WO2017050851A1

WO2017050851A1 - Electronic device for detecting a signal emitted by a locking and/or unlocking sensor of an openable body section of a motor vehicle

Info

Publication number: WO2017050851A1
Application number: PCT/EP2016/072470
Authority: WO
Inventors: Eric Leconte; Pierre Demeyer
Original assignee: Valeo Comfort And Driving Assistance
Priority date: 2015-09-22
Filing date: 2016-09-21
Publication date: 2017-03-30
Also published as: FR3041462B1; CN108780592A; CN108780592B; FR3041462A1

Abstract

The invention relates to an electronic device (10) for detecting a signal emitted by a locking and/or unlocking sensor (100) of an openable body section of a motor vehicle, which comprises: an acquisition stage (20) including an electronic arrangement with a current mirror, which comprises a first branch (21) and a second branch (22) connected in parallel or each provided with a transistor (T1, T2) of which the base or gate is connected to the base or gate of the other transistor, the first branch being suitable for being connected to said sensor; and a detection stage (30) connected to the second branch in order to detect the current passing through said second branch. According to the invention, the second branch comprises an electrical component (D1) suitable for blocking the passage of current below a voltage or current threshold, and for allowing the passage of current above said voltage or current threshold.

Description

ELECTRONIC DEVICE FOR DETECTING A SIGNAL EMITTED BY A SENSOR FOR LOCKING AND / OR UNLOCKING AN OPENING OF A MOTOR VEHICLE

TECHNICAL FIELD TO WHICH THE INVENTION RELATES The present invention generally relates to the locking and unlocking of the opening of motor vehicles.

It relates more particularly to an electronic device for detecting a signal emitted by a sensor for locking and / or unlocking an opening leaf of a motor vehicle, comprising:

an acquisition stage comprising a current mirror electrical assembly, which comprises a first branch and a second branch connected in parallel and each equipped with a transistor whose base or gate is connected to the base or gate of the other transistor, the first branch being adapted to be connected to said sensor, and

a detection stage connected to the second branch for detecting the current flowing through this second branch.

BACKGROUND

It is known to equip the handles of motor vehicle opening sensors to allow a user to be able to control the locking or unlocking of these openings, with or without hand contact on the handle.

Generally, these sensors are connected by at least one electrical wire to the central computer of the vehicle, so that the latter can control the locking or unlocking of the doors.

The signal flowing on this electric wire has a current of low intensity in the absence of control of locking or unlocking (for example 0.1 mA), and a current that varies between this low intensity and a high intensity in the presence of a command (for example 10mA).

In order for the central computer to detect these current variations, it is known to use a detection device as mentioned above, the acquisition stage of which comprises a current mirror electrical assembly.

The connection of the first branch of this current mirror electrical assembly to the sensor makes it possible to obtain on the second branch an intensity which varies exactly as a function of the intensity of the current delivered by the sensor. A first disadvantage of this electrical assembly is that in the absence of control, leakage currents are important (of the order of 0.08mA), which has a significant effect on the charge level of the battery. accumulators of the vehicle, especially when this vehicle is equipped with several openings and therefore several devices as mentioned above.

The second disadvantage is that, in the absence of control, since the intensity of the current flowing in the first branch is small, the occurrence of voltage drops at the emitter of the transistor equipping this first branch is observed. which results in a random behavior of this transistor and therefore the detection of the user's hand problems on the handle of the opening of the vehicle.

OBJECT OF THE INVENTION

In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes a detection device as defined in the introduction, in which the second branch comprises an electrical component adapted to block the passage of the current below a voltage or current threshold, and allowing the current to pass beyond said voltage or current threshold.

Preferably, said electrical component is a diode.

As we know, a diode has a threshold voltage, below which it blocks the passage of the current, and beyond which it releases the passage of the current in one direction.

This threshold voltage thus allows the diode to block the passage of current in the second branch in the absence of control, which limits the leakage currents and thereby to save electrical energy.

This diode is however passing in the presence of a command, so that it does not change the behavior of the current mirror electrical assembly.

Moreover, since the current in the second branch is blocked in the absence of control, there is no longer any voltage drop at the emitter of the transistor equipping the first branch, so that the behavior of the electrical assembly remains according to expectations.

The diode could be replaced by any other electrical component exhibiting a non-linear behavior to block the flow of current in the absence of control of locking or unlocking of the opening of the vehicle.

Other advantageous and non-limiting features of the detection device according to the invention are the following:

the second branch being adapted to be connected on one side to a voltage source, the diode is situated between the transistor equipping this second branch and the voltage source;

the first and second branches are each adapted to be connected on one side to a voltage source and each is equipped with an electrical resistance located between their transistor and the voltage source;

the electrical resistance equipping said first branch has a value lower than that of the electrical resistance equipping said second branch;

said voltage source is formed by the battery of the motor vehicle;

the bases or gates of the transistors equipping said first and second branches are connected to the first branch, between the transistor equipping said first branch and said sensor;

said second branch being connected on one side to an electrical ground, the detection stage is connected to the second branch, between the transistor equipping said second branch and the electrical ground; and

said diode has a threshold voltage greater than 0.1 V. The invention also proposes a motor vehicle comprising a frame on which are articulated at least two openings each equipped with a locking and / or unlocking sensor, a calculator central comprising means for controlling the locking and unlocking of each leaf, and at least two electronic devices as mentioned above, the detection stages of which are connected to the central computer.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

The following description with reference to the accompanying drawing, given by way of non-limiting example, will make it clear what the invention is and how it can be achieved.

