KR102325726B1 - Sensing apparatus for close object using detection of changes in electric field and sensor unit for the same - Google Patents

Abstract

The present invention relates to an object sensing apparatus using electric field change sensing and a sensor unit therefor.
According to an embodiment of the present invention, the proximity of an object is sensed based on a change in capacitance value due to a change in an electric field using an electrode strip portion in which an electrode strip is formed in a closed loop shape, but a plurality of electrodes along one sensor sensing surface Disclosed are a device for detecting an object using electric field change sensing and a sensor unit therefor, in which a strip unit is disposed and configured to sense an object adjacent to a front side of a sensor sensing surface through two or more electrode strip units.

Description

Sensing apparatus for close object using detection of changes in electric field and sensor unit for the same}

The present invention relates to an object sensing device using electric field change sensing and a sensor unit therefor, and more particularly, to an object based on a change in capacitance value according to electric field change using an electrode strip part in which an electrode strip is formed in a closed loop shape. An object sensing device using electric field change sensing configured to detect proximity, but a plurality of electrode strip units are disposed along one sensor sensing surface to detect an object adjacent to the front side of the sensor sensing surface through two or more electrode strip units, and for the same It relates to a sensor unit.

Sensor technologies for detecting the proximity of an object by sensing a change in capacitance according to the proximity of an object have been proposed.

For example, Republic of Korea Patent No. 10-1017096 (registered on February 16, 2011) relates to a sensor strip for detecting obstacles and a coupling structure thereof, and includes: a strip-shaped sensor body having a reference surface coupled to an object on one side; A configuration including a plate-shaped strip electrode embedded in the interior of the sensor body in the longitudinal direction and approaching the reference plane from the peripheral portion to the central portion in the width direction was proposed.

As another example, Republic of Korea Patent No. 10-1255829 (registered on April 11, 2013) relates to a non-contact proximity switch, comprising: a plate injection-molded so that an electrode is embedded; and a sensing unit electrically connected to the electrode to detect a change in capacitance, and a control unit configured to determine whether to control ON/OFF of a switch according to a change in capacitance sensed by the sensing unit and control ON or OFF of the switch A configuration comprising a; provided control board was proposed.

However, although the prior art methods can detect whether an object is close to the sensor, since they use one strip or one plate-shaped electrode, there is a limit to providing an object detection function having directivity in a specific direction. there was.

Republic of Korea Patent Registration 10-1017096 (Registered on February 16, 2011) Republic of Korea Patent Registration 10-1255829 (Registered on April 11, 2013)

The present invention has been devised in view of the above problems, and the proximity of an object is sensed based on a change in capacitance value according to a change in an electric field using an electrode strip in which an electrode strip is formed in a closed loop shape, but one sensor is detected A plurality of electrode strip portions are disposed along the surface to provide an object detection device using electric field change detection configured to detect an object proximate to the front side of the sensor detection surface through two or more electrode strip portions, and a sensor unit therefor. do.

According to one aspect of the present invention for achieving the above object, an electrode strip portion including an electrode strip formed in a closed loop shape and having a variable capacitance value according to an electric field change according to the proximity of an object along one sensor sensing surface a plurality of sensor units arranged to detect an object adjacent to the front side of the sensor sensing surface through two or more electrode strip units; a sensing unit for sensing a change in the capacitance value of the electrode strip unit; and a control unit for determining whether an object is close by using an electrical signal according to a change in the capacitance value sensed by the sensing unit;

Preferably, in the present invention, a plurality of the electrode strip portions having the same closed-loop shape are arranged to have a preset arrangement shape along one sensor sensing surface.

Preferably, the plurality of electrode strip portions each have the same closed loop size.

Preferably, the preset arrangement form is a grid arrangement form.

Preferably, the preset arrangement form is a form in which a plurality of other electrode strip units are surrounded by one electrode strip unit as a center.

Preferably, the plurality of electrode strip portions each have different closed loop sizes, and have an expanded arrangement in which another electrode strip portion having a larger size surrounds one electrode strip portion as a center.

Preferably, the plurality of electrode strip portions include two or more electrode strip portions having different phases of power.

