KR20190093009A - Sensing device and method for operating the same - Google Patents

Abstract

According to the embodiment, a sensing device comprises: a rain sensor including a carbon fine coil; a temperature sensor for sensing a temperature around the rain sensor; a humidity sensor for sensing humidity around the rain sensor; a storage unit configured to store a compensation value for compensating a sensing value of the rain sensor according to the temperature and the humidity; and a control unit checking the temperature and the humidity at the time to acquire the sensing value when the sensing value is acquired through the rain sensor, extracting a compensation value corresponding to the temperature and the humidity from the storage unit, and compensating for the sensing value based on the extracted compensation value. The control unit determines a wiper driving condition corresponding to the sensing value when the compensated sensing value is within a preset sensing range, and recognizes the sensing value as a sensing value generated by a foreign substance when the compensated sensing value is left from the preset sensing range.

Description

SENSING DEVICE AND METHOD FOR OPERATING THE SAME}

The present invention relates to a sensing device, and more particularly, to a sensing device capable of compensating for a sensing value acquired through the rain sensor according to an operating environment of a rain sensor and a method of operating the same.

In general, a windshield wiper is installed on the front windshield of the vehicle to overcome a clock obstacle caused by rain in the rain, and the wiper has a stepwise control of the wiper according to the degree of rainwater dropping. However, since the speed control system of the wiper is adjusted in only a few steps, the driver cannot move the wiper at a desired speed according to the amount of rainwater.

To overcome this problem, the circuit board equipped with the light source and the sensor, which is a light receiving element, is inclined with respect to the surface of the wind shield, thereby minimizing the influence of light reflected from the surface of the wind shield, while receiving only the optical signal reflected by the raindrop itself. There is one configured to increase the rain sensing efficiency. In other words, the light reflected directly from the wind shield falls outside the light receiving range of the light receiving element and is reflected by the wind shield to minimize the amount of light received by the light receiving element, while receiving only the amount of light reflected from the raindrops on the light receiving element. The circuit board including the light source and the light receiving element is disposed to be inclined at an angle with respect to the windshield surface so as to detect only the diffuse reflection signal.

However, since the light emitted from the light source may be directly absorbed by the light receiving element even in a product in which the light source and the light receiving element are inclined with respect to the windshield surface of the vehicle by the circuit board as described above, in terms of the efficiency of rain sensing It is somewhat incomplete and lacking. That is, the light emitted from the light source is spread over a certain angle range, even if the light source and the light receiving element is inclined with respect to the surface of the wind shield, some of the light is directly emitted toward the light receiving element, in addition to the light falling out of the wind shield. Due to the interference light absorbed by the light-receiving element, there is no problem that the raindrop detection efficiency is somewhat reduced, and thus, there is a rather insufficient surface for perfection in terms of rain sensing efficiency.

Even when designed to minimize the ambient interference light caused by the headlight light of the surrounding traffic vehicle, interference light cannot be inevitably blocked, and the light detecting lane sensor itself is a very sensitive sensor product. Since it is inevitable to be influenced by a small amount of ambient light, it is inevitable to have a high precision rain sensing effect, and to implement a structure to minimize the influence of ambient light as described above, it must have a rather complicated structure. It is inevitable to have limitations such as somewhat inefficient in productivity and slightly higher product cost.

In the embodiment according to the present invention, by detecting the change in the impedance by the carbon micro coil (CMC: Carbon Micro Coil) constituting the rain sensor by the rain drops falling on the windshield of the vehicle to detect the rainfall and rainfall An apparatus and a method of operating the same are provided.

In addition, the embodiment provides a sensing device and a method of operating the same, using the sensing layer including the carbon micro coil constituting the rain sensor, to detect the fine rainfall.

In addition, the embodiment provides a sensing device and a method of operating the same that can detect the foreign matter and the rain.

In addition, the embodiment provides a sensing device that can compensate for the detection value obtained through the rain sensor according to the operating environment of the rain sensor and its operation method.

The technical problems to be achieved in the proposed embodiment are not limited to the technical problems mentioned above, and other technical problems not mentioned above are clear to those skilled in the art to which the proposed embodiments belong from the following description. Can be understood.

The sensing device according to the embodiment includes a rain sensor including a carbon fine coil; A temperature sensor for sensing a temperature around the rain sensor; A humidity sensor for sensing humidity around the rain sensor; A storage unit configured to store a compensation value for compensating a detection value of the rain sensor according to the temperature and humidity; And when the detection value is obtained through the rain sensor, confirms the temperature and humidity at the time when the detection value is obtained, extracts a compensation value corresponding to the temperature and humidity from the storage, and extracts the extracted compensation value. And a controller for compensating the detected value based on the compensation value, wherein the controller determines a wiper driving condition corresponding to the sensed value when the compensated sensed value is within a preset sensing range, and the compensated sensed value is pre-set. If it is out of the set detection range, it is recognized that the detection value is a detection value generated by the foreign matter.

The rain sensor may further include a substrate, first and second electrodes disposed on the substrate and spaced apart from each other by a predetermined distance, a first partition wall disposed around the first electrode on the substrate, and on the substrate. A second partition wall disposed to surround the second electrode, a first sensing layer disposed in the first partition wall to cover the first electrode, wherein the carbon micro coil is included therein, and the second partition wall A second sensing layer disposed within and covering the second electrode and including the carbon micro coils therein.

The first partition wall is spaced apart from the second partition wall by a predetermined distance, and the first sensing layer is physically separated from the second sensing layer.

The temperature sensor may sense a temperature around the first and second sensing layers, and the humidity sensor may sense a humidity around the first and second sensing layers.

The rain sensor may output a capacitance value that changes according to a state of the sensing object, and the controller may acquire the detection value based on a difference value between the output capacitance value and a predetermined reference value, and the compensation value may be And a compensation value of the capacitance value or the reference value according to the temperature and humidity.

The controller may include a first frequency generator configured to output a first frequency having an oscillation frequency corresponding to a change in capacitance values of the first and second sensing layers, and a second frequency corresponding to a reference oscillation frequency of the reference value. A second frequency generator for outputting a signal; a difference frequency generator for outputting a difference value between the first frequency and the second frequency; and a filter for filtering the difference value output through the difference frequency generator in a predetermined filtering region. Include.

In addition, the controller compensates any one of the first frequency and the second frequency by using a compensation value stored in the storage unit according to the temperature and humidity.

The compensation value may allow a capacitance value of the rain sensor to maintain a constant value lower than the reference value in a general state in which no sensing object is present on the rain sensor.

In addition, when the difference value is greater than a predetermined value and the capacitance value is lower than the reference value, the controller recognizes that the human body is detected through the rain sensor and outputs the recognized human body detection signal.

On the other hand, the operating method of the sensing device according to the embodiment includes the steps of confirming the change state of the capacitance value of the rain sensor including the carbon micro-coils varying with temperature and humidity; Storing a compensation value of a rain sensor according to the temperature and humidity based on the checked change state; Checking a temperature and humidity around the rain sensor at the time when the detection signal is output, when a detection signal is output through the rain sensor; Checking the compensation value corresponding to the checked temperature and humidity if the temperature and humidity are different from the reference temperature and reference humidity; Obtaining a sensed value corresponding to the sensed signal by applying the checked compensation value; Checking whether a target sensing object is located on the rain sensor based on the sensing value; And outputting a wiper driving signal according to a state of the target sensing object when the target sensing object is positioned on the rain sensor.

The outputting of the sensing signal may include outputting a capacitance value that varies according to a state of a sensing object present on the rain sensor, and obtaining the sensing value may include: outputting the capacitance value; And obtaining the sensed value based on a difference value of a preset reference value, wherein the compensation value is a compensation value of the output capacitance value or a compensation value of the reference value according to the temperature and humidity.

The acquiring of the detected value may include outputting a first frequency having an oscillation frequency corresponding to a change in the output capacitance value, and outputting a second frequency corresponding to the reference oscillation frequency of the reference value. And compensating any one of the first frequency and the second frequency by applying a compensation value corresponding to the identified temperature and humidity, and the first and second frequencies with which one of the frequencies is compensated. Outputting a difference value of and filtering the difference value within a predetermined filtering region.

