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Title:
METHOD FOR MONITORING FUNCTION OF A LUBRICATION SYSTEM AND A LUBRICATION SYSTEM
Document Type and Number:
WIPO Patent Application WO/2014/189440
Kind Code:
A1
Abstract:
The invention pertains to a method to track the function in a lubricating system comprising a feeding element (230) and a container (205) for lubricant, as well as elements (250) to measure the level of lubricant in said container (205). The method comprises the steps to continuously, with the lubricating system in operation, determine the level of lubricant in said container (205); to determine a development in said level of lubricant in said container (205); and to determine said function based on said development. The invention also pertains to a computer program product comprising program code (P) for a computer (200; 210) to implement a method according to the invention. The invention also pertains to a lubricating system and a motor vehicle which is equipped with the lubricating system.

Inventors:
EDLUND JOHAN (SE)
TINGSTRÖM JOHAN (SE)
Application Number:
PCT/SE2014/050597
Publication Date:
November 27, 2014
Filing Date:
May 16, 2014
Export Citation:
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Assignee:
SCANIA CV AB (SE)
International Classes:
F01M11/12; F16N29/00; G01M3/26
Foreign References:
JPS5772011A1982-05-06
US20060037387A12006-02-23
US20040035398A12004-02-26
US20110018723A12011-01-27
DE3512082A11986-10-09
Attorney, Agent or Firm:
GARDEMARK, Niklas (Södertälje, SE)
Download PDF:
Claims:
CLAIMS

1. Method to track the function of a lubricating system comprising a feeding element (230) and a container (205) for lubricant as well as elements (250) adapted for the measurement of the level of lubricant in said container (205), characterised by the steps to:

- continuously, with the lubricating system in operation, determine (s310) the level of lubricant in said container (205);

- determine (s320) the development of said level of lubricant in said container (2.05); and

- determine (s330) said function based on said development.

2. Method according to claim 1, comprising the step to:

- in case of a reducing trend in said development of said level of lubricant, take this as an indication (s330) of a leakage in said lubricating system. 3. Method according to claim 1, comprising the step to:

- in case of an increasing trend in said development of said level of lubricant, take this as an indication (s330) of dilution in said lubricating system.

4. Method according to any one of the previous claims, comprising the step to:

- determine a reference value (VI; V2.) for said level of lubricant at the start of operation of said lubricating system.

5. Method according to any one of the previous claims, comprising the step to:

- in case of a determined indication of an unwanted function of the lubricating system, carry out (s340) a measurement of the level of lubricant under certain predetermined operating conditions.

6. Method according to claim 5, wherein said indication of an unwanted function of said lubricating system is determined (s330) based on a rate of change of said development.

7. Method according to claim 5 or 6, wherein said indication of an unwanted function of said lubricating system is determined (s330) based on a comparison of said determined level of lubricant with a predetermined reference value (VI; Ml). 8. Method according to any one of the previous claims, comprising the step to:

-present (s350) information related to said function of said lubricating system to an operator.

9. Method according to any one of the previous claims, comprising the step to:

- on determination of an unwanted function of the lubricating system., determine and present a measure (s350) to said operator.

10. Method according to any one of the previous claims, comprising the step to:

- at the determination of an unwanted function of the lubricating system, automatically deactivate (s360) the operation of an object (240) of the lubricating system.

11. Lubricating system to lubricate an object (240), comprising:

- elements (200; 210; 500) adapted to track the function of a lubricating system, wherein said lubricating system comprises:

- a feeding element (230);

- a container for the lubricant (205);

- elements (250) adapted to measure the level of lubricant in said container (205), characterised by:

- elements (200; 210; 500) adapted to continuously, with the lubricating system in operation, determine the level of lubricant in said container (205);

- elements (200; 210;500) adapted to determine the development of said level of lubricant in said container (205); and

- elements (200) adapted to determine said function based on said development. 12. Lubricating system according to claim 11, comprising:

- elements (200; 210; 500) adapted to, in case of a reducing trend in said development of said level of lubricant, take this as an indication of a leakage in said lubricating system. 13, Lubricating system according to claim 11 or 12, comprising:

- elements (200; 210; 500) adapted to, in case of an increasing trend in said development of said level of lubricant, take this as an indication of dilution in said lubricating system.

14. Lubricating system according to any one of claims 11-13, comprising:

- elements (200; 210; 500) adapted to determine a reference value (VI; V2) for said level of lubricant at the start of operation of said lubricating system. 15. Lubricating system according to any one of claims 11-14, comprising:

- elements (200; 210; 500; 250) adapted to, in case of a determined indication of an unwanted function of the lubricating system, carry out a measurement of the level of lubricant under certain predetermined operating conditions. 16. Lubricating system according to claim 15, comprising:

- elements (200; 210; 500) adapted to determine an indication of an unwanted function of said lubricating system;

- elements (200; 210; 500) adapted to determine said indication, based on a rate of change of said development.

17. Lubricating system according to claim 15 or 16, comprising:

- elements (200, 210; 500) adapted to determine an indication of an unwanted function of said lubricating system, wherein said indication is determined based on a comparison of said determined level of lubricant with a predetermined reference value (VI; V2).

18. Lubricating system according to any one of claims 11-17, characterised by:

- elements adapted to present information related to said function of said lubricating system to an operator. 19. Lubricating system according to any one of claims 11-18, comprising:

- elements (200; 210; 500; 285; 290) adapted to, at the determination of an unwanted function of the lubricating system, determine and present a measure to said operator. 20, Lubricating system according to any one of claims 11-19, comprising:

- elements (200; 210; 500) adapted to, at the determination of an unwanted function of the lubricating system, automatically deactivate the operation of an object (240) of the lubricating system.

21. Motor vehicle (100; 110) comprising a lubricating system according to any one of claims 11-20. 22. Motor vehicle (100; 110) according to claim 21, wherein the motor vehicle is a truck, a bus or a car.

23. Computer program (P) to track the function in a lubricating system, wherein said computer program (P) comprises program code to cause an electronic control device (200; 500), or another computer (210; 500) connected to the electronic control device (200; 500) to perform the steps according to any one of claims 1-10.

24. Computer program product, comprising a program code stored in a computer-readable medium, in order to perform the method steps according to any one of claims 1-10, when said program code is executed in an electronic control device (200, 500) or in another computer (210, 500) connected to the electronic control device (200, 500).

