KR20200061117A - Device for detecting approach of object, method for detecting approach of object using the device - Google Patents

Abstract

A device for sensing the approach of an object according to one embodiment of the present invention may comprise: a sensor strip including a plurality of unit conductors sequentially arranged thereon along the longitudinal direction thereof; a plurality of RF oscillators connected to the unit conductors, respectively, and providing oscillation frequencies to the unit conductors; a plurality of phase-locked loops disposed in the RF oscillators, respectively, and generating frequency setting voltages for controlling the oscillation frequencies to be maintained to be a predetermined reference frequency; and an MCU for sensing an object approaching the sensor strip on the basis of at least one frequency setting voltage.

Description

Object approach detection device, object access detection method using the same {DEVICE FOR DETECTING APPROACH OF OBJECT, METHOD FOR DETECTING APPROACH OF OBJECT USING THE DEVICE}

The present invention relates to an object approach detection device, an object approach detection method using the same, and more particularly, an object approach detection device that non-contactly detects an object approaching the sensor strip according to a change in capacitance, and an object approach detection method using the same It is about.

Generally, an object approach detection device (sensor) is largely divided into a contact type and a non-contact type. The contact type is a method of determining whether an object is approaching by sensing a change in voltage or a change in electrical load caused by the contact of an object such as an obstacle, and the non-contact type uses a change in capacitance or a change in the electric field to approach the obstacle. It is a way to judge whether or not.

Here, the conventional non-contact sensor includes a capacitive sensing module for sensing capacitance, a control module for determining whether an object is approached using a signal output from the capacitive sensing module, and a control module for controlling the output signal of the capacitive sensing module. Consists of a transmission line that is transmitted to, the capacitive sensing module is coupled to the end of the sensor strip and the strip-shaped sensor strip installed along the periphery of the door or window of the vehicle, for example, to detect the capacitance of the sensor strip It includes a capacitive sensing circuit.

In such a conventional non-contact sensor, when a person's hand or a body part or a foreign object approaches the door or door, the capacitance of the sensor strip changes, and the oscillation frequency of the RF oscillator connected to the sensor strip changes. As the oscillation frequency of the RF oscillator is changed, when the output signal of the capacitive sensing circuit is out of the allowable frequency range, the control module determines that there is an object such as an obstacle.

However, in the conventional non-contact sensor, since one RF oscillator is provided in one sensor strip, it is difficult to detect minute changes in capacitance, and the influx frequency carried on the sensor strip is formed high, so the influence of electromagnetic waves on other devices is affected. There is a limitation that interference may occur between multiple sensors.

Moreover, since the conventional non-contact sensor senses an object only by a change in capacitance, an additional device or algorithm must be implemented to determine in which direction the object is sensed, which increases the complexity of the device.

Korean Registered Patent No. 10-0595733 Korean Patent Publication No. 10-2018-0038839

One aspect of the present invention is provided on an object that is installed on a fixed or moving object to reliably detect an object approaching an object, and provides an object approach detection method using the same.

The technical problem of the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

Object approach detection device according to an embodiment of the present invention, a plurality of unit conductors are connected to each of the unit conductors, a sensor strip continuously arranged along the longitudinal direction, for detecting an object approaching the unit conductor A plurality of RF oscillators that provide an oscillation frequency, each of which is provided for each of the RF oscillators, and which generates a frequency setting voltage that controls the oscillation frequency variable by an object approaching the unit conductor to be maintained at a predetermined reference frequency. And an MCU that detects an object approaching the sensor strip based on the phase locked loop and at least one of the frequency set voltages received from the plurality of phase locked loops.

The MCU may determine that an object has approached the sensor strip when it is determined that the number of unit conductors whose frequency set voltage is greater than or equal to a preset threshold is greater than or equal to a reference number.

When the MCU determines that the average value of all the frequency set voltages received from the plurality of phase locked loops is greater than or equal to a first threshold, the MCU may determine that an object has approached the sensor strip.

The MCU may exclude a frequency set voltage having a magnitude of the frequency set voltage less than a second threshold value in the process of calculating the average value.

The MCU may detect an object approaching the sensor strip by grouping a plurality of the unit conductors and using an average value of a frequency setting voltage calculated for each group.

The MCU may determine that an object has approached the sensor strip when it is determined that the group having the average value equal to or greater than the threshold value is greater than the reference number.

