FR3080399A1 - METHOD FOR CONTROLLING AN ELECTRICAL LOCK FOR DIAGNOSING A FAILURE OF THE ASSOCIATED OPENING CONTROL, OPENING CONTROL AND VEHICLE IMPLEMENTING SUCH A METHOD - Google Patents

Abstract

The invention relates to a method of controlling an electric lock of a motor vehicle door, the control of the release position of the electric lock being initiated by the operation of a switch (3) of a sash opening control, the switch (3) comprising an electronic circuit with an input terminal and an output terminal; the method comprising the steps of: a) measuring the voltage at the input terminal or at the output terminal of the switch (3); b) comparing the measured voltage with a first and a second predetermined and non-zero reference voltage; and c) controlling the release of the electric lock release position if and only if the measured voltage is between the first and the second reference voltage.

Description

METHOD OF CONTROLLING AN ELECTRIC LOCK FOR DIAGNOSING A FAILURE OF THE RELATED OPENING CONTROL, OPENING CONTROL AND VEHICLE IMPLEMENTING SUCH A METHOD

The invention lies in the field of vehicles, such as motor vehicles, the doors of which are fitted with electric locks. The invention also relates to the opening controls incorporating a control function for said electric locks and the methods implemented in said opening controls.

The opening elements of vehicles, for example motor vehicles, are fitted with locks actuated by an interior and / or exterior opening control of the opening with which they are associated. They generally include a strike cooperating with a bolt locked in the closed position by a pawl cooperating with a cam. To allow the opening of the opening, the pawl is released by a mechanism activated following the operation of the opening control by a user of the vehicle.

In mechanical locks, this mechanism is most often a cable. The operation of this cable requires the user to exert a certain force. This is why, in order to assist it, electric locks were developed.

Electric locks (“e-latch” in English) use an electromagnetic type mechanism to release the pawl from the lock. The effort required of the user is very low and the opening opening command is, for example, in the form of a button ("push" in English) that the user will, depending on the case, lift or push. These buttons form a command user interface. When activated, the opening control will control the release of the electric lock via the vehicle's electrical network, multiplexed or not. The opening window controls are therefore electrically connected to a source of electrical energy for the vehicle, such as a battery.

One of the known problems in vehicles comprising electric locks relates to the opening and closing of the opening elements in the event of failure of the main electrical supply, or in the event of interruption or deterioration of the electrical connection between the source d electric power and the door opening control, which can happen in the event of an accident.

One solution is to associate a mechanical system with the opening controls so that you can take over and open the door in all circumstances. Another solution was to provide the doors with an emergency power supply system.

Another known problem concerns the opening and closing of the doors in the event of an internal failure of the door opening control. The release of an electric lock is, in fact, controlled by the interior (COI) or exterior (COE) opening opening command in response to an opening command initiated by the vehicle user. The opening control includes a switch connected to an electronic control unit for this purpose. Said electronic control unit will control the blocking or the release of the electric lock according to the interpretation made of the signals coming from the opening command. However, it may happen that the information from the opening door commands can no longer be interpreted correctly due to internal failures of the said opening order. In some cases, the occupants of the vehicle are trapped in the vehicle. In other cases, the door is opened inadvertently, for example, while the vehicle is moving, or in an accident while the vehicle rolls over.

It goes without saying that, for the safety of the driver and passengers, these inadvertent opening situations of a door must be avoided. With this objective in view, the ISO 26262 standard requires that the door opening controls and the associated locks be diagnosed against internal failures. Unfortunately, the solutions currently proposed are not entirely satisfactory. There is therefore a need to improve solutions for diagnosing such failures, and a need to manage these failures when they are detected, which guarantees the safety of the occupants of a vehicle.

Document US 2017/0314302 provides a diagnostic solution in which the electronic control circuit for an electric lock comprises an electronic control unit provided with a calculation unit and a memory communicating with a plurality of sensors. The electronic control circuit is also connected to the vehicle battery. A circuit for reading the state of the opening door control is controlled by the electronic control circuit and coupled with the sub-assembly forming the door opening control. The readout status of the sash opening control is configured to transform direct current from an electrical power source into alternating current. The reading circuit includes a number of capacitors and resistors, one of the capacitors being mounted in parallel with a contact actuated by the door opening control. The reading circuit will send voltage values to the electronic control circuit, which will be interpreted, as the case may be, as a command to release the electric lock, a command to block the electric lock (default state) or as the indication of a failure of said reading circuit which will be transmitted to the user of the vehicle. In particular, the signal corresponding to the blocking of the electric lock comprises two voltage measurements, successive in time, of different values.