Description:
Method for monitoring function of a lubrication system and a lubrication system TECHNICAL FIELD

The present invention pertains to a method to track the function in a lubricating system. The invention also relates to a computer program product, comprising program code for a computer, to implement a method according to the invention. The invention also pertains to a lubricating system and a motor vehicle which is equipped with the lubricating system.

BACKGROUND

Lubricating systems may be used in different contexts where mechanical parts in an object need to be lubricated. One example of such an object is an engine in a vehicle. At the operation of a vehicle engine, the latter must be supplied with lubricant in order to function as intended. Said lubricant may e.g. be some type of oil. A lubricating system may also be used to lubricate other components in a vehicle, for example wheel shafts, gearbox or a differential device, also called a torque divider. in one type of lubricating system in vehicles, a container which holds said lubricant is included. The lubricating systems also has a pump arranged to pump up said lubricant from the container via a conduit and at a pressure side thereof supply said lubricant to an engine in the vehicle. The lubricant supplied may thus act as a lubricant in said engine, so that friction between said mechanical parts in the engine may be reduced. Thus wear of said engine may be kept at a minimum. Lubricant supplied to said engine may thus, via a conduit intended for this purpose, be led back to said container. Lubricant may be brought back to said container by gravitational effect or by feeding elements for this purpose. Said lubricating system may thus be a closed system. In order to ensure that the required suitable amount of lubricant, one part of which is in said container, is available in the lubricating system, there is a level sensor arranged in the container. When the vehicle and thus the lubricating system are in a suitable operating mode and in a suitable location, a measurement of the lubricant levei in the container is carried out according to prior art technology. Typically, a prevailing amount of lubricant is then detected in the lubricating system at an upstart of the vehicle, where the vehicle may be assumed to stand on a flat surface and the operating conditions for said detection are favourable, for example at idling of said engine. if the lubricant level falls below a certain predetermined value, this may be taken as an indication that lubricant needs to be filled up in the lubricating system. If the lubricant levei falls below a certain predetermined value, this may, alternatively, be taken as an indication that there is a leakage in the lubricating system. if the lubricant level exceeds a certain predetermined value, this may be taken as an indication that a dilution of the lubricant has occurred, and that the lubricating system must be investigated further. Said dilution may have different reasons.

The expression "take as an indication" may comprise to "determine an indication". it is extremely important that the amount of lubricant continuously exceeds a certain level, since too low a level may cause damage in said object which is to be supplied with lubricant by said lubricating system. It is also of the utmost importance to detect any dilution of lubricant in the lubricating system since this may also cause damage in said object, or impact the same negatively in some respect, for example in terms of performance.

According to prior art, in many cases there may be a relatively long period of time between measurements of the prevailing level of lubricant in the lubricating system of the vehicle. This may often be a consequence of unfavourable operating conditions generally prevailing while said vehicle is driven, in order for adequate measurements of the lubricant level to be carried out. This may mean that, when a level of lubricant is detected in the container, where the level fails below a certain predetermined reference value, said level may have fallen below said predetermined reference value a long time ago. Thus damage may have been caused to said object, in the worst case scenario, said object may be subject to a failure. Similarly, this may mean that a level of lubricant in the container may have exceeded a certain predetermined reference value a long time ago. Thus damage may have been caused to said object. In the worst case, said object may be subject to a failure in this case as well. it is thus desirable to, in as efficient a manner as possible, ensure that a lubricant level of said lubricating system is within a certain suitable interval, in order to avoid damage to an object which will be supplied with lubricant by said lubricating system, where the damage is caused by for example leakages or dilution of lubricant. US5831154, EP106349S, US20100194554 describe different methods to determine an oil level in a vehicle,

SUMMARY OF THE INVENTION One objective of the present invention is to provide a novel and advantageous method to track the function in a lubricating system.

Another objective of the invention is to provide a novel lubricating system and a novel and advantageous computer program to track the function in a lubricating system.

Yet another objective of the invention is to provide a method, a lubricating system and a computer program to achieve improved performance in a motor vehicle.

Some of these objectives are achieved with a method to track the function of a lubricating system according to claim 1. Other objectives may be achieved with a lubricating system according to claim 11. The preferred embodiments are specified in the dependent claims.

According to one aspect of the present invention, a method to track the function of a lubricating system, comprising a feeding element and a container for lubricant as well as elements to measure the level of lubricant in said container, are provided. The method comprises the steps: - to continuously determine, with the lubricating system in operation, the ievei of lubricant in said container;

- to determine the development of said Ievei of lubricant in said container; and

- to determine said function based on said development.

According to one aspect of the invention the level of the lubricant in said container is determined with a suitable level gauge. Said level gauge may comprise a mechanical or a non-mechanical sensor. According to one aspect, the sensor may comprise an optical sensor, an acoustic sensor or a sensor of float type.

According to one aspect of the invention, the container with lubricant may, when the lubricating system is in operation, be located on different gradients. According to another aspect, a number of lubricants may be located in different places in the lubricating system, and thus not in the container. According to another aspect, the lubricant in the container may slosh around in the container. The above mentioned factors impact the level of lubricant in the container.

Since a number of different factors, in addition to the amount of lubricant in the lubricating system, impact the Ievei of lubricant in the container, the level of lubricant in said container is, according to the method according to the invention, determined continuously during the lubricating system's operation.

By continuously determining the ievei of said lubricant in said container, a number of measuring points/ measuring values are obtained. By taking into consideration said measuring points/measuring values, a development in said level of lubricant may be determined continuously.

According to one aspect of the present invention, said development may be determined by comparing each measuring value relating to the Ievei of lubricant with a predetermined reference value. Where a measuring value exceeds said predetermined reference value, said development may be determined. According to one aspect of the present invention, said development may be determined by comparing each measuring value relating to the level of lubricant with a predetermined reference value. Where a measuring value falls below said predetermined reference value, said development may be determined.

According to one aspect of the present invention, said development may be determined by determining the number of measuring values regarding the level of lubricant, which exceed a certain predetermined reference level of lubricant during a certain predetermined time period. Where a certain predetermined number of measuring values regarding the level of lubricant exceeds said reference level during a certain predetermined time period, said development may be determined.

