JP2016504227A - Crew detection and classification system - Google Patents

Abstract

The occupant detection system includes a controller, a detection electrode, and a shield electrode, and these electrodes are installed in a vehicle seat. The controller is electrically connected to the detection electrode and the shield electrode by a detection circuit. The controller is configured to send an input signal to the sensing electrode, shield electrode, or both, and measures current, impedance, or capacitance values to determine whether an object is present on the sheet, classifies the object, or Do both. [Selection] Figure 1

Description

Cross-reference of related patent applications

  This application claims benefit to US patent application Ser. No. 13 / 633,590, filed Oct. 2, 2012. Patent applications are hereby incorporated by reference in their entirety.

  The present application relates generally to the field of capacitive sensing systems and sensing methods. More specifically, the present application relates to a vehicle seat capacity detection system and detection method.

There is a need in the occupant classification system for a system and method for accurately classifying occupants from objects placed on a seat.

  These and other features, aspects and advantages of the present invention will become apparent from the following description and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.

FIG. 1 is a schematic diagram illustrating a vehicle seat according to an exemplary embodiment.

FIG. 2 is a schematic diagram of a capacity sensing system according to an exemplary embodiment.

FIG. 3 is a schematic diagram of a capacity sensing system according to another exemplary embodiment.

FIG. 4 is a circuit diagram of an occupant detection system, according to one exemplary embodiment.

FIG. 5 is a schematic view of a vehicle seat including a seat heater and an occupant detection system.

  The figure illustrates an exemplary embodiment in detail. However, it is to be understood that this application is not limited to the details and methods set forth in the specification and illustrated in the figures. It is also to be understood that the terms are for illustrative purposes only and are not to be considered limiting.

  Capacitance or electric field sensors used in occupant classification systems and occupant detection systems (eg, systems that detect occupancy of vehicle seats) can be implemented in a variety of ways. For example, according to one embodiment, AC current may be supplied to a sensing electrode provided on the vehicle seat. The change in current or current to the sensor may be measured and used as an indicator of impedance from the sensing electrode to ground. In certain vehicle seat configurations, a seat heater may be provided. According to one embodiment of the occupant detection system, the electrode may function as both a capacitance detection electrode and a seat heater.

  In the occupant classification system, occupants are classified using information from sensors that detect the characteristics of objects located on the vehicle seat. Some systems detect the total weight on the seat. When classifying occupants using capacitive sensors, the environment on the seat cover is detected using a variety of techniques to identify the occupant's dielectric and conductive properties. A conductive sensing element is disposed in the seat, and according to one embodiment, the impedance from electrode to ground may be used as an indicator of occupant status on the seat cover.

  The occupant detection and classification system is configured so that the environment under the seat does not affect occupant classification. When a seat heater is provided, a resistive heater is usually employed. The resistive heater is essentially an installed wire or conductor disposed on the vehicle seat. The sensing electrodes of the occupant classification and detection system may be disposed on the seat heater. If the orientation between the sensing electrode and the heater changes, the offset capacity changes, which can adversely affect the system's ability to accurately classify passengers. For example, the detection system may be configured to include an offset for the measurement of conduction to an empty sheet. If the empty seat offset in the measurement drifts significantly (e.g., due to changes in the orientation of the electrodes and heater), the system will not be able to accurately occupant classification.

  According to various exemplary embodiments, a vehicle occupant classification detection system can use various conductors as the sensing electrodes. For example, the sensing system may comprise a “sensor” conductor or assembly disposed on the “shield” conductor. The shield conductor is configured to reduce the sensitivity of the sensing system to an object under the shield (eg, seat pan, seat heater, etc.) or interference from the object under the shield. By installing the shield electrode, the occupant detection system can maintain a similar detection configuration for detecting objects on the seat, while the shield prevents the system from detecting objects under the detection electrodes. The capacity sensing occupant classification system may use measurements obtained from the sensing electrodes to classify occupants in the vehicle seat and to determine whether the occupant should be careful to fasten the seat belt.

  According to other exemplary embodiments, the sensing system may use a plurality of electrodes on the opposite side of the thick foam material. There are various electrode configurations, but measurements can be taken. According to yet another exemplary embodiment, the sensing system may combine or integrate the weight sensing concept and the volume sensing concept into a single system. The integrated system can use weight / pressure information along with capacity information to identify occupant status and create favorable classifications.