Preferably, both ends of the electrode strip branched to both sides from the branching point are combined to form one closed loop, and the phase of the power applied to the electrode strip branched in one direction from the branching point and the branching point The phase of the power applied to the electrode strip branched in the other direction is configured to have different phases at one position in the longitudinal direction of the electrode strip.

Preferably, the electrode strip portion is arranged to maintain a predetermined longitudinal distance in a state opposite to the first electrode portion and the first electrode portion formed by disposing the closed loop of the electrode strip, and and a second electrode unit installed to have an area opposite to that of the roof.

Preferably, the first electrode part is configured to form a (+) electrode, and the second electrode part is configured to form a ground or (-) electrode.

Preferably, the control unit determines whether the object is close by using the capacitance value of the electrode strip portion measured in a state in which the object is not approached as a reference value, and comparing the capacitance value of the electrode strip portion measured in the sensing mode with the reference value do.

Preferably, the detection of the change in the capacitance value is performed in a state in which electric fields generated by each of the two or more electrode strip portions overlap each other.

According to another aspect of the present invention, a plurality of electrode strip parts including an electrode strip formed in a closed loop shape and having a variable capacitance value according to an electric field change according to an object proximity are disposed along one sensor sensing surface, the sensor Disclosed is a sensor unit configured to sense an object proximate to a front side of a sensing surface through two or more electrode strip portions.

According to the present invention, the proximity of an object is sensed based on a change in capacitance value according to an electric field change using an electrode strip portion in which the electrode strip is formed in a closed loop shape, but a plurality of electrode strip portions along one sensor sensing surface Since an object disposed and approaching the front side of the sensor sensing surface is sensed through two or more electrode strip portions, it is possible to provide an object detection function having directivity in a specific direction.

In addition, the present invention makes it possible to simply generate a phase difference between each electrode strip part without a circuit element for phase control, and by making the electric fields of two or more electrode strips overlap each other due to this phase difference, it is possible to detect the proximity of an object. It has the advantage of increasing the distance.

1 is a schematic diagram of a sensor unit according to an embodiment of the present invention.
2 is a schematic diagram of a sensor unit according to another embodiment of the present invention.
3 is a schematic diagram of a sensor unit according to another embodiment of the present invention.
Fig. 4 is a schematic view in a perspective direction of the sensor unit of Fig. 1;
5 is a block diagram of a control circuit of an object sensing apparatus using electric field change sensing according to an embodiment of the present invention.
6 is a schematic diagram for explaining a phase change of the power applied to the electrode strip of the electrode strip according to an embodiment of the present invention.
7 is a schematic cross-sectional view of an electrode strip part according to an embodiment of the present invention.
8 is a schematic diagram of electric field overlap between each electrode strip in the object sensing apparatus using electric field change sensing according to an embodiment of the present invention.
9 is a schematic diagram for explaining a sensing state of an electrode strip according to an object sensing apparatus using electric field change sensing according to an embodiment of the present invention.

The present invention may be embodied in various other forms without departing from its technical spirit or main characteristics. Accordingly, the embodiments of the present invention are merely illustrative in all respects and should not be construed as limiting.

The terms 1st, 2nd, etc. are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but another component may exist in between.

As used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprise" or "comprising", "have" and the like are intended to represent the presence of elements or combinations thereof described in the specification, and the possibility that other elements or features may be present or added. It is not precluded.

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

1 is a schematic diagram of a sensor unit according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a sensor unit according to another embodiment of the present invention, and FIG. 3 is a sensor unit according to another embodiment of the present invention A schematic diagram, FIG. 4 is a schematic diagram in a perspective direction of the sensor unit of FIG. 1 , FIG. 5 is a configuration diagram of a control circuit of an object detection device using electric field change detection according to an embodiment of the present invention, and FIG. 7 is an embodiment of the present invention It is a cross-sectional schematic diagram of the electrode strip part according to

The object detection apparatus using electric field change detection of this embodiment includes a sensor unit 110 , a sensing unit 100 , and a control unit 200 , and sets an object 500 close to the front side of the sensor sensing surface SA 2 . It is configured to be sensed through the above electrode strip portions 110a, 110b, and 110c, and provides an object detection function having directivity in a specific direction (the front side direction of the sensor sensing surface SA). As an example, although the embodiment of FIG. 1 includes a total of nine electrode strip parts, in the description of the embodiment of the present invention including FIG. 1 for convenience of explanation, only the three electrode strip parts 110a, 110b, and 110c are denoted by reference numerals. and the symbols for the remaining electrode strip parts are omitted.

