Locking system for motor vehicles detecting approach of the user

The This invention relates to a motor vehicle provided with a A system for detecting the approach of is a user equipped.

Such Detection systems are already in certain motor vehicles Application to when approaching the user automatically activating a door lock or permission to open the door trigger, without this a key must apply or a remote control. This automatic unlocking before opening perform door is generally used a so-called hands-free access system, which system is an exchange of information on a Distance between a vehicle-side identification device and carried by the user perform identifier. If the identifier of the identification device to be correct was recognized, the lock is activated, allowing the user the door can open at the handle flap of the door by simply pulling.

it however, is not desirable, the identifier and / or the ID device at all times enabled to leave because their power consumption is too high. on the other hand have to the identifier and the identification device at any time be activated, as achievement of the user at the vehicle is not predictable. For this Base has been proposed a system for detecting the approach or use of gripping the handle flap by the user, the identification device of the vehicle to activate only when the user makes a move to open the door.

So has been proposed, the door handles equipped with an electrical contactor, to the beginning the operating distance the handle for opening the door capture. This solution however, has the disadvantage that the detection of the approach of the User too late takes place, since the time that is required so that the identification device the Identifier of the user correctly recognizes and activation the lock controls, generally much longer than the time period, which is required to allow the user to an end of the handle the actuating leads. In other words, the door not yet been released in general, when the user actuation path out of the handle to an end has, and it is sometimes necessary that he several times the handle actuated before opening reaches the door.

Also known optical detection system or ultrasonic detection systems to use, but their costs are generally considerably.

in EP-A-0735219 is a system for detecting the approach of the User described to the carried on board interrogator in bring to an "awake", the an antenna used which from a waking state sensor type is Doppler, volume sensor or infrared sensor connected.

in the <patcit><text>DE 196 17 038</text></patcit> is described a motor vehicle, comprising a first electrode in a door handle is integrated, and a second electrode on the surface of Door, a capacitive sensor in the door handle is integrated, wherein the capacitive sensor via an electrical connection is connected to the central control unit, wherein a voltage having opposite poles on the two electrodes and for generating applied an electric field between the door handle and the door , wherein the insertion of the hand of the user between the two Electrodes changes the electric field and this change is measured by the capacitive sensor, thus the purpose of the query can trigger the user ID. Such a system However, making the detection of a change in between the two Electrodes generated electric field, and the introduction of the hand between the two electrodes required, which delays the detection.

Further requiring all currently known solutions additional power connectors between the handle flap and a further part of the door.

The Invention aims to eliminate the above-mentioned disadvantages and to propose a motor vehicle for a new system Detecting the approach is a user equipped, one with respect to the detection of a handle contactor permitted in takes place ahead of detection and its production costs lower than with an optical sensor or ultrasonic sensor, without an additional Conjunction with the handle flap over requiring a power line or a power cable.

To The invention is a motor vehicle, with a system for detecting the approach of a user is provided, as defined in claim 1 is.

These Detecting the capacitance variation could for example via a electronic module are processed, the earlier in the castle a vehicle door is integrated to control diverse functions, such as about the activation of the door locks and the transfer the information on the state of the lock to the other &lt;?page 3?&gt;Locks.

at a particular embodiment, belongs the aforementioned surface a handle for opening flap a vehicle closure member, For example, a door, a fuel valve, a trunk, the grip flap a door lock of a mechanical is connected connection, the electrically conductive and of the mass of the vehicle is insulated between an electrical connection said surface and to serve the aforementioned generator. In this case, the aforementioned dipole one part of the mass of the vehicle and on the other hand from the unit of area and mechanical connection is formed, for example, of a sheathed cable or a control linkage is that a Lever to open the door lock operated.

Advantageous the sensor is provided to an identification device to activate the vehicle, which identification device when it is activated, first checks whether the User performs an authorized identifier with it and then, if the review shows, that the identifier has been properly recognized, at least a function of the vehicle controls, for example, the activation a door lock.

Of the Threshold Cs advantageously results from the following equation: <img img-content="mf" img-format="tif" he="9" wi="36" file="00040001.tif" />where α is a dimensionless coefficient between 0 to 1.

at a particular embodiment, contains the vehicle is a system for performing an automatic recalibration the aforementioned threshold. For example, when the detected capacitance value stably over this threshold Cs during a predetermined amount of time remains, for example in the order 30 s, then takes the minimum capacity value Cmin these newly detected in capacitance value. Conversely, if the detected capacitance value stably under the capacity minimum value Cmin during a predetermined period of time remains, for example in the order 2 seconds, then takes Cmin of these newly detected capacitance value. During automatic recalibration is when the minimum capacity value amended Cmin is the maximum capacity value Cmax also changed, that the ratio Cmax / Cmin is constantly maintained.

