EP4663931A1

EP4663931A1 - Engine operating condition monitoring and management method and apparatus, electronic device, and storage medium

Info

Publication number: EP4663931A1
Application number: EP24917562.1A
Authority: EP
Inventors: Xuping Chen; Xianli Hu
Original assignee: Chongqing Changan Automobile Co Ltd
Current assignee: Chongqing Changan Automobile Co Ltd
Priority date: 2024-04-29
Filing date: 2024-08-05
Publication date: 2025-12-17
Also published as: MX2025008568A; AU2024417778A1; WO2025227543A1; CN118188191A

Abstract

Provided are a method and apparatus for supervising a working condition of an engine, an electronic device, and a storage medium, which belong to the technical field of vehicle engines. The method includes: obtaining a control information set corresponding to the engine; detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and controlling an operating state of an exhaust gas recirculation (EGR) valve of the engine based on the detection result, where the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region. Thus, when the engine is in the working condition transition stage and passes through the EGR working region, the problem of knocks or unstable combustion of the engine can be avoided since the EGR valve is prohibited from acting, and driving experience can be improved advantageously.

Description

The present disclosure claims the priority to Chinese Patent Application No. 202410530982.9, filed with the Chinese Patent Office on April 29, 2024 and entitled "Method and apparatus for supervising working condition of engine, electronic device and storage medium", which is incorporated in its entirety herein by reference.

TECHNICAL FIELD

The present disclosure relates to the technical field of vehicle engines, and in particular to a method and apparatus for supervising a working condition of an engine, an electronic device and a storage medium.

BACKGROUND

A combination of a high compression ratio and exhaust gas recirculation (EGR) mostly serves for a current engine specific for a hybrid vehicle. With the high compression ratio, tolerance of the engine for the EGR is increased. Moreover, sensitivity of the engine to an EGR rate is also significantly increased. In other words, an optimal ignition angle varies greatly at different states of opening/closing the EGR under the same load. If accuracy deviation of an EGR model is large, knocking combustion is likely to actually occur, or incomplete combustion and even misfire appears.
For example, when the engine briefly passes through an EGR working region in a working condition transition stage, an EGR valve is briefly opened and closed and deviation of actual calculation of the EGR rate is large with short working time and strong transient nature of the working condition, resulting in knocks or unstable combustion, which affects driving experience.

SUMMARY OF THE INVENTION

In view of this, an objective of examples of the present disclosure is to provide a method and apparatus for supervising a working condition of an engine, an electronic device and a storage medium, which can avoid the problem of knocks or unstable combustion of an engine in a working condition transition stage.
In order to achieve the above technical objective, the technical solution used by the present disclosure is as follows:
in a first aspect, a method for supervising a working condition of an engine is provided in an example of the present disclosure. The method includes:

obtaining a control information set corresponding to the engine;
detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and
controlling an operating state of an exhaust gas recirculation (EGR) valve of the engine based on the detection result, where the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.

In combination with the first aspect, in some optional embodiments, the control information set includes a working state of the engine, an EGR enable flag, a required EGR rate of the engine, a working state of the EGR valve, an allocated required rotation speed of the engine, a slope of change of the required rotation speed, an allocated required load of the engine, and a slope of change of the required load.
In combination with the first aspect, in some optional embodiments, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result includes:
determining, based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage to obtain the detection result when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
In combination with the first aspect, in some optional embodiments, determining, based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage to obtain the detection result includes:

determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is greater than a threshold A and the slope of change of the required load is greater than a threshold B, where values of the threshold A and the threshold B are positive numbers; and
alternatively, determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is less than a threshold -A and the slope of change of the required load is less than a threshold -B.

In combination with the first aspect, in some optional embodiments, controlling an operating state of an EGR valve of the engine based on the detection result includes:
controlling the EGR valve to be prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through the EGR working region.
In combination with the first aspect, in some optional embodiments, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result includes:
determining that the required rotation speed and the required load of the engine reach an end point of the working condition transition stage and resetting a working condition transition stage flag of the engine to false in a case that an absolute value of the slope of change of the required rotation speed is less than a threshold C, an absolute value of a step size of change of the required rotation speed is less than a threshold D, an absolute value of the slope of change of the required load is less than a threshold E, and an absolute value of a step size of change of the required load is less than a threshold F when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
In combination with the first aspect, in some optional embodiments, the controlling an operating state of an EGR valve of the engine based on the detection result includes:

removing prohibition on the EGR valve when the working condition transition stage flag is false; and
after the prohibition on the EGR valve is removed, controlling the working state of the EGR valve by a conventional control strategy after delay of preset duration when the required EGR rate is greater than or equal to a threshold G; and alternatively, ending current passing identification when the required EGR rate is less than a threshold G.