In this embodiment, the 'object' may be a person or thing that requires approach detection for safety purposes (eg, collision prevention) or for other purposes (eg, power control according to proximity recognition, etc.).

The sensor unit 110 has a structure in which a plurality of electrode strip parts 110a, 110b, and 110c are disposed along one sensor sensing surface SA, and an object that approaches the front side of the sensor sensing surface SA. 500 is configured to be sensed through two or more electrode strip portions 110a, 110b, and 110c. The number of the electrode strip portions 110a, 110b, and 110c is not limited, and for example, 3 to 9 may be provided. For example, the sensor sensing surface SA may be a flat surface or a curved surface having a gentle curvature.

The electrode strip portions 110a, 110b, and 110c include an electrode strip S formed in a closed loop shape, and the electric field formed by the electrode strip S is changed according to the proximity of the object 500. The capacitance values of the strip portions 110a, 110b, and 110c vary.

For example, when a (+) voltage is applied to the electrode strip portions 110a, 110b, and 110c, an electric field is generated between the electrode strip portions 110a, 110b, and 110c and the ground side (eg, the ground electrode, the earth).

As the object 500 approaches the electrode strip S, a change occurs in the electric field between the electrode strip portions 110a, 110b and 110c and the ground side, and electric charges in the object are transferred to the electrode strip portions 110a, 110b, A polarization phenomenon occurs in which (-) charges move toward 110c) and (+) charges move to the opposite side, and the electrostatic capacity of the electrode strip portions 110a, 110b, and 110c increases due to the polarization.

As the object 500 moves away from the electrode strip S, a change occurs in the electric field between the electrode strip portions 110a, 110b, and 110c and the ground side, and the polarization becomes weaker and the electrode strip portions 110a, 110b, and 110c. capacitance is reduced.

The object sensing device of the present embodiment uses the electric field change detection and the capacitance change accordingly.

Referring to FIG. 7 , one electrode strip 110a is essentially an electrode strip constituting one closed loop, and for convenience of description, the electrode strip 110a in one direction and the electrode strip 110a in the other direction based on the branching point SP' can be viewed separately.

Referring to FIGS. 7 and 6 , one electrode strip 110a can be divided into an electrode strip 110a in one direction and an electrode strip 110a′ in the other direction based on the branching point SP. For example, a closed loop is a square shape. In the case of , the electrode strip 110a in one direction and the electrode strip 110a' in the other direction are installed in the body part 110'' so as to be disposed while maintaining a preset lateral distance d, and in another example, the closed loop is circular. In the case of , the electrode strip 110a in one direction and the electrode strip 110a' in the other direction may be installed in the body portion 110'' to have a preset diameter d of a circle. As an example, the body portion 110 ″ may provide a body portion for coupling in which each body portion is provided corresponding to one electrode strip portion and combines them in the form of one sensor unit, as another example, a plurality of electrodes One body portion for coupling the strip portion in the arrangement state of FIGS. 1 to 3 may be provided. Unexplained reference numeral 110''' is a power distribution line.

The cross-sectional widths of the branched electrode strips 110a and 110a' are preferably formed to have the same impedance, respectively.

The electrode strips 110a and 110b may be made of, for example, a strip-shaped conductive material.

The preset lateral distance d is a distance that allows electric fields formed by the branched electrode strips 110a and 110a' to overlap each other.

The lateral spacing d may be appropriately adjusted according to the cross-sectional width of the branched electrode strips 110a and 110a'.

Due to the arrangement of the electrode strips and the phase difference to be described later, it is possible to obtain an effect of preventing a detection error due to a dead point compared to the case of a single wide strip, and due to the overlap of the electric field between the electrode strips in a branched state, It is possible to obtain the effect of providing an increased object proximity sensing distance due to the

The body portion 110'' has a gap that enables the formation of an electric field between the electrode strips 110a, 110b, and 110c and another conductor installed to face the electrode strips 110a, 110b, and 110c. may be provided, and serves as a frame of the sensor strip unit 110 .

The body portion 110'' may be formed of a synthetic resin material or a synthetic rubber material having predetermined strength and elasticity while having dielectric properties.

