KR20200086935A - Apparatus of recognition hand gesture using mirror padding and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and a method for recognizing a hand gesture using a mirror padding. According to the present invention, the method for recognizing a hand gesture by using a hand gesture recognition apparatus includes the steps of: acquiring micro Doppler data corresponding to a user′s hand gesture using a continuous wave radar; generating padding data by expanding a part of the acquired micro Doppler data in a mirror padding scheme; apply the padding data to a trigger algorithm to calculate a dipper value, comparing the calculated dipper value with a reference trigger value, and rearranging the padding data so that the largest dipper value among dipper values greater than the reference trigger value is located in the center; extracting valid data equal to the size of the acquired micro-Doppler data when the padding data is rearranged; generating spectrogram data by applying the valid data to short term Fourier transform (STFT); learning by applying the spectrogram data to a convolutional neural network (CNN); and recognizing a hand gesture corresponding to the spectrogram data.

Description

A hand motion recognition device using mirror padding and a method therefor{APPARATUS OF RECOGNITION HAND GESTURE USING MIRROR PADDING AND METHOD THEREOF}

The present invention relates to an apparatus for recognizing a hand gesture using mirror padding and a method thereof, and more specifically, to generate accurate spectrogram data using a mirror padding technique, and using mirror padding applied to a convolutional neural network (CNN). Hand gesture recognition apparatus and method.

The sensor technology has been used to acquire the user's information or surrounding information to enable the user to perform a desired operation. Recently, as IoT technology has emerged, research to enable a smart device to be controlled using a sensor has been actively conducted.

In addition, by using CW radar, a Doppler signal can be measured according to the speed of an object, and a spectrogram can be used to analyze the motion of an object by analyzing the measured signal.

Spectogram is an image that allows you to see the frequency change over time by performing STFT (Short Term Fourier Transform). Researches to recognize motion by applying this to deep learning technology are actively being conducted.

In order to go through this process, a lot of training data is needed in deep learning.

The technology that is the background of the present invention is disclosed in Korean Patent Publication No. 10-1900414 (announced on September 20, 2018).

Technical problem to be achieved by the present invention relates to an apparatus and method for recognizing a hand motion using mirror padding that generates accurate spectrogram data using a mirror padding technique and applies it to a convolutional neural network (CNN).

According to an embodiment of the present invention for achieving such a technical problem, in the hand motion recognition method using the hand motion recognition device, obtaining a micro Doppler data corresponding to the user's hand motion using a continuous wave radar, the obtained A step of generating a padding data by extending a part of the micro Doppler data in a mirror padding method, applying the padding data to a trigger algorithm to calculate a dipper value, comparing the calculated dipper value with a reference trigger value, and the reference trigger Rearranging the padding data so that the largest dipper value among values larger than the value is located at the center, and when the padding data is rearranged, extracting valid data by the size of the acquired micro-Doppler data, and extracting the valid data. Applying STFT (SHORT TERM FOURIER TRANSFORM) to generate spectrogram data, applying the spectrogram data to a convolutional neural network (CNN), and learning, and micro Doppler data for hand movement to be recognized And converting the input micro Doppler data into spectrogram data, and recognizing the hand motion by applying the spectrogram data to the CNN.

The step of generating the padding data may be extended by adding a portion of data of the front portion and a portion of the rear portion of the micro Doppler data obtained for a predetermined period of time to a mirror padding portion, respectively, to the front and rear portions of the micro Doppler data.

The some data may have a sample size corresponding to 23% to 25% of the micro Doppler data acquired for a certain period of time.

The trigger algorithm may calculate and calculate a dipper value by converting a difference between a value in the current windowing region and a value in the next windowing region into an absolute value, as in the following equation.

Here, k is a constant for the size of the windowing, window[k] is the micro Doppler data value in the kth windowing region, differ[k] is the kth dipper value, and a is the calculated real value. , b is the calculated imaginary value.

The trigger value may be calculated as the sum of the dipper values as in the following equation.

Here, n represents the size of the windowing region.

The reference trigger value may correspond to an average of trigger values extracted by applying the micro Doppler data obtained when it is recognized that there is no movement of the hand motion to the trigger algorithm.

In the step of extracting the valid data, only 1/2 of the sample size of the micro Doppler data is left in the front and rear portions of the largest dipper value, and the remaining padding data value is removed to extract the valid data.

