KR20220077637A - Method for cancelling sun light noise and optical sensing device using the same - Google Patents

Abstract

A solar noise removal method and an optical sensing device using the same are provided. The optical sensing device performs solar signal measurement in a period during which optical signal transmission is not performed, converts the measured solar signal into solar data, which is a digital signal, and stores the converted solar data. Thereafter, the optical signal is transmitted and a signal received according to the optical signal transmission is measured. At this time, the stored solar data is converted into an analog signal to restore the solar signal. Then, the optical reception signal received by optical signal transmission is acquired based on the total reception signal, which is the measured signal, and the restored solar signal.

Description

Method for canceling sun light noise and optical sensing device using the same}

The present invention relates to noise removal, and more particularly, to a method for removing solar noise during optical sensing and an optical sensing device using the same.

Measurement or detection using light or similar physical means has been performed in various industrial fields. An optical sensor using light can be applied to measurement of displacement, distance, or thickness. For example, a method using a light travel time, a method using a light phase difference, or a method using an interference phenomenon are applied to measure a distance by light. .

In measurement using light, a transmitter for outputting an optical signal to a measurement target and a receiver for receiving an optical signal reflected from the measurement target are used.

When a solar signal is received when receiving an optical signal from various types of optical sensors, such as a transceiver integrated with the transmitter and receiver, the optical signal and the solar signal are combined to accurately distinguish the signal. This is not done.

Accordingly, expensive hardware such as an optical filter and an additional photodiode is required to distinguish the solar signal from the optical sensor.

As a related prior art, there is "LiDAR apparatus, LiDAR signal processing apparatus and method" described in Korean Patent No. 2086026.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of removing solar noise by accurately distinguishing a solar signal from an optical signal to be received during optical sensing, and an optical sensing device using the same.

According to an embodiment, a method for removing sunlight noise in an optical sensing device is provided. The method includes the steps of: performing, by the optical sensing device, a solar signal measurement in a period in which optical signal transmission is not performed; converting, by the optical sensing device, the measured sunlight signal into sunlight data, which is a digital signal, and storing the converted sunlight signal; performing, by the optical sensing device, optical signal transmission; measuring, by the optical sensing device, a signal received according to the optical signal transmission; converting, by the optical sensing device, the stored sunlight data into an analog signal to restore a sunlight signal; and obtaining, by the optical sensing device, the optical reception signal received by the optical signal transmission based on the total reception signal that is the measured signal and the restored solar signal.

In an embodiment, the measuring of the solar signal may include measuring the solar signal in a state in which the optical sensing device does not output a transmission trigger signal to the transmitter.

In an embodiment, the performing of the optical signal transmission includes transmitting the optical signal in a state in which the optical sensing device outputs a transmission trigger signal to the transmitter, and restoring the solar signal includes the transmission trigger The solar signal may be restored during a period in which the signal is output.

In an embodiment, the obtaining of the optical reception signal received by the optical signal transmission may include differentially amplifying the entire reception signal and the restored solar signal to obtain the optical reception signal.

According to another embodiment, an optical sensing device is provided. The optical sensing device includes: a transmitter configured to transmit an optical signal; a receiving unit configured to perform optical signal reception; and a control unit configured to control the optical signal transmission and the optical signal reception, wherein the control unit performs a solar signal measurement in a period in which optical signal transmission is not performed, and converts the measured solar signal to a digital signal. Converts and stores the solar data, performs optical signal transmission to measure a signal received according to the optical signal transmission, converts the stored solar data into an analog signal to restore a solar signal, and the measured signal It may be configured to obtain an optical reception signal received by the optical signal transmission based on the total reception signal and the restored solar signal.

In one embodiment, the control unit performs the measurement of the solar signal in a state in which the transmission trigger signal is not output to the transmitter, and transmits the optical signal in a state in which the optical sensing device outputs the transmission trigger signal to the transmitter And, it may be configured to restore the sunlight signal in the period in which the transmission trigger signal is output.