The sensor unit 110 is arranged such that the plurality of electrode strip portions 110a , 110b , and 110c having the same closed loop shape have a preset arrangement shape along one sensor sensing surface SA.

For example, as illustrated in FIGS. 1 and 4 , the plurality of electrode strip portions 110a , 110b and 110c included in the sensor unit 110 have the same closed loop size, respectively, and the preset arrangement form is a grid It may be in the form of a mold arrangement. Symbol a indicates a power application point.

As another example, as illustrated in FIG. 2 , the plurality of electrode strip portions 110a and 110b included in the sensor unit 110 each have the same closed loop size, and the preset arrangement form is one electrode strip portion. A plurality of other electrode strip portions 110b may be disposed around the 110a.

As another example, as illustrated in FIG. 3 , the plurality of electrode strip portions 110a , 110b , 110c , 110d and 110e included in the sensor unit 110 have different closed loop sizes, respectively, and one electrode strip Another electrode strip portion 110a, 110b, 110c, and 110d having a larger size with the portion 110e as the center may have an expanded configuration surrounding the portion 110e.

As illustrated in FIGS. 4 and 7 , the sensor unit 110 includes first electrode parts 110a, 110b, and 110c formed by disposing closed loops of the electrode strip parts 110a, 110b, and 110c, and the The first electrode portions 110a, 110b, and 110c are disposed to face each other and maintain a preset longitudinal distance c, and the opposite area covering the closed loops of the electrode strip portions 110a, 110b, and 110c is formed. and a second electrode part 110' installed to have it.

The first electrode parts 110a, 110b, and 110c form a (+) electrode, the second electrode part 110' is configured to form a ground or (-) electrode, and the first electrode part 110a , 110b, 110c) and an electric field for capacitance sensing is formed based on the electric field formed by the second electrode unit 110'.

The first electrode parts 110a and 110b and the second electrode part 110' may be formed of a conductive material such as a metal plate or a metal braid in a plate shape similar to a strip.

The plurality of electrode strip portions 110a, 110b, and 110c include two or more electrode strip portions 110a, 110b, and 110c having different phases of power.

Referring to Figure 1, the sensor unit 110 of this embodiment is a power supply line is branched to supply power from one power application point (a) to each of the electrode strip parts (110a, 110b, 110c), the power supply The length from the application point (a) to the power connection points (b1, b2, b3, ... bn) of each of the electrode strip parts (110a, 110b, 110c) is formed to have a mutual difference.

Since a difference in length occurs from the power application point (a) to the power connection points (b1, b2, b3, ... bn) of each electrode strip part (110a, 110b, 110c), each electrode strip part ( Between each electrode strip (110a, 110b, 110c) for the AC power applied to the sensor unit 110 by the RF oscillator 152 to be described later at the position of the branching point (SP) of 110a, 110b, 110c (110a, 110b, 110c) there is a phase difference.

The sensing unit 100 senses a change in the capacitance value of the electrode strip units 110a, 110b, and 110c according to a change in an electric field according to the proximity of an object.

The control unit 200 determines whether the object 500 is close by using an electrical signal according to a change in the capacitance value sensed by the sensing unit 100 .

The control unit 200 uses the capacitance values of the electrode strip portions 110a, 110b, and 110c measured in a state where the object 500 is not approached as a reference value, and the electrode strip portions 110a and 110b measured in the sensing mode. , 110c) is compared with the reference value to determine whether the object 500 is close. For example, the reference value may be measured and set in the form of a continuous value according to a preset period. The shape of a continuous value may be understood as a shape of a measurement value pattern.

The sensing mode means a mode set by the controller 200 to monitor whether the object 500 approaches, for example, the electrode strip parts 110a, 110b, 110c are operated by an actuator (eg, a motor). If it is assumed that the device is installed to prevent a safety accident due to collision or jamming of the object 500, a state in which the proximity of an object should be monitored to prevent a safety accident as a state in which the device is operating can be viewed as a detection mode. have.

When the object 500 approaches the sensor unit 110, a change occurs in the capacitance value formed by the first electrode parts 110a, 110b, 110c and the second electrode part 110'. Whether or not there is a change or its degree is sensed by the sensing unit 100 , and the control unit 200 detects the presence (approach) of the object 500 .