According to one aspect of the present invention, said development may be determined by determining the number of measuring values regarding the level of lubricant, which fall below a certain predetermined reference level of lubricant during a certain predetermined period of time. Where a certain predetermined number of measuring values regarding the level of lubricant falls below said reference level during a certain predetermined time period, said development may be determined. According to one aspect of the present invention, said development may be determined by analysing the level of lubricant as a function of time. Where a positive trend in the level of said lubricant may be detected from said analysis, said development may be determined.

According to one aspect, said development may be determined by analysing the level of lubricant as a function of time. Where a negative trend in the level of said lubricant may be detected from said analysis, said development may be determined.

According to one aspect of said invention, a function of said lubricating system may be determined based on said development.

The method may comprise the step to: - in case of a reducing trend in said development of said level of lubricant, take this as an indication of a leakage in said lubricating system.

According to one aspect of the present invention, a reducing trend in said development of said level of lubricant may comprise a case, where a measuring value relating to the level of lubricant falls below a predetermined reference value.

According to one aspect of the present invention, a reducing trend in said development of said level of lubricant may comprise a case, where a certain predetermined number of measuring values relating to the level of lubricant fall below a predetermined reference value during a certain predetermined period of time.

According to one aspect of the present invention a reducing trend in said development of said level of lubricant may comprise a case, where an analysis of the level of lubricant as a function of time indicates a negative/reducing trend.

According to one aspect of the present invention, a reducing trend in said development of said level of lubricant may comprise a case, where an analysis of the level of lubricant as a function of time indicates a negative trend, where a negative trend entails that the level change over a certain time is reducing, i.e. the time derivative is negative and falls below a certain predetermined reference value.

The method may comprise the step to:

- in case of an increasing trend in said deveiopment of said level of lubricant, take this as an indication of dilution in said lubricating system.

According to one aspect of the present invention, an increasing trend in said development of said level of lubricant may comprise a case, where a measuring value relating to the level of lubricant exceeds a predetermined reference value.

According to one aspect of the present invention an increasing trend in said development of said level of lubricant may comprise a case, where a certain predetermined number of measuring values relating to the level of lubricant exceed a predetermined reference value during a predetermined period of time.

According to one aspect of the present invention, an increasing trend in said development of said level of lubricant may comprise a case, where an analysis of the level of lubricant as a function of time indicates a positive/increasing trend.

According to one aspect of the present invention an increasing trend in said development of said level of lubricant may comprise a case, where an analysis of the level of lubricant as a function of time indicates a positive trend, i.e. the time derivative is positive and exceeds a certain predetermined reference value.

The method may comprise the step to:

- determine a reference value for said level of lubricant at the start of operation of said lubricating system.

According to one aspect of the present invention, a reference value for said level of lubricant is determined at the start of operation of said lubricating system, or at the start of operation of an object which is lubricated by the lubricating system. According to one aspect of the present invention, a reference value is determined only where certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a certain predetermined temperature interval. Another condition may be that said lubricating system has been shut off for a certain predetermined time before the measurement was carried out. Other conditions may also be suitable and relevant.

According to one aspect of the present invention, a reference value for said level of lubricant is determined when the lubricating system is in operation. According to one aspect, a reference value is determined only where certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a certain predetermined temperature interva Other conditions may also be suitable and relevant.

Said reference value may be used to determine whether the lubricant needs to be filled up. Said reference value may, according to one aspect of the present invention, be used to calculate new reference values. One reference value, which is determined at said start of operation, provides a level of the lubricant where a considerable part of the lubricant is in the container and where the container is on a plane and horizontal base, or in another favourable condition. This reference value may be used as a base to calculate new reference values. When the lubricating system is in operation, an amount of lubricant is spread out in other parts of the lubricating system, or in objects which are lubricated by the lubricating system. The level of lubricant in the container will thus typically be lower during operation, compared to the level of lubricant at the start of operation of the lubricating system, in the cases where the lubricating system's function is satisfactory.

The method may comprise the step to:

- in case of a determined indication of unwanted function of the lubricating system, carry out a measurement of the level of lubricant under certain predetermined operating conditions.

According to one aspect of the present invention, in case of a determined indication of unwanted function of the lubricating system, a measurement to control suspected leakages or dilution under certain operating conditions may be carried out. According to one example, the lubricating system may be shut off and subsequently a measurement to check the level of the lubricating system may be carried out. According to another aspect of the present invention, measurement may be carried out under other operating conditions, where aspects such as the lubricating system's gradient, the temperature of the lubricant or other factors determine whether the operating conditions are suitable to carry out said measurement. According to one embodiment, unwanted function in said lubricating system may be determined based on a comparison of said determined level of lubricant with a predetermined reference value. According to one embodiment, it may be determined that said function in said lubricating system is not unwanted, based on a comparison of said determined level of lubricant with a predetermined reference value.

Said reference value may either be a measuring value relating to a level of lubricant in a container, where said reference value is determined in connection with a certain predetermined operating condition, e.g. at the start of operation of the lubricating system.

According to one aspect of the present invention, a reference value is calculated based on a measured reference value. According to one alternative, said reference value may be a predetermined value belonging to said lubricating system. Alternatively, said reference value may be based on features of an object, which is supplied with lubricant from said lubricating system. Said reference value may be adjusted. Said reference value is a suitable value.

According to one embodiment, said indication of unwanted function of said lubricating system may be determined based on stored information in the lubricating system.

According to one aspect of the present invention, said stored information may comprise information relating to said lubricating system's previous operation, where said information may comprise measured levels of lubricant at operation, reference values, control measurements and indications of leakages or dilution.

According to one example, a control measurement of the level of lubricant in a container may be carried out in case of a reducing trend in a development of said level. The control measurement may be carried out at certain operating conditions, e.g. at start of operation of the lubricating system. According to one aspect of the present invention, a control measurement is carried out only when certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a predetermined temperature interval. Another condition may be that said lubricating system has been shut off for a predetermined time before the measurement was carried out. Other conditions may be suitable and adequate. Other conditions impacting the level of lubricant may also be comprised in said operating conditions. If the control measurement shows a level of lubricant which is below a certain reference value VI, a leakage may be confirmed. Said reducing trend in a development of said level of lubricant and an indication of said trend showing a leakage may be stored as information in the lubricating system.

