16 can be determined to not work as intended.

Fig. 2 schematically illustrates a compression release brake arrangement 1 , according to some further embodiments. According to these embodiments, the arrangement 1 comprises a valve actuator assembly 7 configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder 8’ of the engine. The arrangement further comprises a first actuator valve 13, a first conduit 9, a second valve 16, a pressure sensor 15, a control arrangement 5, and a first and second pressure reducer 17’, 17”.

According to the embodiments illustrated in Fig. 2, these components, as well as the valve actuator assembly 7, comprises the same features and functions as described in accordance with the embodiments illustrated in Fig. 1.

According to the embodiments illustrated in Fig. 2, the arrangement 1 further comprises a second valve actuator assembly 18 configured to, when supplied with a fluid pressure, perform compression release braking of at least a second cylinder 8” of the engine 3. The second valve actuator assembly 18 comprises the same features and functions as the valve actuator assembly 7. Further, according to the embodiments illustrated in Fig. 2, the arrangement 1 comprises a second conduit 19 connecting the second valve actuator assembly 18 to the second portion 9” of the first conduit 9. Further, the arrangement 1 comprises a second actuator valve 21 configured to control flow in the second conduit 19.

The control arrangement 5 is configured to control the second actuator valve 21. When the control arrangement 5 controls the second actuator valve 21 to an open state, an open connection is provided between the pressure source 1 1 and a compression release brake valve 2’ of the second valve actuator assembly 18. Thereby, a fluid pressure is supplied to the compression release brake valve 2’, and as a result thereof, the second valve actuator assembly 18 performs compression release braking of the second cylinder 8”. Accordingly, the control arrangement 5 can activate the second valve actuator assembly 18 to perform compression release braking of the first cylinder 8’ of the engine, simply by controlling the second actuator valve 21 to an open state.

In order to deactivate the second valve actuator assembly 18, the control arrangement 5 is configured to close the second actuator valve 21 . When the second actuator valve 21 closes, a third pressure reducer 17’” reduces the pressure in a first portion 19’ of the second conduit 19, between the second actuator valve 21 and the compression release brake valve 2’ of the second valve actuator assembly 18. Thereby, the compression release brake valve 2’ of the second valve actuator assembly 18 is subjected to a reduced fluid pressure in the first conduit 9. As a result thereof, the second valve actuator assembly 18 is deactivated and cancels the performance of the compression release braking of the second cylinder 8”. Thus, the control arrangement 5 can deactivate the second valve actuator assembly 18, to cancel the compression release braking of the second cylinder 8” of the engine, simply by controlling the second actuator valve 21 to a closed state.

According to the illustrated embodiments, the third pressure reducer 17”’ is arranged at the second actuator valve 21. As an alternative, or in addition, the compression release brake valve 2’ of the second valve actuator assembly 18 may comprise a pressure reducer configured to reduce the pressure in the first portion 19’ of the second conduit 19, when the second actuator valve 21 is in a closed state.

The arrangement 1 further comprises a second pressure sensor 23 arranged to sense fluid pressure in the first portion 19’ of the second conduit 19 between the second valve actuator assembly 18 and the second actuator valve 21. The control arrangement 5 is configured to control the second valve 16 to the closed state when the second actuator valve 21 is controlled to a closed state and the sensed fluid pressure in the first portion 19’ of the second conduit 19 is above a predetermined threshold value. The predetermined threshold value is set to a value below an opening pressure of the compression release brake valve 2’ of the second actuator valve 21 .

Due to these features, an arrangement 1 is provided capable of detecting a malfunction of the second actuator valve 21 , as well as detecting a malfunction of a component related to the functionality of the second actuator valve 21. Further, an arrangement 1 is provided capable of eliminating, or at least alleviating, such a malfunction, simply by closing the second valve 16. That is, in case the second actuator valve 21 is controlled to the closed state, but fails to close the connection between the pressure source 1 1 and the compression release brake valve 2’ of the second valve actuator assembly 18, the second valve actuator assembly 18 would continue to perform compression release braking of the second cylinder 8”. However, a pressure above the predetermined threshold value, caused by a malfunction of the second actuator valve 21 , or any component related to the functionality thereof, will be detected by the second pressure sensor 23, and the control arrangement 5 will as a result thereof, control the second valve 16 to the closed state. When the second valve 16 is in the closed state, the connection between the pressure source 1 1 and the compression release brake valve 2’ of the second valve actuator assembly 18 is closed. As a result, the second valve actuator assembly 18 is deactivated and the compression release braking of the second cylinder 8” of the engine is cancelled.

