Development and Efficacy of Laser Bird Repeller with PTZ Camera
and Caffe Framework
SUBONG PYON1,*, JONGSU SO1, JUNHYOK PAK1, JINZU SO1, SUNIL KIM1
1School of metallurgical Engineering, Kim Chaek University of Technology, Pyongyang 999093,
DPR OF KOREA
Abstract: - Many researches have been conducted to prevent bird damage not only on farms, orchards, fish
farms and airports but also on industrial and urban environments. In this paper, we describe the construction
and effectiveness of a laser bird repellent system that scaring it away as soon as the bird settles in a large area.
The object classification technique using the Caffe framework detects the bird in real-time captured images of a
PTZ camera over a large area, and when the bird sinks into the area, the PTZ camera combining the laser beam
generator is steered to the target bird, thereby scaring the bird away by attacking it by the laser beam.
Key-Words: - Bird repellent, laser beam, Caffe framework, PTZ camera, Image Classification, Object Detection
Received: March 9, 2024. Revised: August 7, 2024. Accepted: September 11, 2024. Published: October 17, 2024.
1. Introduction
Bird damage not only farms, orchards, fish farms,
airports [1], [2], but also industrial and urban
environments [3], [4]. Common methods for
preventing bird damage include the use of
scarecrows [5], [6], the use of chemicals [6], and the
use of nets [7]. In recent years, studies that use
ultrasound [11], [12], studies that use sound waves
[9], [10], and studies that use laser [13] have also
been carried out to repel bird.
Most birds are known to have a very sensitive
response to light. [14]
Therefore, bird repellent using laser beams has
been widely used in both manual and automatic
modes as a method of chase bird by influencing the
vision of bird in a wide area using the characteristics
of lasers. A manual laser bird repeller is a device
that chases birds by manually controlling the laser
beam collection point of the repeller to the bird
position when a person is monitoring a certain area
and finding the bird.
An automatic laser bird repeller is a system that
allows birds around a track to fly in surprise by
repeatedly moving the laser beam spot along a
predetermined trajectory in a certain area. [14]
Because the automatic laser bird repeller repeats
the operation of illuminating the laser beam along a
certain trajectory, with or without the presence of a
bird, it is judged difficult to extrude it from the
invading area immediately after the bird has
invaded.
This may be one factor that prevents the
automatic laser repeller from having a high bird
repelling effect.
In addition, the long operation time of the laser
beam generator and the control device can have a
strong effect on the compliance degree of the bird
and the lifetime of the devices.
This makes it possible to realize that a bird
repelling approach is necessary to minimize the
operation time of the laser beam generator and the
control device and to scare the bird away that have
invaded the area as quickly as possible.
Recently, methods to automatically track and
classify birds using deep learning [15],[16],17]
together with methods to track birds’ movements
using cameras[18],[19],[20] have been introduced.
The objective of this study was to construct an
intelligent system and measure effect of it to target
and expel the invaded bird with a laser beam by
running a camera controlling device and a laser
beam generator instantly when the bird invaded and
landed within an area that requires bird repelling.
First, the target area is monitored in real time by
a PTZ camera and the intrusion (sinking) position of
the bird object is determined using the object
classification technique by the Caffe framework.
The control device of the PTZ camera coupled
with the laser beam generator is controlled to the
bird position and the bird is expelled from the target
area by outputting the laser beam.
Such a system can increase the bird repellent
performance and efficiency by minimizing the
operation time of the laser beam generator and the
control device of camera, thereby increasing the
service life of the system and reducing the
compliance of the bird, as well as immediately
scaring a wide range of birds.
Section 1 summarizes the architecture and
structure of the system.
Section 2 presents the devices that make up the
system and their combinations, and Section 3
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DOI: 10.37394/232024.2024.4.3
Subong Pyon, Jongsu So, Junhyok Pak,
Jinzu So, Sunil Kim
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summarizes the bird classification using the Caffe
framework.
Section 4 presents the architecture of the
software that comprises the system and Section 5
presents the experimental results.
2. Formation of system
The system's configuration consists of five
components (Fig.1).
Fig 1: Construction of System
2.1 Image entry unit
Capturing and displaying the image in real time on
the PTZ camera.
The Image entry unit consists of a camera, a
network hub, a network line, a control computer,
and image capture and display software.
Image capture and display use an SDK that is
supported by the camera manufacturer.
In addition, due to the different types of cameras,
the obtained images are color-transformed in real
time into RGB images and sent to the following
image processing unit.
2.2 Image processing unit
Processing the acquired real-time image to obtain
the location of the bird.
The image processing unit consists of a control
computer and image processing software.