  According to various exemplary embodiments, the sensing system may use electronic methods (eg, using high frequency current measurements or other methods) to make capacitive measurements. The material of the sensor assembly includes any conductive material for the electrodes (eg, copper, conductive ink, conductive cloth, etc.), and any compressible material (eg, non-woven felt, woven cloth, A foaming material, a member that supplies air to operate the air environment adjustment sheet, or other member that compresses significantly at a pressure of 1 psi or less.

  Referring generally to the figures, an occupant classification system is described that uses sensors (eg, capacitive vehicle sensors) to detect seat occupancy and weight on a seat. An occupant classification system can generally include sensors and shields. In order to detect an occupant, the sensor may be directed to the top of the shield in order to reduce the effect on the sensor measurement by an influencing object (eg a seat heater) placed under the shield. The classification system may have a weight or force sensing function. Upon sensing weight, the sensor and the shield are redirected using a sensor directed under the shield (eg, via electronic switching) to influence an object (eg, an electronic device) placed on the seat ) May be configured to reduce the effect on sensor measurements. The occupant detection and weight or force detection measurements may be shared to determine if the object on the seat is a human and to reduce false detection of the object as a human.

  Referring to FIG. 1, for an exemplary embodiment, a vehicle 10 is shown with a passenger 12 in a seat 14 of the vehicle 10. The seat 14 may include an occupant classification and detection system 16. As shown in FIG. 1, the occupant classification system 16 may generally be located on the seat 14 below where the occupant 12 of the vehicle 10 sits, and may be located on the seat 14 or other location on the vehicle 10. Also good.

  The occupant classification system 16 generally includes a sensor for detecting and classifying the occupation of the seat 14, a shield, and an electronic device. For example, the sensor is used to provide measurements corresponding to the action of the object on the sensor due to both the conductivity and weight of the object. Sensor readings may be evaluated to determine the presence of an object or occupant on the seat 14. The occupant classification system 16 may comprise a seat heating system and / or a system for the seat 14 of other vehicles 10 and may be configured to operate in conjunction therewith.

  The occupant classification system 16 includes a capacitance or electric field sensor that includes a sensing electrode. In general, a capacitance sensor can detect characteristics such as proximity, position, and weight of an object. Various measurements with the sensing electrode may be used to detect the presence of an object in the sheet. For example, the system may measure a change in capacitance (eg, a change in electrical properties between two conductive objects). When the occupant 12 sits on the seat 14, the system can detect the change in capacitance and the occupant classification system 16 can determine the presence of the occupant 12.

  According to one embodiment, the capacitance-based occupant classification system 200 includes an upper electrode 202 and a lower plate electrode 204, as shown in FIG. 2A. In the embodiment of FIG. 2A, the upper plate electrode 202 is the detection electrode 202 and the lower plate electrode 204 is a shield electrode. During a typical or normal measurement mode or configuration, the system 200 detects a change in the signal on the sensing electrode (ie, the upper electrode 202 closest to the occupant 206) to determine the presence of the occupant. The shield electrode (lower electrode 204) is disposed under the detection electrode in the vehicle seat. The detection electrode and the shield electrode may be changed to other configurations in order to measure the force on the sheet surface.

  Referring to FIG. 2B, in one exemplary embodiment, the role or function of the sensing and shielding electrodes may be switched when the occupant classification and detection system operates in force or weight measurement mode. In the weight measurement mode, the system 200 may be configured to be less sensitive to the presence of an occupant and may be used to determine the weight of the occupant 206. During the weight measurement mode, the capacitance or electric field detection is performed using the measured value obtained by the lower electrode 204 (shield electrode in the occupant detection measurement) farthest from the occupant, and the upper electrode 202 closest to the occupant 206 is the shield electrode. It is switched to become. The electrodes 202, 204 may be switched using electronic or mechanical switches configured to change the flow of current through the electrodes. Instead of using the lower sensing electrode to measure the presence of an occupant, in force or weight measurement mode, the system electronics and / or software can determine the capacitance (or current or impedance) between the sensor and the shield (electrodes 202, 204). You may comprise so that it may measure. The measured capacitance (measurement representative of capacitance or current or impedance or related measurement) may be compared to a threshold value. The difference between the measured value and the threshold value is considered to be caused by a change in the relative position of the sensor due to the force on the sheet. Since the occupant 206 is shielded from the measurement of the upper electrode 202, the measurement can be performed without being greatly affected by the conductive or dielectric properties of the occupant 206.