Further, since the arrangement 1 comprises the second pressure sensor 23, and since the control arrangement 5 is configured to control the second valve 16 to a closed state, when the second actuator valve 21 is controlled to a closed state and the sensed fluid pressure is above a predetermined threshold value, an arrangement 1 is provided capable of detecting the malfunction and capable of eliminating a malfunction within a short time-period.

The control arrangement 5 may be configured to perform a function check of the

arrangement 1 by controlling the second actuator valve 21 to an open state, changing the opening state of the second valve 16, and monitoring fluid pressure in the first portion 19’ of the second conduit 19.

Thus, according to such embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the second actuator valve 21 to an open state, controlling the opening state of the second valve 16 from a closed state to an open state, and monitoring fluid pressure in the first portion 19’ of the second conduit 19, using the second pressure sensor 23. If the fluid pressure in the first portion 19’ rises, the components 5, 21 , 23, and 16 can be determined to work as intended. If no rise in fluid pressure in the first portion 19’ can be monitored, or if a lower pressure than expected is monitored in the first portion 19’, one or more of the components 5, 21 , 23, and 16 can be determined to not work as intended.

Further, according to these embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the second actuator valve 21 to an open state, controlling the opening state of the second valve 16 from an open state to a closed state, and monitoring fluid pressure in the first portion 19’ of the second conduit 19. If a reduction in fluid pressure in the first portion 19’ is monitored, the components 5, 21 , 23, and 16 can be determined to work as intended. If no reduction in fluid pressure in the first portion 19’ can be monitored, or if a lower reduction in fluid pressure than expected is monitored in the first portion 19’, one or more of the components 5, 21 , 23, and 16 can be determined to not work as intended.

Still further, the control arrangement 5 may be configured to perform a function check of the arrangement 1 by controlling the second valve 16 to an open state, changing the opening state of the second actuator valve 21 , and monitoring fluid pressure in the first portion 19’ of the second conduit 19.

Thus, according to such embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the second valve 16 to an open state, controlling the opening state of the second actuator valve 21 from a closed state to an open state, and monitoring fluid pressure in the first portion 19’ of the second conduit 19, using the second pressure sensor 23. If the fluid pressure in the first portion 19’ rises, the components 5, 21 , 23, and 16 can be determined to work as intended. If no rise in fluid pressure in the first portion 19’ can be monitored, or if a lower pressure than expected is monitored in the first portion 19’, one or more of the components 5, 21 , 23, and 16 can be determined to not work as intended.

Further, according to these embodiments, the control arrangement 5 may perform a function check of the arrangement 1 by controlling the second valve 16 to an open state, controlling the opening state of the second actuator valve 21 from an open state to a closed state, and monitoring fluid pressure in the first portion 19’ of the second conduit 19. If a reduction in fluid pressure in the first portion 19’ is monitored, the components 5, 21 , 23, and 16 can be determined to work as intended. If no reduction in fluid pressure in the first portion 19’ can be monitored, or if a lower reduction in fluid pressure than expected is monitored in the first portion 19’, one or more of the components 5, 21 , 23, and 16 can be determined to not work as intended. In the embodiments described herein, the control arrangement 5 may, in case one or more of the components 5, 21 , 23, and 16 is determined to not work as intended, issue an error code to a control system of the engine, and/or a control system of the vehicle, hosting the compression release brake arrangement 1 .

Fig. 3 schematically illustrates an engine 3, according to some embodiments. The engine 3 comprises four cylinders 8’, 8”, 8”’, 8”” arranged in line. The engine 3 illustrated in Fig. 3 may thus be referred to as an inline-four cylinder engine. The engine 3 may comprise another number of cylinders than four, which may be arranged in another configuration than in inline, as is further explained herein.

The engine 3 comprises a compression release brake arrangement 1 configured to perform compression release braking of at least one cylinder 8’ of the engine 3. Below, reference is made to Fig. 3, as well as to Fig. 1 and Fig. 2. The engine 3 may comprise one compression release brake arrangement 1 per cylinder 8’, 8”, 8”’, 8””. According to such embodiments, the engine 3 may comprise one compression release brake arrangement 1 , according to the embodiments illustrated in Fig. 1 , per cylinder 8’, 8”, 8”’, 8””. Thus, according to such embodiments, the engine 3 illustrated in Fig. 3 may comprise four actuator valves, four pressure sensors 15 and four second valves 13. Thereby, an individual actuation, and cancelation, of compression release braking can be performed of each cylinder 8’, 8”, 8”’, 8””. Further, the detection of, and the elimination of, a malfunction of an actuator valve of a compression release brake arrangement 1 can be performed individually per cylinder 8’, 8”, 8”’, 8””.

