METHOD FOR DETECTING A CONTACT STATE OF A STARTER SWITCH OF A MOTOR VEHICLE

Abstract

The invention relates to a method 100 for detecting a contact state of a motor vehicle starter switch, the method 100 comprising the steps of: Receiving 101 a raw signal reflecting information on a contact state of the switch; Filtering 102 bounces of the raw signal; Determining 103 a first contact state of the switch from the filtered raw signal; Determining 105 a second contact state of the switch from the received raw signal; When the second determined contact state is different from a second previously determined contact state, triggering 106 a time counter; When the time counter has expired, Comparing 107 the first and second determined contact states; When they are different, selecting 108 the second determined contact state as security information. Figure to be published with the abstract: Figure 2

Description

Title of the invention: METHOD FOR DETECTING A CONTACT STATE OF A STARTER SWITCH OF A MOTOR VEHICLE TECHNICAL FIELD OF THE INVENTION

[0001] One aspect of the invention relates to a method for detecting a contact state of a starter switch of a motor vehicle. The invention finds a particularly interesting application in the field of motor vehicles equipped with a thermal engine and / or an electric motor. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Vehicles are known that are equipped with an ignition key. To start the vehicle, the key is inserted into a lock and then turned from a position, called OFF, to a position, called ON. To turn off the vehicle, the key is turned in the opposite direction so as to move from the ON position to the OFF position.

[0003] Vehicles equipped with an electronic start card are also known. According to one embodiment, when the driver wishes to start the vehicle, he inserts the key into a slot provided for the card, then presses a start button. To turn off the vehicle, the driver presses the start button again.

[0004] With regard to contactless electronic start cards, equipped with his electronic start card, the driver gets into the passenger compartment of the vehicle, then presses a start button to start the vehicle and presses it again to turn it off.

[0005] When the driver turns the ignition key in the lock of his vehicle, the ignition switch of the vehicle changes from an open position to a closed position. From a raw signal reflecting information on the contact state of the ignition switch, namely an open state, called OFF, or a closed state, called ON of the ignition switch, a computer of the vehicle executes a step of filtering said raw signal.

[0006] Indeed, when the driver turns the vehicle's ignition key in the vehicle's lock, the electrical contact of the ignition switch is not necessarily perfectly made the first time, which generates bounces on the raw signal. Such filtering is also known by the English terminology of "anti-bounce". This filtering step makes it possible to attenuate these bounces of the raw signal.

[0007] From this filtered signal, the computer deduces a contact state of the starter switch, and therefore the driver's desire to start or turn off the engine of the vehicle.

[0008] According to this method, when a software error related to the filtering of the raw signal occurs, the deduced contact state of the starter switch may be erroneous. Thus, if the contact state of the starter switch is closed and the method detects an erroneous contact state of the starter switch, namely open in this case, then this method may prevent the driver from starting the engine of his vehicle.

[0009] Conversely, if the contact state of the starter switch is open and the method detects an erroneous contact state of the starter switch, namely closed, then the vehicle engine can be kept running while the driver wishes to turn it off. Summary of the invention

[0010] The aim of the invention is to overcome the drawbacks of the prior art by proposing a method for detecting a contact state of a starting switch of a motor vehicle making it possible to avoid poor detection of the contact state of said switch.

[0011] In this context, the invention thus relates, in its broadest acceptance, to a method for detecting a contact state of a starting switch of a motor vehicle, the vehicle comprising a computer provided with a first module for detecting a first contact state of the starting switch and a second module for detecting a second contact state of the starting switch, the method comprising the steps of: • Receive a raw signal reflecting information on a contact state of the starter switch, the raw signal being received by the first detection module and the second detection module; • Filter bounces, using the first detection module, from the raw signal; • Determine, by means of the first detection module, a first contact state of the starter switch from the filtered raw signal; • Determine, by means of the second detection module, a second contact state of the starter switch from the raw signal received; • When the second determined contact state is different from a previously determined second contact state, trigger a time counter; • When the time counter has expired, • Compare the first determined contact state with the second determined contact state; • When the first contact state and the second contact state determined are different, select the second contact state determined as security information.

[0012] By means of the method according to the invention, the first contact state determined from a filtered raw signal is compared to a second contact state determined from said unfiltered raw signal. Since the second contact state is not filtered, software processing is almost non-existent. Thus, if a fault appears during the software processing executed by the first module, this fault will not be reproduced by the second module. The comparison between the first contact state obtained by filtering the raw signal and the second contact state obtained by the unfiltered raw signal thus makes it possible to identify a possible software fault generated during the filtering. In this case, the contact state used by the safety functions of the vehicle is the second contact state.