In the appended drawing, FIG. 1 is an electrical diagram of a device detection device according to the invention.

As a preliminary, it will be recalled that a transistor is an electrical component which may in particular be of the "bipolar" type, in which case it will comprise a collector, a base and an emitter, or of the "field effect" type, in which case it will comprise a drain, a grid and a source.

The present invention is generally applicable to motor vehicles. A motor vehicle generally comprises a frame on which are articulated opening (doors, tailgate). These doors are equipped, on their edges, with a lock that not only locks the door in the closed position, but also to lock the door in this position so as to prohibit access to the passenger compartment of the vehicle.

The vehicle also comprises a central computer, which includes means for controlling the lock, to allow to lock or unlock the door.

The locking or unlocking of these openings is controlled in particular according to the wish of the user of the vehicle. Each of these openings is for that equipped with a lever that the user can manipulate to control the unlocking or locking of the doors.

Here we will be more specifically interested in the opening levers that are equipped with a locking sensor and unlocking.

We will consider here a sensor of a particular kind, namely a sensor for determining the area of support of the hand of the user on the lever. Such a sensor makes it possible for example to detect a support on the outer face of the lever (to control the locking of the opening) or on the inner face of the lever (to control the unlocking of this opening).

Here, as shown in FIG. 1, this sensor 100 is equipped with its own microprocessor (illustrated in the figure as a current source) and with a single electrical wire 101 that not only powers the microprocessor, but also to transmit an output signal S0 to the central computer.

In the present case, this output signal S0 has a current of variable intensity, which makes it possible to code the support area of the user on the handle.

More specifically here, the output signal S0 has a current of reduced intensity, of the order of 0.1 mA, in the absence of a hand detected on the handle. This reduced intensity current makes it possible to supply the microprocessor of the sensor 100.

On the other hand, the output signal S0 has a current of variable intensity in the presence of a hand detected on the handle.

This current then has a form of slots varying between this reduced intensity and a maximum intensity (of the order of 10mA), these slots having different shapes depending on the area on which the support is exerted by the user on the handle.

In summary, the output signal S0 carries binary coded information by current modulation.

The invention then relates more precisely to the electronic device 10 which will make it possible to detect the output signal S0, so as to convert the information of the output signal S0 into information coded in binary, this time by voltage modulation.

As is clearly shown in FIG. 1, this electronic device 10 comprises for this purpose an acquisition stage 20 of the output signal S0, and a detection stage 30 connected to the central computer.

The acquisition stage 20 comprises a current mirror electrical assembly.

Conventionally, such an assembly comprises a first branch 21 and a second branch 22 connected in parallel, which are each equipped with a transistor T1, T2 (here a bipolar transistor) whose bases are directly connected to one another. By "directly" is meant that no electrical component is here between the bases of the transistors.

These two branches 21, 22 are connected, on one side, to a first voltage source. Here, this voltage source is a BAT accumulator battery fitted to the motor vehicle, which is adapted to deliver a voltage V1. Transistors T1, T2 are thus connected by their transmitters to this BAT accumulator battery.

The first branch 21 is connected, on the opposite side, to the electric wire

101 of the sensor 100. The transistor T1 is connected by its collector and by its base to the electrical wire 101.

The second branch 22 is connected, on the opposite side to the BAT accumulator battery, to a MAS electrical mass. The transistor T2 is thus connected by its collector to this electrical mass MAS, via an electrical resistance R3.

Here, to reduce the intensity of the electric current flowing through the second branch 22 to a ratio of the current emitted by the sensor 100, each branch 21, 22 is equipped with an electrical resistor R1, R2 situated between its transistor T1, T2 and the BAT battery.

The electrical resistance R1 equipping the first branch 21 has a value lower than that of the electrical resistance R2 equipping the second branch 22. In this way, it is possible to write:

i2 = he. R1 / R2,

with it the current flowing in the first branch 21 and i2 the current flowing in the second branch 22.

According to a particularly advantageous characteristic of the invention, the second branch 22 further comprises an electrical component adapted to block the passage of the current below a voltage or current threshold, and to allow the current to pass beyond said threshold voltage or current.

This electrical component must therefore have a non-linear behavior.

Here, this electrical component is a diode D1, which is located between the storage battery BAT and the electrical resistance R2, and whose cathode is turned towards this electrical resistance R2.

It has a threshold voltage between 0.1 V and 1 V, here equal to about 0.7V.

The detection stage 30 is in turn controlled by the second branch 22, between two states, according to whether a current flows in the second branch 22 or not.

It comprises for this purpose a transistor T3, here a field effect transistor, whose gate is connected to the second branch 22 of the acquisition stage 20, via an electrical resistor R4. The gate of this transistor T3 is more precisely connected to the second branch 22, between the transistor T2 and the electrical resistance R3.