The method and the reading circuit associated with the opening opening control are interesting but complex, in particular by the variety of signals which may indicate a failure of the reading circuit, or by the need to transform a direct current into an alternating current. . There is therefore a need to simplify the methods and circuits used.

The document WO2006 / 002186 proposes a method for controlling an electric lock, in which the electric lock is actuated by a motor through an H-bridge. A microprocessor is used to control the interactions of said H-bridge with the motor. and the lock. This architecture is interesting but does not respond to the problem of detecting internal failures in the interior or exterior opening controls.

The document KR200163820U-Y1 proposes a device comprising a system of resistance bridges and capacitors to control the activation signal emitted.

The object of the invention is to provide a response to at least one of the drawbacks of the prior art. In particular, the invention aims to provide a new opening command and a new method of controlling an electric lock which are simple, capable of identifying internal failures and therefore which prevents inadvertent opening of the doors.

To this end, and according to a first aspect, the invention relates to a method for controlling an electric lock of a motor vehicle opening, the electric lock being able to be placed in the blocking position preventing the opening of the opening or in the release position authorizing an opening of the opening, the control of the release position being initiated by the actuation of a switch of an opening opening control by a user of the vehicle, the switch comprising an electronic circuit with an input terminal and an output terminal; the method being remarkable in that it comprises the following stages:

a) measurement of the voltage at the input terminal or at the switch output terminal by means of analog voltage measurement;

b) comparison of the measured voltage with a first and a second predetermined and non-zero reference voltage, the first reference voltage being less than the second reference voltage; and

c) control of the release position of the electric lock if and only if the measured voltage is between the first and the second reference voltage.

As will have been understood on reading the definition which has just been given, the invention consists in defining a range of voltage values corresponding to a valid actuation signal of the switch of the door opening control switch , and trigger the release of the electric lock only upon receipt of such a valid signal. When the measured voltage is outside of said range of values, the electric lock is set or maintained in the blocking position. The invention is remarkable in that the internal failure states of the switch, including a fault in the supply of electrical energy by rupture of the power cable, are diagnosed as such and lead to the maintenance of the lock in the locked position. The method of controlling an electric lock according to the invention therefore responds to the problem of preventing inadvertent opening situations of the opening.

According to a preferred implementation, in step a), the voltage is measured at the input terminal of the switch. This aspect of the process is advantageous in that it simplifies the arrangement of the various electronic components used. When the voltage is measured at the input terminal of the switch, the output terminal of the latter is advantageously connected to ground.

Preferably, the switch being part of a control circuit for the electric lock, the method is remarkable in that the voltage measurement carried out in step a) is a ratiometric voltage measurement calculated to be a ratio between the voltage U2 measured at the input terminal or at the switch output terminal and the initial supply voltage U1 measured at the control circuit input, so that the ratiometric voltage is equal to the ratio U2 / U1. This aspect of the process is particularly advantageous in that it makes it possible to dispense with the presence of a voltage regulator and to absorb voltage variations, or to simplify the management of a supply by different supply sources. such as, for example, the main battery and a backup battery, the backup battery taking over from the main battery when the latter is discharged.

Advantageously, the method further comprises a step of sending an alert message to the user indicating a failure of the switch:

when the measured voltage is less than the first reference voltage, and / or when following a comparison of the measured voltage with a third and a fourth predetermined and non-zero reference voltage, the third reference voltage being less than the fourth reference voltage and greater than the second reference voltage, the measured voltage is between the third and the fourth reference voltage.

This aspect of the process alerts the user to a switch failure so that they can have it repaired.

According to a second aspect, the subject of the invention is a command to open a vehicle window comprising an electric lock, the electric lock being able to be placed in the blocking position preventing the opening of the window or in the release position. authorizing an opening of the opening, the opening control comprising a switch operable by a user to control the setting in the release position of the lock; said opening command being remarkable in that said switch comprises an electronic circuit with an input terminal and an output terminal between which two contacts are arranged in series, a first contact being a normally open contact and a second contact being a normally closed contact, and in that the normally closed contact is mounted in parallel with a resistor R1.