In an embodiment, the control unit may include: a control unit configured to control an optical signal transmission operation of the transmitter and an optical signal reception operation of the receiver, and perform solar signal measurement; a first signal converter configured to convert a signal output from the receiver into a digital signal and transmit it to the control unit when measuring the solar signal; a second signal converter configured to convert and output the signal provided from the control unit into an analog signal; and a differential amplifier configured to differentially amplify and output the signal output from the receiver and the signal output from the second signal converter.

In one embodiment, the control unit stores the digital signal transmitted from the first signal conversion unit as solar data when measuring the solar signal, and converts the solar data into the second optical signal during the optical signal transmission operation of the transmitter. It may be configured to provide a signal conversion unit.

In one embodiment, the signal input to the first input terminal of the differential amplifier is a total received signal that is a signal output from the receiver, and the total received signal is a solar signal and an optical reception signal received by transmitting the optical signal. Including, the signal input to the second input terminal of the differential amplifier may be the restored solar signal.

According to an embodiment of the present invention, it is possible to effectively remove solar noise by accurately distinguishing a solar signal from a received optical signal without additional hardware configuration in the optical sensing device. In particular, accurate noise estimation is possible by pre-measuring a solar signal, ie, noise, in one optical sensing device while considering the occupancy time of the transmission trigger signal. In addition, when actually measuring an optical signal, as noise removal is performed on a received signal based on pre-measured noise, more accurate noise removal can be achieved.

By applying the method and apparatus according to an embodiment of the present invention, it is possible to extend the application to a transceiver integrated sensor other than an optical sensing device.

1 is a diagram showing the structure of an optical sensing device according to an embodiment of the present invention.
2 is an operation timing diagram of an optical sensing device according to an embodiment of the present invention.
3 is a diagram illustrating a detailed structure of a control unit of an optical sensing device according to an embodiment of the present invention.
4 is a flowchart of a solar noise removal method according to an embodiment of the present invention.
5 is a structural diagram illustrating a computing device for implementing a method for removing solar noise according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In this specification, expressions described in the singular may be construed in the singular or plural unless an explicit expression such as “a” or “single” is used.

In addition, terms including ordinal numbers such as first, second, etc. used in an embodiment of the present invention may be used to describe the constituent elements, but the constituent elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. 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.

Hereinafter, a solar noise removal method light and an optical sensing device using the same according to an embodiment of the present invention will be described with reference to the drawings.

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

1 , an optical sensor, that is, an optical sensing device 1 according to an embodiment of the present invention, includes a transmitter 11 for transmitting an optical signal, a receiver 12 for receiving an optical signal, and a transmitter 11 . and a control unit 13 for controlling the receiving unit 12 . The receiver 12 may be formed of a photodiode or the like.

The transmitter 11 transmits an optical signal to the measurement object, the receiver 12 receives the optical signal reflected from the measurement object, and the controller 13 performs measurement based on the received optical signal. In this case, the solar signal may be received through the receiver 12 . In this case, the solar signal is added to the signal output from the receiver 12 in addition to the optical signal from the measurement target. Therefore, as the measurement is made based on the signal output from the receiver 12 , that is, the signal to which the noise solar signal is added to the optical signal from the measurement target, accurate measurement is not made.

In an embodiment of the present invention, a signal transmitted by the transmitter 11 and then received by the receiver 12 is divided into a solar signal as follows.

라고 하고, 태양광 신호를

이라고 하며, 그리고 수신부(12)에서 출력되는 전체 수신 신호를

라고 한다. For convenience of explanation, a signal transmitted by the transmitting unit 11 in the optical sensing device 1 and then received by the receiving unit 12, that is, a light receiving signal by transmission

and the solar signal

, and the entire received signal output from the receiving unit 12 is

It is said

)와 송신에 의한 광 수신 신호(

)가 합쳐져서 수신부(12)에서 출력되는 신호는

가 된다. When the optical sensing device 1 receives the light signal, when the sunlight signal comes in, the sunlight signal (