For example, the sensing unit 100 is connected to the sensor unit 110 and is connected to an RF oscillator whose oscillation frequency varies according to a change in the capacitance value of the sensor unit 110 , and the RF oscillator, , when the oscillation frequency of the RF oscillator is changed from the reference oscillation frequency according to the change in the capacitance value, a phase locked loop portion for controlling the RF oscillator to maintain the reference oscillation frequency. .

The control unit 200 is connected to the phase-locked loop unit and uses an electrical signal received from the phase-locked loop unit while the RF oscillator 152 controls the phase-locked loop unit to maintain a reference oscillation frequency. It comprises an MCU (micro controller unit; microcontroller unit) for determining whether the object 500 is close.

For example, referring to FIG. 5 , the second electrode part 110 ′ may form a ground state and the first electrode parts 110a , 110b , and 110c may be connected to the RF oscillator 152 .

In this embodiment, when a change in the capacitance of the sensor unit 110 occurs, an RF oscillator 152 for outputting a signal corresponding thereto and a capacitance sensing circuit including a phase locked loop unit are configured.

The capacitance sensing circuit is electrically connected to the MCU 250 and receives the output signal of the phase locked loop unit to determine whether the object 500 is close.

The control circuit of this embodiment will be described in more detail with reference to FIG. 5 .

For example, the RF oscillator 152 is preferably a Voltage Controlled Oscillator (VCO) capable of adjusting a frequency with a voltage, but the type of the RF oscillator 152 is not limited in the present invention.

The phase locked loop unit serves to keep the oscillation frequency of the RF oscillator 152 constant. That is, the phase locked loop unit is a frequency control circuit configured to automatically correct a difference between a set reference oscillation frequency and an oscillation frequency according to a change in the capacitance value of the sensor unit 110 .

That is, when the oscillation frequency of the RF oscillator 152 is changed from the reference oscillation frequency according to a change in the capacitance value, a circuit for controlling the RF oscillator 152 to always maintain the set reference oscillation frequency is the PLL.

The MCU 250 is connected to the phase locked loop unit to determine whether the object 500 is close to the object 500 based on a change in the oscillation frequency value of the RF oscillator 152 according to the change in the capacitance value. A reference oscillation frequency value of the RF oscillator 152 may be preset in the MCU 250 .

That is, when the capacitance value in the sensor unit 110 changes according to the proximity of the object 500, the oscillation frequency of the RF oscillator 152 changes from the reference oscillation frequency, and accordingly, in the phase-locked loop unit, the RF By controlling the voltage applied to the oscillator 152 to cancel the change in frequency, the oscillation frequency of the RF oscillator 152 is maintained constant. In the description of the present embodiment, a voltage at which the oscillation frequency of the RF oscillator 152 is set to maintain the reference oscillation frequency may be understood as a 'frequency setting voltage', and the oscillation frequency of the RF oscillator 152 changes from the reference oscillation frequency. The voltage applied to offset this can be understood as a 'frequency adjustment voltage'.

The frequency adjustment voltage value for controlling the oscillation frequency of the RF oscillator 152 is transmitted to the MCU 250 through an analog-to-digital converter (ADC) 251 in the form of an electrical signal, and the input electrical signal value is transmitted to the MCU ( If the allowable range of the electrical signal reference value preset in 250 is exceeded, it is determined that the object 500 approaches the sensor unit 110 .

Meanwhile, the MCU 250 is connected to an input unit 162 for control setting input/output and a power supply unit 163 for supplying power through a transmission line 253 , and an actuator module 170 and an alarm unit through an interface 264 . (180) is connected. For example, the interface 264 may include a variety of interfaces usable to the actuator module 170 and the alarm unit 180 including a known RS232 interface.

The MCU 250 detects an electrical signal (eg, a voltage value for frequency adjustment) output from the phase-locked loop unit, determines whether the object 500 is close or not, and generates an alarm signal notifying the detection of the object.

In addition, the input unit 162 connected to the MCU 250 is a part to which a user inputs a manipulation signal or a reset signal, and the power unit 163 includes the sensor unit 110 , the RF oscillator 152 , and the phase lock. As a function of supplying driving power to the loop unit and the MCU 250 , for example, DC power of DC 5V is provided.

The phase locked loop part of this embodiment will be described in more detail.