According to a further feature of the invention, the vehicle is a system for performing a number of basic capacity detections, each Frequencies different generated correspond to the detected basic capacitance values be an equal number then averaged by optionally not coincident Values ​​are eliminated, the said average value then with the predetermined threshold value Cs is compared to the optionally to enable identification device. If all frequencies generated of the same row to be not coincident, basic observations lead, the system is intended that the identification device not activated to keep the Deactivation upright.

at an advantageous embodiment, The sensor is intended only an imaginary part of the admittance of dipole for to detect a fixed frequency, derived from a stable oscillator is output, which serves as a high frequency wave generator, to the Acquisition against existing more or less conductive liquids insensitive to make, for example, against the handle flap into contact stagnant salt water. In this case even a proper function the system in total flooding the handle flap be sought.

Advantageous can an inductance parallel to the equivalent connected impedance of the dipole and be so determined that the detected Capacitance value the remaining capacity the dipole is eliminated in the absence of the user.

According to a another feature, the metallic surface of an overmolded covers insulation be to them from external influences to protect.

Of course, could be the capacity the dipole alternatively be measured by other methods, namely for example by inserting the capacitor in a Oscillator circuit whose frequency is measured by measuring the impulse response the capacitor at output of high-frequency pulses or by Measuring the admittance of the capacitor on the module at a fixed Frequency, which is delivered by a stable oscillator.

Of the stable frequency generator, starting from one of the timer a microcontroller or bound signal from the microcontroller can be obtained even with this microcontroller to an electronic module include can, which is integrated in the lock.

Around to make the subject matter of the invention better understood, will hereinafter be purely by way of example and not limitation, an embodiment describes the accompanying in the Drawings, there is shown, in which shows:

&lt;?page 4?&gt;

<figref idrefs="S16">1</figref> a functional diagram of a Motor vehicle according to the invention,

<figref idrefs="S16">2</figref> a schematic view a door of a Motor vehicle according to the invention,

<figref idrefs="S17">3</figref> an electric basic scheme of the detection system of a vehicle according to the invention,

<figref idrefs="S17">4</figref> an electrical schematic the closer the Detecting system of a vehicle according to the invention, and

<figref idrefs="S16">5</figref> simplifies the electrical Diagram of a variant to <figref idrefs="S17">3</figref>,

at the embodiment illustrated in the drawings, in <figref idrefs="S16">1</figref> dashed a motor vehicle door <figref>1</figref> stated a sensor <figref>2</figref>, An identification device <figref>3</figref> and a castle <figref>4</figref> contains. The sensor <figref>2</figref> is destined to the approach of a user <figref>5</figref> at the door <figref>1</figref> to grasp how with arrow <figref>6</figref> is specified. If the user<figref>5</figref> than adequate near the door <figref>1</figref> detected is, the sensor <figref>2</figref> via a line <figref>7</figref> to identification device <figref>3</figref> a signal to this to activate. When the ID device<figref>3</figref> activated is, they exchanged with a user <figref>5</figref> entrained identifier Information signals, such as with the two opposite arrows <figref>8</figref>. <figref>9</figref> illustrated is. Once the identification device<figref>3</figref> the identifier the user <figref>5</figref> as correctly recognizes, sending it over the management <figref>10</figref> a control signal to the castle <figref>4</figref>, around its activation elicit. The sensor<figref>2</figref> is arranged to the approach the user <figref>5</figref> early enough to capture to activation of the castle <figref>4</figref> to permit before the user <figref>5</figref> by an arrow <figref>11</figref> specified activity this very castle <figref>4</figref> about a handle flap actuated to the door <figref>1</figref> to open.

If However, the activation at the time not yet completed is, at which the user stops raising the grip flap, may be provided be, further to use a lock that a dual action to the door handle unnecessarily making, for example, in the French Patent Application FR 2767348 Castle described. In this case carried out the opening the door at the same time to activate it.

Around the door <figref>1</figref> to open, must the user <figref>5</figref> a door opening flap <figref>12</figref> seize and thereby exercise a pulling force, to Open of the castle <figref>4</figref> about a sheathed cable <figref>13</figref> or to cause a control linkage, the grip flap <figref>12</figref> with an opening lever <figref>14</figref> combines, of the castle <figref>4</figref> connected is. As in<figref idrefs="S16">2</figref> It can be seen that contains handle flap <figref>12</figref> a metallic surface portion <figref>15</figref>. electrically connected to the sensor <figref>2</figref> via the cable <figref>13</figref> and the lever <figref>14</figref> is connected, the electrically conductive and of the mass of the vehicle are isolated. The surface section<figref>15</figref> can also be covered by a molded-on insulation in order to external influences to protect. Alternatively, the entire grip flap <figref>12</figref> said metallic surface form. When using the mechanical connection<figref>13</figref> between grip flap <figref>12</figref> and acquisition module <figref>2</figref> avoids an additional connection to the door.