The determining of whether the target sensing object is located may include determining that the target sensing object is located on the rain sensor when the difference value exists in the filtering area, and wherein the difference value is the filtering. If it is out of the area, determining that the object other than the target sensing object is located on the rain sensor.

The determining of the location of the other object may include determining that the human body is detected through the rain sensor when the difference value is greater than a predetermined value and the output capacitance value is lower than the reference value. Steps.

According to the embodiment, when the rainfall occurs, it is possible to immediately detect the rainfall in response to this, thereby improving the convenience of the driver in the rain.

In addition, according to the embodiment, by detecting the rainfall using the carbon micro coil, it is possible to provide a rain sensor having a different characteristic (response characteristics, precision, accuracy, power consumption, miniaturization, etc.) compared to the conventional optical method.

In addition, according to the embodiment, it is possible to measure rainfall even with a slight change in the impedance of the carbon fine coil, and set the reaction area of the rain sensor for avoiding the detection of foreign matters, so that the wiper is driven by the foreign matters in advance. You can prevent it.

In addition, the embodiment compensates for the detection value detected by the rain sensor according to the operating environment of the rain sensor. That is, in the embodiment, by compensating the detection value according to the ambient temperature and humidity of the rain sensor operation, it is possible to obtain a more accurate detection value to improve the operation reliability of the sensing device.

In addition, in the embodiment, by resetting the reference value of the rain sensor in accordance with the temperature and humidity, it is possible to prevent the malfunction of the sensing device according to the operating environment.

1 is a block diagram showing the configuration of a sensing device according to an embodiment of the present invention.
2 is a cross-sectional view showing a detailed structure of the rain sensor of FIG. 1 according to an embodiment of the present invention.
3 is a diagram illustrating a modified example of the electrode of FIG. 2.
4 is a view illustrating a carbon micro coil included in the sensing layer of FIG. 2.
FIG. 5 is a diagram illustrating a capacitor function of the carbon micro coil of FIG. 4.
6 illustrates the characteristics of the carbon micro coil of FIG. 4.
7 is a graph illustrating characteristics of a rain sensor that changes according to a temperature change according to an exemplary embodiment of the present invention.
8 is a graph illustrating a compensation algorithm according to a change in temperature according to an embodiment of the present invention.
9 is a flowchart illustrating a method of operating a sensing device according to a first embodiment of the present invention step by step.
10 is a flowchart illustrating a step-by-step method of operating a sensing device according to a second embodiment of the present invention.
11 is a graph showing the characteristics of the rain sensor that changes according to the humidity change according to an embodiment of the present invention.
12 is a flowchart illustrating a step-by-step method of operating a sensing device according to a third embodiment of the present invention.
FIG. 13 is a cross-sectional view illustrating a detailed structure of the rain sensor of FIG. 1 according to another exemplary embodiment.
FIG. 14 is a diagram for describing sensing sensitivity of a two-line electrode structure compared to FIG. 13.
FIG. 15 is a diagram for describing sensing sensitivity of the four-line electrode structure illustrated in FIG. 13.
16 is a diagram illustrating an example of a control unit according to an embodiment of the present invention.
17 to 19 are diagrams illustrating a change in a difference frequency value according to the first embodiment of the present invention.
20 is a view illustrating a change of a difference frequency value according to the second embodiment of the present invention.
FIG. 21 is a graph showing a change characteristic of a carbon micro coil that varies according to the type of sensing object.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other. In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the present invention. It should be understood to include equivalents and substitutes.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

1 is a block diagram showing the configuration of a sensing device according to an embodiment of the present invention.

Referring to FIG. 1, the sensing device 100 includes a rain sensor 110, a temperature sensor 120, a humidity sensor 130, a storage 140, and a controller 150.

The sensing device 100 in the present invention may be installed inside the vehicle. Preferably, the rain sensor 110 is installed on the inside of the windshield of the vehicle, detects the sensing object present on the windshield. Preferably, the rain sensor 110 detects raindrops falling on the windshield of the vehicle. Preferably, the rain sensor 110 has a characteristic that the capacitance value changes according to the presence or absence of raindrops falling on the windshield or the amount of raindrops. That is, the rain sensor 110 detects a change in capacitance value according to the presence or absence of the raindrops or the amount of raindrops, and outputs a detection value accordingly.

To this end, the rain sensor 110 forms a sensing region at a predetermined position of the windshield, and thus detects information according to the state of raindrops generated in the sensing region.

The temperature sensor 120 measures the temperature and outputs the measured temperature data. In this case, the temperature sensor 120 may detect a temperature around the rain sensor 110 and output temperature data according thereto. Preferably, the temperature sensor 120 may be installed inside the rain sensor 110 to detect a temperature inside the rain sensor. Preferably, the temperature sensor 120 is installed at a position adjacent to a sensing layer (to be described later) constituting the rain sensor 110, and may sense a temperature around the sensing layer.

The humidity sensor 130 measures humidity and outputs the measured humidity data. In this case, the humidity sensor 130 may detect humidity around the rain sensor 110 and output humidity data according thereto. Preferably, the humidity sensor 130 may be installed inside the rain sensor 110 to detect humidity inside the rain sensor. Preferably, the humidity sensor 130 is installed at a position adjacent to the sensing layer (to be described later) constituting the rain sensor 110, it can detect the humidity around the sensing layer.

To this end, the sensing device may include a case surrounding the circumference of the rain sensor 110, the temperature sensor 120, and the humidity sensor 130, and within the one case, the rain sensor 110. ), The temperature sensor 120 and the humidity sensor 130 may be disposed.

The storage 140 may store data necessary for the operation of the sensing device 100 or data necessary during the operation of the sensing device 100. Preferably, the storage 140 compensates for the detection value of the rain sensor 110 according to temperature data measured through the temperature sensor 120 or humidity data measured through the humidity sensor 130. The reward table can be stored. The storage unit 140 may be various storage devices such as a ROM, a RAM, an EPROM, a flash drive, a hard drive, and the like in hardware.

The rain sensor 110 is affected by temperature and humidity. In other words, the sensing layer constituting the rain sensor 110 has a characteristic that a capacitance value changes according to a change in force or dielectric constant applied to the rain sensor 110. However, even when the force is not applied or the dielectric constant does not change on the sensing layer, the capacitance value changes according to the temperature change or humidity change. Therefore, in the present invention, the change characteristic of the capacitance value that changes according to the temperature and humidity is checked, and a compensation value according to the checked change characteristic is determined. The compensation table for the determined compensation value may be stored in the storage 140.

Preferably, the compensation table includes a first compensation table including a compensation value according to temperature, a second compensation table including a compensation value according to humidity, and a second compensation table including a compensation value according to temperature and humidity. It may include. At this time, since the rain sensor 110 is affected by both the temperature and humidity, it is necessary to compensate for the detection value in consideration of both the temperature and humidity. Therefore, in the present invention, a compensation value for compensating the detected value is determined in the storage unit 140 according to temperature and humidity, and a compensation table is created and stored in the storage unit 140.

Therefore, the compensation table may include a compensation value corresponding to temperature / humidity. For example, the compensation table may include a first compensation value applied under conditions of A temperature and B humidity, a second compensation value applied under conditions of A temperature and C humidity, and a third compensation value applied under conditions of D temperature and B humidity. And a fourth compensation value applied under the conditions of the D temperature and the C humidity. That is, the compensation table may be configured as a compensation value considering both temperature and humidity, not a compensation value for any one of temperature and humidity.

The controller 150 controls the rain sensor 110, the temperature sensor 120, and the humidity sensor 130 and accordingly drives the wiper based on the sensed value output through the rain sensor 110. The driving conditions can be determined.

In this case, the controller 150 determines whether compensation of the detection value output through the rain sensor 110 is necessary based on the temperature data and the humidity data sensed by the temperature sensor 120 and the humidity sensor 130. can do. That is, the detection value may be a capacitance value output through the rain sensor 110. In this case, the controller 150 sets a reference value for the capacitance value, and determines whether the raindrop exists and the amount of the raindrop based on a difference value between the set reference value and the capacitance value output through the rain sensor 110. Calculate.