The phase locked loop unit of this embodiment includes a variable capacitance diode 141 having one end connected to the RF oscillator 152 , a phase locked loop IC 142 , a phase locked loop IC 142 , and a variable capacitance diode 141 . It includes a signal line 143 for frequency adjustment to be connected, and a capacitor 144 for frequency detection. Unexplained reference numeral 147 is an oscillator that provides a reference frequency to the phase locked loop IC 142 . In the present embodiment, the frequency detection capacitor 144 is used as a frequency sensing means for continuously sensing the oscillation frequency of the RF oscillator 152 . Of course, if the oscillation frequency of the RF oscillator 152 can be transferred to the phase locked loop IC 142, other well-known elements may be used as the frequency sensing means in addition to the illustrated capacitor 144 for frequency detection.

The variable capacitance diode 141 has a property of having a variable capacitance according to an applied voltage, and one end is connected to the frequency adjustment signal line 143 while the other end is grounded.

In a state where the oscillation frequency of the RF oscillator 152 maintains the reference oscillation frequency without proximity of the object 500, the frequency setting voltage corresponding to the reference oscillation frequency maintains the set value.

When the oscillation frequency of the RF oscillator 152 is about to deviate from the reference oscillation frequency due to the proximity of the object 500, a voltage for frequency adjustment is applied to the variable capacitance diode 141 or the voltage for frequency adjustment being applied is appropriately changed. Let the reference oscillation frequency be maintained.

To apply or change the voltage for frequency adjustment, it will be understood that, in addition to the voltage for frequency setting that was initially applied to the variable capacitance diode 141 to oscillate the reference oscillation frequency, the voltage for frequency adjustment is further applied under the condition of + or -. can From another point of view, it may be understood as a viewpoint of applying a frequency adjustment voltage for adaptively maintaining a reference oscillation frequency instead of a frequency setting voltage.

The RF oscillator 152 and the phase locked loop IC 142 are connected in parallel with respect to the variable capacitance diode 141 .

The phase locked loop IC 142 is controlled by the MCU 250 , and continuously detects the oscillation frequency of the RF oscillator 152 through the frequency detection capacitor 144 , and oscillates the RF oscillator 152 . When the frequency is changed from the reference oscillation frequency, the frequency adjustment voltage is supplied to the variable capacitance diode 141 through the frequency adjustment signal line 143 to control the oscillation frequency of the RF oscillator 152 to maintain the reference oscillation frequency. .

In the control, the electrical signal received by the MCU 250 from the phase-locked loop unit uses a frequency adjustment voltage output from the phase-locked loop IC 142 to supply the variable capacitance diode 141 . .

Preferably, a loop filter 145 for filtering unnecessary signals from an input voltage to the RF oscillator 152 may be installed on the signal line 143 for frequency adjustment.

With this configuration, for example, the oscillation frequency of the RF oscillator 152 can be constantly maintained by using the phase-locked loop IC 142 of the phase-locked loop unit in the object detection mode.

That is, when the object 500 is positioned around the sensor unit 110 and the capacitance of the sensor unit 110 changes, the oscillation frequency of the RF oscillator 152 changes. At this time, the phase-locked loop IC 142 is variable The oscillation frequency is maintained constant by appropriately changing the voltage for frequency adjustment applied to the capacitive diode 141 .

In this embodiment, the MCU 250 controls the driving of the phase-locked loop IC 142 of the phase-locked loop unit, while changing the frequency adjustment voltage through the frequency adjustment signal line 143 connected to the loop filter 145 . detect Then, the MCU 250 determines whether the object 500 is close based on the sensed voltage value.

For example, when it is determined by the MCU 250 that the object 500 approaches the sensor unit 110 , the MCU 250 controls the alarm unit 180 to generate an alarm signal notifying the detection of the object.

For example, when the electrode strip portions 110a, 110b, and 110c of the present embodiment are installed at the corners of the hatchback door of the vehicle and the door of the vehicle is an automatic door, the MCU 250 determines whether an object is detected. You can control whether the actuator module that automatically opens or closes the .

The MCU 250 may store the change in voltage for frequency adjustment as a reference signal, and may be implemented as a hardware configuration for implementing a corresponding algorithm or by loading software for a function such as determining whether the object 500 is present. In addition, two or more MCUs may execute distributed processing to share control functions.

