FR3100362A1 - Method of controlling a vehicle device - Google Patents

Abstract

Method for checking at least one device of a motor vehicle, comprising the steps of: - detecting a predetermined driving condition, - performing at least one diagnostic of the vehicle device (10, 20), - calculating, preferably repeatedly over time, a ratio of the number of diagnoses carried out over a number of occurrences of detection of the predetermined driving condition, and compare the calculated ratio with a threshold ratio, - if the calculated ratio is greater than the threshold ratio , and preferably if the calculated ratio remains greater than the threshold ratio increased by a safety coefficient, then shift in time a diagnosis to be carried out on the vehicle device. Figure 1

Description

Method of controlling a vehicle device

The present invention relates generally to a method of controlling a vehicle device. In particular, the invention relates to the field of diagnostics carried out while driving, automatically on vehicle devices. Such vehicle devices can be, for example, engine components (exhaust gas recycling valve, fuel injectors, air shutter, etc.) or more complex devices (exhaust gas treatment device, complete injection, selective catalysis device, etc.).

It is known to monitor the frequency of these diagnoses, and even to verify that the vehicle or a fleet of vehicles complies with the conditions of occurrence of diagnoses. In particular, it is known to follow an IUPR parameter (for In Use Performance Ratio in English or In Use Performance Ratio) which corresponds to a ratio of the number of diagnoses made to a number of occurrences of detection of a condition of predetermined rolling. It may be imposed by legislation or standards to have a minimum value for this parameter. For example, one can impose a minimum value (0.33 for example) for an exhaust gas treatment system, and another minimum value (0.26 for example) for a secondary air injection system relating to a start at cold.

Document CN106647352 relates to a statistical and transmission device for an In Use Performance Ratio (IUPR) and relates to a vehicle. The statistics and transmission device includes a transceiver device and a receiver, the transceiver device for acquiring and storing IUPR information of the vehicle. However, this document does not provide any solution for proposing optimal use of the vehicle control means and in particular the diagnostic means.

The document FR3064390 relates to a motor vehicle equipped with an on-board computer, the vehicle comprising at least one component monitored by a command control unit, a diagnostic tool operating with diagnostic software, arranged to monitor a Performance Ratio In Use (IUPR). However, here again, this document does not provide any solution for proposing optimum use of the vehicle control means and in particular the diagnostic means.

An object of the present invention is to respond to the drawbacks of the prior art mentioned above and in particular, first of all, to propose a method for controlling a vehicle device which makes it possible to optimize the use of means of diagnosis of a vehicle, while remaining in conformity with the legislative and/or normative requirements.

For this, a first aspect of the invention relates to a method for controlling at least one device of a motor vehicle, comprising the steps consisting in:
- detect a predetermined driving condition,
- perform at least one diagnosis of the vehicle device,
- calculating, preferably repeatedly over time, a ratio of the number of diagnoses made to a number of occurrences of detection of the predetermined driving condition, and comparing the calculated ratio with a threshold ratio,
- if the calculated ratio is greater than the threshold ratio, and preferably if the calculated ratio is greater than the threshold ratio increased by a safety coefficient, then shifting in time a diagnosis to be carried out on the vehicle device.

The method according to the implementation above compares the calculated IUPR ratio with a threshold value, and if the IUPR ratio is higher, then it is possible, while remaining compliant with the standard, to shift the diagnosis(s) to come, which limits the use of diagnostic means, data storage, transmission, their costs of use and their associated wear. Unnecessary and redundant diagnostics can therefore be avoided.

Advantageously, the control method comprises a step consisting in monitoring whether the vehicle device is used according to at least one context of use,
and the step of shifting the diagnosis of the vehicle device to be performed is interrupted if the usage context is detected, so as to perform the diagnosis of the vehicle device while the vehicle device is being used according to the usage context . According to the implementation above, the future diagnostic(s) to be performed are finally performed when a particular context of use is detected. For example, provision can be made, in the case where the diagnoses to come can be shifted in time, to limit the diagnostic phases to the times when the organ to be checked is for example in a steady state or in a particular temperature condition. For example. This implementation allows diagnostics to be performed only when the vehicle device is used in a context where the diagnostic measurements are invariant and reliable.

In other words, one aspect of the invention relates to a method for controlling at least one device of a motor vehicle, comprising the steps consisting in:
- detect a predetermined driving condition,
- perform at least one diagnosis of the vehicle device,
- calculating, preferably repeatedly over time, a ratio of the number of diagnoses made to a number of occurrences of detection of the predetermined driving condition, and comparing the calculated ratio with a threshold ratio,
- if the calculated ratio is greater than the threshold ratio, and preferably if the calculated ratio is greater than the threshold ratio increased by a safety coefficient, then the control method comprises a step consisting in monitoring whether the vehicle device is used according to at least one context of use,
and a diagnosis of the vehicle device to be performed is actually performed if the usage context is detected, i.e. while the vehicle device is being used according to the usage context.