Based on from <figref idrefs="S17">3</figref> will now be apparent, that this area <figref>15</figref> from a high-frequency wave generator <figref>16</figref> supplied with power is, the generator <figref>16</figref> already in an electronic Module M may be present, which in the castle <figref>4</figref> integrated is. Under these conditions defined the couple, on the one hand from the set to the ground vehicle V and the other part of the unit area <figref>15</figref> - Electric wire <figref>13</figref> educated is a Strahlungsdipol whose equivalent impedance Z₁ in <figref idrefs="S17">3</figref> illustrated is. This impedance Z₁ is generally constant and consists of a small capacitance C1, which results from the remaining capacity of the cable <figref>13</figref> and a parallel conductance g₁ results, whose value the resistive losses between the unit (handle flap cable lock) and the mass of the vehicle is, which conductance in Depending on undesirable can vary mass losses, for example, at present at the door Water. The value of the admittance of the dipole must be minimized, to limit the radiation effect around the vehicle. With In other words, this dipole is determined so that it is like a untuned antenna behaves, the opposite of the generator <figref>16</figref> undersized output wavelength is. The dipole includes also in parallel a capacitor C variable Capacity, between the aforementioned surface <figref>15</figref> and the user's hand <figref>5</figref> is defined. This variable capacity C increases with the approach hand to the face <figref>15</figref>, If the user with the surface of the hand <figref>15</figref> in contact arrives, the capacitance is infinite, disappears, the capacitor C and the user acts thus as a radiating element of the antenna, whereby the antenna is extended transfer and more high-frequency waves will. In contrast, if an over-molded insulation on the surface<figref>15</figref> scheduled is, can never be a direct contact between surface <figref>15</figref> and The user's hand <figref>5</figref> present. The aforementioned dipole contains further in series with the capacitor C, an impedance Z₂. the equivalent is to pair user / mass, said impedance Z₂ in the general respect C is low and of a capacitor C₂ consists, the parallel to a conductance g₂ switched is.

following was on <figref idrefs="S17">4</figref> Referring, an electronic circuit only for Mes&lt;?page 5?&gt;sen of the imaginary part represents the admittance of the dipole. In that only the imaginary part the admittance is measured, there is the advantage that only the capacitive part of the dipole detected and the resistance value Dipole will be omitted, which resistance in the presence of a more or less conductive liquid fluctuate and thus performed can distort measurement. Since the frequency used is constant, can the Strahlungsdipol model with the corresponding electrical diagram simplified in Z is shown. in<figref idrefs="S17">4</figref> is be seen that the equivalent Impedance Z of the dipole contains a conductance g, equivalent to the whole of the conductances g₁ and G₂ is, and in parallel a variable capacitance C ', which is equivalent is the total of the capacities C₁, C₂ and C from <figref idrefs="S17">3</figref>,

Of the generator <figref>16</figref> is a stable oscillator which is a sinusoidal voltage signal U (t) outputs, with U (t) = Ucos (2.pi.f₀· T). This voltage signal produced in the dipole Z a current over a amplifier A1 in a voltage U₂(T) is converted, with the terminals of the a resistor R_m, R_m connected is, on the one hand to the generator <figref>16</figref> and on the other hand is connected to the dipole Z.

The Voltage U (t) is also present at the positive input of a comparator A₀ to whose negative input the Average of the signal, and thus at a zero value, namely due to the capacitor <figref>25</figref>, Of the negative input connects to the ground, and a resistor <figref>26</figref> further between the two inputs the comparator A₀ is arranged. This A comparator₀ enables the zero crossings of the Voltage U (t) to detect and are at each of these passages a Pulse. A monostable multivibrator T detected depending on the case, the rising and falling edges of the output signal from A₀ and generates pulses, the fishing district a Cp supplied will. These pulses control an electronic switch I, the the output signal U₂(T) of the operational amplifier A₁ receives. Thus, by scanning / blocking interception of voltage U₂carried out (T) and receive a voltage, the above an operational amplifier A₂ an evaluable output U_S creates, with which the intercepted instantaneous value of the current i (to) at the time t₀ can be obtained, such as U (t₀) = 0. i (t) = 2 · π · fo · applies C '· U, wherein C 'the capacity of the equivalent Capacitor, U, the peak amplitude of U (t) and f₀ the Frequency of U (t). The current value i (t) is indeed independent of conductance g.