6 is a schematic diagram for explaining a phase change of the power applied to the electrode strip of the electrode strip portion according to an embodiment of the present invention.

The electrode strip portion 110a is formed by combining both ends of the electrode strips 110a and 110a' branched to both sides from the branching point SP to form a single closed loop, and from the branching point SP in one direction A1 ), the phase of the power applied to the branched electrode strip 110a and the phase of the power applied to the electrode strip 110a ′ branched from the branching point SP in the other direction A2 in the longitudinal direction of the electrode strip In a state configured to have different phases at the positions PP1 or PP2 , the capacitance value is changed by the approach of the object 500 .

For example, the power applied from the branch point SP in the direction A1 of one side of the closed loop of the electrode strip 110a is applied in the same phase as in FIG. 6B , and the branch point SP ) and has a zero (zero) phase at the point PP1.

Power applied from the branch point SP to the other side direction A2 of the closed loop of the electrode strip 110a' is applied in the same phase as in FIG. 6(c), and the branch point SP From , it has a non-zero phase at the point PP2 that arrives through the closed-loop path.

By the way, the PP1 position and the PP2 position are only grasped from the viewpoints of different directions with respect to the branch point (SP), and represent essentially the same position. The phase of the power applied to (A1) and the phase of the power applied to the other direction (A2) of the closed loop are in a state having the same effect as having different phases.

In this way, when the electrode strip part 110a, 110a' has the same effect as when power having two different phases is applied at an arbitrary position (eg, PP1 position or PP2 position), the electrode strip part 110a, 110a'), it is possible to obtain the effect of preventing a detection error due to a dead point.

The dead point prevention effect will be described with reference to FIG. 9 .

The RF oscillator 152 is connected to the sensor unit 110 so that an AC power waveform according to an oscillation frequency can be applied to the sensor unit 110 .

For example, when the frequency oscillated by the RF oscillator 152 is 1 GHz, dead points appear at intervals of about 15 cm on an electrode strip formed within a length of about 2 m.

For example, Fig. 9 (a) illustrates the position of the dead point of any one electrode strip, and Fig. 9 (b) is the position of the dead point of another electrode strip that has a phase difference from the electrode strip. to exemplify

In the object approach sensing device according to the present embodiment, due to the phase difference between the electrode strips 110a and 110a' in the branched state, the dead points are formed at different positions for each electrode strips 110a and 110a' in the branched state. Accordingly, since there is always an electrode strip in which a dead point is not formed at any one position of the electrode strips 110a and 110a', when an object approaches the electrode strips 110a and 110a', it is detected at a specific position due to the dead point. No object detection error problem.

On the other hand, in the sensor unit 110 of this embodiment, the phase of the applied power is configured to have different phases at one position (PP1 or PP2) in the longitudinal direction of the electrode strips 110a and 110a', a separate phase change Without using devices (e.g., capacitors, inductors, etc.) for This has the advantage of preventing it.

8 is a schematic diagram of electric field overlap between each electrode strip in the object sensing apparatus using electric field change sensing according to an embodiment of the present invention.

The change in the capacitance value is detected in a state in which electric fields generated by each of the two or more electrode strip portions 110a, 110b, and 110c overlap each other.

As described above, the sensor unit 110 of this embodiment is from the power application point (a) to the power connection points (b1, b2, b3, ... bn) of each of the electrode strip parts (110a, 110b, 110c). Since the mutual length difference occurs, each for the AC power applied to the sensor unit 110 by the RF oscillator 152 at the position of the branching point SP of each of the electrode strip parts 110a, 110b, 110c. There is a phase difference between the electrode strips 110a, 110b, and 110c.

When a phase difference occurs between each of the electrode strip portions 110a, 110b, and 110c, as shown in FIG. 8, an electric field overlap is made between each of the electrode strip portions 110a, 110b, and 110c, and the sensor unit ( A sensing distance capable of detecting the approach of the object 500 through 110) is increased.