In a second aspect, an apparatus for supervising a working condition of an engine is further provided in an example of the present disclosure. The apparatus includes:

an acquisition unit, configured for, obtaining a control information set corresponding to the engine;
a detection unit, configured for, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and
a control unit, configured for, controlling an operating state of an EGR valve of the engine based on the detection result, where the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.

In a third aspect, an electronic device is further provided in an example of the present disclosure. The electronic device includes a processor and a memory coupled to each other, where the memory stores a computer program, and the computer program causes the electronic device to execute the above method when executed by the processor.
In a fourth aspect, a computer-readable storage medium is further provided in an example of the present disclosure. The computer-readable storage medium stores a computer program, and the computer program causes a computer to execute the above method when running on the computer.
The invention using the above technical solution has the following advantages:
in the technical solution according to the present disclosure, whether the engine is in the working condition transition stage is detected by means of the control information set corresponding to the engine, and then the operating state of the EGR valve of the engine is controlled based on the detection result, where the EGR valve is prohibited from operating when the detection result indicates that the engine is in the working condition transition stage and passes through the EGR working region. Thus, when the engine is in the working condition transition stage and passes through the EGR working region, the problem of knocks or unstable combustion of the engine can be avoided since the EGR valve is prohibited from acting, and driving experience can be improved advantageously.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be further described by means of non-limiting examples provided in the accompanying drawings. It should be understood that the following accompanying drawings show merely some examples of the present disclosure, and thus should not be regarded as the limitations to the scope. Those of ordinary skill in the art would further be able to derive other relevant accompanying drawings from these accompanying drawings without making creative efforts.

FIG. 1 is a schematic diagram showing that an engine passes through an exhaust gas recirculation (EGR) working region in a working condition transition stage according to an example of the present disclosure;
FIG. 2 is a schematic flowchart of a method for supervising a working condition of an engine according to an example of the present disclosure; and
FIG. 3 is a block diagram of an apparatus for supervising a working condition of an engine according to an example of the present disclosure.

Reference numerals: 200-apparatus for supervising working condition of engine; 210-acquisition unit; 220-detection unit; and 230-control unit.

DETAILED DESCRIPTION

The present disclosure will be described in detail below in combination with the accompanying drawings and the particular examples. It should be noted that in the accompanying drawings or the description, identical figure numbers are used for similar or identical parts. Implementation modes not shown or described in the accompanying drawings are forms known to those of ordinary skill in the art in the pertinent technical field. In the description of the present disclosure, the terms "first", "second", etc. are merely used to distinguish the description and cannot be understood as indicating or implying relative importance.
With reference to FIG. 1, the inventor finds through research that in a hybrid power mode, a power control unit (PCU) usually allocates corresponding required power to an engine according to a power demand of a driver, a current battery power capability, a maximum power capability of the engine and a power capability of an electric motor, determines a rotation speed and a load required to satisfy required power according to a principle of optimal energy consumption, and then controls the engine to gradually change from a rotation speed and a load of a current working condition to a final required rotation speed and load separately according to a slope to some extent. In a hybrid driving mode of a hybrid vehicle, especially after the engine is started due to the power demand, the PCU allocates extremely high power to the engine when the power demand of the driver is high and the battery power is limited. An initial working condition point of the engine is located in a lower left corner of an exhaust gas recirculation (EGR) working region, and a final working condition point may be located outside the EGR working region. Alternatively, the power demand of the driver is suddenly reduced significantly, such that the initial working condition point of the engine is changed from an upper right corner outside an EGR working region, and a final working condition point may be located outside the EGR working region, as shown in FIG. 1. In such a process of change of the working condition, the engine briefly passes through an EGR working region, an EGR valve is briefly opened and closed and deviation of actual calculation of the EGR rate is large with short working time and strong transient nature of the working condition, resulting in knocks or unstable combustion, which affects driving experience.
To this regard, the inventor provides the following examples through long-term research, exploration and experimentation, so as to solve the above technical problem.