) and the optical reception signal by transmission (

) is added and the signal output from the receiver 12 is

becomes

)와 복원된 태양광 신호(

)를 차동 증폭하여 송신에 의한 광 수신 신호(

)를 구분한다. 즉,

를 이용하여, 태양광 신호와 수신하고자 하는 광신호의 구분이 가능하도록 한다.In this way, considering that the sunlight signal is added to the total received signal and acts as noise, the embodiment of the present invention measures the sunlight signal, converts it to digital, and then restores it to an analog signal. For convenience of description, the restored analog signal is referred to as a restored sunlight signal. All received signal (

) and the restored solar signal (

) by differentially amplifying the optical reception signal (

) is separated. in other words,

By using , it is possible to distinguish the solar signal from the optical signal to be received.

2 is an operation timing diagram of an optical sensing device according to an embodiment of the present invention.

)와 태양광 신호(

)가 합쳐진 신호

이다. In the optical sensing device 1 according to the embodiment of the present invention, as shown in FIG. 2 , the transmitter 11 transmits an optical signal according to a transmission trigger signal (TX Trigger) from the controller 13 . Accordingly, the signal transmitted from the transmitter 11 and reflected by the measurement target is received by the receiver 12, and the signal output from the receiver 12 is transmitted as a light reception signal (

) and the solar signal (

) combined signal

to be.

)이다. In order to measure and restore the solar signal, in an embodiment of the present invention, the solar signal is measured in the absence of a transmission trigger signal (TX Trigger). In other words, in a state in which there is no transmission trigger signal (TX Trigger), that is, in a period in which the transmission trigger signal (TX Trigger) is not output from the control unit 13 , the control unit 13 receives the reception signal measured by the reception unit 12 . measure At this time, since the optical transmission operation by the transmitter 11 is not performed, the optical signal measured by the receiver 12 is the solar signal (

)to be.

) 중 송신에 의한 광 수신 신호(

)가 제거된 순수한 광신호(

)를 측정한다. 그리고, 측정된 태양광 신호(

)를 ADC(아날로그-디지털 변환)을 거쳐 디지털 신호로 변환하여 해당하는 디지털 값을 저장한다. 저장된 디지털 값을 설명의 편의상, 태양광 데이터라고 명명한다. In this way, in the period in which the transmit trigger signal (TX Trigger) is not output, the entire received signal (

) light reception signal by transmission (

) removed from the pure optical signal (

) is measured. And, the measured sunlight signal (

) is converted into a digital signal through ADC (analog-digital conversion) and the corresponding digital value is stored. The stored digital values are called solar data for convenience of explanation.

)를 실제 측정하고자 할 때, 저장된 태양광 데이터를 DAC(디지털-아날로그 변환)를 이용하여 아날로그 신호로 변환하여 태양광 신호를 복원한다. Thereafter, in a state in which the transmission trigger signal (TX Trigger) is present, that is, in the period in which the transmission trigger signal (TX Trigger) is output from the control unit 13, the optical reception signal (

), converts the stored solar data into an analog signal using DAC (digital-analog conversion) to restore the solar signal.

)와 복원된 태양광 신호(

)를 차동 증폭하여 송신에 의한 광 수신 신호(

)만을 출력한다. 이에 따라 태양광 노이즈가 제거된 수신 신호가 획득되며, 그 결과 광학 감지 장치를 이용한 정확한 측정이 이루어질 수 있다. After restoring the sunlight signal, the total reception signal (

) and the restored solar signal (

) by differentially amplifying the optical reception signal (

) is printed only. Accordingly, a received signal from which solar noise is removed is obtained, and as a result, accurate measurement using the optical sensing device can be performed.

On the other hand, in synchronization with the transmission trigger signal (TX Trigger) being output to the transmitter 11, the solar signal restoration based on the stored data may be performed immediately, or from the time the transmission trigger signal (TX Trigger) is output. In fact, after a set time in consideration of the time that the signal is reflected and received from the measurement target has elapsed, the solar signal restoration based on the stored data may be performed.