Advantageously, the diagnosis of the vehicle device to be carried out is carried out if the context of use is detected and if the calculated ratio is included in a target ratio range, the target ratio range preferably being strictly greater than the threshold ratio. According to the implementation above, the future diagnosis(es) to be carried out are finally carried out only when the calculated ratio is in a target range, for example close to the threshold ratio, which delays the future diagnosis as much as possible, while ensuring that diagnostics are performed only when the vehicle device is used in an environment where diagnostic measurements are invariant and reliable

Advantageously, the control method comprises a step consisting in monitoring whether the vehicle device is used according to at least a first context of use of the vehicle device, or according to at least a second context of use, and in which:
- if the first context of use is detected, then the step of shifting the diagnosis of the vehicle device to be carried out is interrupted, so as to carry out the diagnosis of the vehicle device while the vehicle device is used according to the first context of use,
- if the second context of use is detected, then the step consisting in shifting the diagnosis of the vehicle device to be carried out is maintained as long as said at least first context of use is not detected and as long as the calculated ratio is greater than the threshold ratio, and preferably as long as the calculated ratio is greater than the threshold ratio plus a safety factor.

According to the implementation above, the future diagnostic(s) to be performed are finally performed when a first particular context of use is detected. For example, provision can be made, in the case where the diagnoses to come can be shifted in time, to limit the diagnostic phases to the times when the organ to be checked is for example in a steady state or in a particular temperature condition. For example. On the other hand, if a second context of use is detected (the component to be checked is for example in a transient state or in an unfavorable temperature condition for example), then the diagnosis will be shifted, for example to avoid an unreliable measurement .

Advantageously, the step consisting in carrying out at least one diagnosis of the vehicle device is carried out when the predetermined driving condition is detected. In other words, the calculated ratio is a ratio of the number of diagnoses actually performed during the predetermined driving condition over a number of occurrences of detection of the predetermined driving condition during which a diagnosis could be made.

Advantageously, the control method includes a diagnostic planning step consisting of:
- compare the calculated ratio with the threshold ratio to determine if a diagnosis can be shifted,
- if the diagnosis can be delayed, then checking whether the vehicle device will be used in the future according to a predetermined context of use, for example by checking whether a particular route is planned or by checking whether the vehicle is used according to usual use , and predicting a time at which the vehicle device will be used according to the predetermined context of use,
- if a time is scheduled at which the vehicle device will be used according to the predetermined context of use, then estimate the ratio calculated at this scheduled time,
- schedule the diagnosis at the scheduled time if the estimated ratio is greater than the threshold ratio, and preferably if the estimated ratio is greater than the threshold ratio plus the safety coefficient.

According to the implementation above, the future diagnostic(s) to be carried out are shifted and an opportune moment is determined according to an upcoming trip (it can be based on a route planned on a navigation device of the vehicle, or based on a history of known and usual journeys), to plan to carry out the diagnosis at the best time (steady state, or optimum temperature for the diagnosis, for example when driving on a section of motorway during which the speed will be constant ).

Advantageously, the step consisting in shifting the diagnosis of the vehicle device to be carried out is interrupted as soon as the calculated ratio is less than or equal to the threshold ratio, and preferably as soon as the calculated ratio is less than or equal to the threshold ratio increased by a safety factor. In all cases, the future diagnosis is only shifted if the calculated ratio is greater than the threshold ratio, and/or the future diagnosis is launched as soon as the calculated ratio is less than or equal to the threshold ratio, regardless of the context of the use of the device to be controlled.

A second aspect of the invention relates to a motor vehicle comprising at least one vehicle device, and preferably a plurality of vehicle devices, the diagnosis of which is carried out according to the control method according to the first aspect of the invention. It is understood that each vehicle device to be controlled may have a specific threshold ratio and/or specific contexts of use.

A third aspect of the invention relates to a computer program comprising program code instructions for the execution of the steps of the control method according to the first aspect of the invention when said program is executed on a computer.

A fourth aspect of the invention relates to a computer program product comprising program code instructions recorded on a medium usable in a computer, comprising computer-readable programming means for carrying out the steps of the control method according to the first aspect of the invention when said program runs on a computer

It is understood that all the technical characteristics above can be combined with each other or separated from each other as long as there is no technical inconsistency or incompatibility.

Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of embodiments of the invention given by way of non-limiting examples and illustrated by the appended drawings, in which:

represents a schematic view of a vehicle, a vehicle device of which can be controlled according to the method according to the invention;

represents an example of driving of the vehicle of FIG. 1 during which the method according to the invention can be implemented.