Example 1

With reference to FIG. 2, the present disclosure provides a method for supervising a working condition of an engine. The method is applicable to a hybrid vehicle, so as to monitor and control the working condition of the engine of the hybrid vehicle. The method for supervising a working condition of an engine may include:

step 110, a control information set corresponding to the engine is obtained;
step 120, based on the control information set, whether the engine is in a working condition transition stage is detected to obtain a detection result; and
step 130, an operating state of an EGR valve of the engine is controlled based on the detection result, where the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.

The steps of the method for supervising a working condition of an engine are described in detail below, as follows:
in step 110, the control information set may include, but not limited to, a working state of the engine, an EGR enable flag, a required EGR rate of the engine, a working state of the EGR valve, an allocated required rotation speed of the engine, a slope of change of the required rotation speed, an allocated required load of the engine, and a slope of change of the required load.
It should be noted that the acquisition mode of various types of data in the control information set is a conventional mode, which is not described herein.
In step 120, the step that based on the control information set, whether the engine is in a working condition transition stage is detected to obtain a detection result may include:
based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage is determined to obtain the detection result when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
For example, if the working state of the engine is an operating state, it indicates that the engine is in running. The EGR enable flag is on, i.e. on flag.
The step that based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage is determined to obtain the detection result includes:

it is determined that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is greater than a threshold A and the slope of change of the required load is greater than a threshold B, where values of the threshold A and the threshold B are positive numbers; and
alternatively, it is determined that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is less than a threshold -A and the slope of change of the required load is less than a threshold -B.

In the example, the threshold A and the threshold B may be calibrated. Specific values of the threshold A and the threshold B are usually slightly less than corresponding maximum rise rates provided by a PCU, and may be differently set according to different driving modes. When the condition "the slope of change of the required rotation speed is greater than the threshold A and the slope of change of the required load is greater than the threshold B" is satisfied, it means that the working condition of the engine enters the working condition transition stage of passing through the EGR working region by means of acceleration.
Alternatively, when the condition "the slope of change of the required rotation speed is less than the threshold -A and the slope of change of the required load is less than the threshold -B" is satisfied, it means that the working condition of the engine enters the working condition transition stage of passing through the EGR working region by means of deceleration.
In the example, a working condition transition stage flag position of the engine is true when the engine is in the operating mode transition phase.
In the example, step 130 that an operating state of an EGR valve of the engine is controlled based on the detection result may include:
the EGR valve is controlled to be prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through the EGR working region.
Understandably, when the engine is in the working condition transition stage and passes through the EGR working region, the EGR valve is prohibited from acting. Thus, the situation that the working condition of the engine briefly passes through the EGR working region, such that the EGR valve is briefly opened and closed and deviation of actual calculation of an EGR rate is large, resulting in knocks or unstable combustion can be avoided. That is, the EGR valve is prohibited from acting, thereby improving stability of combustion of the vehicle engine advantageously, reducing energy consumption, and improving driving experience.
In an optional embodiment, step 120 may include:
it is determined that the required rotation speed and the required load of the engine reach an end point of the working condition transition stage and a working condition transition stage flag of the engine is reset to false in a case that an absolute value of the slope of change of the required rotation speed is less than a threshold C, an absolute value of a step size of change of the required rotation speed is less than a threshold D, an absolute value of the slope of change of the required load is less than a threshold E, and an absolute value of a step size of change of the required load is less than a threshold F when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
In the example, the threshold A is greater than the threshold C, the threshold B is greater than the threshold E, and various thresholds may be flexibly set according to actual conditions. As an example, the threshold C may be set to 500 rpm/s or below; the threshold D may be set to 30 rpm or less; the threshold E may be set to 50 Nm/s or below; and the threshold F may be set to 5 Nm or less. The words "less" and "below" include this number.
In an optional embodiment, step 130 may include:

step 131, prohibition on the EGR valve is removed when the working condition transition stage flag is false; and
step 132, after the prohibition on the EGR valve is removed, the working state of the EGR valve is controlled by a conventional control strategy after delay of preset duration, and current passing identification is ended when the required EGR rate is greater than or equal to a threshold G; and
step 133, after the prohibition on the EGR valve is removed, current passing identification is ended when the required EGR rate is less than a threshold G.