According to one example, a control measurement of the level of lubricant in a container may be carried out in case of a reducing trend in a development of said level. The control measurement may be carried out at certain operating conditions, e.g. at start of operation of the lubricating system. According to one aspect of the present invention, a control measurement is carried out only when certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a certain predetermined temperature interval. Another condition may be that said lubricating system has been shut off for a certain predetermined time before the measurement was carried out. Other conditions may be suitable and adequate. Other conditions impacting the level of lubricant may also be comprised in said operating conditions, if the control measurement shows a level of lubricant which is above a certain reference value VI, a leakage may be ruled out. Said reducing trend in a development of said level of lubricant and an indication that said trend does not show a leakage may be stored as information in the lubricating system.

According to one aspect of the present invention, a control measurement of the level of lubricant in a container may be carried out in case of an increasing trend in the development of said level. The control measurement may be carried out at certain operating conditions, e.g. at start of operation of the lubricating system. According to one aspect of the present invention, a control measurement is carried out only when certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a certain predetermined temperature interval. Another condition may be that said lubricating system has been shut off for a certain predetermined time before the measurement was carried out. Other conditions may be suitable and adequate. Other conditions impacting the level of lubricant may also be comprised in said operating conditions, if the control measurement shows a level of lubricant which is above a certain reference value V2, dilution may be confirmed. Said increasing trend in the development of said level of lubricant is stored in the lubricating system. An indication of said trend showing dilution may be stored as information in the lubricating system.

According to one example a control measurement of the level of lubricant in a container may be carried out in case of an increasing trend of the development of said level. The control measurement may be carried out at certain operating conditions, e.g. at start of operation of the lubricating system. According to one aspect of the present invention, a control measurement is carried out only when certain conditions of said lubricating system or its surrounding environment are met. Such a condition may be that the lubricating system is located on a plane and horizontal base. Another condition may be that a temperature of the lubricant is within a predetermined temperature interval. Another condition may be that said lubricating system has been shut off for a predetermined time before the measurement was carried out. Other conditions may be suitable and adequate. Other conditions impacting the level of lubricant may also be comprised in said operating conditions. If the control measurement shows a level of lubricant which is below a certain reference value V2, dilution may be ruled out. Said increasing trend in a development of said level of lubricant and an indication that said trend does not show dilution may be stored as information in the lubricating system.

Said stored information may be used to adjust the reference values relating to the level of lubricant, time intervals and reference value of the level change over time. Thus the lubricating system is self-learning according to one aspect of the present invention. The lubricating system is thus an adaptive lubricating system. According to one aspect., more frequent measurements of the level of lubricant in a container may be carried out when an increasing or a reducing trend is determined.

The method may comprise the step to:

- present information related to said function of said lubricating system to an operator.

The method may comprise the step to:

- on determination of a wanted function in the lubricating system, to present information to an operator.

The method may comprise the step to:

- on determination of an unwanted function of the lubricating system, to determine and present a measure to said operator. According to one aspect of the present invention, information relating to the prevailing level of lubricant in the container may be presented to an operator, information relating to the prevailing rate of change of the level during a certain time period, and potential other information connected to a development of said level of lubricant, may be presented to an operator, e.g. via a screen. According to one aspect of the present invention, a determined unwanted function of the lubricant may be presented to said operator via a lamp or a loudspeaker or another suitable device.

According to one aspect of the present invention, a measure is presented to said operator. Such a measure may comprise a call for the operator to control the lubricating system to a certain operating mode, where a control measurement of the level of the lubricating system may be carried out. Another measure may be that the lubricant should be filled up in the system. Another measure may be that the operator should shut off the lubricating system or an object comprised in the lubricating system or connected to the lubricating system. Another measure may be that the operator must shut the lubricating system off.

The method may comprise the step to: - at the determination of an unwanted function of the lubricating system, automatically shut off the lubricating system.

The method may comprise the step to:

- at the determination of an unwanted function of the lubricating system, automatically deactivate the operation of said object of the lubricating system.

According to one aspect, the lubricating system may be automatically shut off when an unwanted function of the lubricating system is determined. According to one aspect, an object comprised in said lubricating system may by shut off automatically when an unwanted function of the lubricating system is determined. According to one aspect, an object which is supplied with lubricant by said lubricating system may be shut off automatically when an unwanted function of the lubricating system is determined. The method may be implemented in existing motor vehicles. Program code to track the function of a lubricating system may, according to one aspect of the invention, be installed in a control device of the vehicle when the same is manufactured. A purchaser of the vehicle may thus be afforded the opportunity to select the performance function as an extra option. Alternatively, program code to perform the method according to the invention may be installed in a control device of the vehicle, when upgraded at a service station. In this case, the software may be uploaded into a memory in the control device.

Program code to track the function of a lubricating system may be updated or replaced. In addition, different parts of the program code may be replaced independently of each other. This modular configuration is advantageous from a maintenance perspective.

According to one aspect of the present invention, a lubricating system is provided to lubricate an object, where said lubricating system comprises:

- elements adapted to track the function in a lubricating system;

- a feeding element;

- a container for the lubricant;

- elements for measurement of the level of lubricant in said container; - elements to continuously, with the lubricating system in operation, determine the level of lubricant in said container;

- elements to determine the development of said level of lubricant; and

- elements to determine said function based on said development.

According to one aspect of the present invention, said lubricating system comprises said object to be lubricated. According to one aspect of the present invention, said object is supplied with lubricant by the lubricating system, but is not comprised in said lubricating system.

The lubricating system may comprise elements adapted to, at a reducing trend of said development of said level of lubricant, take this as an indication of a leakage in said lubricating system. The lubricating system may comprise elements adapted to, at a reducing trend of said development of said level of lubricant, determine an indication of a leakage in said lubricating system. The lubricating system may comprise elements adapted to, at an increasing trend of said development of said level of lubricant, take this as an indication of dilution in said lubricating system. The lubricating system may comprise elements adapted to, at an increasing trend of said development of said level of lubricant, determine an indication of dilution in said lubricating system. The lubricating system may comprise elements adapted to determine a reference value for said level of lubricant at the start of operation of said lubricating system. The lubricating system may comprise elements adapted to, in case of a determined indication of an unwanted function of the lubricating system, carry out a measurement of the level of lubricant under certain predetermined operating conditions. The lubricating system may comprise elements adapted to determine an indication of an unwanted function of said lubricating system, where said indication comprises a rate of change in said development. The lubricating system may comprise elements adapted to determine an indication of an unwanted function of said lubricating system, where said indication is determined based on a comparison of said determined level of lubricant with a predetermined reference value.