FIG. 1 represents a vehicle, comprising several vehicle devices, such as for example an exhaust gas recycling system 10, an exhaust gas treatment device 20, etc. One could also consider an injection device, a probe oxygen or lambda sensor,…, and you can just as easily have a petrol engine vehicle as a diesel engine. The vehicle also comprises means for launching diagnostics on a regular and/or repeated basis, and in particular there is provided a computer 40 (in other words, an on-board computer) equipped with processors and memory units for storing program instructions and/or results and/or vehicle device parameter records. A communication unit 30 is also provided which makes it possible, for example, to receive or send diagnostic results to a remote server, by radio waves. Diagnostic instructions can also be received from a remote server.

FIG. 2 represents, for example, the rotational speed vr of an engine of the vehicle of FIG. 1 over time during a journey made by the vehicle, and we will be interested in controlling the exhaust gas treatment device 20 . After a driving time t1 (for example 10 minutes from start, 5 minutes at more than 40 km/h, 30 consecutive seconds of idling and if for example if the rotation speed of the engine is greater than a rotation speed minimum vr _m ), the vehicle enters a predetermined rolling condition CRP, during which a diagnosis of the exhaust gas treatment device 20 is considered possible.

It should be noted that the conditions which define the predetermined driving condition CRP are an example, and that these conditions can also depend on the component to be controlled. In particular, if it is a question of diagnosing a cold start air circuit, the predetermined driving condition can be detected if the engine is running and if the engine water temperature is below 40°C For example.

To return to the example of the exhaust gas treatment device 20, the method according to the invention will therefore detect the predetermined driving condition CRP. In parallel or subsequently, a calculation of the In-Use Performance Ratio (hereinafter referred to as IUPR) is carried out, by calculating the ratio of the number of diagnoses carried out over a number of occurrences of detection of the predetermined driving condition. For this purpose, reference is made to the recordings and history of the vehicle, if any. It is possible to plan to perform this IUPR calculation on a regular basis, and to update a database on board or off the vehicle.

Then, the method compares the calculated ratio with a threshold ratio, which can be a value imposed by a standard (for example 0.33 for the exhaust gas treatment device 20), or it can be chosen to compare the calculated ratio with the threshold ratio plus a safety coefficient (for example, 0.43 is taken as the plus ratio for the exhaust gas treatment device 20).

In the case where the calculated ratio is greater than the criterion retained, then the method can choose to shift the next diagnostic(s) in time, so as to limit the use of the vehicle's resources. Thus the value of the IUPR is still in line with the standards, but there is a saving in resources, by requiring less of the various vehicle systems.

Still in the case where the calculated ratio is greater than the criterion retained, then the process can choose to shift the next diagnostic(s) in time, and to launch the next diagnostic(s) only when the diagnostic conditions are such that the errors measurement are limited. Thus the value of the IUPR is always in line with the standards, and the diagnoses made are reliable.

For the example of the exhaust gas treatment device 20, it is known that the measurement of the oxygen level with an oxygen sensor presents a high uncertainty in the transient phases of engine speed. Consequently, it may be chosen to wait for a first context of use C1 in which the exhaust gas treatment device 20 to be diagnosed is used in a stable state (for example, when the speed of rotation vr varies from less of 500 rpm).

Additionally or alternatively, it is also possible to decide not to carry out diagnostics during a second context of use C2 in which the exhaust gas treatment device 20 to be diagnosed is used in a transient state (for example, when the speed of rotation vr varies by more than 500 rpm).

Returning to FIG. 2, the path of the vehicle comprises four occurrences O1, O2, O3, and O4 of detection of the predetermined driving condition CRP.

During the occurrences O1 and O4 of detection of the predetermined rolling condition CRP, the rotational speed of the engine is transient (for example, the rotational speed vr varies by more than 500 revolutions/min). It is then considered that the engine is in the context of use C2.

During the occurrences O2 and O3 of detection of the rolling condition CRP, the rotational speed of the engine presents two transitory phases (context of use C2), surrounding a phase of stable use during which it is considered while the engine is is then in the context of use C1.

In a first scenario, at time t1, the IUPR is greater than the criterion used. It will therefore be decided to postpone in time the next diagnostic(s) to be carried out. In particular, no diagnosis will be performed during occurrences O1, O2, O3, O4 and when the second context of use C2 is detected. According to this implementation, it is avoided to carry out measurements with a large uncertainty, which makes reliable and increases the robustness of the diagnoses.

On the other hand, when the first context of use C1 is detected, during the stable phases of the occurrences O2 and O3, it can be decided to launch the diagnosis of the exhaust gas treatment device 20. It can be decided to do this at each time the first usage context C1 is detected, or only the first time, or only the second time. Thus, the measurements taken are reliable and the diagnoses are improved.