When it is determined that the group having the average value of the threshold value or more is less than the reference number, the MCU counts the frequency set voltage generated for each unit conductor and the number of unit conductors equal to or greater than a preset reference value, and the counting result is greater than the reference number If it is confirmed that the preset group is reconfigured, and the group having the average value of the frequency set voltage calculated for each reconfigured group is less than the reference number, it is possible to detect an object approaching the sensor strip.

In addition, a plurality of unit conductors according to an embodiment of the present invention, a sensor strip continuously arranged along a longitudinal direction, a plurality of RF oscillators connected to each of the unit conductors, and a plurality of provided for each of the RF oscillators The object approach detection method using the object access detection device including an MCU for detecting an object approaching the sensor strip based on a phase locked loop and an electrical signal received from the plurality of phase locked loops, the plurality of RF oscillators Generates a frequency setting voltage that provides an oscillation frequency to the unit conductor under the control of the MCU, and controls the oscillation frequency varied by an object approaching the unit conductor to maintain a predetermined reference frequency. The MCU detects an object approaching the sensor strip based on at least one frequency setting voltage received from the plurality of phase locked loops.

Detecting an object approaching the sensor strip may be determined as an object approaching the sensor strip when it is determined that the number of unit conductors having the frequency set voltage equal to or greater than a preset threshold is greater than or equal to a reference number.

Detecting an object approaching the sensor strip may be detecting an object approaching the sensor strip using an average value of a frequency setting voltage calculated for each group by grouping a plurality of the unit conductors.

According to one aspect of the present invention described above, an object approaching the sensor strip can be detected by using a change amount of a frequency setting voltage for controlling an oscillation frequency variable according to the object approach, and in this process, one sensor strip can be detected. It is possible to reliably determine whether or not an object is approached by using a plurality of frequency setting voltages generated with respect to.

1 is a conceptual diagram showing a schematic configuration of an object approach detection device according to an embodiment of the present invention.
2 to FIG. 2 are views for explaining an embodiment in which the object approach detection device of FIG. 1 detects an object.
5 and 6 are views for explaining another embodiment in which the object approach detection device of FIG. 1 detects an object.
6 is a flowchart illustrating a schematic flow of an object approach detection method according to an embodiment of the present invention.

For a detailed description of the present invention, which will be described later, reference is made to the accompanying drawings that illustrate, by way of example, specific embodiments in which the invention may be practiced. These examples are described in detail enough to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the invention are different, but need not be mutually exclusive. For example, the specific shapes, structures, and properties described herein can be implemented in other embodiments without departing from the spirit and scope of the invention in connection with one embodiment. In addition, it should be understood that the location or placement of individual components within each disclosed embodiment can be changed without departing from the spirit and scope of the invention. Therefore, the following detailed description is not intended to be taken in a limiting sense, and the scope of the present invention, if appropriately described, is limited only by the appended claims, along with all ranges equivalent to those claimed. In the drawings, similar reference numerals refer to the same or similar functions across various aspects.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

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

The object approach detection device 1 according to the present invention is installed on an object that is fixed or moved, such as a vehicle, an elevator, or a door, to detect an object approaching the object.

That is, the object approach detection device 1 according to the present invention detects an object approaching an installed object, and provides the result to the control module 2 provided in the object, thereby driving the scaffold (side step) or An operation corresponding to an object approaching an object, such as opening or closing a window or a door, may be performed by the control module 2.

At this time, the object approach detection apparatus 1 according to the present invention may determine whether or not the object is approached by using the frequency adjustment voltage generated to control the oscillation frequency that changes as the object approaches to maintain the reference frequency.

Specifically, the object approach detection apparatus 1 according to an embodiment of the present invention may include a sensor strip 100, an RF oscillator 200, a phase locked loop 300, and an MCU 400.

The sensor strip 100 is a band-shaped member having a variable capacitance value according to the approach of an object, and may be installed on an object that is fixed or moved. For example, the sensor strip 100 may be installed on various objects such as a vehicle door, a window, or a sliding gate, an elevator door.

The sensor strip 100 is a thin strip-shaped conductor (eg, a metal material) inserted in a rubber-like insulator with good flexibility. Since the conductor acts as an electrode of a capacitor, there is an access object nearby. The capacitance and the absence of capacitance appear differently.

At this time, in the sensor strip 100 according to an embodiment of the present invention, a plurality of unit conductors 110, 120, and 130 have a length direction of the sensor strip 100 differently from a conventional sensor strip provided as one conductor. It can be characterized by being arranged continuously.