As will be understood, the use of a double contact normally open and normally closed with the paralleling of the normally closed contact with the resistor R1 makes it possible to define a specific voltage in the electronic circuit of the switch when the latter is actuated . It is this specific voltage which is then recognized and considered as a valid signal for actuation of the switch by the user. Failure at the normally open contact (closed or shorted) will result in zero measured voltage. As seen above, a zero measured voltage (therefore less than the first reference value) does not cause the electric lock to be released.

Optionally, the electronic circuit of the switch further comprises a resistor R5 mounted in parallel with the normally open contact. This configuration makes it possible to refine the possibilities of diagnosing switch failures by detecting failures of the normally closed contact. Indeed, when the latter is faulty (i.e. open or short-circuited) the voltage measured will be different from the expected voltage and will not cause the release of the electric lock.

Preferably, the output terminal of the switch is connected to ground.

Ideally, the door opening control according to the second aspect of the invention is implemented in the method according to the first aspect of the invention.

According to a third aspect, the invention relates to a vehicle comprising an opening fitted with an electric lock and at least one opening control according to the second aspect of the invention, the vehicle being remarkable in that it further includes an electronic control unit forming an analog voltage measurement means and comprising a memory and a microcontroller being configured to:

measure the voltage at the input terminal or at the output terminal of the switch, compare the measured voltage with a first and a second predetermined non-zero reference voltage, the first reference voltage being less than the second reference voltage , and order the electric lock release position if and only if the measured voltage is between the first and the second reference voltage.

According to a preferred embodiment, the microcontroller is configured to measure the voltage at the input terminal of the switch and the output terminal of said switch is connected to ground.

Preferably, the switch and the electronic control unit are part of a control circuit for the electric lock, said circuit being electrically supplied:

by a voltage regulator and the microcontroller is configured to perform direct voltage measurements, or by an electric power supply battery and the microcontroller is configured to perform ratiometric voltage measurements.

According to a preferred embodiment, the electronic control unit comprises an input supply resistor R2. Preferably, the electronic control unit further comprises:

a grounding resistor R4, and / or a resistor R3 disposed between the microcontroller and its connection to the switch.

The invention will be well understood and other aspects and advantages will appear clearly on reading the following description given by way of example with reference to the accompanying drawing plates in which:

Figure 1 shows a control circuit of an electric lock according to a first embodiment of the invention;

Figure 2 shows a control circuit of an electric lock according to a second embodiment of the invention; and FIG. 3 shows a control circuit for an electric lock according to a third embodiment of the invention.

In the description which follows, the term “understand” is synonymous with “include” and is not limiting in that it authorizes the presence of other elements in the vehicle or the opening control of the window to which it relates, or other steps in the process to which it relates. It is understood that the term "understand" includes the terms "consist of". In the different figures, the same references designate identical or similar elements.

The method and the vehicle implementing the method will be described jointly. Reference will firstly be made to FIG. 1 illustrating a first embodiment of a control circuit 1 of an electric lock according to the invention.

For reasons of clarity, the control circuit and the method will be described in relation to a single opening command, however the person skilled in the art will easily adapt the following description to the management of several opening commands of the same opening element such as an interior opening control (COI) and an exterior opening control (COE). The opening controls can be of any kind, such as button or lever.

The control circuit comprises a switch 3 for opening the sash and an electronic control unit 5. The control unit 5 conventionally comprises at least one memory 7 and at least one microcontroller 9.

The control unit 5 is connected to the multiplex network on board the vehicle. It is recalled, if necessary, that the multiplexed networks are digital communication networks allowing the electrical equipment, or the subsets of electrical equipment, to communicate with one another with a reduced number of wires. The implementation of such multiplexed networks on a vehicle is known to those skilled in the art and will not be detailed further. For example, the invention can implement a CAN type network (acronym for Controller Area Network), LIN type (acronym for Local Interconnect Network), MOST type (acronym for Media Oriented System Transport), Flexray type, or other types of multiplexed networks.

The switch 3 of the sash opening control comprises an electronic circuit with an input terminal and an output terminal between which two contacts (NO, NC) are arranged in series, a first contact being a normally open contact NO and a second contact being a normally closed NC contact. According to the invention, the normally closed contact NF is mounted in parallel with a resistor R1.