According to further embodiments, the engine 3 may comprise a compression release brake arrangement 1 , according to the embodiments illustrated in Fig. 2. According to such embodiments, the valve actuator assembly 7 may be arranged at a first cylinder 8’, the second valve actuator assembly 18 may be arranged at a second cylinder 8”, a third valve actuator assembly may be arranged at a third cylinder 8’”, and a fourth valve actuator assembly may be arranged at a fourth cylinder 8’”. The first portion 9’ of the first conduit 9 of the compression release brake arrangement 1 illustrated in Fig. 2 may be connected to the valve actuator assembly 7 at the first cylinder 8’, and to the third valve actuator assembly at the third cylinder 8’”. Further, the first portion 19’ of the second conduit 19 of the

compression release brake arrangement 1 illustrated in Fig. 2 may be connected to the second valve actuator assembly 18 at the second cylinder 8” and to the fourth valve actuator assembly at the fourth cylinder 8””. Thus, according to such embodiments, the engine 3 may comprise two pressure sensors 15, 23, i.e. the pressure sensor 15 arranged to sense fluid pressure in the first portion 9’ of the first conduit 9, and the second pressure sensor 23 arranged to sense fluid pressure in the first portion 19’ of the second conduit 19. The control arrangement 5 may be configured to selectively control the first and second actuator valves 13, 21 to perform a full compression release braking of the engine 3 by opening both of the first and second actuator valves 13, 21 , and to perform a 50% compression release braking of the engine 3 by opening one of the first and second actuator valves 13, 21. According to some embodiments, the engine 3 comprises cylinders arranged in V- configuration, such as a V-6 or V-8 engine. Thus, in such embodiments, the cylinders of the engine are arranged in a first row and in a second row. According to such embodiments, the engine may comprise a compression release brake arrangement 1 , according to the embodiments illustrated in Fig. 2, wherein the first portion 9’ of the first conduit 9 is connected to valve actuator assemblies of cylinders of the first row of cylinders, and wherein the first portion 19’ of the second conduit 19 is connected to valve actuator assemblies of cylinders of the second row of cylinders. Thus, according to such embodiments, the engine may comprise two pressure sensors 15, 23, i.e. one pressure sensor 15, 23 per row of cylinders. Further, according to such embodiments, the control arrangement may activate valve actuator assemblies of cylinders of the first row of cylinders by opening the first actuator valve 13, and may activate valve actuator assemblies of cylinders of the second row of cylinders by opening the second actuator valve 23.

The engine 3, as referred to herein, may be referred to as an internal combustion engine, and may for example be a compression ignition engine, such as a diesel engine, or an Otto engine with a spark-ignition device, wherein the Otto engine may be configured to run on gas, petrol, alcohol or similar volatile fuels or combinations thereof.

Fig. 4 illustrates a vehicle 25, according to some embodiments. The vehicle 25 comprises wheels 31 and an engine 3 according to the embodiments illustrated in Fig. 3. The engine 3 is configured to provide motive power to the vehicle 25 via one or more of the wheels 31 of the vehicle 25. The vehicle 25 illustrated in Fig. 4 is a truck. Flowever, the engine 3, as referred to herein, may be comprised in 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. Further, the engine 3, as referred to herein, may be a stationary internal combustion engine, for example an internal combustion engine of an engine driven generator.

Fig. 5 illustrates a method 100 of controlling a compression release brake arrangement for an engine. The compression release brake arrangement may be a compression release brake arrangement 1 according to the embodiments illustrated in Fig. 1 , or may be a compression release brake arrangement according to the embodiments illustrated in Fig. 2, and the engine may be an engine 3 according to embodiments illustrated in Fig. 3.

Therefore, below, reference is made to Fig. 5 as well as to Fig. 1 , Fig. 2 and Fig. 3. The method 100, illustrated in Fig. 5, is a method 100 of controlling a compression release brake arrangement 1 for an engine 3, wherein the arrangement 1 comprises: a valve actuator assembly 7 configured to, when supplied with a fluid pressure, perform compression release braking of at least a first cylinder 8’ of the engine 3,

a first conduit 9 arranged to connect the valve actuator assembly 7 to a pressure source 1 1 ,

a first actuator valve 13 configured to control flow in the first conduit 9, a pressure sensor 15 arranged to sense fluid pressure in a first portion 9’ of the first conduit 9 between the valve actuator assembly 7 and the first actuator valve 13, and

a second valve 16 configured to control flow in the first conduit 9, and wherein the method 100 comprises the steps of:

controlling 1 10 the first actuator valve 13 to a closed state,

sensing 120 fluid pressure in the first portion 9’ of the first conduit 9, and controlling 130 the second valve 16 to a closed state in case the sensed fluid pressure is above a predetermined threshold value.