The reference value may be set based on reference temperature data and reference humidity data. In this case, if the temperature data and the humidity data obtained through the temperature sensor 120 and the humidity sensor 130 are different from the reference temperature data and the reference humidity data, the controller 150 is stored in the storage unit 140. The reference value is changed using the stored compensation table. When the reference value is changed, the controller 150 may change the temperature data and the humidity data used to change the reference value into reference temperature data and humidity data.

As described above, the controller 150 may calculate the presence and the amount of raindrops by compensating the reference value based on the temperature data and the humidity data.

Alternatively, the controller 150 may compensate for the capacitance value output through the rain sensor 110 according to the temperature data and the humidity data. That is, the compensation table may be a compensation value to be applied to the capacitance value according to temperature and humidity. Therefore, when the capacitance value is output through the rain sensor 110, the controller 150 checks the temperature data and the humidity data output through the temperature sensor 120 and the humidity sensor 130. Thereafter, the controller 150 checks a compensation value to be applied to the capacitance value according to the temperature data and the humidity data using the compensation table. The controller 150 may calculate the presence of raindrops and the amount of raindrops based on a difference value between a predetermined reference value and a capacitance value to which the compensation value is applied.

In other words, the compensation table stored in the storage 140 may be a compensation value to be applied to the capacitance value output through the rain sensor 110, or may be a compensation value to be applied to a predetermined reference value.

Hereinafter, the detailed structure of the rain sensor 110 and the operation of the controller 150 according to the embodiment of the present invention will be described in more detail.

2 is a cross-sectional view illustrating a detailed structure of the rain sensor of FIG. 1 according to an exemplary embodiment of the present disclosure, FIG. 3 is a diagram illustrating a modified example of the electrode of FIG. 2, and FIG. 4 is included in the sensing layer of FIG. 2. It is a figure which shows a carbon micro coil, FIG. 5 is a figure explaining the capacitor function which the carbon micro coil of FIG. 4 has, and FIG. 6 shows the characteristic of the carbon micro coil of FIG.

2 to 6, the rain sensor 110 may include a substrate 111, a first electrode 112, a second electrode 113, a first partition wall 114, a second partition wall 115, and a first partition wall. The sensing layer 116, the second sensing layer 117, the driving element 118, and the protective layer 119 are included.

The rain sensor 110 is disposed inside the windshield of the vehicle, and thus detects a change in impedance according to a pressure applied to the outside of the windshield, and outputs a detection value accordingly.

The substrate 111 is mounted with the first electrode 112, the second electrode 113, the first partition wall 114, the second partition wall 115, the first sensing layer 116, and the second sensing layer 117. It is a base substrate. The substrate 111 may have a thickness satisfying a range of 50 μm to 125 μm.

The first electrode 112 and the second electrode 113 are disposed at positions spaced apart from each other on the substrate 111 by a predetermined interval. That is, the electrode is composed of a plurality of like the first electrode 112 and the second electrode 113, according to the object located adjacent to the first sensing layer 116 and the second sensing layer 117. The impedance of the first sensing layer 116 and the second sensing layer 117 is sensed as the state is changed. Each of the first electrode 112 and the second electrode 113 may be formed to have a thickness of 25 μm.

In this case, the first electrode 112 may be an electrode of positive polarity, and the second electrode 113 may be an electrode of negative polarity.

The first partition wall 114 is disposed on the substrate 111 to surround the first electrode 112 and the second partition wall 115 is disposed to surround the second electrode 113. do.

The first partition wall 114 may have a single closed loop shape at a position spaced apart from the first electrode 112 by a predetermined distance. For example, the first partition wall 114 may have a square shape at a position spaced apart from the first electrode 112 by a predetermined distance. Alternatively, the first partition wall 114 may be deformed into various shapes such as a circle shape, a polygonal shape, an ellipse shape, and a triangular shape.

 The second partition wall 115 may be formed to have a single closed loop shape at a position spaced apart from the second electrode 113 at a predetermined interval. For example, the second partition wall 115 may be disposed to have a square shape at a position spaced apart from the second electrode 113 at a predetermined interval. Alternatively, the second partition wall 115 may be deformed into various shapes such as a circle shape, a polygonal shape, an ellipse shape, and a triangular shape.

Meanwhile, the first partition wall 114 and the second partition wall 115 are spaced apart from each other by a predetermined interval. Preferably, a predetermined space is formed between the first partition wall 114 and the second partition wall 115.

That is, when the first partition wall 114 and the second partition wall 115 are in contact with each other, the first sensing layer 116 covering the first electrode 112 and the second electrode 113 covering the first partition wall 114 and the second partition wall 115 are formed. There is no space between the second sensing layers 117. Accordingly, a region where the sensing sensitivity of the sensing object is relatively low exists between the first sensing layer 116 and the second sensing layer 117. In other words, in the present invention, an electric field is generated around the first electrode 112 and the second electrode 113. In this case, when the space between the first sensing layer 116 and the second sensing layer 117 does not exist, the electric field is canceled with each other, a region having a weak electric field exists in a specific region. Therefore, in the present invention, a predetermined spaced space is formed between the first partition wall 114 and the second partition wall 115 so that the generated intensity of the electric field is uniformly displayed as a whole.

In addition, the first partition wall 114 and the second partition wall 115 may serve as a dam to physically separate the first sensing layer 116 and the second sensing layer 117. In addition, the first partition wall 114 and the second partition wall 115 may be formed to dispense while maintaining the flatness of the upper surface of the first sensing layer 116 and the second sensing layer 117. have. In this case, the first partition wall 114 and the second partition wall 115 may be formed of silicon.

The first sensing layer 116 is disposed on the substrate 111 to cover the first electrode 112. The second sensing layer 117 is disposed on the substrate 111 to cover the second electrode 113.

In this case, the first sensing layer 116 is disposed in the first partition wall 114. The second sensing layer 117 is disposed in the second partition wall 115. That is, the first partition wall 114 may be disposed surrounding the first sensing layer 116. In addition, the second partition wall 115 may be disposed to surround the second sensing layer 117.

The first sensing layer 116 and the second sensing layer 117 may have a predetermined thickness and may be disposed on the substrate 111, respectively. In this case, the thickness of the first sensing layer 116 may be the same as the thickness of the first partition wall 114. In addition, the thickness of the second sensing layer 117 may be the same as the thickness of the second partition wall 115.

That is, in the present invention, the first sensing layer 116 covering the first electrode 112 and the second sensing layer 117 covering the second electrode 113 are physically separated from each other. At this time, when the first electrode 112 and the second electrode 113 are disposed in the same sensing layer, there is a problem that the signal-to-noise ratio (SNR) due to interference between each other is worsened. In contrast, in the present invention, the first sensing layer 116 covering the first electrode 112 and the second sensing layer 117 covering the second electrode 113 are physically separated from each other to improve signal sensing characteristics. You can.

In this case, the first sensing layer 116 and the second sensing layer 117 are formed of a conductive material dispersed therein, and have a property of changing impedance according to a pressure applied from the outside.

Preferably, the first sensing layer 116 and the second sensing layer 117 have carbon micro coils (CMCs) having a spring shape dispersed therein. That is, the first sensing layer 116 and the second sensing layer 117 are deposited at least one of hydrocarbon-based, ie, acetylene, methane, propane and benzene on the substrate 111 by chemical vapor deposition (CVD). Is formed.

Alternatively, the first sensing layer 116 and the second sensing layer 117 may be manufactured using a metal catalyst based on nickel, nickel-iron, or the like.

As shown in FIG. 4, the carbon micro coil may have a shape that is curled like a pig tail rather than a straight line, and is an amorphous carbon fiber having a unique structure that the fiber material may not have. And, the carbon micro coil has a super elasticity extending to a length of 10 times or more of the original coil length.

FIG. 4A illustrates the carbon micro coils formed in the first sensing layer 116 and the second sensing layer 117, and FIG. 4B is a detailed view of the carbon micro coils.

Morphology of the first sensing layer 116 and the second sensing layer 117 has a 3D-helical / spiral structure, and the crystal structure is amorphous.

In other words, the first sensing layer 116 and the second sensing layer 117 are formed by growing carbon fibers in a coil shape, and thus the first sensing layer 116 and the second sensing layer 116 are formed. The sensing layer 117 has a cross-sectional structure in which carbon fibers are grown in a coil shape.