Preferably, the electronic control unit 5 comprises an input supply resistor R2 in order to lower the input voltage of the microcontroller 9, for example so that it is less than 5 V. If necessary and for this purpose, it is possible to provide a divider bridge comprising two resistors R3 and R4 at the input of the microcontroller 9. The resistor R4 is a grounding resistor.

The method according to the invention will preferably implement such a door opening control. The method comprises a first step a) of measuring the voltage at the input terminal or at the output terminal of the switch by means of analog voltage measurement. This analog voltage measurement means is formed by the electronic control unit 5, the microcontroller 9 of which is configured to measure the voltage at the input terminal or at the output terminal of the switch 3. In FIG. 1, the voltage is measured at the input terminal of switch 3. The output terminal of switch 3 is connected to ground.

In a second step, or step b), the measured voltage is compared with a first and a second predetermined and non-zero reference voltage, the first reference voltage being less than the second reference voltage. The values of the first and second reference voltages are stored in memory 7 of the electronic unit. The first and second reference voltages define a range of voltage values corresponding to the activation of switch 3, that is to say to the positioning of the NO contact in the closed position and of the N F contact in the open position. When the switch 3 is activated, the electric current flows through the resistor R1 and the voltage measured at the input terminal of the said switch 3 is lower than the voltage measured when the switch is not activated (NO contact open and NC contact closed ). The range of values thus defined takes into account possible voltage variations. For example, if the voltage expected when switch 3 is activated is 1 V and when it is inactive is 3.9 V. The first and second reference voltages selected may be 0.5 V and 1.5 V respectively. The range of values is chosen to distinguish, no doubt possible, the actuated state of the switch from its inactive (or idle) state.

In a third step, or step c), the setting in the release position of the electric lock is controlled by the electronic unit 5 if and only if the measured voltage is between the first and the second reference voltage, this is that is to say, it probably corresponds to an activation state of the switch and therefore reflects the will of a user to open the door.

When the measured voltage is greater than the second reference value, if for example it corresponds to the expected voltage when the switch 3 is inactive (i.e. around 3.9 V in our example), no release command will be transmitted to the electric lock which will remain, by default, blocked.

In the event of an internal failure of switch 3, when the NO contact remains in the closed position or is placed in short-circuit, the measured voltage will be zero, therefore less than the first reference voltage. No release command will be transmitted to the electric lock which will remain, by default, blocked. Optionally, the method further comprises a step of sending an alert message to the user indicating a failure of the switch when the measured voltage is lower than the first reference voltage.

Reference will now be made to FIG. 2 illustrating a second embodiment of a control circuit 1 of an electric lock according to the invention.

In this exemplary embodiment, the electronic circuit of the switch 3 further comprises a resistor R5 mounted in parallel with the normally open contact NO. This configuration makes it possible to refine the possibilities of diagnosing switch failures by detecting failures of the normally closed NC contact. Indeed, when the latter is faulty (i.e. open or short-circuited), the measured voltage will be different from the expected voltage when the switch 3 is activated, and will not cause the release of the electric lock.

Those skilled in the art will benefit from defining a third and a fourth predetermined and non-zero reference voltage, the third reference voltage being less than the fourth reference voltage, corresponding to the passage of current through the resistor R5. The values of the third and fourth reference voltages are also kept in memory 7 of the electronic unit. The fourth reference voltage is lower than the voltage when the switch 3 is inactive. Thus, when the measured voltage is between the third and the fourth reference voltage, no release command will be transmitted to the electric lock which will remain, by default, blocked.

Optionally, the method further comprises a step of sending an alert message to the user indicating a failure of the switch when, following a comparison of the voltage measured with the third and fourth predetermined reference voltage and non-zero, the measured voltage is between the third and the fourth reference voltage.

In general, the control circuit can be supplied with electricity through a voltage regulator and the microcontroller 9 is configured to carry out direct voltage measurements as illustrated in FIG. 1. According to a variant of the invention illustrated in FIG. 2, the control circuit is supplied with electricity by the main supply battery of the vehicle, or by a backup battery, for example, integrated into the opening. Since the electric power supply is then unregulated and can vary between 9 V and 16 V, the microcontroller is preferably configured to perform metric voltage ratio measurements.