[0013] In addition to the characteristics which have just been mentioned in the preceding paragraph, the method according to this aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations.

[0014] According to a non-limiting aspect of the invention, when the first contact state and the second contact state determined are identical, the method comprises a step of selecting the first contact state as security information.

[0015] According to a non-limiting aspect of the invention, the method comprises a step of synchronizing at least two cores of the computer to transmit the first determined contact state to the two cores, the synchronizing step being successive to the step of determining a first contact state.

[0016] According to a non-limiting aspect of the invention, the time recorded by the time counter is at least equal to the time required by the first detection module to determine the first contact state.

[0017] According to a non-limiting aspect of the invention, when the first contact state and the second contact state determined are different, the method comprises a step of recording information reflecting the difference in a non-volatile memory of the vehicle.

[0018] According to a non-limiting aspect of the invention, when the first contact state and the second contact state determined are different, the method comprises a step of resetting the calculator.

[0019] According to a non-limiting aspect of the invention, when a reset of the computer is carried out, the method comprises a step of counting the reset, the step of resetting the computer being prohibited when the number of resets reaches a threshold value.

[0020] According to a non-limiting aspect of the invention, the raw signal received is a logic signal.

[0021] Another aspect of the invention relates to a motor vehicle comprising a computer configured to perform the steps of the method according to any of the aforementioned aspects.

[0022] According to one aspect of the invention, the computer comprises a first module for detecting a first contact state of a vehicle starter switch and a second module for detecting a second contact state of the starter switch, the second detection module being a detection module, called ASIL.

[0023] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0024] The figures are presented for information purposes only and in no way limit the invention.

[0025] [Fig.l] schematically illustrates a vehicle according to a non-limiting aspect of the invention.

[0026] [Fig.2] shows, schematically, the steps of a method according to a non-limiting aspect of the invention. DETAILED DESCRIPTION

[0027] Unless otherwise specified, the same element appearing in different figures presents a unique reference.

[0028] [Fig.l] schematically illustrates a motor vehicle 1 conforming to a non-limiting implementation of the invention.

[0029] In this exemplary embodiment, the vehicle 1 is a motor vehicle equipped with a thermal engine 2.

[0030] The vehicle 1 comprises a computer 3, for example an engine computer formed by a microprocessor.

[0031] The computer 3 is provided with a first detection module 4 of a first contact state of a starting contactor 5 and a second detection module 6 of a second contact state of the starting contactor 5.

[0032] The first detection module 4 is configured to execute data processing of the thermal engine 2. The second detection module 6 is, for its part, configured to control the data processing executed by the first detection module 4. The second detection module 6 is, for example, a so-called ASIL C module (for “Automotive System Integrity Level” level C).

[0033] The starter switch 5 can be operated by means of a starter key.

[0034] During a transition between an open position and a closed position of the starter switch 5, a raw signal reflecting information on the contact state of the starter switch 5 is generated.

[0035] From this raw signal, the computer 3 is configured to execute the steps of a method 100 for detecting a contact state of the starter switch 5 of the vehicle 1 according to the invention as illustrated in [Fig.2].

[0036] The method 100 comprises a step 101 of receiving the raw signal reflecting an in training on a contact state of the starter contactor 5. According to a non-limiting embodiment, the raw signal is a logic signal which can take the value of OV or 5V.

[0037] The same raw signal is received by both the first detection module 4 and the second detection module 6.

[0038] Then, from this received raw signal, the first detection module 4 executes a step of filtering 102 the rebounds of the raw signal. This filtering step makes it possible to avoid false detections.

[0039] The first detection module 4 executes a successive step of determining 103 a first contact state of the starting contactor 5 from the previously filtered raw signal.

[0040] According to a non-limiting embodiment, the first detection module 4 executes a successive step of synchronizing 104 at least two cores (not illustrated) of the computer 3. Thus, the first contact state determined during step 103 is transmitted to the two cores.

[0041] In parallel with steps 102 to 104, the method 100 comprises a step of determining 105, by means of the second detection module 6, a second contact state of the starting contactor 5 as a function of the raw signal received during step 101.

[0042] When the second contact state determined by the second detection module 6 is different from a second contact state previously determined by the second detection module 6, the method 100 comprises a step, executed by the second detection module 6, of triggering 106 a time counter.

[0043] If the second determined contact state is different from a second previously determined contact state, this reflects a transition from a closed state to an open state, or vice versa, of the starting contactor 5.

[0044] The time recorded by the time counter is at least equal to the time required by the first detection module 4 to determine the first contact state.

[0045] In the present case, the time recorded by the time counter is equal to the time required by the first detection module 4 to determine the first contact state and to synchronize the two cores.