  Referring to FIG. 2C, when the force applied to the bottom of the sheet increases, the member 208 located between the sensor (electrode 204) and the shield (electrode 202) is compressed. This compression causes the electrodes 202, 204 to move closer together, so that the capacitance between the two electrodes 202, 204 increases correspondingly. The capacitance between the electrodes 202, 204 (or other measurement that indicates a change in the relative position between the electrodes 202, 204) is used to estimate the force applied to the seat by the occupant 206. The force on the seat is used to distinguish between an occupant (ie, a human) and an inanimate object (eg, a computer).

  3A and 3B disclose other exemplary embodiments of capacitive or electric field occupant classification and detection systems. The system 300 shown in FIGS. 3A and 3B is similar to the system 200 of FIGS. 2A-2C and includes an upper electrode 302 and a lower electrode 304 that detect an occupant 306. The system 300 further includes an electronic device 310 configured to supply a current or signal to drive the electrodes 302, 304 and to provide measurements to the electrodes 302, 304 (eg, sensing and signal processing circuitry). ).

  The occupant classification and detection system disclosed herein may comprise a controller, processor or electronic control unit (ECU) that controls the system and receives various measurements from system components (eg, sensing electrodes). The controller is configured to interact with other vehicle systems such as, for example, vehicle safety systems (eg, airbags and seat belt systems). The controller may provide a signal to the vehicle safety system indicating whether an adult is located in the vehicle seat so that the safety device can be activated when appropriate. The controller of the occupant classification system may be incorporated in another vehicle system such as a controller used in a vehicle safety system.

  In particular, referring to FIG. 3A, according to one exemplary embodiment, the system 300 includes an occupant detection mode or configuration for detecting the occupant 306 while shielding interference from below the system 300. The system 300 includes a switch 312 that electrically connects the upper electrode 302 to the detection port 316 of the electronic device 310, and a switch 314 that electrically connects the lower electrode 304 to the shield port 318 of the electronic device 310. In the configuration of FIG. 3A, the upper electrode 302 is a detection electrode, and the lower electrode 304 is a shield electrode.

  With reference to FIG. 3B, according to one exemplary embodiment, the system 300 includes a weight or force detection mode or configuration that reduces the sensitivity of the occupant 306 to electrical characteristics to determine the weight of the occupant 306. May be used. In the embodiment of FIG. 3B, the conductor or upper electrode 302 near the occupant 306 is switched to ground 320 and the conductor or lower electrode 308 away from the occupant 306 is switched to the detection port 316 of the electronics 310. In the configuration of FIG. 3B, the upper electrode 302 is a shield electrode, and the lower electrode 304 is a detection electrode.

  The electronic device 310 employed by the system may be software and any analog or digital circuit that can control the occupant classification system 300. Also, according to various exemplary embodiments, switches 312, 314 may be any electronically or mechanically actuated switch that can change the flow of current. The electronic device 310 may be configured to control switching of the switches 312 and 314. For example, the system 300 may generally be in an occupant detection configuration and switched to a weight detection configuration for verification only if the detection configuration determines that the occupant is an adult. Alternatively, switching may be performed periodically at certain time intervals.

  By adding a weight or force measurement to the electric field or volume measurement, the system can sort if an object looks large in the volume detection system 200, 300 (eg, looks like an adult) but is physically small Or can be distinguished. For example, capacitive loads or electrical interference caused by electronic devices on the seat are measured when the detection node is located above the shield node, especially if these devices are plugged into the vehicle's 12 volt outlet. May cause an increase in capacitance. Such electronic devices include mobile phones, smart phones, personal digital assistants (PDAs), global positioning systems (GPS), optical disc (eg, DVD, Blu-Ray, etc.) players, laptop computers or any other electronic Including equipment. Electronic devices can appear large to capacitive sensors because they are conductors and are properly connected to the ground. If the electronic device or other object on the seat is mistakenly recognized as an adult, the seat belt reminder may enter and cause discomfort. The exemplary embodiment described above solves the problem of discomfort by integrating a low cost force measurement and a capacity sensing system. The weight detection configuration is also used for fault diagnosis identification of empty seat and volume detection systems and similar measurement electronics, and the connection outside the sensor is used for weight measurement and volume measurement, resulting in lower cost. It will be a solution.