According to some embodiments, the first actuator valve 13 is connected to the pressure source 1 1 via a second and a third portion 9”, 9’” of the first conduit 9, and wherein the second portion 9” of the first conduit 9 connects the first actuator valve 13 to the second valve 16.

According to some embodiments, the method 100 further comprises the steps of:

performing 140 a function check of the arrangement 1 by:

controlling 141 the first actuator valve 13 to an open state,

changing 142 the opening state of the second valve 16, and

monitoring 143 fluid pressure in the first portion 9’ of the first conduit 9.

According to some embodiments, the arrangement 1 further comprises:

a second valve actuator assembly 18 configured to, when supplied with a fluid pressure, perform compression release braking of at least a second cylinder 8” of the engine 3,

a second conduit 19 connecting the second valve actuator assembly 18 to the second portion 9” of the first conduit 9,

a second actuator valve 21 configured to control flow in the second conduit 19, and a second pressure sensor 23 arranged to sense fluid pressure in a first portion 19’ of the second conduit 19 between the second valve actuator assembly 18 and the second actuator valve 21 ,

and wherein the method 100 further comprises:

controlling 1 1 1 the second actuator valve 21 to a closed state,

sensing 121 fluid pressure in the first portion 19’ of the second conduit 19, and controlling 131 the second valve 16 to the closed state in case the sensed fluid pressure in the first portion 19’ of the second conduit 19 is above a predetermined threshold value.

It will be appreciated that the various embodiments described for the method 100 are all combinable with the control arrangement 5 as described herein. That is, the control arrangement 5 may be configured to perform any one of the method steps 1 10, 1 1 1 , 120,

121 , 130, 131 , 140, 141 , 142, and 143 of the method 100.

Fig. 6 illustrates computer-readable medium 200, according to some embodiments. The computer-readable medium 200 comprises instructions which, when executed by a computer, cause the computer to carry out the method 100 according to some embodiments described herein.

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 5, as referred to herein, may be connected to one or more components of the engine 3, and to one or more components of compression release brake arrangement 1 , such as the first actuator valve 13, the second valve 16, the pressure sensor 15, the second actuator valve 21 , and the second pressure sensor 23, in order to perform the method 100 illustrated in Fig. 5.

One skilled in the art will appreciate that the method 100 of controlling a compression release brake arrangement 1 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 5, ensures that the control arrangement 5 carries out the desired control, such as the method steps 1 10, 1 1 1 , 120, 121 , 130, 131 , 140, 141 , 142, and 143 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 5 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 5 may further comprise a memory unit, wherein the calculation unit may be connected to the memory unit, which may provide the calculation unit with, for example, stored program code and/or stored data which the calculation unit may need to enable it to do calculations. The calculation unit may also be adapted to store partial or final results of calculations in the memory unit. The memory unit may comprise a physical device utilised to store data or programs, i.e., sequences of instructions, on a temporary or permanent basis. According to some embodiments, the memory unit may comprise integrated circuits comprising silicon-based transistors. The memory unit may comprise e.g. a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments.

The control arrangement 5 is connected to components of the compression release brake arrangement 1 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 5. These signals may then be supplied to the calculation unit. One or more output signal sending devices may be arranged to convert calculation results from the calculation unit to output signals for conveying to other parts of the vehicle's control system and/or the component or components for which the signals are intended. Each of the connections to the respective components of the compression release brake arrangement 1 for receiving and sending input and output signals may take the form of one or more from among a cable, a data bus, e.g. a CAN (controller area network) bus, a MOST (media orientated systems transport) bus or some other bus configuration, or a wireless connection. In the embodiments illustrated, the compression release brake arrangement 1 comprises a control arrangement 5 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. 1 and 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 1 10, 1 1 1 , 120, 121 , 130, 131 , 140, 141 , 142, and 143 according to some embodiments when being loaded into one or more calculation units of the control arrangement 5. The data carrier may be, e.g. a CD ROM disc, as is illustrated in Fig. 6, or a ROM (read-only memory), a PROM (programable read-only memory), an EPROM (erasable PROM), a flash memory, an

EEPROM (electrically erasable PROM), a hard disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer program product may furthermore be provided as computer program code on a server and may be downloaded to the control arrangement 5 remotely, e.g., over an Internet or an intranet connection, or via other wired or wireless communication systems.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended 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 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.