In the example, the required EGR rate of the engine may be calculated based on an actual rotation speed of the engine and an actual load of the engine. If the required EGR rate is less than the threshold G, it indicates that a current passing identification function is ended. If the required EGR rate is greater than or equal to the threshold G, a control function of the EGR valve is switched into a conventional EGR control function after preset duration T is delayed, and a current passing identification determination function is ended. The threshold G may be the same as a minimum required EGR rate in the conventional control strategy of the PCU, and the preset duration T delayed may be short. For example, the preset duration T delayed may be set to 1 second or less. In addition, the conventional control strategy is an existing control strategy, which is not described herein.
In the example, a process of a passing identification may be understood as executing steps 110 to 130 once. After a passing identification determination is completed, steps 110 to 130 may be repeated.
Based on the above design, the problems of knocks or unstable combustion caused by brief opening of the EGR valve during the transition period can be avoided by identifying that the transient working condition of the engine passes through the EGR working region and temporarily closing the EGR valve during a transient transition period passing through the EGR working region.

Example 2

With reference to FIG. 3, the present disclosure further provides an apparatus 200 for supervising a working condition of an engine. The apparatus 200 for supervising a working condition of an engine includes at least one software functional module that may be stored in a storage module in a form of software or firmware or solidified in an operating system (OS) of an electronic device. A processing module is configured for executing executable modules stored in the storage module, such as a software functional module and a computer program included in the apparatus 200 for supervising a working condition of an engine.
The apparatus 200 for supervising a working condition of an engine includes an acquisition unit 210, a detection unit 220 and a control unit 230. Each unit may has a function as follows:

the acquisition unit 210 is configured for obtaining a control information set corresponding to the engine;
the detection unit 220 is configured for detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and
the control unit 230 is configured for controlling an operating state of an EGR valve of the engine based on the detection result, where the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.

Optionally, the detection unit 220 may be configured for determining, based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage to obtain the detection result when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
Optionally, the detection unit 220 may be further configured for determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is greater than a threshold A and the slope of change of the required load is greater than a threshold B, where values of the threshold A and the threshold B are positive numbers; and
alternatively, determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is less than a threshold -A and the slope of change of the required load is less than a threshold -B.
Optionally, the control unit 230 may be configured for controlling the EGR valve to be prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through the EGR working region.
Optionally, the detection unit 220 may be further configured for:
determining that the required rotation speed and the required load of the engine reach an end point of the working condition transition stage and resetting a working condition transition stage flag of the engine to false in a case that an absolute value of the slope of change of the required rotation speed is less than a threshold C, an absolute value of a step size of change of the required rotation speed is less than a threshold D, an absolute value of the slope of change of the required load is less than a threshold E, and an absolute value of a step size of change of the required load is less than a threshold F when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
Optionally, the control unit 230 may be further configured for:

Example 3

An electronic device is provided in an example of the present disclosure. The electronic device may include a processing module and a storage module. A computer program is stored in the storage module, and when the program causes the electronic device to execute corresponding steps of the above method for supervising a working condition of an engine when executed by the processing module.
In the example, the processing module may be an integrated circuit chip having a signal processing capability. The above processing module may be a general-purpose processor. For example, the processor may be a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, a discrete gate or a transistor logic device, a discrete hardware component, etc., and can implement or execute the methods, steps and logic block diagrams disclosed in the examples of the present disclosure.
The storage module may be, but not limited to, a random access memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, etc. In the example, the storage module may be configured for storing a control information set, an EGR working region, various thresholds, etc. Clearly, the storage module may be further configured for storing a program, and the processing module executes the program after receiving an execution instruction.
It should be noted that those skilled in the pertinent field can clearly understand that for convenience and brevity of description, for specific working processes of the electronic device and the apparatus described above, reference can be made to a process corresponding to each step in the above method, which is not excessively described herein.