  In the exemplary embodiment of FIGS. 2 and 3, the change in the physical position of the sensor relative to the shield is measured electronically, and any configuration of electrodes without significant influence due to the occupant's conductive and dielectric properties. Can be used. In other exemplary embodiments, instead of detecting the capacitance between the sensor and the shield electrode, the system uses a high frequency (eg, about 100 kHz, 100 kHz or more, etc.) AC current that flows only between the sensor and the shield. Multiple measurements in multiple configurations for calculating can be used. A significant increase in the measured current indicates an increase in the sensor to shield the capacitance indicating a change in the relative position of the sensor and the shield due to increased force from the occupant. According to other embodiments, the capacitance between the sensor and the shield electrode may be a change in the RC time constant, a change in the response of the system to a step voltage to the electrodes, a change in charge shared between the electrodes, or any other measure of capacitance. It can be measured by analyzing any method.

FIG. 4 illustrates an exemplary or exemplary circuit diagram of an occupant detection system 400 according to one exemplary embodiment. The occupant detection system 400 includes a detection circuit 402 that electrically connects the detection electrodes 410, a shield electrode 412, switches SW _DS and SW _load, and an electronic device 420. The detection circuit 402 also includes a signal generation device 406, such as an amplifier or transistor, disposed between the electronic device 420 and the shield electrode 412. The sensing electrode 410 can include a conductor such as an inductor, a sensing node, or other device disposed outside the electronic device 420. The shield electrode 412 can also include a conductor or other device, such as a shield node disposed between the shield electrode 412 and the signal generator 406. If the sensing circuit 402 is found outside the electronic device 420, the electronic device 420 may comprise a sensing circuit 402, such as a switch, an amplifier or other device component. For example, the components of the electronic device 420 and the detection circuit 402 may be integrated, and may be disposed in a common housing or on a common circuit board. Meanwhile, the sensing and shielding electrodes 410 and 412 are outside the housing and are electrically coupled to the electronic device 420. However, one of ordinary skill in the art will recognize that other configurations are possible with respect to other embodiments.

  The electronic device 420 generally includes a controller 422 and a signal processing device 424. The signal processing device 424 generally includes a sine wave output device 425, a current detection circuit 426, and a demodulation and filtering device 427. The signal processing device 424 generates an output signal, measures current, and generates an input signal corresponding to the measured current.

The controller 422 may be a microprocessor or an electronic control unit (ECU) and controls the occupant detection system 400. The controller 422 determines when the signal processing device 424 generates an output signal, opens and closes the switches SW _DS and SW _load , and interprets the input signal received from the signal processing device.

  As described further below, the system 400 is used to obtain a representative indication of force on the vehicle seat, such as when the weight of the occupant directs the sensing electrode 410 toward the shield electrode 412. Operated to get measurements. The electronics 420 is used to calculate the impedance between the sensing electrode 410 and the shield electrode 412, which can be used to classify the occupant. The electronic device 420 is also used to calculate the impedance between the sensing electrode 410 and the ground, and can be used to detect an occupant. The electronics 420 is also used to calculate the impedance between the sensing electrode 410 and both the shield electrode 412 and ground, and can be used for both occupant detection and classification.

The controller 422 may be a microprocessor or an electronic control unit (ECU) and controls the occupant detection system 400. The controller 422 determines when the signal processing device 424 generates an output signal, opens and closes the switches SW _DS and SW _load , and interprets the input signal received from the signal processing device 424.

By opening and closing the switches SW _DS and SW _load , the detection circuit 402 of the occupant detection system 400 has four different configurations (ie, the switches SW _DS and SW _load are closed / open, closed / closed, open / open and open / open, respectively). (Closed). When SW _DS is closed, the amplitude of the output signal of shield electrode 412 changes, and when SW _load is closed, impedance Z _SW is introduced between the sensor and shield electrodes 410 and 412.