In the captured real-time image, motion detection is
performed to obtain all motion objects and to
classify each object into a bird or not.
If the moving object is judged to be a bird, the
PTZ position of the bird becomes the input
parameter of the following control panel movement
unit.
2.3 Control panel movement unit
Places the focus center of the camera in the center of
the target bird.
The focus of the camera is placed at the center of
the bird by controlling the camera by software to the
PTZ position of the bird.
And according to the mode of attack, the camera
control panel is further controlled.
The camera and the laser beam generator are
integrated, and the focus center of the camera and
the laser scanning center are aligned.
2.4 Laser beam control unit
If a bird is detected in the image processing unit,
laser attack according to the mode of attack is
performed with the movement of the camera control
panel.
The laser beam control unit consists of a laser
beam control panel, a laser beam control program,
and a laser beam generator.
When the laser attack signal and the attack mode are
transmitted to the laser beam controller, the
controller initiates the attack by switching on the
power of the connected laser beam generator and
stops the generation of the laser beam by switching
off the power of the laser beam generator when the
attack termination signal is transmitted.
Depending on the mode of attack, the attack
effect can be enhanced by selectively transmitting or
simultaneously transmitting the attack signal to a
laser beam generator of blue (420 nm), green (532
nm), or red (650 nm).
2.5 User interface
It is an interface program that enables RS-485
communication with the computer and the bird
detector and network communication with the
camera as user interface of the intelligent laser bird
repellent system, and to manually and automatically
browse the recording data, view the statistical data,
and set various settings together with the control of
the laser beam attack and camera control unit.
3. Devices
The system includes a PTZ camera, a laser beam
controller, a laser beam generator, a coupling sleeve,
and a control computer for real-time image
acquisition of the bird monitoring area.
3.1 PTZ camera
HIKVISION (type number DS-2DC6120IY-A,
Firmware V5.3.22 build 181120, resolution 1280 x
720) was used as the main device for the Image
entry unit.
The camera is outdoor, capable of PTZ control
through a computer network, supports the ONVIF
protocol, and has a 3D Position (3D Position)
function.
3.2 Laser beam controller
It is a device for controlling the start and stop of
operation of each laser beam generator.
ARM32-bit CortexTM-M3 CPU Core was used as a
central processing chip to ensure good performance.
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The circuit of this device consists of the main
circuit, the power circuit, the communication circuit,
and the gain control circuit (Fig.2).
Fig 2: Configuration of laser beam controller
The input power is AC 220 V and is stabilized by
DC 12 V and 5 V in the supply circuit to supply the
main circuit and the peripheral circuit.
The resulting signal, which consists of an ARM
chip and its driving circuits, operates on this chip to
control the laser beams through the amplifier circuit.
The communication circuit part used RS485 or
Ethernet communication mode as a circuit for
transmitting and receiving data between the chip
and the computer and between the chip and the
camera.
3.3 Laser beam generators
The laser beam generator (1000 mW Class-III
Laser) had 1000 mW power of red, green and blue
and was fixed to the coupling sleeve and coupled to
the inside of the PTZ camera.
At this time, the overnight lighting LEDs inside
the PTZ camera were first separated from the fixture
and the coupling sleeve was fixed there.
3.4 Connecting bush
The laser beam generator is fixed to the camera and
is a device for matching the focus of the camera
with the laser scanning center.
A laser beam generator of three colors, red, blue
and green, was installed in two each.
The laser beam generator and the connecting bush
for mounting on the camera are shown in Fig. 3.
After all mounting, the bolts of the connecting
bush were adjusted so that the focus of the laser
beams was matched to the viewing image focus of
the camera.
Fig 3: Laser beam generator and connecting
bush
3.5 A computer for control
In the computer for control, a bird repellent program
is executed, such as processing images captured in
real time through a local area network (Ethernet)
from an IP camera, classifying birds using the Caffe
model, and transmitting attack start and attack finish
signals to the laser beam controller using RS-485.
The operating system is Windows 7-x64, the
computer processor is Intel Core (TM) i5-3340 M
CPU @ 2.70 GHz, and RAM 4.00 GB.
4. Moving Object Detection and Bird
Classification
4.1 Moving Object Detection
First, we detected moving objects in the surveillance
area image captured in real time from the camera.
Motion detection was used with the Background
Modeling Detector (Aforge.Net Framework 2.2.5
version).
The difference threshold (DifferenceThreshold) of
the detector was set to standard value 10 and the
background update frame value
(FramesPerBackgroundUpdate) was set to standard
value 5.
4.2 Train data gathering
First, training data were collected for bird
classification using Caffe.