The lubricating system may comprise elements to determine an indication of an unwanted function in said lubricating system, based on empirically determined information, where said empiricaliy determined information comprises information about continuously determined levels of lubricant, determined development and determined level of lubricant at the control measurement. The lubricating system may comprise elements adapted to present information related to said function of said lubricating system to an operator.

The lubricating system may comprise elements adapted to, at the determination of an unwanted function of the lubricating system, determine and present a measure to said operator.

The lubricating system may comprise elements adapted to, at the determination of an unwanted function of the lubricating system, automatically shut off the lubricating system. The device may comprise elements adapted to, at the determination of an unwanted function of the lubricating system, automatically deactivate the operation of an object of the lubricating system.

The lubricating system may comprise:

- elements adapted to determine an indication of an unwanted function of said lubricating system;

- elements adapted to determine said indication, based on a rate of change of said development.

The lubricating system may comprise elements adapted to, at the determination of an unwanted function of the lubricating system, automatically shut off an object which is supplied with lubricant by said lubricating system.

The above objectives are also achieved with a motor vehicle comprising the method according to the invention, in order to track the function of a lubricating system. The motor vehicle may be a truck, a bus or a car. According to one aspect of the invention, a computer program is provided to track the function in a lubricating system, wherein said computer program comprises program code to cause an electronic control device or another computer, connected to the electronic control device, to perform the steps according to any of claims 1-10.

According to one aspect of the invention, a computer program is provided to track the function in a lubricating system, wherein said computer program comprises program code stored on a computer readable medium to cause an electronic control device or another computer, connected to the electronic control device, to perform the steps according to any of claims 1-10.

According to one aspect of the invention, a computer program product comprising program code stored in a computer-readable medium is provided to perform the method steps according to any of the claims 1-10, when said program code is executed in an electronic control device or in another computer connected to the electronic control device.

Additional objectives, advantages and novel features of the present invention will be apparent to one skilled in the art from the following details, and through exercising the invention. While the invention is described below, it should be apparent that the invention is not limited to the specifically described details. One skilled in the art, having access to the teachings herein, will recognise additional applications, modifications and incorporations in other areas, which are within the scope of the invention.

GENERAL DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and the additional objects and advantages thereof, reference is now made to the following detailed description, which is to be read together with the accompanying drawings, in which the same reference designations pertain to identical parts in the various figures, and in which:

Figure 1 schematically illustrates a vehicle, according to one embodiment of the invention; Figure 2 schematically illustrates a lubricating system, according to one embodiment of the invention;

Figure 3a schematically illustrates a flow chart of a method., according to one embodiment of the invention;

Figure 3b schematically illustrates in more detail a flow chart of a method, according to one aspect of the invention;

Figure 4a schematically illustrates a diagram, according to one aspect of the invention; Figure 4b schematically illustrates a diagram, according to one aspect of the invention; Figure 5 schematically illustrates a computer, according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE FIGURES

A side view of a vehicle 100 is shown with reference to Figure 1. The exemplary vehicle 100 consists of a tractor 110 and a trailer 112. The vehicle 100 comprises a lubricating system 299 to lubricate at least one object 240 of the vehicle 100. Said lubricating system 299 and said object 240 are described in further detail with reference to, for example, Figure 2. The vehicle may be a heavy goods vehicle, such as a truck or a bus. The vehicle may, alternatively, be a car. The vehicle may alternatively be a truck, a dumper, a crane, or another suitable platform comprising a lubricating system adapted to lubricate at least one object in the vehicle. it should be pointed out that the invention is suitable for application in any suitable lubricating system comprising at least one object which must be lubricated, and is therefore not limited to lubricating systems of motor vehicles. The method according to the invention and the lubricating system according to one aspect of the invention are well suited to platforms other than motor vehicles comprising a lubricating system, such as e.g. watercraft. The watercraft may be of any suitable type, such as e.g. motor boats, ships, ferries, submarines, hovercraft or vessels. The method according to the invention and the lubricating system according to one aspect of the invention are also suitable for e.g. systems comprising for example a stone crusher or similar.

The method according to the invention and the lubricating system according to one aspect of the invention are also suitable for e.g. systems comprising industrial engines and/or engine driven industrial robots.

The method according to the invention and the lubricating system according to one aspect of the invention are also suitable for different types of power plants, e.g. electricity production comprising a diesei generator.

The method according to the invention and the lubricating system according to the invention are also well suited for any suitable engine system comprising an engine and an appurtenant lubricating system, such as e.g. in a locomotive or another platform.

The method according to the invention and the lubricating system according to the invention are well suited for any type of system comprising an NQ x -gerterator and an appurtenant lubricating system.

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

The term "conduit" herein means a passage to hold and transport a fluid, such as a reducing agent in liquid form. The conduit may be a conduit of any dimension. The conduit may consist of any suitable material, such as plastic, rubber or metal.

The term "lubricant" herein means a substance which is suitable for use when lubricating an object in said lubricating system. Said object 240 may be an engine in said vehicle 100. Said lubricant is according to one embodiment so-called lubricating oil. Said lubricating oil may be an ethylene based lubricating oil. Said lubricant may be a wet substance intended to reduce friction in an object, such as an engine, between moveable parts therein and to reduce wear of these parts. Said lubricant may be a suitable fluid intended to reduce friction in an object, such as an engine, between moveable parts therein and to reduce wear of these parts.

Said lubricant may be a synthetic lubricant. Said lubricant may be an organic lubricant. Said lubricant may be formed by a mixture of a synthetic lubricant and an organic lubricant. Said lubricant may be any suitable lubricant. Said lubricant may have a suitable viscosity. Said lubricant may have a suitable density.

Naturally, other types of suitable lubricants may be used according to the method according to the invention and the lubricating system according to the invention. Lubricating oil is given herein as an example of a lubricant, however, a person skilled in the art will realise that the method according to the invention and the lubricating system according to the invention may be realised for other types of lubricants.