According to another embodiment of the present invention, in a hand motion recognition apparatus using mirror padding, a data acquisition unit that acquires micro Doppler data corresponding to a user's hand motion using a continuous wave radar, and a part of the obtained micro Doppler data Data generation unit that expands the mirror padding method to generate padding data, applies the padding data to a trigger algorithm to calculate a dipper value, compares the calculated dipper value with a reference trigger value, and is greater than the reference trigger value The padding data is rearranged based on the largest value among the dipper values, and when the padding data is rearranged, valid data is extracted as much as the size of the acquired micro Doppler data, and the valid data is stored in a STRT (SHORT TERM FOURIER TRANSFORM). Control unit for generating spectrogram data by applying, learning by applying the spectrogram data to a convolutional neural network (CNN), and when the micro Doppler data for the hand motion to be recognized is input, the input micro Doppler data It includes a recognition unit that converts spectrogram data and applies the spectrogram data to a CNN to recognize hand gestures.

As described above, according to the present invention, the discontinuity between the raw data and the padding data can be prevented by using the mirror padding technique, and hand motion can be efficiently recognized by increasing the quality training data required for deep learning. .

1 is a block diagram showing the configuration of a hand gesture recognition apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a hand gesture recognition method using a hand gesture recognition device according to an embodiment of the present invention.
3 is a view for explaining step S210 of FIG. 2.
4 is a view for explaining step S220 of FIG. 2.
5 is a view for explaining step S240 of FIG.
6 is a view for explaining step S250 of FIG. 2.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part “includes” a certain component, this means that other components may be further included rather than excluding other components unless otherwise specified.

Then, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice.

1 is a block diagram showing the configuration of a hand gesture recognition apparatus according to an embodiment of the present invention.

As illustrated in FIG. 1, the hand motion recognition device 100 includes a data acquisition unit 100, a data generation unit 120, a control unit 130, and a recognition unit 140.

First, the data acquisition unit 100 acquires micro Doppler data corresponding to a user's hand motion in real time using a continuous wave radar.

Here, the micro Doppler (Micro Doppler) data is a wave such as sound or light is changed data according to the movement state of its own movement or observer in the 300MHz ~ 30GHz band, in the present invention is measured using a radar. .

Next, the data generating unit 120 expands a part of the micro Doppler data in a mirror padding method to generate padding data.

Here, the mirror padding method is a method of copying data in a selected area and arranging it in front of or behind existing data.

That is, the data generation unit 120 mirrors the partial data of the front portion and the partial data of the rear portion of the micro-Doppler data acquired for a predetermined time, respectively, and expands them by adding them to the front and rear portions of the micro-Doppler data, respectively.

Here, some data is set to a sample size corresponding to 23% to 25% of the micro-Doppler data acquired for a certain period of time, more preferably to a sample size corresponding to 24%.

Next, the controller 130 applies padding data to the trigger algorithm to calculate a dipper value, compares the calculated dipper value with a reference trigger value, and focuses the padding around the largest value among the dipper values greater than the reference trigger value. Relocate the data.

In addition, when the padding data is rearranged, the control unit 130 extracts valid data as much as the size of the acquired micro Doppler data, and generates spectrogram data by applying the valid data to a STRT (SHORT TERM FOURIER TRANSFORM).

Here, the reference trigger value is an average of the trigger values extracted by applying the micro Doppler data obtained when the hand motion is not recognized to the trigger algorithm.

Next, the recognition unit 140 applies spectrogram data to CNN (Convolutional Neural Network) to learn and recognizes hand movements corresponding to the spectrogram data.

Here, CNN (Convolutional Neural Network) is a type of deep neural network (Deep Neural Network), and may be trained using a reverse transmission algorithm. In the present invention, it is used to recognize hand motion corresponding to spectrogram data.

Hereinafter, a method of recognizing a hand motion using a hand motion recognition device will be described with reference to FIGS. 2 to 6.

2 is a flowchart illustrating a hand gesture recognition method using a hand gesture recognition device according to an embodiment of the present invention.

First, the data acquisition unit 110 acquires micro Doppler data corresponding to a user's hand operation using a continuous wave radar (S210).

3 is a view for explaining step S210 of FIG. 2.