That is, as shown in the sensor strip 100 according to the present invention, the first unit conductor 110, the second unit conductor 120 and the third unit conductor 130, the longitudinal direction of the sensor strip 100 Accordingly, it may be in a continuously arranged form.

In the illustrated embodiment, the plurality of unit conductors 110, 120, and 130 are shown as being three, but are not limited thereto, and the unit conductors are provided in two or more than four, and the number of the unit conductors is limited. It is not.

The RF (Radio Frequency) oscillator 200 may be a module that provides an oscillation frequency for detecting an object approaching the sensor strip 100 to the sensor strip 100. The RF oscillator 200 may oscillate a variable oscillation frequency in response to a change in the capacitance of the sensor strip 100 due to the approach of an object.

At this time, a plurality of RF oscillators 200 according to the present invention may be provided, and more specifically, may be provided for each unit conductor (110, 120, 130). That is, the first RF oscillator 210 is connected to the first unit conductor 110, the second RF oscillator 220 is connected to the second unit conductor 120, and the third RF oscillator 230 is the third It may be connected to the unit conductor 130.

Thus, each RF oscillator (210, 220, 230) is connected to each unit conductor (110, 120, 130) is designed to be carried on a specific unit conductor to which the oscillation frequency is connected.

The phase lock loop (PLL, 300) may be a module that controls the oscillation frequency variable according to the approach of the object to be maintained at a predetermined reference frequency. That is, when the oscillation frequency of the RF oscillator 200 is changed from the reference oscillation frequency according to the change in the capacitance value, the phase locked loop 300 is connected to the RF oscillator 200, the RF oscillator 200 is the reference oscillation It may be a frequency control circuit that automatically corrects a difference from the oscillation frequency according to a change in the capacitance value to maintain the frequency.

To this end, the phase locked loop 300 may control the voltage applied to the RF oscillator 200 to offset the change in frequency to maintain the oscillation frequency of the RF oscillator 200 constant. In this process, when the oscillation frequency changes from the reference oscillation frequency, the phase locked loop 300 applies a predetermined voltage for canceling it to the RF oscillator 200, hereinafter, for convenience of explanation, the phase locked loop 300 300) will be described by defining the voltage applied to offset the change in frequency generated by the frequency set voltage.

Meanwhile, in one embodiment of the present invention, the phase locked loop 300 may be provided in each of the plurality of RF oscillators 210, 220, and 230. For example, the first phase locked loop 310 is provided in the first RF oscillator 210, the second phase locked loop 320 is provided in the second RF oscillator 220, and the third phase locked loop 330. May be provided in the third RF oscillator 230.

In this case, the first phase-locked loop 310 controls the oscillation frequency of the first RF oscillator 210 to be maintained at a reference frequency, and the second phase-locked loop 320 controls the oscillation frequency of the second RF oscillator 220. Is controlled to be maintained at the reference frequency, and the third phase locked loop 330 may control the oscillation frequency of the third RF oscillator 230 to be maintained at the reference frequency. However, the number of phase locked loops 300 is not limited to the illustrated embodiment, and as long as it corresponds to the number of RF oscillators 200 and unit conductors 110, 120, 130 as described above, the number thereof There are no restrictions.

The MCU (Micro Controller Unit 400) can control the overall operation of the object approach detection device 1 according to the present invention.

For example, the MCU 400 controls the plurality of RF oscillators 210, 220, and 230 to generate the oscillation frequency generated for each RF oscillator 210, 220, 230 to each unit conductor 110, 120, 130. It can be controlled to be provided.

In particular, the MCU 400 is connected to the phase locked loop 300 to access the object approaching the sensor strip 100 based on at least one frequency set voltage received from the plurality of phase locked loops 310, 320, 330. Can be detected.

Specifically, the MCU 400 detects an electrical signal (frequency set voltage value) output from the phase locked loop 300 to determine whether an object is approaching, while an actuator module (not shown) that automatically opens or closes a window or door of a car Time) to detect whether or not the predetermined control signal can be transmitted to the phase lock loop 300 of the capacitive sensing circuit.

In the above, the schematic configuration of the object approach detection device 1 according to an embodiment of the present invention has been described, and the object approach detection device 1 shown in FIG. 1 will be described below with reference to FIGS. 2 to 6 together. The specific operation process of the will be described.