That is, the first sensing layer 116 and the second sensing layer 117 has an object approaching the area where the rain sensor 110 is mounted, and accordingly the impedance change according to the pressure applied from the approaching object Occurs. In other words, the carbon micro coils disposed in the first sensing layer 116 and the second sensing layer 117 vary in length depending on the approach of the object or the pressure applied from the object.

Meanwhile, the first sensing layer 116 and the second sensing layer 117 are manufactured by mixing a carbon micro coil (CMC) in a curing agent and an epoxy resin. In addition, the first sensing layer 116 and the second sensing layer 117 may use silicon instead of the epoxy resin. In addition, the first sensing layer 116 and the second sensing layer 117 may use a glass frit instead of the epoxy or the silicon.

In addition, the carbon micro coil has an impedance change due to the interaction between the carbon micro coils according to the concentration of the solution between the mixture as described above. Herein, the impedance change has been described above, but the impedance change may also be referred to as capacitance change or inductance change.

Here, the carbon micro coil has a different property from that of the carbon nanotubes. That is, the carbon nanotubes have a form in which carbon is connected in a hexagon in the form of nanotubes.

However, the carbon fine coil in the present invention has a form in which carbon is grown into coils of micro units using a catalyst rather than structural forms of carbon.

The carbon nanotubes as described above obtain specific measurement values by changing the impedance from the conductor to the non-conductor by using the characteristics of the conductor and the non-conductor according to the form of bonding of the elements themselves.

However, in the case of carbon micro coils, in the form of a coil made of carbon in micro units, the characteristics of L varying as the coil is stretched and contracted due to a change in force or permittivity, and the characteristics of C due to the distance between the carbon micro coils, etc. As a result, the impedance is changed according to the interaction between the carbon micro coils.

That is, the carbon micro coil itself has a property of a conductor, but since the hardener and epoxy resin as described above have intrinsic properties of the insulator, the carbon micro coil has an inherent capacitance value internally. When the distance between the coils changes, the characteristics of the capacitance value change accordingly.

In addition, the first electrode 112 and the second electrode 113 detect the impedance change of the first sensing layer 116 and the second sensing layer 117, and accordingly detect the sensing signal according to the impedance change. Transfer to the controller 150.

That is, in general, REAL TERM of impedance is made of resistance, POSITIVE IMAGINARY TERM is made of inductance, and NEGATIVE IMAGINARY TERM is made of capacitance, and the resistance, inductance, and capacitance are summed up.

Accordingly, like the general resistor, the inductor and the capacitor, the rain sensor 110 also uses a pair of electrodes 112 to detect the impedance change occurring in the first sensing layer 116 and the second sensing layer 117. 113) is required. The first electrode 112 and the second electrode 113 optimize the sensing characteristics of the first sensing layer 116 and the second sensing layer 117, and the first sensing layer 116 and the first sensing layer 116 are optimized. 2 serves to connect the sensing layer 117 and the driving element 118.

In this case, when pressure is applied to the rain sensor 110, the capacitance decreases according to the strength of the pressure, whereby the resistance value and the inductance value increase opposite to the capacitance.

In this case, the sensed impedance value is the sum of the resistance value, the inductance value, and the capacitance. Accordingly, the impedance value decreases linearly according to the degree of force or permittivity applied to the surface. In addition, in the embodiment, only the inductance value or the capacitance value may be detected, and thus the amount of raindrops existing on the windshield on which the rain sensor 110 is installed may be sensed.

3 is a diagram illustrating various embodiments of a shape of an electrode illustrated in FIG. 2.

In this case, the electrodes 112 and 113 have a structure as shown in FIG. 3 and are formed on the substrate 111. At this time, the line width of each of the electrodes 112 and 113 preferably satisfies a range of 10 μm to 2 mm.

As shown in FIG. 3A, the electrodes 112 and 113 may be spaced apart from each other at a predetermined interval and have a rod shape extending in the length direction.

In addition, as shown in (b) of FIG. 3, the electrodes 112 and 113 may be spaced apart from each other at regular intervals and may have a wavy shape that is bent at least one time. In this case, the electrodes 112 and 113 may have symmetrical shapes.

In addition, as illustrated in FIG. 3C, the electrodes 112 and 113 may be spaced apart from each other at regular intervals and may have a rectangular spiral shape that is bent a plurality of times. In addition, as an example of the modification of FIG. 3C, the electrodes 112 and 113 may have a “c” shape bent twice. In this case, it is preferable that the electrodes 112 and 113 are disposed in the edge region of the substrate 111 so that impedance change detection can be made within a wider range.

In addition, as illustrated in FIG. 3D, the electrodes 112 and 113 may be provided in plural. In other words, as described above, the electrodes 112 and 113 include a first electrode 112 and a second electrode 113. In addition, the first electrode 112 may include a rod-shaped first-first electrode 112A and a second-first electrode 112B that are spaced apart from each other by a predetermined interval. In addition, the second electrode 113 is disposed above the first electrode 112 and includes a rod-shaped 2-1 electrode 113A and a 2-2 electrode 113B spaced apart from each other by a predetermined interval. can do. In this case, the first electrode 112 may be disposed in the horizontal direction on the substrate 111, and the second electrode 113 may be disposed in the vertical direction crossing the first electrode on the first electrode. Can be.

Meanwhile, the rain sensor 110 includes a driving element 118 disposed on the bottom surface of the substrate 111. The driving element 118 may include an analog front end (AFE). In this case, the AFE performs a differential amplification function, and there is a difference in the state of change of impedance according to the sensing object depending on whether the differential amplification is positive or negative.

Accordingly, the driving element 118 detects a change state of the impedance value based on a reference value according to the differential amplification state, and determines that the raindrop exists when the degree of change state is out of a threshold value. Can be.

In addition, a protective layer 119 is disposed on the substrate 111. Preferably, the protective layer 119 may protect the first sensing layer 116 and the second sensing layer 117. The protective layer 119 may sense the first and the second from an external environmental factor. It may be a protective film for protecting the layers 116 and 117. In this case, the protective layer 119 may be an adhesive film. Accordingly, in the rain sensor 110 as described above, the protective layer 119 has adhesiveness, and thus, the protective layer 119 may be directly attached onto the front glass with an adhesive member.

In addition, as described above, the impedance includes a real part and an imaginary part, and the imaginary part comprises a positive imaginary part and a negative imaginary part, wherein the carbon micro coil is included. The rain sensor 110 may detect the amount of raindrops using two characteristic changes of the positive imaginary part (inductive) and the negative imaginary part (capacitive).

That is, when raindrops exist, the force applied to the rain sensor 110 varies according to the amount of raindrops. At this time, the carbon micro coil is composed of a very fine coil group as its name, it is also a dielectric having a dielectric constant. In this case, the force is measured through the change of the inductive component, that is, the characteristic change of the carbon fine coil, and the intensity of the applied pressure may be measured by the capacitive change caused by the change of the dielectric constant.

That is, each layer constituting the rain sensor 110 serves as a dielectric having a specific dielectric constant. If the force is applied as described above, the thickness of the internal dielectric layer is changed at the electrode position. A change in the distance between the carbon micro coils or a change in the length of each carbon micro coil causes a capacitive change. Therefore, in the embodiment, the presence of raindrops and the amount of raindrops may be detected by detecting a change in impedance values according to the inductive and capacitive values of the rain sensor 110 as described above.

Meanwhile, referring to FIG. 6, as illustrated in FIG. 6A, the carbon micro coil may serve as a series capacitor in which a plurality of capacitors are connected in series with each other.

In addition, as shown in FIG. 6B, the carbon micro coil may serve as a parallel capacitor in which a plurality of capacitors are connected in parallel to each other.

7 is a graph illustrating characteristics of a rain sensor that changes according to a temperature change according to an exemplary embodiment of the present invention.

On the other hand, the rain sensor 110 is the presence of raindrops and the presence of the raindrops based on the change in the impedance value changed by the carbon micro coils dispersed in the first sensing layer 116 and the second sensing layer 117 The amount is detected. However, the impedance value may change depending on the sensing object to be actually sensed, or may vary depending on the environment around which the rain sensor 110 is installed.