With reference to Figure 2, a lubricating system 299 in the vehicle 100 is displayed. The lubricating system 299 may be arranged in the tractor 110. The lubricating system 299 may comprise at least one object 240. The lubricating system 299 is arranged to lubricate said object 240 with lubricant in a suitable manner. Said object comprises a number of components which require lubrication in a suitable manner.

Said object 240 may according to one aspect be comprised in said lubricating system. According to one aspect said object 240 may be supplied with lubricant by said lubricating system, but not comprised in said lubricating system.

Said object 240 may be an engine. Said engine may be a combustion engine arranged, via a transmission intended for this purpose (not displayed) to drive driving wheels (not displayed) in said vehicle 100. According to one example embodiment, said object 240 may be a gearbox in said transmission of said vehicle 100. According to one example embodiment, said object may be a differential device in said transmission of the vehicle 100. The device 299 comprises, according to this example, a container 205 which is arranged to hold said lubricant. The container 205 is arranged to contain a suitable amount of lubricant. Said container 205 is arranged with a suitable valve configuration (not displayed), through which valve configuration for example service staff may tap lubricant from the lubricating system. Said container 205 is also arranged to be refillable with lubricant as and when needed.

A first conduit 271 is arranged to lead said lubricant to a pump 230 from the container 205. The pump 230 may be any suitable pump. The pump 2.30 may be a membrane pump comprising at least one filter. The pump 2.30 may be arranged to be driven with an electric motor (not shown). The pump 230 may be arranged to pump up said lubricant from the container 2.05 via the first conduit 271, and to supply, via a second conduit 272, said lubricant to said object 240 for lubrication.

A third conduit 2.73 is arranged between said object 240 and said container 205. The third conduit 273 is arranged to recycle said lubricant supplied to the object 240 to the container 205. This may according to one example embodiment occur by way of gravitational effect. According to one alternative the recycling of lubricant may occur through means (not displayed} designed for this purpose, for example an additional pump. Thus a closed system for said lubricant is provided.

The first control device 200 is arranged for communication with the pump 230 via a link L230. The first control device 200 is arranged to control the operation of the pump 230. According to one example, the first control device 200 is arranged to control the pump 230 with an electric motor (not shown). According to one example, the first control device 200 is arranged to control the operation of the pump by changing a prevailing engine speed RPM in the pump 230. According to another example, the first control device 200 is arranged to control the operation of the pump by changing a stroke in the pump 230.

The first control device 200 is arranged for communication with a level sensor 250 via a link L250. Said level sensor 250 is arranged to continuously detect a prevailing level of lubricant in the container 205, Said level sensor 250 may be arranged to intermittently detect a prevailing level of lubricant in the container 205. Said level sensor 250 is arranged to continuously detect a prevailing level of lubricant in the container 205 during the operation of the vehicle 100. Said level sensor 250 is arranged to continuously detect a prevailing level of lubricant in the container 205 during travelling with the vehicle 100. Said level sensor 250 is arranged to continuously send signals S250, comprising information regarding a prevailing level of lubricant in the container 205, to the first control device 200 via the link 1.250. it should be pointed out that said level of lubricant represents a certain volume of lubricant in the container. Since the container's configuration is known, a detected level of lubricant in the container 205 may be converted to a corresponding volume of lubricant in the container 205, and vice versa. Thus, the method according to the invention may be based on determined levels of lubricant in the container and/or determined volume measurements relating to lubricant in the container 205.

Said level sensor 250 may comprise an optical sensor. Thus for example laser lights may be used to determine said prevailing level of lubricant in the container 205.

Said level sensor 250 may comprise an acoustic sensor. Thus for example sound waves may be used to determine said prevailing level of lubricant in the container 205.

Said level sensor 250 may comprise a so-called float sensor.

Said level sensor 250 may be a mechanical sensor. Said level sensor 250 may be a non- mechanical sensor, for example said optical sensor. Said level sensor 250 may be an electromechanical sensor, for example said float-sensor.

The first control device 200 is arranged for communication with the object 240 via a link L240. The first control device 200 is arranged to control the operation of said object. In case said object is an engine, an engine speed of said engine may for example be impacted. In case said object is a gearbox, gear steps in the gearbox may be impacted, for example by way of up-shifting or down-shifting. In case said object is a differential device, gear steps in the differential device may be impacted, for example by way of up-shifting or downshifting.

The first control device 200 is arranged to continuously, with the lubricating system in operation, determine the level of lubricant in said container 205. The first control device 200 is arranged to determine the development of said level of lubricant in said container 205, The first control device 200 is arranged to determine said function, based on said development.

The first control device 200 is arranged to, at a reducing trend of said development in said level of lubricant, take this as an indication of a leakage in said lubricating system. The first control device 200 is arranged to, at an increasing trend of said development in said level of lubricant, take this as an indication of dilution in said lubricating system. The first control device 200 is arranged to determine a reference value for said level of lubricant at the start of operation of said lubricating system. The first control device 200 is arranged, in case of a determined indication of an unwanted function of the lubricating system, to carry out a measurement of the level of lubricant under certain predetermined operating conditions. The first control device 200 is arranged to determine said indication of an unwanted function, based on a comparison of said determined level of lubricant with a predetermined reference value. The first control device 200 is arranged to present information related to said function in said lubricating system to an operator via a presentation element 285. The first control device 200 is arranged to, at the determination of an unwanted function in the lubricating system, determine and present a measure to said operator. The first control device 200 is arranged to, at the determination of an unwanted function of the lubricating system, automatically deactivate the operation of an object 240 of the lubricating system.

The first control device 200 is arranged for communication with said presentation means 285 via a link L285. The said presentation element 285 may be arranged in a driver's cabin in the vehicle 100. The said presentation element 285 may be fixed in the vehicle 100. The said presentation element 285 may be a mobile electronic device. The said presentation element 285 may comprise e.g. a display screen. The first control device 200 is arranged, through said presentation element 285, to present relevant information relating to the innovative method in order to track the function in a lubricating system for an operator of the vehicle 100, The first control device 200 may be arranged to present, via said presentation element 285, a result as to whether or not a function of the lubricating system 299 is adequate. The first control device 200 may be arranged to present, via said presentation element 285, a suitable measure to said operator, where inadequate function of the lubricating system 299 is determined.