As shown in FIG. 3, the data acquisition unit 110 acquires micro Doppler data, which is data changed by a user's hand motion, in real time.

Next, the data generation unit 120 expands a part of the obtained micro Doppler data in a mirror padding method to generate padding data (S220).

4 is a view for explaining step S220 of FIG. 2.

As shown in FIG. 4, the data generating unit 120 mirrors padding of some data in the front part and some data in the rear part of the micro Doppler data acquired for a predetermined period of time to add padding data to the front and rear parts of the micro Doppler data, respectively. To create.

At this time, some of the data padded by the mirror is data corresponding to 23% to 25% of the micro Doppler data acquired for a certain period of time.

For example, if the sample size of the acquired micro Doppler data is 2400, and some data that is mirror padded is 24% of the micro Doppler data, the data generator 120 acquires 576 in the front and rear portions of the acquired micro Doppler data, respectively. Add the data for the dog.

Then, the controller 130 applies padding data to the trigger algorithm to calculate the dipper value, compares the calculated dipper value with the reference trigger value, and places the largest dipper value among the dipper values greater than the reference trigger value in the center. The padding data is rearranged (S230).

At this time, the controller 130 calculates a dipper value as shown in Equation 1 below.

Here, k is a constant for the size of the windowing, window[k] is the micro Doppler data value in the kth windowing region, differ[k] is the kth dipper value, and a is the calculated real value. , b is the calculated imaginary value.

In other words, the dipper value means a value calculated by calculating a difference between the size of the micro-Doppler data in the k-th windowing region and the size of the micro-Doppler data in the k+1th windowing region.

At this time, as shown in Equation 1, the controller 130 calculates the sum of the square of the real part value and the square of the imaginary part value in order to reduce the computation amount.

Then, the controller 130 calculates a trigger value by applying the calculated dipper value to Equation 2 below.

Here, n represents the size of the windowing region.

That is, as shown in Equation 2, the trigger value of each windowing region corresponds to the sum of dipper values existing in the windowing region.

In addition, the reference trigger value refers to a value corresponding to the average of the extracted trigger values by applying the acquired micro Doppler data to the trigger algorithm when it is recognized that there is no hand movement.

Next, the controller 130 extracts the rearranged padding data as valid data as much as the size of the previously acquired micro Doppler data (S240).

5 is a view for explaining step S240 of FIG.

As shown in FIG. 5, the valid data extracted by the control unit 130 is shown.

Here, the control unit 130 extracts valid data by leaving only 1/2 of the sample size of the micro Doppler data at the front and rear of the largest dipper value and removing the remaining padding data value.

That is, as shown in FIG. 5, the control unit 130 extracts valid data by placing it at a time corresponding to 1 second so that the largest dipper value is displayed in the center.

Next, the valid data extracted from the control unit 130 is applied to a STRT (SHORT TERM FOURIER TRANSFORM) to generate spectrogram data (S250).

6 is a view for explaining step S250 of FIG. 2.

As shown in FIG. 6, the controller 120 generates spectrogram data and displays the color by changing the color according to the size of the generated spentogram.

That is, the larger the value of the data of the spectogram is, the redr the color, and the smaller the blue.

Then, the control unit 130 applies the spectrogram data generated from step S250 to the convolutional neural network (CNN) to learn (S260).

At this time, the controller 130 learns the hand motions corresponding to the spectrogram data and the spectrogram data together.

Next, when the micro Doppler data for the hand motion to be recognized is input, the recognition unit 140 converts the input micro Doppler data into spectrogram data, and applies the spectrogram data to the CNN to perform the hand motion. Recognize (S270).

That is, the recognition unit 140 recognizes a hand motion using a deep learning technique.