Referring to FIG. 7, FIG. 7A shows a temperature graph in which temperature is changed with time. And, FIG. 7B shows a capacitance value of the rain sensor 110 that changes according to the temperature corresponding to FIG. 7A.

At this time, the experiment on the change of the capacitance value of the capacitance value in the reliability chamber, in the state that does not arrange the object around the rain sensor 110, only changing the temperature conditions as shown above Show the change.

Referring to (a) and (b) of FIG. 7, it can be seen that the capacitance value of the rain sensor 110 also increases as the temperature increases based on an initial value, and conversely, as the temperature decreases. It was confirmed that the capacitance value of the rain sensor 110 is also reduced.

That is, in the operating environment of the rain sensor 110, the rain sensor 110, the capacitance value is changed in proportion to the change in the temperature, accordingly the problem that the wiper malfunctions according to the change in the capacitance value This will occur. Therefore, in the present invention, through the experiment to determine the degree of change in the capacitance value of the rain sensor 110 according to the temperature change, according to the compensation table for compensating the capacitance value changed by the temperature accordingly Write.

In this case, the compensation table may be applied to a reference value for confirming the degree of change in the capacitance value, and may be applied directly to the capacitance value.

In other words, the compensation table may include a compensation value for compensating a reference value for determining a driving condition of the wiper according to the temperature. Alternatively, the compensation table may include a compensation value for compensating the capacitance value output from the rain sensor 110 according to the temperature.

In other words, the reference value in the normal state (the state that the rain does not fall) is set in the sensing device. When the capacitance value is detected through the rain sensor 110, the presence of the raindrop and the amount of the raindrop are detected based on the difference between the detected capacitance value and the reference value. In this case, the sensing device compensates for any one of the reference value and the sensed capacitance value based on the temperature data obtained through the temperature sensor 120.

8 is a graph illustrating a compensation algorithm according to a change in temperature according to an embodiment of the present invention.

That is, referring to FIG. 8, "base_extracted_data" means a reference value, "raw_filtered_extracted_data" means a capacitance value without noise, and "thermal_filtered_extracted_data" means a temperature value from which noise is removed. Accordingly, in the present invention, the reference value or the capacitance value obtained through the rain sensor 110 is flexibly changed by applying a compensation algorithm according to temperature in the general state, and thus the reference value and the rain sensor 110 are changed accordingly. Let there be a certain difference between the capacitance values of That is, the capacitance value obtained through the rain sensor 110 in a normal state may have a value lower than the reference value. Accordingly, the presence of the raindrops and the amount of raindrops can be detected only when the capacitance has a value higher than the reference value. This is because the wiper is not driven when the change in the capacitance value of the rain sensor 110 is caused by a human body rather than a raindrop. This will be described in detail later.

For example, in a state where the reference temperature is set to 10 degrees and the reference value is set to "10pF", it is assumed that the capacitance value obtained through the rain sensor 110 is "30pF". In this case, when the temperature data at the time when the capacitance value is obtained is 10 degrees, the presence of raindrops and the amount of raindrops are detected based on "20pF" which is a difference value between the reference value and the capacitance value. On the other hand, when the temperature data at the time when the capacitance value is obtained is 30 degrees, the controller 150 checks the compensation value corresponding to the temperature data by using the compensation table stored in the storage 140. In this case, the compensation value may be a value applied to the reference value. Alternatively, the compensation value may be a value applied to the capacitance value obtained through the rain sensor 110. The compensation value is a value applied to the reference value, and when the compensation value corresponding to the temperature data is "25", the controller 150 may change the reference value from 10pF to 35pF. In this case, since the capacitance value detected by the rain sensor 110 is lower than the reference value, the controller 150 may ignore the obtained capacitance value. In addition, when the compensation value is a value applied to the capacitance value, and the compensation value applied to the temperature data is "25", the controller 150 may determine the capacitance value obtained through the rain sensor 110. You can compensate from 30pF to 5pF. In this case, since the compensated capacitance value is lower than the reference value, the controller 150 may ignore the capacitance value detected by the rain sensor 110.

9 is a flowchart illustrating a method of operating a sensing device according to a first exemplary embodiment of the present disclosure, and FIG. 10 is a flowchart illustrating a method of operating a sensing apparatus according to a second exemplary embodiment of the present disclosure.

Referring to FIG. 9, in order to apply a compensation algorithm, in the present invention, a change characteristic of a capacitance value of the rain sensor 110 that changes according to a change in temperature is checked in step 100.

When the change characteristic of the capacitance value according to the temperature is confirmed, a compensation value for compensating the capacitance value changed according to the temperature to a normal value is determined, and a compensation table is created based on the determined compensation value. 140) (step 110). In this case, the compensation table may include a compensation value for compensating the capacitance value obtained through the rain sensor 110 according to a temperature.

Thereafter, the controller 150 obtains a capacitance value transmitted through the rain sensor 110 in an operation environment of the sensing apparatus (operation 120).

When the capacitance value is obtained, the temperature data at the point of time when the capacitance value is obtained is checked (step 130).

Then, when the temperature data is not the reference temperature, the controller 150 checks a compensation value corresponding to the checked temperature data by using the stored compensation table. When the compensation value is confirmed, the controller 150 applies the compensation value to the obtained capacitance value (step 140).

Thereafter, the controller 150 obtains a detection value based on a difference value between the capacitance value to which the compensation value is applied and a preset reference value, and detects the presence and the amount of raindrops based on the detected value (step 150).

Referring to FIG. 10, in order to apply a compensation algorithm, in the present invention, a change characteristic of a capacitance value of the rain sensor 110 that changes according to a change in temperature is checked in step 200.

When the change characteristic of the capacitance value according to the temperature is confirmed, a compensation value for compensating the capacitance value changed according to the temperature to a normal value is determined, and a compensation table is created based on the determined compensation value. In operation 140, the compensation table may include a compensation value for compensating a predetermined reference value according to a temperature.

In operation 220, the controller 150 acquires a capacitance value transmitted through the rain sensor 110 in an operating environment of the sensing device.

When the capacitance value is obtained, the temperature data at the point of time when the capacitance value is obtained is checked (step 230).

Then, when the temperature data is not the reference temperature, the controller 150 checks a compensation value corresponding to the checked temperature data by using the stored compensation table. When the compensation value is confirmed, the controller 150 applies the compensation value to a preset reference value (step 240).

Thereafter, the controller 150 obtains a detection value based on a difference value between the reference value to which the compensation value is applied and the obtained capacitance value, and detects the presence of raindrops and the amount of raindrops based on this (step 250).

11 is a graph showing the characteristics of the rain sensor that changes according to the humidity change according to an embodiment of the present invention.

Meanwhile, referring to FIG. 11, the capacitance value of the rain sensor 110 is influenced not only by the temperature but also by the humidity. That is, in the normal state, while changing the humidity with time, the change state of the capacitance value of the rain sensor 110 is changed accordingly.

Referring to FIG. 11, it can be seen that the capacitance value of the rain sensor 110 changes according to humidity. That is, it was confirmed that the capacitance value increases as the humidity increases, and the capacitance value decreases as the humidity decreases.

Therefore, the present invention compensates for the capacitance value obtained through the reference value or the rain sensor 110 in consideration of the change in the humidity as well as the temperature.

12 is a flowchart illustrating a step-by-step method of operating a sensing device according to a third embodiment of the present invention.

Referring to FIG. 12, in order to apply a compensation algorithm, in the present invention, a change characteristic of a capacitance value of the rain sensor 110 that changes according to a change in temperature and humidity is checked in step 300.

When the change characteristic of the capacitance value according to the temperature and humidity is confirmed, a compensation value for compensating the capacitance value changed according to the temperature and humidity to a normal value is determined, and a compensation table is prepared based on the determined compensation value. In operation 310, the compensation table may include a compensation value for compensating a predetermined reference value according to temperature and humidity. Alternatively, the compensation table may include a compensation value for compensating the capacitance value obtained through the rain sensor 110 according to temperature and humidity.

In operation 320, the controller 150 acquires a capacitance value transmitted through the rain sensor 110 in an operating environment of the sensing device.