FIG. 2 is a diagram illustrating a specific configuration of the RF oscillator 200 and the phase locked loop 300 constituting the object approach detection device 1 shown in FIG. 1.

In FIG. 2, for the convenience of description, only the specific configurations of the first RF oscillator 210 and the first phase locked loop 310 are shown, but other RF oscillators 220 and 230 and other phase locked loops 320 and 330 It should also be understood that it is the same as the configuration shown in FIG. 2.

The first RF oscillator 210 may be composed of an oscillation circuit and an amplification circuit.

The oscillation circuit is an element that generates an oscillation frequency according to an electrical control signal received from the MCU 400, and the amplification circuit may be an element that amplifies and outputs the oscillation frequency generated by the oscillation circuit. That is, the first RF oscillator 210 may apply the oscillation frequency generated by the oscillation circuit and amplified by the amplification circuit to the first unit conductor 110.

The first phase locked loop 310 is controlled by the MCU 400, and may be composed of a frequency divider, a frequency comparator, and a frequency-voltage converter.

The frequency divider may be a module that is connected to the first RF oscillator 210 and divides the oscillation frequency oscillated from the first RF oscillator 210 at a predetermined ratio. That is, the frequency divider can be adjusted by dividing a relatively high frequency oscillated from the first RF oscillator 210 to a frequency low enough to be recognized by a frequency comparison described later. For example, the frequency divider can be set to a frequency division rate of 1/100 or more (eg, 1/100, 1/200,..), taking into account the specifications of the MCU 400 and the frequency comparator, etc. It can be set to an appropriate dispensing rate.

The frequency comparator continuously measures the oscillation frequency of the first RF oscillator 210 through a frequency detection means such as a capacitor for frequency detection, and the oscillation frequency of the RF oscillator 210 is a reference oscillation frequency preset by the MCU 400. It can detect whether it changes from.

The frequency-to-voltage converter supplies a frequency setting voltage to the first RF oscillator 210 through the signal line for frequency adjustment when the oscillation frequency deviates from the reference frequency so that the oscillation frequency of the first RF oscillator 210 maintains the reference oscillation frequency. Can be controlled.

Due to the above-described configuration, when the oscillation frequency of the first RF oscillator 210 is intended to deviate from the reference oscillation frequency by an object approaching the first unit conductor 110, the first phase locked loop 310 is The reference oscillation frequency may be maintained by applying the frequency setting voltage or by appropriately changing the frequency setting voltage being applied.

Here, it may be understood that applying or changing the frequency setting voltage further applies the frequency setting voltage under the condition of + or-in addition to the frequency setting voltage previously applied to oscillate the reference oscillation frequency.

In addition, the voltage value for frequency adjustment for controlling the oscillation frequency of the first RF oscillator 210 is transmitted to the MCU 400 through an analog-to-digital converter (ADC) in the form of an electrical signal, and the input electrical signal value is When the allowable range of the electrical signal reference value preset in the MCU 400 is exceeded, it is determined that the object has approached the first unit conductor 110.

Hereinafter, a specific process of detecting whether an object is approached by the object approach detection apparatus 1 according to the present invention will be described using the basic operation of the RF oscillator and the phase locked loop.

3 and 4 are diagrams for explaining a specific process of detecting whether an object is approached by the object approach detection device 1.

First, as illustrated in FIG. 3, when an object is not approached to the sensor strip 100, each RF oscillator 210, 220, 230 connected to each unit conductor 110, 120, 130 is an MCU 400 Oscillation frequency equal to the reference frequency set by) can be oscillated. In this case, each of the phase locked loops 310, 320, and 330 does not generate a separate frequency setting voltage for controlling the oscillation frequency.

At this time, as illustrated in FIG. 4, when an object approaches the first unit conductor 110, the capacitance of the first unit conductor 110 is changed, and accordingly, the first unit conductor 110 and The oscillation frequency of the connected first RF oscillator 210 may deviate from the reference frequency. Accordingly, the first phase locked loop 310 connected to the first RF oscillator 210 may generate a first frequency set voltage for controlling the oscillation frequency of the first RF oscillator 210.

In addition, when an object approaches the first unit conductor 110, the capacitance of the second unit conductor 120 adjacent to the first unit conductor 120 may also be varied. That is, even if an object does not directly approach the front of the second unit conductor 120, when an object enters the electric field region of the second unit conductor 120, the capacitance of the second unit conductor 120 changes. Therefore, the oscillation frequency of the second RF oscillator 210 connected to the second unit conductor 120 also changes from the reference frequency, and the second RF is fixed in the second phase locked loop 320 connected to the second RF oscillator 210. A second frequency setting voltage for controlling the oscillation frequency of the oscillator 220 may be generated.