In addition, a transmission trigger signal (TX Trigger) may be directly output to the transmitter 11 in synchronization with solar signal measurement being performed and solar data stored.

On the other hand, in the embodiment of the present invention, the controller 13 of the optical sensing device 1 controls the transmitter 11 and the receiver 12 to synchronize the transmission and reception, so that the transmission signal of the optical sensing device 1 is transmitted.

To this end, the control unit 13 of the optical sensing device 1 may be configured as follows.

3 is a diagram illustrating a detailed structure of a control unit of an optical sensing device according to an embodiment of the present invention.

In the optical sensing device 1 including the transmitter 11, the receiver 12, and the controller 13, the controller 13 is a micro controller unit (MCU) 131, ADC ( and an analog to digital converter) 132 , a digital to analog converter (DAC) 133 , and a differential amplifier 134 .

The MCU 131 is configured to control the optical signal transmission operation of the transmitter 11 and the optical signal reception operation of the receiver 12 , and is also configured to perform a solar removal operation. The MCU 131 outputs a transmission trigger signal (TX Trigger) to the transmitter 11 during an optical signal transmission operation, and does not output a transmission trigger signal (TX Trigger) to the transmitter 11 during a sunlight removal operation. The MCU 131 is configured to store sunlight data obtained through the receiving unit 12 during the sunlight removal operation. This MCU 131 may also be called a control unit.

The ADC 132 is configured to convert a signal output from the receiver 12 into a digital signal and transmit it to the MCU 131 . In particular, the ADC 132 is configured to convert the sunlight signal output from the receiver 12 into a digital signal, that is, sunlight data, and transmit it to the MCU 131 during the sunlight removal operation.

)가 복원되어 차동 증폭기(134)로 제공된다. The DAC 133 is configured to convert the signal provided from the MCU 131 into an analog signal and output it, and in particular, convert the solar data provided from the MCU 131 into an analog signal and transmit it to the differential amplifier 134 . do. By this DAC 133, the sunlight signal (

) is restored and provided to the differential amplifier 134 .

)와 DAC(133)로부터 출력되는 신호인 복원된 태양광 신호(

)를 차동 증폭하여 송신에 의한 광 수신 신호(

)만을 출력한다. The differential amplifier 134 differentially amplifies the signal output from the receiver 12 and the signal output from the DAC 133 and outputs it, and is particularly configured to output a measurement optical signal. In particular, the differential amplifier 134 receives the entire received signal (

) and the restored sunlight signal (

) by differentially amplifying the optical reception signal (

) is printed only.

On the other hand, in an embodiment of the present invention, the control unit 13 of the optical sensing device 1 controls the transmitting unit 11 and the receiving unit 12 to synchronize transmission and reception to receive the transmission signal of the corresponding optical sensing device 1 . can do.

Based on the optical sensing device 1 having such a structure, the following solar noise removal method may be performed.

4 is a flowchart of a solar noise removal method according to an embodiment of the present invention.

In an embodiment of the present invention, the optical sensing device 1 performs a solar signal measurement before performing optical signal transmission, as shown in FIG. 4 ( S100 ). In this case, the MCU 131 does not output the transmission trigger signal (TX Trigger) to the transmitter 11 . Accordingly, the receiver 12 receives only the sunlight signal.

Next, the signal according to the measurement of the sunlight signal is converted into a digital signal and stored as sunlight data (S110). When measuring the sunlight signal, the signal output from the receiver 12 is converted into a digital signal by the ADC 132 . The MCU 131 stores the measured digital signal as solar data.

Thereafter, the optical signal transmission operation is performed to measure the measurement target and measure the received signal (S120, S130). In this case, the MCU 131 outputs a transmission trigger signal (TX Trigger) to the transmission unit 11 . Accordingly, the transmitting unit 11 transmits an optical signal to the measurement target, and the receiving unit 12 receives a signal reflected from the measurement target (light reception signal by transmission), and at this time, the solar signal is also received by the receiving unit 12 is received The entire received signal, which is the signal received by the receiving unit 12 , is output to the differential amplifier 134 .