8 (a) to (c) briefly show the change in the range of the electric field according to the period of the oscillation frequency, and the maximum distance (range) of the overlapping electric field is in each of the electrode strip portions 110a, 110b, and 110c. It can be seen that the distance (range) of each electric field increased by the

For example, in FIG. 8A , the electric field a1 formed by the electrode strip portion 110a on the left side is the largest, the electric field b1 formed by the electrode strip portion 110b in the middle, and the electrode strip portion 110c on the right side are The magnitude of the electric field c1 formed decreases in the order, and the combined electric field a1+b1+c1 shows an electric field that is further increased in the overlapping portion while including each electric field.

The difference in the magnitude of the electric field can be understood through the fact that, when the waveform applied to each of the electrode strip portions 110a, 110b, and 110c is a sinusoidal wave, a difference in amplitude occurs according to a phase difference even in the same waveform.

8 is a schematic diagram prepared to help understanding of the overlap of electric fields generated by each of the electrode strip portions 110a, 110b, and 110c, and the expression of each electric field is shown in each of the electrode strip portions 110a, 110b, and 110c. It does not limit the shape of the electric field generated by

Although the present invention has been described with reference to the accompanying drawings in terms of preferred embodiments, it will be apparent to those skilled in the art that many various and obvious modifications can be made therefrom without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed by the appended claims to cover many such modifications.

100: sensing unit
110: sensor unit
110a, 110b, 110c: electrode strip part (first electrode part)
110': second electrode part
200: control unit
500: object

Claims (13)

A plurality of electrode strip portions including an electrode strip formed in a closed loop shape and having a variable capacitance value according to an electric field change according to the proximity of an object are disposed along one sensor sensing surface, and an object adjacent to the front side of the sensor sensing surface is disposed. a sensor unit configured to sense through two or more electrode strip portions;
a sensing unit for sensing a change in the capacitance value of the electrode strip unit; and
a control unit that determines whether an object is close by using an electrical signal according to a change in the capacitance value sensed by the sensing unit;
The electrode strip portion combines both ends of the electrode strips branched to both sides from the branching point to form one closed loop, and based on the setting of the length of the electrode strip constituting the closed loop and the oscillation frequency condition defining the AC power waveform, The phase of the power applied to the electrode strip branched in one direction from the branch point and the phase of the power applied to the electrode strip branched in the other direction from the branch point are configured to have different phases at one position in the longitudinal direction of the electrode strip An object detection device using electric field change detection, characterized in that.
According to claim 1,
An object sensing apparatus using electric field change sensing, characterized in that the plurality of electrode strip units having the same closed-loop shape are arranged to have a preset arrangement shape along one sensor sensing surface.
3. The method of claim 2,
An object sensing apparatus using electric field change sensing, characterized in that each of the plurality of electrode strip units has the same closed loop size.
4. The method of claim 3,
The object detection apparatus using electric field change detection, characterized in that the preset arrangement form is a grid arrangement form.
4. The method of claim 3,
The preset arrangement form is an object sensing apparatus using electric field change sensing, characterized in that a plurality of other electrode strip units are arranged around one electrode strip unit.
3. The method of claim 2,
An object using electric field change sensing, characterized in that the plurality of electrode strip portions each have different closed loop sizes, and that another electrode strip portion having a larger size as the center of one electrode strip portion has an expanded arrangement shape surrounding the periphery. detection device.
According to claim 1,
The plurality of the electrode strip portion is an object sensing device using electric field change detection, characterized in that it includes two or more electrode strip portions having different phases of power.
delete According to claim 1,
The sensor unit is
The first electrode part formed by disposing the closed loop of the electrode strip part and the first electrode part are arranged to maintain a predetermined longitudinal distance in a state to face each other and have an opposed area covering the closed loop of the electrode strip part An object detection device using electric field change detection, characterized in that it includes a second electrode part installed.
10. The method of claim 9,
The object sensing apparatus using electric field change sensing, characterized in that the first electrode part forms a (+) electrode, and the second electrode part is configured to form a ground or (-) electrode.
According to claim 1,
The control unit is
The capacitance value of the electrode strip measured in a state where no object is in proximity is used as a reference value,
An object sensing apparatus using electric field change sensing, characterized in that it is determined whether an object is close by comparing the capacitance value of the electrode strip part measured in the sensing mode with the reference value.
According to claim 1,
The object sensing apparatus using electric field change sensing, characterized in that the detection of the change in the capacitance value is performed in a state in which the electric fields generated by each of the two or more electrode strip portions overlap each other.
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