As described above, according to the exemplary embodiment of the present invention, a discontinuity point between raw data and padding data may be prevented by using a mirror padding technique, and quality learning data required for deep learning learning may be increased.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely examples, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: hand gesture recognition device, 110: data acquisition unit,
120: data generation unit, 130: control unit,
140: recognition unit

Claims (14)

In the hand gesture recognition method using the hand gesture recognition device,
Obtaining micro Doppler data corresponding to a user's hand motion using a continuous wave radar,
Generating a padding data by expanding a part of the obtained micro-Doppler data in a mirror padding method;
The padding data is applied to a trigger algorithm to calculate a dipper value, compares the calculated dipper value with a reference trigger value, and sets the padding data so that the largest dipper value among the reference trigger values is located in the center. Relocating,
When the padding data is rearranged, extracting valid data as much as the size of the obtained micro Doppler data,
Generating spectrogram data by applying the effective data to a STFT (SHORT TERM FOURIER TRANSFORM),
Learning by applying the spectrogram data to a convolutional neural network (CNN), and
When the micro Doppler data for the hand motion to be recognized is input, converting the input micro Doppler data into spectrogram data, and applying the spectrogram data to the CNN to recognize the hand gesture. Recognition method. According to claim 1,
The step of generating the padding data,
A method of recognizing a hand motion by partially padding the data of the front part and the part of the back part of the micro-Doppler data acquired for a predetermined time, and extending them by adding them to the front and back parts of the micro-Doppler data respectively. According to claim 2,
The some data is hand motion recognition method having a sample size corresponding to 23% to 25% of the micro-Doppler data acquired for a certain period of time. According to claim 1,
The trigger algorithm,
As shown in the following equation, the hand motion recognition method for calculating and calculating a dipper value by converting the difference between the current windowing area value and the next windowing area value to an absolute value:

Here, k is a constant for the size of the windowing, window[k] is the micro Doppler data value in the kth windowing region, differ[k] is the kth dipper value, and a is the calculated real value. , b is the calculated imaginary value. According to claim 4,
The trigger value is,
A hand motion recognition method calculated as the sum of the dipper values as in the following equation:

Here, n represents the size of the windowing region. The method of claim 5,
The reference trigger value is,
A hand motion recognition method corresponding to an average of trigger values extracted by applying the micro-Doppler data obtained when the hand motion is recognized as no motion. According to claim 1,
In the step of extracting the effective data,
A hand motion recognition method of extracting the valid data by leaving only 1/2 of the sample size of the micro Doppler data at the front and rear of the largest dipper value, and removing the remaining padding data value. In the hand motion recognition device using the mirror padding,
Data acquisition unit for acquiring micro Doppler data corresponding to a user's hand motion using a continuous wave radar,
A data generating unit for generating a padding data by extending a part of the obtained micro-Doppler data in a mirror padding method,
The padding data is applied to a trigger algorithm to calculate a dipper value, compares the calculated dipper value with a reference trigger value, and rearranges the padding data based on the largest value among the dipper values larger than the reference trigger value, When the padding data is rearranged, a control unit for extracting valid data as much as the size of the acquired micro-Doppler data, and applying the valid data to STFT (SHORT TERM FOURIER TRANSFORM) to generate spectrogram data,
When the spectrogram data is learned by applying it to a convolutional neural network (CNN), and when micro-doppler data for a hand motion to be recognized is input, the input micro-doppler data is converted into spectrogram data, A hand motion recognition device including a recognition unit that recognizes hand motion by applying gram data to the CNN. The method of claim 8,
The data generation unit,
A hand motion recognition device that extends a partial pad data of a portion of the micro Doppler data and a portion data of a rear portion of the micro Doppler data acquired for a predetermined period of time to be added to the front and rear portions of the micro Doppler data. The method of claim 9,
The part of the data is a hand motion recognition device having a sample size corresponding to 23% to 25% of the micro Doppler data acquired for a predetermined time. The method of claim 8,
The trigger algorithm,
A hand motion recognition device that calculates and calculates a dipper value by converting a difference between a current windowing area value and a value in the next windowing area to an absolute value, as shown in the following equation:

Here, k is a constant for the size of the windowing, window[k] is the micro Doppler data value in the kth windowing region, differ[k] is the kth dipper value, and a is the calculated real value. , b is the calculated imaginary value. The method of claim 11,
The trigger value is,
A hand motion recognition device calculated as the sum of the dipper values as in the following equation:

Here, n represents the size of the windowing region. The method of claim 12,
The reference trigger value is,
A hand motion recognition device corresponding to an average of trigger values extracted by applying the micro Doppler data obtained when it is recognized that there is no movement of the hand motion to the trigger algorithm. The method of claim 8,
The control unit,
The hand motion recognition device extracts the valid data by removing only the remaining half of the sample size of the micro-Doppler data in the front and rear parts of the largest dipper value, and removing the remaining padding data value.

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