Meanwhile, the third unit conductor 130 spaced apart from the first unit conductor 120 at a relatively long distance may maintain the capacitance value, and accordingly, the third phase locked loop 330 generates a frequency setting voltage. You may not.

The MCU 400 may finally determine whether an object approaches the sensor strip 100 based on at least one frequency setting voltage value received from the plurality of phase locked loops 310, 320, and 330.

In one embodiment of the present invention, the MCU 400 may determine that an object has approached the sensor strip 100 when the number of unit conductors having a frequency set voltage equal to or greater than a preset threshold is greater than or equal to a reference number.

For example, when it is determined that the magnitude of the first frequency set voltage value or the amount of change in the first frequency set voltage is greater than or equal to a threshold, the MCU 400 may estimate that an object approaches the first unit conductor 110. Similarly, when it is determined that the magnitude of the second frequency set voltage or the amount of change in the second frequency set voltage is greater than or equal to a threshold value, the MCU 400 may estimate that the object has approached the vicinity of the second unit conductor 120. have.

At this time, when the above-mentioned reference number is set to 2, the MCU 400 is the first and second unit conductors (110, 120) because it was confirmed that the object has been detected, finally the object approached the sensor strip 100 You can judge that.

In another embodiment of the present invention, when it is determined that the average value of all the frequency set voltages received from the plurality of phase locked loops is greater than or equal to a first threshold, it may be determined that an object approaches the sensor strip. That is, when the MCU 400 determines that the average value of the first frequency set voltage and the second frequency set voltage is equal to or greater than a preset threshold, the MCU 400 may finally determine that an object approaches the sensor strip 100.

At this time, the MCU 400 may exclude the frequency setting voltage having a magnitude of the frequency setting voltage less than a second threshold different from the above-described first threshold in the process of calculating the average value. For example, when the first frequency set voltage value is greater than or equal to the second threshold, the MCU 400 may include the first frequency set voltage in the voltage value for determining object access. On the other hand, when it is determined that the second frequency set voltage value is less than the second threshold value, the MCU 400 may exclude the second frequency set voltage from the voltage value list for calculating the average value. Accordingly, the object approach detection apparatus 1 according to the present invention can exclude measurement values due to errors or distortions from the average value calculation process, thereby improving the accuracy of detection.

In another embodiment of the present invention, the MCU 400 may group a plurality of unit conductors to detect an object approaching the sensor strip using an average value of a frequency setting voltage calculated for each group. In this regard, it will be described with reference to FIGS. 5 and 6 together.

5 and 6 are diagrams for explaining another embodiment in which the MCU 400 detects an object approaching the sensor strip 100.

Initially, the MCU 400, as shown in Figure 5, the first and second unit conductors 110 and 120 as a first group, and the third, fourth and fifth unit conductors 130, 140 and 150 as a second group Can be classified as

The MCU 400 may calculate the average frequency setting voltage value for each group, and count the number of groups in which the average value of the frequency setting voltage is greater than or equal to a preset threshold. When the number of counted groups is greater than or equal to a preset reference number, the MCU 400 may determine that the object has approached the sensor strip 100.

At this time, when the reference number is set to 2, the MCU 400, as shown in FIG. 6, when it is determined that the group having an average value equal to or greater than a threshold value is less than the reference number, presets the frequency setting voltage generated for each unit conductor. Count the number of unit conductors above the reference value, and if the counting results show that it is above the reference number, reconfigure the preset group, and recheck whether the group with the average value of the frequency setting voltage calculated for each reconstructed group is below the reference number. Thus, an object approaching the sensor strip can be detected.

In this case, referring to FIG. 6, since the number of groups in which the average value of the frequency setting voltage is greater than or equal to a preset threshold is counted in two (second group, third group), the MCU 400 is configured to use the sensor strip 100 It can be judged that the object has approached.

That is, the object approach detection apparatus 1 according to the present invention automatically measures the reliability of the measured values for each group, and if it is determined that the reliability is relatively low, the reliability of the measurement result is reconstructed by reconfiguring the group set primarily. It can improve itself, and the object detection direction can be determined by itself using the average frequency setting voltage measured for each group.