Example 4

A computer-readable storage medium is further provided in an example of the present disclosure. The computer-readable storage medium stores a computer program, and the computer program causes a computer to execute the method for supervising a working condition of an engine of the above example when running on the computer.
By means of the description of the above embodiments, those skilled in the art can clearly understand that the present disclosure can be implemented by means of hardware or software plus a necessary general hardware platform. Based on such understanding, the technical solution of the present disclosure can be embodied in a form of a software product. The software product can be stored in a non-volatile storage medium (which can be a compact disc read-only memory (CD-ROM), a USB flash drive, a mobile hard disk, etc.), and includes several instructions to enable a computer device (which can be a personal computer, an electronic device, or a network device) to execute the method of various implementation scenarios of the present disclosure.
In the examples according to the present disclosure, it should be understood that the apparatus, device and method disclosed can be implemented in other ways. The apparatus, device and method examples described above are merely schematic. For example, flowcharts and block diagrams in the accompanying drawings show system structures, functions and operations, which can be implemented according to systems, methods and computer program products in the plurality of examples of the present disclosure. In this regard, each block in the flowcharts or the block diagrams can represent a module, a program segment, or a part of a code, which includes one or more executable instructions configured for implementing logical functions specified. It should also be noted that each block in the block diagrams and/or the flowcharts, and combinations of the blocks in the block diagrams and/or the flowcharts, can be implemented by means of dedicated hardware-based systems that execute specified functions or actions, or can be implemented by means of combinations of dedicated hardware and computer instructions. In addition, the functional modules in the examples of the present disclosure can be integrated together to form an independent part, or each module can be present separately, or two or more modules can be integrated to form an independent part.
What are described above are merely the examples of the present disclosure, and are not used for limiting the scope of protection of the present disclosure, and various modifications and changes can be made to the present disclosure by those skilled in the art. Any modification, equivalent substitution, improvement, etc. within the spirit and principle of the present disclosure shall fall within the scope of protection of the present disclosure.

Claims

A method for supervising a working condition of an engine, characterized by comprising:
obtaining a control information set corresponding to the engine;

detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and

controlling an operating state of an exhaust gas recirculation (EGR) valve of the engine based on the detection result, wherein the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.
The method according to claim 1, characterized in that, the control information set comprises a working state of the engine, an EGR enable flag, a required EGR rate of the engine, a working state of the EGR valve, an allocated required rotation speed of the engine, a slope of change of the required rotation speed, an allocated required load of the engine, and a slope of change of the required load.
The method according to claim 2, characterized in that, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result comprises:
determining, based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage to obtain the detection result when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
The method according to claim 3, characterized in that, determining, based on the slope of change of the required rotation speed and the slope of change of the required load, whether the engine is in the working condition transition stage to obtain the detection result comprises:
determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is greater than a threshold A and the slope of change of the required load is greater than a threshold B, wherein values of the threshold A and the threshold B are positive numbers; and

alternatively, determining that the engine is in the working condition transition stage and passes through the EGR working region when the slope of change of the required rotation speed is less than a threshold -A and the slope of change of the required load is less than a threshold -B.
The method according to claim 4, characterized in that, controlling an operating state of an EGR valve of the engine based on the detection result comprises:
controlling the EGR valve to be prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through the EGR working region.
The method according to claim 2, characterized in that, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result comprises:
determining that the required rotation speed and the required load of the engine reach an end point of the working condition transition stage and resetting a working condition transition stage flag of the engine to false in a case that an absolute value of the slope of change of the required rotation speed is less than a threshold C, an absolute value of a step size of change of the required rotation speed is less than a threshold D, an absolute value of the slope of change of the required load is less than a threshold E, and an absolute value of a step size of change of the required load is less than a threshold F when the working state of the engine is an operating state, the EGR enable flag is on, and the working state of the EGR valve is a closed state.
The method according to claim 6, characterized in that, the controlling an operating state of an EGR valve of the engine based on the detection result comprises:
removing prohibition on the EGR valve when the working condition transition stage flag is false; and

after the prohibition on the EGR valve is removed, controlling the working state of the EGR valve by a conventional control strategy after delay of preset duration when the required EGR rate is greater than or equal to a threshold G; and alternatively, ending current passing identification when the required EGR rate is less than a threshold G.
An apparatus for supervising a working condition of an engine, characterized by comprising:
an acquisition unit configured for, obtaining a control information set corresponding to the engine;

a detection unit configured for, detecting, based on the control information set, whether the engine is in a working condition transition stage to obtain a detection result; and

a control unit configured for, controlling an operating state of an EGR valve of the engine based on the detection result, wherein the EGR valve is prohibited from acting when the detection result indicates that the engine is in the working condition transition stage and passes through an EGR working region.
An electronic device, characterized by comprising a processor and a memory coupled to each other, wherein the memory stores a computer program, and the computer program causes the electronic device to execute the method according to any one of claims 1-7 when executed by the processor.
A computer-readable storage medium, characterized by storing a computer program, wherein the computer program causes a computer to execute the method according to any one of claims 1-7 when running on the computer.