In the case where the calculated ratio is lower than the criterion retained, then the diagnosis is immediately launched, whatever the context of use C1 or C2 of the moment. Thus, the IUPR will comply with the standard.

It will be understood that various modifications and/or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention.

In particular, it is possible to choose or add other conditions to determine the contexts of use. For example, we can add to consider the temperature of the engine, or the load, or the speed.

It is also understood that other devices or components may be involved, such as the recycling injection devices already mentioned, but the method can also be used to diagnose electronic or electrical or even hydraulic components of the vehicle (water pump, power steering, airbags, etc.).

Claims (10)

Method for controlling at least one device of a motor vehicle, comprising the steps consisting in:
- detect a predetermined driving condition (CRP),
- performing at least one diagnosis of the vehicle device (10, 20),
- calculating, preferably repeatedly over time, a ratio of the number of diagnoses made to a number of occurrences of detection of the predetermined driving condition (CRP), and comparing the calculated ratio (IUPR) with a threshold ratio ,
- if the calculated ratio (IUPR) is higher than the threshold ratio, and preferably if the calculated ratio (IUPR) is higher than the threshold ratio increased by a safety coefficient, then shift in time a diagnosis to be carried out on the vehicle (10, 20). Control method according to the preceding claim, comprising a step consisting in monitoring whether the vehicle device (10, 20) is used according to at least one context of use (C1, C2),
and wherein the step of shifting the diagnosis of the vehicle device (10, 20) to be performed is interrupted if the context of use (C1, C2) is detected, so as to perform the diagnosis of the vehicle device (10 , 20) while the vehicle device (10, 20) is being used according to the context of use (C1, C2). Control method according to the preceding claim, in which the diagnosis of the vehicle device (10, 20) to be carried out is carried out if the context of use (C1, C2) is detected and if the calculated ratio (IUPR) is included in a target ratio range, the target ratio range preferably being strictly greater than the threshold ratio. Control method according to claim 1, comprising a step consisting in monitoring whether the vehicle device (10, 20) is used according to at least a first context of use (C1) of the vehicle device (10, 20), or according to at least one second context of use (C2), and in which:
- if the first context of use (C1) is detected, then the step consisting in shifting the diagnosis of the vehicle device (10, 20) to be carried out is interrupted, so as to carry out the diagnosis of the vehicle device (10, 20) while the vehicle device (10, 20) is being used according to the first context of use (C1),
- if the second context of use (C2) is detected, then the step consisting in shifting the diagnosis of the vehicle device (10, 20) to be carried out is maintained as long as said at least first context of use (C1) n is not detected and as long as the calculated ratio (IUPR) is greater than the threshold ratio, and preferably as long as the calculated ratio (IUPR) is greater than the threshold ratio plus a safety coefficient. Control method according to one of the preceding claims, in which the step consisting in carrying out at least one diagnosis of the vehicle device (10, 20) is carried out when the predetermined driving condition (CRP) is detected. Control method according to one of the preceding claims, comprising a diagnostic planning step consisting of:
- compare the calculated ratio (IUPR) with the threshold ratio to determine if a diagnosis can be shifted,
- if the diagnosis can be shifted, then checking whether the vehicle device (10, 20) will be used in the future according to a predetermined context of use (C1, C2), for example by checking whether a particular route is planned or by checking whether the vehicle is used according to usual use, and predicting a time at which the vehicle device (10, 20) will be used according to the predetermined context of use (C1, C2),
- if a time is scheduled at which the vehicle device (10, 20) will be used according to the predetermined context of use (C1, C2), then estimating the calculated ratio (IUPR) at this scheduled time,
- schedule the diagnosis at the scheduled time if the estimated ratio is greater than the threshold ratio, and preferably if the estimated ratio is greater than the threshold ratio plus the safety coefficient. Control method according to one of the preceding claims, in which the step consisting in shifting the diagnosis of the vehicle device (10, 20) to be carried out is interrupted as soon as the calculated ratio (IUPR) is less than or equal to the threshold ratio, and preferably as soon as the calculated ratio (IUPR) is less than or equal to the threshold ratio plus a safety factor. Motor vehicle comprising at least one vehicle device (10, 20), and preferably a plurality of vehicle devices (10, 20), the diagnosis of which is carried out according to the test method according to one of the preceding claims. Computer program comprising program code instructions for executing the steps of the control method according to one of Claims 1 to 7 when said program is executed on a computer. Computer program product comprising program code instructions recorded on a medium that can be used in a computer, comprising computer-readable programming means for carrying out the steps of the control method according to one of Claims 1 to 7 when the said program is running on a computer.