When the capacitance value is obtained, the controller 150 checks the temperature data and the humidity data at the point of time when the capacitance value is obtained (step 330).

Then, when the temperature data is not the reference temperature or the humidity data is not the reference humidity, the controller 150 checks a compensation value corresponding to the checked temperature and humidity data by using the stored compensation table. When the compensation value is confirmed, the controller 150 applies the compensation value to a predetermined reference value or the obtained capacitance value (step 340).

Thereafter, the controller 150 acquires a detection value based on a difference value between the reference value and the capacitance value finally obtained as the compensation value is applied, and detects the presence of the raindrop and the amount of the raindrop on the basis of the step (350) ).

FIG. 13 is a cross-sectional view illustrating a detailed structure of the rain sensor of FIG. 1 according to another exemplary embodiment.

Referring to FIG. 13, in comparison with FIG. 1, the rain sensor 110 has only the structure of the electrode, and the same for the other components. Therefore, in the description of FIG. 13, only the structure of the electrode will be described.

In FIG. 1, an electrode includes a first electrode 112 and a second electrode 113, each of which is a power supply electrode to which a positive polarity and a negative polarity are applied.

Alternatively, referring to FIG. 13, the first electrode 112 includes a first feed electrode 112A and a first floating electrode 112B. In addition, the second electrode 113 includes a second feed electrode 113A and a second floating electrode 113B.

That is, the first electrode 112 includes a first feed electrode 112A that is fed and a first floating electrode 112B that is floated around the first feed electrode 112A. In addition, the second electrode 113 includes a second feed electrode 113A which is fed and a second floating electrode 113B which is floated around the second feed sensing electrode 208.

The first feed electrode 112A and the second feed electrode 113A are connected to a feed terminal (not shown), and thus are electrically connected to the driving element 118.

The first floating electrode 112B and the second floating electrode 113B are closely disposed with the first feed electrode 112A and the second feed electrode 113A, respectively, and thus the first sensing layer 116 and The rate of change of the capacitance value inside the second sensing layer 117 is increased. In other words, the first embodiment of the present invention has an electrode structure including only the feed electrode.

The electrode structure including only the feed electrode senses a state of the sensing object only with a change in capacitance value generated between the feed electrodes. However, such a sensing electrode structure has a relatively low difference between the capacitance value when no sensing object is present and the capacitance value when a sensing object is present, and thus, it is difficult to secure detailed sensing sensitivity. there was.

That is, a two-line electrode structure including only the feed electrode as described above is a typical antenna structure, and an EMC (Electro Magnetic Compatibility) issue occurs when the entire wavelength of the two-line electrode is synchronized with a quarter wavelength of a specific frequency. Done.

In addition, a typical sensor mechanism measures the change amount as a ratio of the capacitance change amount to the basic capacitance value. At this time, in order to increase the detection sensitivity, the basic capacitance value should be low or the capacitance change amount should be large. However, in the two-line electrode structure, there is a limit to lowering the basic capacitance value or increasing the capacitance change amount.

Therefore, in this invention, a floating electrode is arrange | positioned around a feed electrode as mentioned above. In this case, each of the first floating electrode 112B and the second floating electrode 113B may be connected to a ground terminal (not shown) and grounded.

At this time, in order to increase the detection sensitivity, the lengths of the first floating electrode 112B and the first feed electrode 112A may be adjusted while minimizing the distance between the first floating electrode 112B and the first feed electrode 112A. It should be maximized.

Therefore, it is preferable that the first floating electrode 112B and the first feed electrode 112A are closely disposed with each other while being spaced apart at a predetermined interval on the substrate 101. In addition, the first floating electrode 112B and the first feed electrode 112A may be disposed at least once in a quadrangular shape on the substrate 101 so as to have a maximum length in a limited space. have. The first floating electrode 112B and the first feed electrode 112A may be disposed in a rectangular shape or a rectangular spiral shape, respectively.

More specifically, the first feed electrode 112A may be extended by turning a plurality of times in a square shape or a square spiral shape from one end connected to the feed terminal to the other end disposed in the first sensing layer 116. That is, the first feed electrode 112A may be turned a plurality of times by extending from one end to a straight line and turning it once so that the path is changed at right angles to have a quadrangular shape, and turning the inside twice.

The first floating electrode 112B may have the same shape as the first feed electrode 112A at a position spaced apart from the first feed electrode 112A by a predetermined distance. That is, the first floating electrode 112B may extend by being turned a plurality of times in a square shape or a square spiral shape from one end connected to the ground terminal to the other end disposed in the first sensing layer 116.

Meanwhile, the first feed electrode 112A may be disposed at the outermost portion of the first sensing layer 116, and the first floating electrode 112B may be closely disposed in the first feed electrode 112A. have.

Further, the other end of the first feed electrode 112A and the other end of the first floating electrode 112B are not disposed in the same direction, but the first feed electrode 112A in the first sensing layer 116. An electrode part including the other end of the second electrode) and an electrode part including the other end of the first floating electrode 112B may be disposed to face each other.

In addition, as described above, the second feeding electrode 113A and the second floating electrode 113B may also be disposed.

Hereinafter, the operation of the controller 150 will be described in more detail.

The controller 150 may include the driving element 118. The controller 150 is connected to the first electrode 112 and the second electrode 113, thereby generating an oscillation frequency according to the presence of the raindrops and the impedance change corresponding to the amount of raindrops, and the oscillation The presence of raindrops and the amount of raindrops are determined according to the difference between the frequency and the reference frequency.

In this case, the controller 150 detects whether a difference frequency between the oscillation frequency and the reference frequency belongs in a preset filtering region, and corresponds to the difference frequency only when the difference frequency exists within the preset filtering region. Digital values can be output.

In this case, the above operation is performed by the controller 150 including the driving element 118, but this is only an example, and the controller 150 may include the first electrode 112 and the second electrode. Only a digital value according to the sensing signal transmitted from the electrode 113 may be output, and accordingly, the following specific sensing operation may be performed in the vehicle controller disposed in the vehicle.

That is, the controller 150 may include one of a low pass filter (LPF) and a band pass filter (BPF) according to the characteristics of the rain sensor 110.

In addition, the low pass filter and the band pass filter have different filtering frequency ranges.

In this case, the capacitance value of the rain sensor 110 may have a different decrease amount depending on the type of the object placed on the carbon micro coil, and may also increase according to the type of the object. This will be described in detail later.

That is, the capacitance value may decrease when pressure is applied by the human body to the carbon fine coil, and otherwise increase when pressure is applied by an object such as an object.

Hereinafter, the sensing sensitivity of a general 2-line sensing electrode structure and the sensing sensitivity of a 4-line sensing electrode structure according to an exemplary embodiment of the present invention will be described.

14 is a view for explaining the sensitivity of the two-line electrode structure according to the prior art, Figure 15 is a view for explaining the sensitivity of the four-line electrode structure according to an embodiment of the present invention.

First, referring to FIG. 14, the controller 150 generates a first frequency f1, and accordingly, the controller 150 generates the first frequency f1 and accordingly changes the capacitance value according to the internal capacitance value Cr and the capacitance value Cs of the sensing layer. The amount of change will be output.

In this case, the change ratio when the rain does not fall on the rain sensor 110 and the change ratio when the rain falls are as follows.

Ro = Cs / Cr: Change ratio when no rain

Rr = (Cs + ΔCr) / Cr: change ratio in the rain

Herein, Cs is a capacitance value in the sensing layer, Cr is a reference capacitance value in the controller 150, and ΔCr is a capacitance value that may additionally occur when it rains.

As described above, when the ΔCr is increased as much as possible under the same Cr condition, the Rr increases accordingly, and based on this, the controller 150 signals the change rate according to the increasing Rr.

Referring to FIG. 15, FIG. 15A illustrates capacitance values that may occur in the upper direction and the lower direction of the rain sensor 110, and FIG. 15B illustrates a side direction of the rain sensor 110. Shows the capacitance value that can occur.