The first control device 200 is arranged for communication with a communication device 280 via a link L280. The said communication device 280 may be arranged in a driver's cabin in the vehicle 100. Said communication device 280 may comprise a sender-receiver. Said communication device 280 is arranged for communication with a terminal 290 via a link L290, external to the vehicle. The first control device 200 is arranged to continuously or intermittently send signals S280, via said communication device 280, to said terminal 290. Said signals may comprise information regarding a prevailing volume of said lubricant in said container 205. Said signals may comprise information regarding a prevailing level of said lubricant in said container 205. Said signals may comprise information regarding a determined development of a level or volume of lubricant in said container 205. Said signals may comprise information regarding a determined function of said development of a level or volume of lubricant in said container 205. Said signals may comprise information about a determined measure regarding said object 240 or lubricating system 299. Said terminal 290 may be comprised in a service station, workshop, a trucking company owner- station or a so-called fleet management system. Thus the staff at said terminal may continuously be updated regarding the status of said lubricating system. According to one embodiment, the first control device 200 may be arranged to send signals S280, comprising said detected level or volume of said lubricant in the container 205. Thus said terminal may be arranged to carry out the steps according to the invention, for example to determine the development of said level of lubricant in said container 205 and/or to determine said function based on said development.

A second control device 210 is arranged for communication with the first control unit 200 via a link L210. The second control device 210 may be detachably connected to the first control device 200. The second control device 210 may be a control unit external to the vehicle 100. The second control device 210 may be arranged to carry out the method steps according to the invention. The second control device 210 may be used to transfer program code to the first control device 200, in particular program code to perform the method according to the invention. Alternatively, the second control device 210 may be arranged for communication with the first control device 200 via an internal network in the vehicle. The second control device 210 may be arranged to carry out substantially the same functions as the first control device 200, such as e.g. to determine the development of said level of lubricant in said container and/or to determine said function based on said development.

Figure 3a schematically illustrates a flow chart of a method to track the function of a lubricating system to lubricate at least one object 240, where said lubricating system comprises a feeding element 2.30 and a container 205 for lubricant, and elements 250 for level measurement of lubricant in said container 205. The method comprises a method step s301. The step s301 comprises the steps to:

- continuously, with the lubricating system in operation, determine the level of lubricant in said container 205;

- determine the development of said level of lubricant; and

- determine said function based on said development.

Following the method step s301 the method is completed.

Figure 3a schematically illustrates a flow chart of a method to track the function of a lubricating system to lubricate at least one object 240, where said lubricating system comprises a feeding element 230 and a container 205 for lubricant, and elements 250 for level measurement of lubricant in said container 205, according to one aspect of the invention.

The method comprises a method step s310. The method step s310 comprises the step to continuously determine the level of lubricant in said container 205. Continuously may mean that the level of lubricant is determined when a vehicle, in which the lubricating system is located, is in operation. This means that the level of the lubricating system is impacted by the vehicle's gradient, the temperature of the lubricant, the operating mode of the vehicle's engine etc. According to the method according to the invention, a continuous measurement of the level of lubricant is made regardless of the above said impacting factors.

Following the method step s310, a subsequent method step s320 is completed.

The method step s320 comprises the step to determine a development of said level of said lubricant. The method may comprise the step to, by continuously determining the level of said lubricant in said container 205, obtain a number of measuring points. By considering measuring points with respect to the level of lubricant in relation to predetermined reference levels VI, V2 the development of said levei of lubricant may be determined. By considering measuring points with respect to predetermined reference levels VI, V2 during a certain time interval, the development of said level of lubricant may be determined. By considering the level change over time, a development of said level of lubricant may be determined. The method step may comprise the step to determine at least one reference value VI, V2 for said level of lubricant at the start of operation of said lubricating system. Following the method step s320, a subsequent method step s330 is completed.

The method step s330 comprises the step to determine the function of said lubricating system. The method step comprises the step to, in case of a reducing trend in said development of said level of lubricant, take this as an indication of a leakage in said lubricating system. The method step comprises the step to, in case of an increasing trend in said development of said level of lubricant, take this as an indication of dilution in said lubricating system. The method steps may comprise the step to analyse a rate of change, in order to determine an indication of an unwanted function in said lubricating system. The method step may comprise the step to compare said determined levei of lubricant with a predetermined reference value, in order to determine an indication of an unwanted function of said lubricating system. Following the method step s330., a subsequent method step s340 is completed.

The method step s340 comprises the step to determine a measure. The method step may comprise the step to, in case of a determined indication of unwanted function of the lubricating system 299, carry out a measurement of the level of lubricant under certain predetermined operating conditions. The method step may comprise the step to, in case of a determined indication of an unwanted function of the lubricating system 299, carry out more frequent measurements of said level of said lubricant. Following the method step s340, a subsequent method step s350 is completed.

The method step s.350 comprises the step to present a measure to an operator. The method step comprises the step to present information related to said function of said lubricating system to an operator. The method step may comprise the step to, at the determination of an unwanted function in the lubricating system 299, to determine and present a measure to said operator.

Following the method step s350, a subsequent method step s360 is completed. The method step s.360 comprises the step to, at the determination of an unwanted function of the lubricating system, automatically deactivate the operation of an object 240 of the lubricating system 299.

Following the method step s360 the method is completed. Alternatively, the method starts again at the method step s310.

Figure 4a schematically illustrates a diagram according to one aspect of the present invention. In the diagram an example of measuring data representing a prevailing lubricant level V is illustrated, in the diagram said lubricant level V is specified in litres L In the diagram said lubricant level V is specified as a function of time T. The time T is specified in seconds s. Said lubricant level V may alternatively be specified in terms of level of lubricant in said container 205. At a first point in time 11, the lubricating system 299 is started. Herein a first level VI of lubricant prevails in the container 205. Herein it is apparent that a continuously detected level V of lubricant in the container 205 increases over time. Such a development may indicate some form of dilution of lubricant in the lubricating system 299, which dilution may be caused by leakages of for example coolant or another fluid in the vehicle 100.

By determining a development of said level V in the form of for example an adaptation Vmeanl, for example through a suitable calculation method, a trend in said development may be determined. in Figure 4a said development has a positive trend. This may be determined in a number of different ways. According to a first variant, a positive trend in said development may be determined if a predetermined number of measuring values V exceed a predetermined reference value V2. within a predetermined time interval. Said predetermined time interval is defined, according to this example, by a time period T3-T4. Said predetermined time interval may be for example 5 or 60 seconds. Said predetermined time interval may be longer than 60 seconds, for example 5 minutes.