[0046] The time required for the first detection module 4 to determine the first contact state and to synchronize the two cores may, for example, be between 20 ms and 40 ms, typically 30 ms. Thus, the time recorded by the time counter may be 30 ms.

[0047] When the time counter has expired, the method 100 comprises a step, executed by the computer 3, of comparing 107 the first contact state determined during step 103 with the second contact state determined during step 105.

[0048] If the first and second contact states determined are different, the method 100 comprises a step of selecting 108 the second contact state determined by the second detection module 6 as security information.

[0049] Information reflecting a contact state determined from a raw signal is more robust than information determined from a filtered signal that has undergone software processing. Software processing can actually generate errors during data processing. Thus, thanks to the method according to the invention, if there is a difference between the first and second contact states determined, the safety software functions of the computers of the vehicle 1 will use the second contact state as input data.

[0050] When the first contact state and the second contact state determined are different, the method 100 may comprise a step of recording 109 information reflecting the difference in a non-volatile memory of the vehicle 1. Thus, during a diagnosis of the vehicle 1 carried out by the after-sales service, the latter will be able to identify the fault and remedy it if necessary, for example by updating the on-board software by the first detection module 4.

[0051] Furthermore, according to a non-limiting implementation, when the first contact state and the second contact state determined are different, the method 100 comprises a step of resetting 110 the computer 3. Resetting the computer 3 can make it possible to remedy a fault in the operation of the on-board software by the first detection module 4.

[0052] Nevertheless, if the reset does not remedy this operating fault despite several resets of the computer 3, it is pointless to continue these resets.

[0053] Thus, when a reset of the computer 3 is carried out, the method 100 comprises a step of counting 111 said reset, the step of resetting 110 the computer 3 being prohibited when the number of resets reaches a threshold value, for example 2.

[0054] According to a non-limiting implementation, if the first contact state and the second contact state determined are identical, the method 100 comprises a step of selecting 112 the first contact state as security information. In this case, the second contact state makes it possible to confirm the veracity of the first contact state determined.

Claims

Claims

1. Method (100) for detecting a contact state of a starter switch (5) of a motor vehicle (1), said vehicle (1) comprising a computer (3) provided with a first detection module (4) of a first contact state of said starter switch (5) and a second detection module (6) of a second contact state of said starter switch (5), said method (100) comprising the steps of: • Receiving (101) a raw signal reflecting information on a contact state of said starter switch (5), said raw signal being received by said first detection module (4) and said second detection module (6); • Filtering (102) bounces, by means of said first detection module (4), of said raw signal; • Determining (103), by means of said first detection module (4), a first contact state of said starter switch (5) from said filtered raw signal;• Determine (105), by means of said second detection module (4), a second contact state of said starter switch (5) from said received raw signal; • When said determined second contact state is different from a previously determined second contact state, trigger (106) a time counter; • When said time counter has expired, • Compare (107) said first determined contact state with said second determined contact state; • When said first determined contact state and said second determined contact state are different, select (108) said second determined contact state as security information.;

2. Method (100) according to the preceding claim, characterized in that when the first contact state and the second contact state determined are identical, the method (100) comprises a step of selecting (112) said first contact state as se- security.

3. Method (100) according to any one of the preceding claims, characterized in that it comprises a step of synchronizing (104) at least two cores of the computer (3) to transmit the first determined contact state to said at least two cores, said step of synchronizing (104) being successive to the step of determining (103) a first contact state.

4. Method (100) according to any one of the preceding claims, characterized in that the time counted by the time counter is at least equal to the time required by the first detection module (4) to determine (103) the first contact state.

5. Method (100) according to any one of the preceding claims, characterized in that when the first contact state and the second contact state determined are different, the method (100) comprises a step of recording (109) information reflecting said difference in a non-volatile memory of the vehicle (1).

6. Method (100) according to any one of the preceding claims, characterized in that when the first contact state and the second contact state determined are different, the method (100) comprises a step of resetting (110) the calculator (3).

7. Method (100) according to the preceding claim, characterized in that when a reset of the computer (3) is carried out, the method (100) comprises a step of counting (111) said reset, the step of resetting (110) the computer (3) being prohibited when the number of resets reaches a threshold value.

8. Method (100) according to any one of the preceding claims, characterized in that the received raw signal is a logic signal.

9. Motor vehicle (1), characterized in that it comprises a computer (3) configured to execute the steps of the method (100) according to any one of the preceding claims.

10. Vehicle (1) according to the preceding claim, characterized in that the computer (3) comprises a first detection module (4) of a first contact state of a starting switch (5) of the vehicle (1) and a second detection module (6) of a second contact state of said starting switch (5), said second detection module (6) being a detection module, called ASIL.

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