Referring to FIG. 15A, the capacitance value generated in the upper direction is referred to as C21 and the capacitance value generated in the lower direction is referred to as C1 between the first feed electrode 112A and the second feed electrode 113A. can do. The capacitance value generated in the upper direction between the first feed electrode 112A and the first floating electrode 112B may be referred to as C31. In addition, a capacitance value generated in the upper direction between the second feed electrode 113A and the second floating electrode 113B may be referred to as C32. In addition, a capacitance value generated in the lower direction between the first floating electrode 112B and the second floating electrode 113B may be referred to as C0.

In addition, referring to FIG. 15B, a capacitance value generated in the lateral direction between the first floating electrode 112B and the second floating electrode 113B may be referred to as C22.

Here, since C0 and C1 are matters commonly applied to the four-line electrode structure of the present invention and the conventional two-line electrode structure, they are excluded from the following comparison.

In the present invention, by applying a floating electrode in addition to the feed electrode as described above, ΔCr, which means a capacitance value additionally generated when rain falls, is made as large as possible.

The following is a comparison of the conventional two-line electrode structure and the four-line electrode structure of the present invention when the rain falls and when the rain does not fall.

First, the conventional two-line electrode structure can be expressed as follows.

(1) Cs1 = C21, Ro = C21 / Cr

: Change ratio of the conventional two-line electrode structure when no rain

Here, Cs1 denotes a capacitance value in the sensing layer of the two-line electrode structure, Cr denotes a reference capacitance value in the controller 150, and Ro denotes a change ratio of the capacitance value when no pressure is applied. do.

(2) Cs1 = C21 + ΔCr21, Rr = (C21 / Cr) + (ΔCr21 / Cr)

: Change ratio of the conventional two-line electrode structure when it rains

Next, the four-line electrode structure according to the present invention can be expressed as follows.

(1) Cs2 = C21 + (C31 / C32 / C22), Ro = (C21 / Cr) + ((C31 / 32 / C22) / Cr)

: Change ratio of 4-line electrode structure of the present invention when no rain

Here, Cs1 denotes a capacitance value in the sensing layer of the four-line electrode structure, Cr denotes a reference capacitance value in the controller 150, and Ro denotes a change ratio of the capacitance value when no rain falls.

(2) Cs2 = C21 + ΔCr21 + ((C31 + ΔCr31) / (C32 + ΔCr32) / (C22 + ΔCr22))

Rr = (C21 / Cr) + (ΔCr21 / Cr) + ((C31 + ΔCr31) / (C32 + ΔCr32) / (C22 + ΔCr22) / Cr)

: Change ratio of 4-line electrode structure of the present invention when it rains

As described above, in the four-line electrode structure of the present invention, in contrast to the existing two-line electrode, the floating sensing electrode corresponding to the portion of (C31 + ΔCr31) / (C32 + ΔCr32) / (C22 + ΔCr22) / Cr ”. There is a change in the additional capacitance value by, and the detection sensitivity can be improved based on the change in the additional capacitance value.

16 is a diagram illustrating a configuration of the controller 150 according to an embodiment of the present invention.

Referring to FIG. 16, the controller 150 includes a first frequency generator 151, a second frequency generator 152, a difference frequency generator 153, a filter 154, and an analog to digital converter 155.

The first frequency generator 151 is connected to the rain sensor 100 and generates a first frequency according to the impedance change of the rain sensor 100.

The first frequency generator 151 may be configured as an LC oscillation circuit.

Preferably, the first frequency generator 151 is configured to generate an oscillation frequency that is changed by a change in inductance value or capacitance value of the carbon fine coil by using a carbon fine coil and a capacitor constituting the sensing layer. .

That is, the first frequency generator 151 oscillates the oscillation frequency by the rain sensor 100 using the carbon fine coil of the rain sensor 100.

In other words, the inductance value of the carbon fine coil and the capacitance value of the capacitor constituting the sensing layer of the rain sensor 100 determine the oscillation frequency of the first frequency generator 151.

The second frequency generator 152 may be a reference oscillator, and generates a second frequency corresponding to the reference oscillation frequency.

In this case, the first frequency generated by the first frequency generator 151 may have a minute change. Accordingly, in the first embodiment of the present invention, the filter 154 is configured as a low pass filter.

In the following description, it is assumed that the filter 154 is configured as a low pass filter.

In this case, the first frequency generated when no pressure (pressure due to raindrops) is applied to the rain sensor 100 and the second frequency generated by the second frequency generator 152 may be set to have the same value. have.

In addition, when pressure is applied to the rain sensor 100, the difference between the first frequency and the second frequency increases according to the strength of the applied pressure, and whether the raindrop exists and the raindrops are based on the increased difference value. Allow you to determine the amount of.

In this case, when the inductance of the carbon micro coil included in the rain sensor 100 is referred to as L, and the capacitance of the capacitor is referred to as C, the first frequency ω ₀ generated by the first frequency generator 151 is represented by Equation 1 Same as

The first voltage value V ₀ corresponding to the first frequency generated by the first frequency generator 151 is represented by Equation 2 below.

In addition, the second voltage value Vr corresponding to the second frequency generated by the second frequency generator 152 is expressed by Equation 3 below.

The difference frequency generator 153 is connected to the first frequency generator 151 and the second frequency generator 152, and includes a first frequency generated by the first frequency generator 151 and a second frequency generator 152. Outputs a difference value corresponding to the difference in the second frequency generated by

In this case, the difference value Vdmod generated by the difference frequency generator 153 is expressed by Equation 4 below.

Here, the reason why the difference value has the same value as in Equation 4 is that the first frequency generated by the first frequency generator 151 when the pressure is not applied to the rain sensor 100 and the This is because the second frequencies generated by the second frequency generator 152 have the same value.

The filter 154 filters the output value generated by the difference frequency generator 153 and outputs the filtered output value.

At this time, the filter 154 has a filtering region corresponding to a frequency range of a predetermined size, and filters the output value of the difference frequency generator 153 within the filtering region.

Here, the filtering region may be determined by the type of the filter 154 and the change characteristic of the carbon micro coils when the pressure is applied.

Change characteristics of the carbon micro coil will be described in more detail below.

Meanwhile, the type of the filter 154 may be determined by the structure of the carbon fine coil.

That is, the inductance value of the carbon fine coil does not change within a large range according to the pressure intensity but changes minutely, and according to the minute changing value, the first frequency generated by the first frequency generator 151 is When there is no significant difference from the second frequency generated by the second frequency generator 152, the filter 154 may be configured as a low pass filter.

In addition, when the first frequency generated by the first frequency generator 151 is significantly different from the second frequency generated by the second frequency generator 152 according to the change in inductance value of the carbon micro coil. The filter 154 may be configured as a band pass filter.

In other words, the type of the filter 154 may be determined by a structure such as the area of the carbon fine coil in the sensing layer constituting the rain sensor 100.

The analog-to-digital converter 155 converts an output value output through the filter 154 into a digital value and outputs it.

17 to 19 illustrate changes in difference frequency values according to the first embodiment of the present invention.

Referring to FIG. 17, when the pressure is not applied, the first frequency generated by the first frequency generator 151 and the second frequency generated by the second frequency generator 152 may have the same frequency. have.

Therefore, in such a general situation, the output value filtered by the filter 154 is almost a DC voltage level according to the output value output from the difference frequency generator 153.

Referring to FIG. 18, as the pressure is applied, an output value filtered by the filter 154 generates a frequency shift within a predetermined filtering region.

In other words, when a change in inductance value of the carbon fine coil occurs as the pressure is applied, a change in the first frequency generated by the first frequency generator 151 occurs, and thus the first frequency and the first There will be a difference of two frequencies.

In this case, the difference frequency between the first frequency and the second frequency increases as the pressure intensity increases.

Accordingly, in the embodiment of the present invention, the strength of the pressure may be measured according to the value of the difference frequency between the first frequency and the second frequency. In other words, in the embodiment of the present invention, the strength of the pressure is measured according to the frequency domain change amount according to the signal output from the filter 154.

In an embodiment, the filtering region of the filter 154 is determined according to the change characteristic of the carbon micro coil generated by a foreign object and an object such as the human body, and the first frequency and the second frequency within the determined filtering region. It is possible to selectively measure the amount of raindrops only when a difference in frequency occurs.