7 is a flowchart illustrating a schematic flow of an object approach detection method according to an embodiment of the present invention.

The object approach detection method according to the present invention can be performed by the object approach detection device 1 according to the present invention shown in FIG. 1, and the object approach detection device 1 is configured to be an object approach detection method described later. Software (application) for performing the steps may be installed in advance.

First, when the object approach measurement mode is initiated, the plurality of RF oscillators 200 may provide oscillation frequencies to respective unit conductors 110, 120, and 130 under control of the MCU 400 (710 ).

Then, when the object approaches the sensor strip 100, the phase lock loops 310, 320, and 330 set the frequency to control the oscillation frequency varied by the object approaching the unit conductor to be maintained at a predetermined reference frequency. A voltage may be generated (720).

Finally, the MCU 400 may detect an object approaching the sensor strip 100 based on at least one frequency setting voltage received from the plurality of phase locked loops 300 (730).

Since the detailed contents of each step constituting the object approach detection method according to the exemplary embodiment of the present invention have been described above, repeated description will be omitted.

Although described above with reference to embodiments, those skilled in the art understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Will be able to.

1: Object approach detection device
100: sensor strip
200: RF oscillator
300: phase locked loop
400: MCU

Claims (10)

A sensor strip in which a plurality of unit conductors are continuously arranged along the longitudinal direction;
A plurality of RF oscillators connected to each of the unit conductors and providing an oscillation frequency for sensing an object approaching the unit conductors;
A plurality of phase locked loops provided for each of the RF oscillators and generating a frequency setting voltage to control the oscillation frequency varied by an object approaching the unit conductor to be maintained at a predetermined reference frequency; And
And an MCU that detects an object approaching the sensor strip based on at least one frequency set voltage received from a plurality of the phase locked loops.
According to claim 1, The MCU,
When it is determined that the number of unit conductors having a frequency set voltage equal to or greater than a preset threshold is greater than or equal to a reference number, it is determined that an object has approached the sensor strip, an object approach detection device.
According to claim 1, The MCU,
When it is determined that the average value of all the frequency set voltages received from the plurality of phase locked loops is greater than or equal to a first threshold, it is determined that an object has approached the sensor strip, the object approach detection device.
According to claim 3, The MCU,
An object approach detection device for excluding a frequency set voltage having a magnitude of the frequency set voltage less than a second threshold in the process of calculating the average value.
According to claim 1, The MCU,
An object approach detection device for detecting an object approaching the sensor strip by grouping a plurality of the unit conductors and using an average value of a frequency setting voltage calculated for each group.
According to claim 5, The MCU,
When it is determined that the group having the average value equal to or greater than the threshold value is greater than or equal to the reference number, it is determined that an object has approached the sensor strip.
The MCU of claim 5,
If it is determined that the group having the average value is greater than or equal to the threshold value is less than the reference number, counting the number of unit conductors having a preset reference value or more for the frequency set voltage generated for each unit conductor, and counting results are determined to be greater than or equal to the reference number. An object approach detection device for reconfiguring a set group and re-checking whether a group having an average value of a frequency set voltage calculated for each reconstructed group is less than a reference number to detect an object approaching the sensor strip.
A sensor strip in which a plurality of unit conductors are continuously arranged along a longitudinal direction, a plurality of RF oscillators connected to each of the unit conductors, a plurality of phase lock loops provided for each of the RF oscillators, and a plurality of phase locks In the object access detection method using an object access detection device including an MCU for detecting an object approaching the sensor strip based on the electrical signal received from the loop,
The plurality of RF oscillators provide an oscillation frequency to the unit conductor under the control of the MCU,
The phase locked loop generates a frequency setting voltage that controls the oscillation frequency varied by an object approaching the unit conductor to be maintained at a predetermined reference frequency,
And the MCU detects an object approaching the sensor strip based on at least one frequency setting voltage received from the plurality of phase locked loops.
The method of claim 8, wherein detecting the object approaching the sensor strip,
If it is determined that the number of unit conductors having a frequency set voltage equal to or greater than a preset threshold is greater than or equal to a reference number, it is determined that an object has approached the sensor strip, and the object approach detection method.
The method of claim 8, wherein detecting the object approaching the sensor strip,
A method of sensing an object approach by grouping a plurality of the unit conductors to detect an object approaching the sensor strip using an average value of a frequency setting voltage calculated for each group.

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