The electronic circuit from <figref idrefs="S17">4</figref> and their Operation for obtaining only the imaginary part of the admittance of Dipole Z will not be described in detail and it was to the French Patent Application FR 2768508 refers to the name of the Applicant.

Instead of the instantaneous value of the current during the passage of the voltage signal trap by 0, could Alternatively, the phase shift between voltage and current as well as the amplitude of the current to be measured, the value of desired capacity independently to obtain the resistance, although required in this case a computing unit is.

The Meaning the circuit of <figref idrefs="S17">4</figref> lies in that they can come together with the microcontroller application, which is available at the electronic module that the door lock is integrated by simply adding a power interface is used.

Further can outside a high-frequency signal generated and superimposed on the measurement signals be detected differently, for example by means Antenna, capacitive crosstalk, induction, etc. It can the measured current amplitude and phase overlays and random error result to the current measurements in the generator modulated radio frequency interference. Of course are the measurements taken not sensitive to the so-called "Hochfrequenzhüllkurvendetektionserscheinungen", the undesirable and in the unmodulated interference are present, since the measurement no DC component considered.

Around to suppress the measurement error, of a disturbance the type radiation field arising, a series of n basic detections carried out, wherein n is a predetermined integer, and wherein each detection of a different frequency fi corresponds with i between 0 and n. Based on these n measurements the mean is taken, wherein above all Measurements are eliminated that an excessive deviation towards the have further measurements. After this average is with the Kapazitätsschwellwert Cs compared to activate the identification device of the vehicle or not.

If in an extreme disorder with a very wide spectrum or at a deterioration in a part of the system the entirety of frequencies not coincident detections boils, can not reliably an average value is obtained and the system will not "accidentally" in a state one in which the deactivation of the lock is maintained.

Of the Kapazitätsschwellwert Cs is obtained by the system during installation on the vehicle, namely Teaching the capacity minimum value Cmin and the maximum capacity value Cmax, the maximum Nichtannäherungs- or approaching state the user to the surface <figref>15</figref> correspond.

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Of the Threshold Cs given by the following equation: <img img-content="mf" img-format="tif" he="9" wi="36" file="00110001.tif" />where 0 | α | 1.

Of the Value of the coefficient is α preferably assumed to be less than 1, because the capacitance curve the capacitor depending of the distance between surface and hand exponential type. To detect the approach of the reach your hands if this still far enough from the handle flap is removed to allow activation of the castle, before the user the actuating completed the grip flap, it is therefore preferable to the value of Minimum capacity Cmin stronger weight than the value of the maximum capacity Cmax. For example, the Kapazitätsschwellwert Cs so determined to a distance of about 10 cm between hand and handle flap corresponds.

at the in <figref idrefs="S17">3</figref> illustrated Case Cmin equal to C₁ and Cmax maximum is C₂ + C₁, However, if the value of C₁ with respect to C₂ is too high to provide a reliable detection the capacitance variation reached, an additional inductance L are used, the impedance Z parallel to the dipole (see <figref idrefs="S16">5</figref>) Is connected to the Detection of C₁ to eliminate. For example is L · C₁· (2πfo)² equivalent to selected to 1, to C₁ the detected by the module M value to eliminate, where C 'then only a function of C, and C₂ is and C 'between 0 and C₂ varies.

During the life of the system, the automatic recalibration of Cs are held ready in order to avoid that the sensing system for longer time can be blocked in a state of permanent activation of the identification device leads, whereby an unloading of the vehicle battery may be caused. If For example, the vehicle is sufficiently close to a wall or Post is parked, the detected capacity may rise accordingly and the cause activation of the identification device. For this Basic can be provided that when the detected capacitance value in stably over this threshold Cs during a predetermined amount of time remains, the minimum capacity value Cmin is then replaced by this new value to the Kapazitätsschwellwert Cs move accordingly and thus the identification device disable. then, if this error is suppressed, is the detected capacitance value again replaced smaller than Cmin and after a predetermined period of time the system Cmin by these newly detected capacitance value, if it remains stable during this period. Thus, taking the minimum capacity value Cmin after a certain period of time again habitually reference value at.

Also is preferable to the maximum capacity value Cmax therefore be amended to that the same ratio Cmax / Cmin is maintained.

Although the invention in connection with a particular embodiment has been described, it is on course in no way limited, but closes all technical modifications of the means described and their combinations; with, provided that these fit into the scope of the invention, the defined in the claims is.