According to a preferred implementation of the invention, the voltage measurement carried out in step a) is a ratiometric voltage measurement calculated to be a ratio between the voltage U2 measured at the input terminal or at the output terminal of the switch and the initial supply voltage U1 measured at the input of the control circuit, so that the ratiometric voltage is equal to the ratio U2 / U1. A ratio of the use of available energy is thus determined. The reference voltages will then be replaced by ratiometric reference voltages.

Figure 3 illustrates a third embodiment of the invention in which the voltage is measured at the switch output terminal. In this embodiment, the resistance R3 5 does not appear since it is optional.

Claims (10)

1. A method of controlling an electric lock of a motor vehicle opening, the electric lock being able to be placed in the blocking position preventing the opening of the opening or in the release position authorizing an opening of the opening, the control of the release position being initiated by the actuation of a switch (3) of a door opening control by a user of the vehicle, the switch (3) comprising an electronic circuit with a terminal d input and an output terminal; the method being characterized in that it comprises the following stages: a) measurement of the voltage at the input terminal or at the output terminal of the switch (3) by an analog voltage measurement means; b) comparison of the measured voltage with a first and a second predetermined and non-zero reference voltage, the first reference voltage being less than the second reference voltage; and c) control of the release position of the electric lock if and only if the measured voltage is between the first and the second reference voltage. 2. Method according to claim 1, characterized in that, in step a), the voltage is measured at the input terminal of the switch (3). 3. Method according to one of claims 1 or 2, the switch (3) being part of a control circuit (1) of the electric lock, the method is characterized in that the voltage measurement carried out in step a) is a ratiometric voltage measurement calculated to be a ratio between the voltage U2 measured at the input terminal or at the output terminal of the switch (3) and the initial supply voltage U1 measured at the input of the control circuit (1), so that the ratiometric voltage is equal to the ratio U2 / U1. 4. Method according to one of claims 1 to 3, characterized in that it further comprises a step of sending an alert message to the user indicating a failure of the switch (3): when the measured voltage is less than the first reference voltage, and / or when following a comparison of the measured voltage with a third and a fourth predetermined and non-zero reference voltage, the third reference voltage being less than the fourth reference voltage and greater than the second reference voltage, the measured voltage is between the third and the fourth reference voltage. 5. Control for opening a vehicle opening comprising an electric lock, for implementing a method according to one of claims 1 to 4, the electric lock being able to be placed in the blocking position preventing the opening of the opening or in the release position authorizing an opening of the opening, the opening control comprising a switch (3) operable by a user to control the placing in the release position of the lock, said opening control being characterized in that said switch (3) comprises an electronic circuit with an input terminal and an output terminal between which two contacts are arranged in series, a first contact being a normally open contact (NO) and a second contact being a contact normally closed (NC), and in that the normally closed contact is mounted in parallel with a resistor (R1). 6. Opening control according to claim 5, characterized in that the electronic circuit of the switch further comprises a resistor (R5) mounted in parallel with the normally open contact (NO). 7. Vehicle comprising an opening fitted with an electric lock and at least one opening control according to one of claims 5 or 6, the vehicle being characterized in that it further comprises an electronic control unit ( 5) forming an analog voltage measurement means and comprising a memory (7) and a microcontroller (9), the microcontroller (9) being configured to: measure the voltage at the input terminal or at the output terminal of the switch (3), compare the measured voltage with a first and a second predetermined and non-zero reference voltage, the first reference voltage being less than the second reference voltage, and order the release position of the electric lock if and only if the measured voltage is between the first and the second reference voltage. 8. Vehicle according to claim 7, characterized in that the microcontroller (9) is configured to measure the voltage at the input terminal of the switch (3) and in that the output terminal of said switch (3) is connected to the mass. 9. Vehicle according to one of claims 7 or 8, characterized in that the switch (3) and the electronic control unit (5) are part of a control circuit (1) of the electric lock, said circuit being electrically powered by a voltage regulator and the microcontroller (9) is configured to perform direct voltage measurements, or by an electric power supply battery and the microcontroller (9) is configured to perform ratiometric voltage measurements. 10. Vehicle according to one of claims 7 to 9, characterized in that the control unit 5 electronics (5) includes an input supply resistor (R2); preferably, the electronic control unit (5) further comprises: a grounding resistor (R4), and / or a resistor (R3) disposed between the microcontroller (9) and its connection to the switch (3).