According to a second variant, a positive trend in said development may be determined if an individual value V exceeds a reference value V2 at a point in time, herein illustrated with the point in time T3.

According to a third variant, a positive trend of said development may be determined if a determined derivative of said adaptation Vmeanl, at a certain point in time or within a certain time interval, for example a time interval Τ1-Ϊ2, exceeds a predetermined value Vderl.

Said predetermined reference value V2 may be an adaptive!y adjustable value. Said predetermined value Vderl may be an adaptively adjustable value.

Figure 4b schematically illustrates a diagram according to one aspect of the present invention, in the diagram an example of measuring data representing a prevailing lubricant level V is illustrated, in the diagram said lubricant level V is specified in litres L. in the diagram said lubricant level V is specified as a function of time T. The time T is specified in seconds s. Said lubricant level V may alternatively be specified in terms of level of lubricant in said container 205.

At a first point in time Tl, the lubricating system 299 is started. Herein a first level V2 of lubricant prevails in the container 205. Herein it is apparent that a continuously detected level V of lubricant in the container 205 decreases over time. Such a development may indicate some form of leakage of lubricant in the lubricating system 299.

By determining a development of said level V in the form of an adaptation Vmean2, for example through a suitable calculation method, a trend in said development may be determined. in Figure 4b said development has a negative trend. This may be determined in a number of different ways.

According to a first variant, a negative trend in said development may be determined if a predetermined number of values V fall below a predetermined reference value VI within a predetermined time interval. Said predetermined time interval is defined according to this example by a time period T3-T4. Said predetermined time interval may be for example 5 or 60 seconds. Said predetermined time interval may be longer than 60 seconds, for example 5 minutes.

According to a second variant, a negative trend in said development may be determined if an individual value V fails below a reference value VI at a point in time, herein illustrated with the point in time T3. According to a third variant, a negative trend in said development may be determined if a determined derivative of said adaptation Vmean2, at a certain point in time or within a certain time interval, for example a time interval T1-T2, falls below a predetermined value Vder2. Herein a negative trend in said development may be determined.

Said predetermined reference value VI may be an adaptive!y adjustable value. Said predetermined value Vder2 may be an adaptively adjustable value. With reference to Figure 5, a diagram of an embodiment of a system 500 is shown. The control units 200 and 2.10, which are described with reference to Figure 2, may in one embodiment comprise the system 500. The unit 500 includes a non-volatile memory 520, a data processing unit 510 and a read/write memory 550. The non-volatile memory 52.0 has a first memory part 530 wherein a computer program, such as an operative system, is stored to control the function of the unit 500. Further, the unit 500 includes a bus controller, a serial communications port, an I/O device, an A/D converter, a date-time input and transmission unit, an event counter and an interrupt controller (not shown). The nonvolatile memory 52.0 also has a second memory part 540. A computer program P is provided, which may comprise procedures to track the function of a lubricating system. The computer program P may comprise procedures to continuously, with the lubricating system in operation, determine the level of lubricant in said container. The computer program P may comprise procedures to continuously determine the development of said level of lubricant. The computer program P may comprise procedures to continuously determine said function based on said development.

The computer program P may comprise procedures to track the function in a lubricating system by, in case of a reducing trend in said development of said level of lubricant, taking this as an indication of a leakage in said lubricating system. The computer program P may comprise procedures to track the function in a lubricating system by, in case of an increasing trend in said development of said level of lubricant, taking this as an indication of a dilution in said lubricating system. The computer program P may comprise procedures to track the function of a lubricating system by determining a reference value for said level of lubricant at the start of operation of said lubricating system. The computer program P may comprise procedures to track the function of a lubricating system by, in case of a determined indication of an unwanted function of the lubricating system, carrying out a measurement of the level of lubricant under certain predetermined operating conditions. The computer program P may comprise procedures to track the function of a lubricating system, wherein said indication of an unwanted function of the lubricating system comprises a rate of change of said development. The computer program P may comprise procedures to track the function of a lubricating system, wherein said indication of an unwanted function of said lubricating system is determined based on a comparison of said determined level of lubricant with a predetermined reference value. The computer program P may comprise procedures to track the function of a lubricating system by presenting information related to said function of said lubricating system to an operator. The computer program P may comprise procedures to track the function of a lubricating system by, at the determination of an unwanted function of the lubricating system, determining and presenting a measure to said operator.

The computer program P may comprise procedures to track the function of a lubricating system by, at the determination of an unwanted function of the lubricating system, automatically deactivating the operation of an object 240 in the lubricating system. The above procedures may be carried out each separately or combined in a suitable manner.

The program P may be stored in an executable manner or in a compressed manner in a memory 560 and/or a read/write memory 550.

A statement that the data processing unit 510 performs a certain function means that the data processing unit 510 performs a certain part of the program which is stored in the memory 560 or a certain part of the program stored in the read/write memory 550. The data processing unit 510 may communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is intended for communication with the data processing unit 510 via a data bus 511. The read/write memory 550 is arranged for communication with the data processing unit 510 via a data bus 514. The links, e.g., L210, L230, L240, L300, L280 and L285 may be connected to the data port 599 (see Figure 2). When data is received in the data port 599, it is temporarily stored in the second memory part 540. When in-data received is temporarily stored, the data processing unit 510 is ready to carry out execution of code in the manner described above.

According to one embodiment, signals received in the data port 599 comprise information about the level of lubricant. The signals received in the data port 599 may be used by the device 500 to track the function of a lubricating system. Parts of the methods described herein may be carried out by the device 500 with the help of the data processing unit 510, which runs the program stored in the memory 560 or the read/write memory 550. When the unit 500 runs the program, the procedures described herein are executed.

The foregoing description of the preferred embodiments of the present invention has been furnished for illustrative and descriptive purposes. It is not intended to be exhaustive, or to limit the invention to the variants described. Many modifications and variations will obviously be apparent to one skilled in the art. The embodiments have been chosen and described in order to best explicate the principles of the invention and its practical applications, and to thereby enable one skilled in the art to understand the invention in terms of its various embodiments and with the various modifications that are applicable to its intended use.