The source of transistor T3 is in turn connected to the electrical ground MAS while its drain is connected to a second voltage source via an electrical resistance R5. Here, this second source of tension is formed by the power supply VCC of the central computer and it delivers a voltage V2.

The values of voltages and electrical resistances are as follows:

V1 = 12V,

V2 = 5V,

R1 = 100 Ω,

R2 = 400 Ω,

R3 = 2000 Ω,

R4 = 1000 Q,

R5 = 2200 Ω.

They could of course be chosen otherwise.

The operation of the detection device 10 is then as follows.

In the absence of detected support on the handle, the current flowing in the first branch 21 of the acquisition stage 20 has a low intensity, here equal to 0.1 mA. This current makes it possible in particular to supply the microprocessor of the sensor 100.

In this case, the voltage across the diode D1 is lower than its threshold voltage, so that the intensity of the current flowing in the second branch 22 of the acquisition stage remains zero. As a result, the power consumption of the detection device 10 remains reduced.

On the other hand, when a support is detected on the handle, the current emitted by the sensor 100 has a intensity that varies in slots, between said low intensity 0.1 mA and a high intensity (here 10 mA), in order to generate a signal output S0 relative to the area of the handle on which the user has pressed.

When the intensity is high, the voltage across the diode D1 is greater than its threshold voltage, so that the intensity of the current flowing in the second branch 22 of the acquisition stage 20 is equal to the intensity high, multiplied by the ratio R1 / R2.

This current makes it possible to control the transistor T3, so that the voltage measured at the node N1 situated between the transistor T3 and the electrical resistance R5 varies.

So, the central calculator that is plugged into this node N1 can read a signal S1 modulated in voltage, relative to the area of the handle on which the user presses.

The present invention is not limited to the embodiment described and shown, but the art can apply any variant within his mind.

In particular, the transistors of the acquisition stage could be of the field effect type. In a variant also, the transistor of the detection stage could be of the bipolar type.

According to another variant of the invention, it would have been possible to use in place of a diode another electrical component, such as for example a transistor whose gate would be connected to the first branch 21. One could also use a zener diode, a varistor, or any other electrical component ad hoc.

In another variant, to damp the parasitic signals flowing on the electrical wire 101 of the sensor 100, a capacitor could have been connected in parallel with the sensor 100.

According to another variant of the invention, the sensor used on the handle of the opening could be of another type. It could thus be only adapted to detect a support of the hand of the user on the handle (without being able to determine the area of the handle at which this support is exercised). It could also operate "without contact" to detect the presence of the hand of the user when it is a short distance from the handle.

Claims

1. Electronic device (10) for detecting a signal (S0) emitted by a sensor (100) for locking and / or unlocking a motor vehicle leaf, comprising:

an acquisition stage comprising an electrical current mirror assembly, which comprises a first branch (21) and a second branch (22) connected in parallel and each equipped with a transistor (T1, T2) whose base or gate is connected to the base or gate of the other transistor (T1, T2), the first branch (21) being adapted to be connected to said sensor (100), and

a detection stage (30) connected to the second branch (22) for detecting the current flowing through this second branch (22),

characterized in that the second leg (22) comprises an electrical component (D1) adapted to block the flow of current below a voltage or current threshold, and to allow the current to pass beyond said voltage threshold or current.

2. Electronic device (10) according to the preceding claim, wherein said electrical component is a diode (D1).

Electronic device (10) according to one of the preceding claims, wherein, the second leg (22) being adapted to be connected on one side to a voltage source (BAT), the diode (D1) is located between the transistor (T2) equipping this second branch (22) and the voltage source (BAT).

4. Electronic device (10) according to one of the preceding claims, wherein the first and second legs (21, 22) are each adapted to be connected on one side to a voltage source (BAT) and are each equipped with an electrical resistor (R1, R2) located between their transistor (T1, T2) and the voltage source (BAT).

5. Electronic device (10) according to the preceding claim, wherein the electrical resistance (R1) equipping said first branch (21) has a value less than that of the electrical resistance (R2) equipping said second branch (22).

An electronic device (10) according to one of the three preceding claims, wherein said voltage source (BAT) is formed by the battery of the motor vehicle.

7. Electronic device (10) according to one of the preceding claims, wherein the bases or gates of the transistors (T1, T2) equipping said first and second branches (21, 22) are connected to the first branch (21), between the transistor (T1) equipping this first branch (21) and said sensor (100).

An electronic device (10) according to one of the preceding claims, wherein, said second branch (22) being connected on one side to an electrical ground (MAS), the detection stage (30) is connected to the second branch (22), between the transistor (T2) equipping this second branch (22) and the electrical ground (MAS).

9. Electronic device (10) according to one of the preceding claims, wherein said diode (D1) has a threshold voltage greater than 0.1 V.

10. A motor vehicle comprising a frame on which are articulated at least two openings each equipped with a locking sensor and / or unlocking, and a central computer having means for controlling the locking and unlocking of each leaf, characterized in that it comprises at least two electronic devices according to one of the preceding claims, the detection stages of which are connected to the central computer.