Then, the sunlight signal is restored based on the stored sunlight data when measuring the sunlight signal (S140). The MCU 131 outputs the stored sunlight data to the DAC 133 , and the DAC 133 converts the sunlight data into an analog signal and outputs it to the differential amplifier 134 . Accordingly, the entire received signal and the restored sunlight signal are input to the differential amplifier 134 .

)와 -단자로 입력되는 복원된 태양광 신호(

)를 차동 증폭하여 송신에 의한 광 수신 신호(

)만을 측정 신호로 출력한다. Thereafter, by differentially amplifying the total received signal and the restored solar signal measured according to the optical signal transmission operation, only the optical reception signal by transmission is obtained ( S150 ). The differential amplifier 134 is, for example, the entire received signal input to the + terminal (

) and the restored sunlight signal input to the - terminal (

) by differentially amplifying the optical reception signal (

) is output as a measurement signal.

According to this embodiment of the present invention, since the solar signal is measured during a period in which the optical signal transmission operation is not performed, it is possible to more accurately estimate the solar signal, that is, noise. In particular, if noise is estimated using a separate illuminance sensor without considering the occupancy time of the transmit trigger signal, a sensor that measures noise (illuminance sensor) and a sensor that measures the original signal combined with the noise (receiver of the optical sensing device) ), it is difficult to accurately estimate the noise, that is, the sunlight signal. However, according to an embodiment of the present invention, one optical sensing device pre-measures a solar signal, that is, noise while considering the occupancy time of the transmission trigger signal, and when actually measuring the optical signal, it is received based on the pre-measured noise. As noise is removed from the signal, more accurate noise estimation can be made compared to the case of measuring noise using different sensors.

In addition, when noise is estimated in a state in which other signals having different magnitudes or frequencies are added to the same signal, accurate estimation, such as different noise estimates, is not made. However, in an embodiment of the present invention, it is possible to remove noise from the entire received signal by acquiring separately measured noise through restoration, rather than separating the noise from the entire received signal.

5 is a structural diagram illustrating a computing device for implementing a method for removing solar noise according to an embodiment of the present invention.

As illustrated in FIG. 5 , the method for removing solar noise according to an embodiment of the present invention may be implemented using the computing device 100 .

The computing device 100 may include at least one of a processor 110 , a memory 120 , an input interface device 130 , an output interface device 140 , and a storage device 150 . Each of the components may be connected by a bus 160 to communicate with each other. In addition, each of the components may be connected through an individual interface or a separate bus centering on the processor 110 instead of the common bus 160 .

The processor 110 may be implemented in various types such as an application processor (AP), a central processing unit (CPU), a graphic processing unit (GPU), and the like, and executes a command stored in the memory 120 or the storage device 150 . It may be any semiconductor device that does The processor 110 may execute a program command stored in at least one of the memory 120 and the storage device 150 . The processor 110 may be configured to implement the functions and methods described based on FIGS. 1 to 4 above.

The memory 120 and the storage device 150 may include various types of volatile or non-volatile storage media. For example, the memory may include a read-only memory (ROM) 121 and a random access memory (RAM) 122 . In an embodiment of the present invention, the memory 120 may be located inside or outside the processor 110 , and the memory 120 may be connected to the processor 110 through various known means.

The input interface device 130 is configured to provide data to the processor 110 , and the output interface device 140 is configured to output data from the processor 110 . For example, the input interface device 130 may process a signal received by the receiver of the optical sensing device into a signal that the processor 110 can process and transmit it to the processor 110 .

The output interface device 140 may be configured to output data provided from the processor 110 . For example, the output interface device 140 may output a control signal provided from the processor 110 to a transmitter and/or a receiver of the optical sensing device so that a transmission/reception operation of the optical sensing device is performed. The input interface device 130 and the output interface device 140 may be collectively referred to as an interface device.