Meanwhile, a compensation value corresponding to the compensation algorithm in the present invention may be applied to the first frequency, and may alternatively be applied to the second frequency. That is, the first frequency is a frequency corresponding to the capacitance value changed in the rain sensor 110, and the second frequency is a reference frequency. Therefore, when the compensation table is applied to a reference value, the controller 150 may compensate the second frequency according to the temperature and humidity. In addition, when the compensation table is applied to the capacitance value, the controller 150 may compensate the first frequency according to the temperature and humidity.

Referring to FIG. 19, when the difference between the first frequency and the second frequency is caused by a foreign matter that is not approached by an object such as the human body, the difference frequency may have a frequency outside the filtering region of the filter 154. have.

In this case, since the difference frequency is not included in the filtering area as shown in FIG. 19, in this case, the strength of the pressure may not be measured.

20 is a view illustrating a change of a difference frequency value according to the second embodiment of the present invention.

Referring to FIG. 20, when the design of the rain sensor 100 increases the pressure intensity, the first frequency is different from the second frequency, and the increase or decrease of the first frequency is large according to the pressure intensity. The filter 154 may be configured as a band pass filter.

In this case, the filtering region of the filter 154 may have a different frequency range than that of the low pass filter.

The strength of the pressure may be measured according to the degree of movement of the difference frequency generated by the change of the difference frequency in the filtering region.

In this case, when the filter 154 is a band pass filter, the output value of the difference frequency generator 153 is expressed by Equation 5 below.

21 is a graph showing a change characteristic of a carbon micro coil according to an embodiment of the present invention.

Referring to FIG. 21, the carbon micro coils have different change characteristics according to contact between stones, water, and the human body.

In other words, the carbon micro coils generate different output values according to the above materials.

As a result of the change in the output value of the carbon micro coil, different changes occurred according to the contact area and the contact direction even with the same stone. As the size of the stone increases, the weight and the contact area increase to increase the output value.

Further, even when a nonmagnetic material such as paper or a magnetic material such as a servo motor comes into contact, a large change in output value occurs without being influenced by a magnetic field. The output value of the carbon micro coil according to the present invention has a distinctive characteristic when the pressure is applied by the human body and when the pressure is applied by another object such as water or a mobile phone.

That is, the output value of the carbon micro coil has a negative value when the human body contacts, and has a positive value when an object such as water or a mobile phone contacts.

Therefore, in the present invention, the difference between the first frequency generated by the first frequency generator 2191 and the second frequency generated by the second frequency generator 2192 is based on the characteristics of the carbon fine coil. It can be distinguished whether it is caused by or by another object.

Accordingly, in the present invention, the reaction region of the rain sensor 100, that is, the filtering region of the filter 154 is determined based on the characteristics of the carbon micro coils reacted by the raindrops.

According to the embodiment, when the rainfall occurs, it is possible to immediately detect the rainfall in response to this, thereby improving the convenience of the driver in the rain.

In addition, according to the embodiment, by detecting the rainfall using the carbon micro coil, it is possible to provide a rain sensor having a different characteristic (response characteristics, precision, accuracy, power consumption, miniaturization, etc.) compared to the conventional optical method.

In addition, according to the embodiment, it is possible to measure rainfall even with a slight change in the impedance of the carbon fine coil, and set the reaction area of the rain sensor for avoiding the detection of foreign matters, so that the wiper is driven by the foreign matters in advance. You can prevent it.

In addition, the embodiment compensates for the detection value detected by the rain sensor according to the operating environment of the rain sensor. That is, in the embodiment, by compensating the detection value according to the ambient temperature and humidity of the rain sensor operation, it is possible to obtain a more accurate detection value to improve the operation reliability of the sensing device.

In addition, in the embodiment, by resetting the reference value of the rain sensor in accordance with the temperature and humidity, it is possible to prevent the malfunction of the sensing device according to the operating environment.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, but are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be interpreted that the contents related to this combination and modification are included in the scope of the embodiments.

Although the above description has been made with reference to the embodiments, these are merely examples and are not intended to limit the embodiments, and those of ordinary skill in the art to which the embodiments pertain may have various examples that are not illustrated above without departing from the essential characteristics of the embodiments. It will be appreciated that eggplant modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to these modifications and applications will have to be construed as being included in the scope of the embodiments set forth in the appended claims.

Claims (10)

A rain sensor comprising a carbon fine coil;
A temperature sensor for sensing a temperature around the rain sensor;
A humidity sensor for sensing humidity around the rain sensor;
A storage unit configured to store a compensation value for compensating a detection value of the rain sensor according to the temperature and humidity; And
When the detection value is obtained through the rain sensor, the temperature and humidity at the time when the detection value is obtained are checked, a compensation value corresponding to the temperature and humidity is extracted from the storage unit, and based on the extracted compensation value. A control unit for compensating the detected value;
The control unit,
If the compensated detection value is within the preset detection range, determine a wiper driving condition corresponding to the detection value,
When the compensated detection value is out of the preset detection range, it is recognized that the detection value is a detection value caused by a foreign substance.
Sensing device. The method of claim 1,
The rain sensor,
Outputs a capacitance value that changes depending on the state of the sensing object.
The control unit,
Obtaining the detection value based on a difference value between the output capacitance value and a predetermined reference value,
The compensation value is,
The compensation value of the capacitance value or the reference value of the reference value according to the temperature and humidity
Sensing device. The method of claim 2,
The control unit,
A first frequency generator for outputting a first frequency having an oscillation frequency corresponding to a change in capacitance values of the first and second sensing layers;
A second frequency generator for outputting a second frequency corresponding to the reference oscillation frequency of the reference value;
A difference frequency generator for outputting a difference value between the first frequency and the second frequency;
And a filter for filtering the difference value output through the difference frequency generator within a predetermined filtering region.
Sensing device. The method of claim 2,
The compensation value is,
In a general state in which a sensing object is not present on the rain sensor, the capacitance value of the rain sensor is maintained to be lower than the reference value.
Sensing device. The method of claim 3, wherein
The control unit,
When the difference value is larger than a predetermined value and the capacitance value is lower than the reference value, the human body is recognized through the rain sensor and the detected human body detection signal is output.
Sensing device. Confirming a change state of a capacitance value of a rain sensor including a carbon micro coil that changes according to temperature and humidity;
Storing a compensation value of a rain sensor according to the temperature and humidity based on the checked change state;
Checking a temperature and humidity around the rain sensor at the time when the detection signal is output, when a detection signal is output through the rain sensor;
Checking the compensation value corresponding to the checked temperature and humidity if the temperature and humidity are different from the reference temperature and reference humidity;
Obtaining a sensed value corresponding to the sensed signal by applying the checked compensation value;
Checking whether a target sensing object is located on the rain sensor based on the sensing value; And
Outputting a wiper driving signal according to a state of the target sensing object when the target sensing object is positioned on the rain sensor;
Method of operation of the sensing device. The method of claim 6,
The step of outputting the detection signal,
Outputting a capacitance value that varies according to a state of a sensing object present on the rain sensor,
Acquiring the detection value,
Obtaining the sensed value based on a difference value between the output capacitance value and a predetermined reference value,
The compensation value is,
Compensation value of the output capacitance value or compensation value of the reference value according to the temperature and humidity
Method of operation of the sensing device. The method of claim 7, wherein
Acquiring the detection value
Outputting a first frequency having an oscillation frequency corresponding to a change in the output capacitance value;
Outputting a second frequency corresponding to a reference oscillation frequency of the reference value;
Compensating any one of the first frequency and the second frequency by applying a compensation value corresponding to the identified temperature and humidity;
Outputting a difference value between the first and second frequencies with which any one frequency is compensated;
Filtering the difference value within a predetermined filtering region.
Method of operation of the sensing device. The method of claim 8,
Checking whether the target sensing object is located,
Determining that a target sensing object is located on the rain sensor when the difference value exists within the filtering area;
If the difference value is out of the filtering area, determining that an object other than the target sensing object is located on the rain sensor;
Method of operation of the sensing device. The method of claim 9,
Determining that the other object is located,
Determining that the human body is sensed through the rain sensor when the difference value is greater than a preset value and the output capacitance value is lower than the reference value.
Method of operation of the sensing device.

Images