In each of the four circuit configurations, the current is measured by signal processor 424, thereby providing _four current measurements M ₁ , M ₂ , M ₃ and M ₄ . M ₁ is measured when SW _DS is closed and SW _load is open, M ₂ is measured when SW _DS is closed and SW _load is closed, M ₃ is measured when SW _DS is open and SW _load is open M ₄ is measured when SW _DS is open and SW _load is closed.

From these four current measurements, a number proportional to the impedance between the sensing electrode 410 and the shield electrode 412 (ie, the force value) is calculated by the controller 422 as follows.

This equation is obtained from the following equation.

Thus, -Z _{sensor / shield} / Z _sw is proportional to the impedance between the sensing electrode 410 and the shield electrode 412 and is used to determine the relative force on the vehicle seat to classify the occupant. be able to. For example, occupant classification results can be used to determine whether a seat belt reminder should be inserted or whether an airbag should be deployed.

From the current measurements M ₁ , M ₂ , M _3, and M ₄ , the number corresponding to the impedance between the sensing electrode 410 and ground (ie, the detected value) is also calculated as follows.

This equation is obtained from the following equation.

Here, Z _SW is offset and does not need to be known, but should be a sufficiently large number for a meaningful change in computation, and Z _{sensor / shield} is the above -Z _{sensor / shield} / Z Obtained from the equation for _sw . An i _oc value corresponding to (ie, inversely proportional to) the impedance between sensing electrode 410 and ground can be used to determine whether an occupant or object is present (ie, detect the occupant).

  According to one exemplary embodiment, the occupant detection system may include a normalization circuit 404. The normalization circuit 404 allows the electronic device 420 to adjust measurement variations due to changes in gain, offset shift, and phase shift in the detection circuit 402.

The normalization circuit 404 includes a high reference impedance device 442 and a low reference impedance device 444, each having a different known impedance. Corresponding switches SW _refhi and SW _reflo selectively connect the high and low reference impedance devices 442 and 444, respectively, to ground. For example, the signal processing device 424 generates an AC current of 100 kHz at a constant voltage and measures the reference currents M _refhi and M _reflo . The reference current M _refhi is measured when SW _refhi is closed and SW _reflo is open, and the reference current M _reflo is measured when SW _refhi is open and SW _reflo is closed.

The detection circuit 402 includes a switch SW _sens to disconnect the detection circuit 402 and the normalization circuit 404. When the current measurements M ₁ , M ₂ , M ₃ and M ₄ are measured, SW _sens is closed. When the reference currents M _refhi and M _reflo are measured, SW _sens is opened, whereby the normalization circuit 404 is disconnected from the detection circuit 402.

By measuring the reference currents M _refhi , M _reflo with respect to impedance devices 442, 444 where the impedance is known and _decoupling the normalization circuit 404 from the sensing circuit 402, the microprocessor 422 calculates the independent system impedance of the sensing circuit 402. it can. In this way, the microprocessor 422 can determine changes in gain, offset shift, and phase shift within the sensing circuit 402, and more accurately detect and classify occupants.

  For various exemplary embodiments, the shield may be driven with any potential or signal that is compatible with the measurement concept and associated electronic components. For example, the shield may be driven with the same or the same signal as the sensor signal, may be connected to a fixed DC level, and may be driven with various signals to enable the multiple measurement concepts described above. Good.

  Although the occupant classification systems 200, 300 are shown with multiple functions utilized together, the systems 200, 300 are at least available with more than all of the mechanisms or functions described. For example, in other exemplary embodiments, more electrodes can be used in the systems 200,300.

  FIG. 5 shows an occupant detection and classification system 500. System 500 incorporates the elements of the system described above. System 500 may include a seat heater. The seat heater may comprise a seat back heating element 512 and / or a seat bottom heating element 514. The sheet bottom heating element 514 is located below the layer of the seat cover or seat pad 520. The heating element may be controlled by a seat heater controller 561. A similar controller can also be used for both occupant detection, detection and seat heater.

  The system 500 includes a detection mat 520 that is divided into a detection electrode and a shield electrode by a compressible member. The detection mat 520 is located at the bottom of the sheet, ideally below the sheet foam layer. The sensor measures the weight or force on the sheet by calculating the impedance between the sensing electrode and the shield electrode using the electronic device 310 described above in connection with the weight sensing mode. According to this embodiment of the system 500, an occupant detection configuration (ie, sensing electrode measurement based on capacitance) is not required. Occupant detection is primarily based on force or weight sensing measurements and calculations. For example, a seat occupant is determined when a force measurement exceeds a threshold for a occupant of a particular size. In one embodiment, it is not necessary to determine the occupant's actual weight as a measure of the impedance between the sensing electrode and the shield electrode that can be used to associate with a particular size occupant.