Meanwhile, the computing device 100 may include a network interface device (not shown). In this case, the network interface device may be configured to receive data input through the network and transmit it to the processor 110 , or to transmit the processing result of the processor 110 to another device through the network. For example, the network interface device may be configured to transmit a sensor signal measured by the optical sensing device output from the processor 110 to another device.

At least a part of the method for removing solar noise according to an embodiment of the present invention may be implemented as a program or software executed in the computing device 100, and the program or software may be stored in a computer-readable medium.

In addition, at least a part of the method for removing solar noise according to an embodiment of the present invention may be implemented as hardware capable of being electrically connected to the computing device 100 .

The embodiment of the present invention is not implemented only through the apparatus and/or method described above, and may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention, a recording medium in which the program is recorded, etc. Also, such an implementation can be easily implemented by those skilled in the art to which the present invention pertains from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (9)

A method for removing solar noise in an optical sensing device, comprising:
performing, by the optical sensing device, a solar signal measurement in a period in which optical signal transmission is not performed;
converting, by the optical sensing device, the measured sunlight signal into sunlight data, which is a digital signal, and storing the converted sunlight signal;
performing, by the optical sensing device, optical signal transmission;
measuring, by the optical sensing device, a signal received according to the optical signal transmission;
converting, by the optical sensing device, the stored sunlight data into an analog signal to restore a sunlight signal; and
obtaining, by the optical sensing device, an optical reception signal received by the optical signal transmission based on the total reception signal that is the measured signal and the restored solar signal
How to include. According to claim 1,
The step of measuring the solar signal is
The method of performing the solar signal measurement in a state in which the optical sensing device does not output a transmission trigger signal to the transmitter. According to claim 1,
The transmitting of the optical signal includes transmitting the optical signal in a state in which the optical sensing device outputs a transmission trigger signal to the transmitter,
The step of restoring the sunlight signal is restoring the sunlight signal in a period in which the transmission trigger signal is output. According to claim 1,
The obtaining of the optical reception signal received by the optical signal transmission includes differentially amplifying the entire reception signal and the restored solar signal to obtain the optical reception signal. a transmitter configured to perform optical signal transmission;
a receiving unit configured to perform optical signal reception; and
a control unit configured to control the optical signal transmission and the optical signal reception
including,
the control unit
In a period in which optical signal transmission is not performed, solar signal measurement is performed, the measured solar signal is converted into solar data, which is a digital signal, and stored, and optical signal transmission is performed and received according to the optical signal transmission Measures a signal to be used, converts the stored solar data into an analog signal to restore a solar signal, and is received by transmitting the optical signal based on the total received signal that is the measured signal and the restored solar signal An optical sensing device, configured to obtain a light received signal. 6. The method of claim 5,
The control unit performs the measurement of the solar signal in a state in which the transmission trigger signal is not output to the transmitter, and performs the optical signal transmission in a state in which the optical sensing device outputs the transmission trigger signal to the transmitter, the transmission trigger and recover the solar signal in a period in which the signal is output. 6. The method of claim 5,
the control unit
a control unit configured to control an optical signal transmission operation of the transmitter and an optical signal reception operation of the receiver, and perform solar signal measurement;
a first signal converter configured to convert a signal output from the receiver into a digital signal and transmit it to the control unit when measuring the solar signal;
a second signal converter configured to convert and output the signal provided from the control unit into an analog signal; and
a differential amplifier configured to differentially amplify and output a signal output from the receiver and a signal output from the second signal converter
comprising, an optical sensing device. 8. The method of claim 7,
The control unit stores the digital signal transmitted from the first signal converter as sunlight data when measuring the sunlight signal, and provides the sunlight data to the second signal converter during the optical signal transmission operation of the transmitter. configured, an optical sensing device. 9. The method of claim 8,
The signal input to the first input terminal of the differential amplifier is a total received signal that is a signal output from the receiver, and the total received signal includes a solar signal and a light received signal received by transmitting the optical signal, and the The signal input to the second input terminal of the differential amplifier is the restored sunlight signal.

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