  The system 500 includes a controller 522 for controlling a signal (eg, voltage or current) disposed on the detection mat 520, a detection electrode, and a shield electrode. The controller 522 is configured to make occupant classification and / or detection decisions and provide corresponding signals to other vehicle systems and subsystems via buses or other electrical connections. Controller 522 may be connected to the vehicle communication bus via connection 524.

  According to other embodiments, measurements obtained using an occupant detection configuration and corresponding signal processing may be used to determine wet seat conditions. Sheet wetting can affect measurements obtained with the weight detection configuration. The determination of the wet sheet condition can be used to make adjustments corresponding to the calculation of the measured value obtained using the sheet wet condition, and is necessary as information on the sheet wet condition that the sensor affects the shield measurement. is there. The use of electric field or capacitive sensing to detect wet sheet conditions is disclosed in US Patent Publication No. 2007/0192007 (incorporated herein by reference).

  The force and weight based occupant detection system 500 described above may operate with a seat belt tension sensor. For example, as described in US Pat. No. 6,260,879 (incorporated herein by reference), the downward force on the vehicle seat may be the result of two different factors. One of the components may be due to the mass of the occupant and the other component may be a force due to tension applied to the vehicle seat belt. A seat belt tension measurement sensor may be provided to determine a force acting downward on the vehicle seat as a result of the seat belt tension. The tension in the seat belt measured by the seat belt tension sensor provides a numerical value for the presence of a child seat or other object that is tightened.

  The specific form of each component is shown in the figure, but each form may be in other forms that facilitate the function to be performed by that component. For example, although the electrodes are shown as flat electrodes, other shapes of electrodes may be defined in other exemplary embodiments. Further, although a specific shape of the switch is shown in FIG. 3, in other exemplary embodiments, the switch may operate in other shapes or in different directions. The detection and classification system described in detail above may be employed in an existing occupant detection system described in US patent application Ser. No. 12 / 541,825 (current US Pat. No. 8,138,772). Good. Prior patent applications are incorporated by reference in their entirety.

  For the purposes of this disclosure, the term “connection” means that two components (electrical, mechanical, or magnetic) are joined directly or indirectly to each other. Such a joint can be stationary or movable in nature. Such a joint is integrally defined as two components (electrical or mechanical) and any additional intermediate members with each other, or two components as a single, unitary body, or Two components and an additional intermediate member can be attached to obtain. Such a bond may be permanent in nature, or may be movable or separable in nature.

  Although the present disclosure has been described with reference to illustrative embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. . For example, although different exemplary embodiments may be described as including one or more features that provide one or more benefits, the described features are interchangeable or described exemplary In other embodiments, other embodiments may be combined with each other. Because the technology of the present disclosure is relatively complex, not all changes related to the technology can be foreseen. The present disclosure, which is described with reference to the exemplary embodiments and specified in the following claims, is clearly as broad as possible. For example, unless specifically stated otherwise, a claim referring to a single specific element also includes the plurality of such specific elements.

It is also important to note that the structure and configuration of the elements of the system as shown in the preferred and other exemplary embodiments are for illustrative purposes only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art having reviewed this disclosure will recognize many modifications (e.g., without departing from the advantages of the listed subject matter and the novel teachings) It is easy to recognize that various element dimensions, ranges, structures, shapes and ratios, parameter values, mounting configurations, materials, colors, orientations, etc. can be used. For example, an element shown as being integrally formed can be composed of a plurality of parts, an element shown as being a plurality of parts can be integrally formed, and the operation of the assembly can be It can be reversed, otherwise it can be changed, the structure and / or components of the system, or the length and width of connectors and other elements can be changed, and adjustments and attachments placed between the elements The nature or number of positions can be changed. Note that the elements and / or assemblies of the system can be constructed from any of a wide variety of materials with sufficient strength and durability. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and configuration of the preferred and other exemplary embodiments without departing from the scope of this disclosure.

Claims (21)

A sensing electrode that can be mounted in the seat portion of the vehicle seat;
A shield electrode installed under the detection electrode in the vehicle seat;
A sensing circuit operatively connected to the sensing electrode and the shield electrode;
A controller functionally connected to the detection circuit;
The controller is configured to pass current through the shield electrode;
The detection circuit is configured to supply a signal to the shield electrode, the shield electrode resulting from a change in the position of the detection electrode relative to the shield electrode due to the weight of an object disposed on the vehicle seat A system for detecting an occupant in a vehicle, wherein the system is configured to detect a change in current to the vehicle.   The system of claim 1, wherein the controller is configured to classify the object by calculating an impedance between the shield electrode and the sensing electrode based on a change in current.   The system of claim 2, wherein the sensing electrode is grounded when a change in current is detected.   The system of claim 2, wherein the controller is configured to classify an occupant based on a plurality of measurements obtained by the sensing circuit.   The system of claim 4, wherein the controller determines whether to enable a seat belt indicator or an airbag.   The system of claim 4, wherein a compressible material is disposed between the sensing electrode and the shield electrode.   The sensing circuit is configured to supply a signal to the sensing electrode, configured to detect a change in current to the sensing electrode due to an electric field that affects characteristics of an object on the vehicle seat, and the controller includes: The system of claim 2, configured to classify the object based on a change in current to the sensing electrode.   The system of claim 2, further comprising a belt tension sensor operatively connected to the controller, wherein the controller is configured to classify the object based on a signal from the belt tension sensor. A sensing electrode that can be mounted in the seat portion of the vehicle seat;
A shield electrode installed under the detection electrode in the vehicle seat;
A sensing circuit operatively connected to the sensing electrode and the shield electrode;
A controller functionally connected to the detection circuit;
The controller detects a relative force applied to the vehicle seat by an object by using a result of each measurement value performed when a plurality of signals are respectively applied to the shield electrode, and the detection electrode and the shield electrode A system for detecting an occupant in a vehicle, wherein the system is configured to detect the presence of the object in the vehicle seat by calculating a force value associated with an impedance between the vehicle and the vehicle.   The system of claim 9, wherein a compressible material is disposed between the sensing electrode and the shield electrode.   The system of claim 10, wherein the controller determines whether to enable a seat belt indicator or an airbag.   The system of claim 9, wherein each of the plurality of signals is substantially the same.   One of the plurality of signals is applied to the sensing electrode, and the controller detects the presence of a wet sheet by calculating a detection value related to the impedance from the sensing electrode to ground. The system of claim 9, wherein the system is configured.   The plurality of signals include a first signal, a second signal, and a third signal, and the controller applies the first signal to the detection electrode by the detection circuit, and similarly the second signal and the third signal. The system of claim 13, wherein the system is operative to configure a signal to be applied to the shield electrode.   The controller is operative to configure the sensing circuit to interconnect a plurality of impedances between the sensing electrode and the shield electrode, and used to calculate the detected value and the force value. The system of claim 14, wherein each measurement is obtained when the impedance is different.   The measurement values are a first current measurement value, a second current measurement value, a third current measurement value, and a fourth current measurement value, and the first current measurement value and the second current measurement value are the second current measurement value, The system of claim 15, wherein a signal is applied when applied to the shield electrode, and the third and fourth current measurements are generated when the third signal is applied to the shield electrode. .   The first current measurement value and the third current measurement value are generated when none of the plurality of impedances is connected between the detection electrode and the shield electrode, and the second current measurement value and the fourth current measurement value The system of claim 16, wherein a current measurement occurs when the plurality of impedances are connected between the sensing electrode and the shield electrode.   The system of claim 9, further comprising a belt tension sensor operatively connected to the controller, wherein the controller is configured to classify the object based on a signal from the belt tension sensor.   One of the plurality of signals is applied to the shield electrode, and the controller results from a change in the position of the sensing electrode relative to the shield electrode due to the weight of the object placed on the vehicle seat. The system of claim 9, configured to detect a change in current to the shield electrode.   The system of claim 19, wherein the controller is configured to classify the object by calculating a change in impedance between the shield electrode and the sensing electrode based on a change in current. 21. The system of claim 20, wherein the sensing electrode is grounded when the controller detects a change in current passing through the shield electrode.