The training data were constructed by storing the
bird candidates obtained by motion detection
described above as files in real time and classifying
them as bird and no-bird.
When selecting bird images, flying birds were not
selected as bird candidates, and only sedentary birds
were selected as learning objects.
The bird images collected for training were
31,000 (23,000 magpies, 8,000 crows), and the no-
bird images were 30,500 color BMP files, which
were stored in different folders (bird images in birds
folder and other images in others folder).
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After deep learning, the data to be used for testing
are stored in the Test folder (3,000 bird images,
3,000 no-bird images).
4.3 Bird Training
For deep learning, preprocessing of the training data
was performed first.
For preprocessing, gray-scale and image size
conversion are used, and image size conversion is
set to 50*41. After pre-processing, deep learning is
performed, when the Mobile Network 2.0 version
(mobilenet_v2) is used.
The mobile network version 2.0 is composed of four
overlay layers (Convolution Layer), four selection
layers (Pooling Layer), and two fully connected
layers (Fully Connected Layer) with a gray-tone
image of size 198 x 161 as input to the neural
network and the position of five reference points as
output.
In Solver.prototxt, change only the maximum
number of iterations (max_iter) to 500,000 times,
and in Train.prototxt, change the input layer to
ImageData.
layer {
name: "data"
type: "ImageData"
top: "data"
top: "label"
include {
phase: TRAIN
}
transform_param{
scale: 0.0078125 # 128
mirror: true
}
image_data_param{
source: "./prototxt/trainval2.txt"
#batch_size: 32
batch_size: 16
shuffle: 1
is_color: false
new_height: 41
new_width: 50
}
}
Since our system is a Binary Classification (Binary
Classification) problem that perform laser attack if it
is a bird and does not perform laser attack if it is not
a bird, the number of the last output network
(num_output) is set to 2.
Deep learning is done by re-learning (finetuning)
the default model of Mobile Network version 2.0.
After the training was completed, the test data were
tested to obtain a classification accuracy of 95.2%.
4.4 Bird Classification
We used the newly constructed network model to
perform bird classification in real time.
The resulting images of motion detection from the
real-time input image from the camera were fed into
the input of the bird classification library using the
newly constructed network model, and the outputted
classification accuracy was judged to be bird if it
was more than 0.5, laser attack was performed, or
not.
5. Software
The software was written for the 64-bit operating
system using the C-Sharp development language of
Microsoft Visual Studio 2015.
Interface for camera SDK. HCNetSdkCom, SDK
of HIKVISION camera, is used. In the
CHCNetSDK.cs file, the CHCNetSDK class that
maps all internal functions and structures of the
SDK library in C-Sharp language is defined and
used. The use of all functions of the camera, such as
camera connection, setting, real-time image
collection and display, and camera control, is
conducted through this face-to-face.
Interface for image process library. A library
including image processing modules necessary for
the system was prepared and used. The function to
convert the YUV12 image acquired by the camera
to RGB image (GIP_CovertToRGB function),
initialization of Caffe library (GIP_CaffeInit) and
bird classification (GIP_CaffeClassify) functions
have been implemented, and real-time image
processing is performed through this interface.
Function of capturing and display from camera.
The image of the PTZ camera is captured in real
time and displayed by dividing the screen according
to the number of cameras.
Function of control panel manual control and
camera setting. The camera SDK is used to
manually control the PTZ movement of the camera
and includes the camera setting function, such as the
movement speed and the basic positioning.
Function of auto and manual attack. In the
manual attack, if any position in the real-time
captured display image is selected as a rectangle, the
camera moves the PTZ to that position, allowing the
laser beam generation to start operation as well.
At the end of the attack, the laser beam is returned
to the default position, and the laser beam
generation is also stopped.
In an automatic attack, if a bird classification is
performed in real time and judged to be a bird, i.e.,
the bird classification result has a similarity value of
0.5 or more, then PTZ moves the camera to the
scene position, initiates the generation of the laser
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Subong Pyon, Jongsu So, Junhyok Pak,
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beam, returns to the default position after the attack
according to the attack mode, and stops the
generation of the laser beam.
Function of attack history view. The ability to
browse video data recorded on a hard disk during an
attack on a bird by recording time.
Function of statistics view. It is a function of
browsing the statistics of attack on birds on a bar
chart.
The start and end dates were selected so that the
number of bird invasions and the number of attack
successes during the period were displayed as
statistics.
Function of system configuration. The system
setup consists of the network control functions such
as IP address and user and password setting of the
cameras and COM communication setup functions
such as COM port and communication band, video
storage location setting, and laser attack mode
setting functions.
6. Results
6.1 Test condition
For the experiment, a square airspace area of 200m
x 200m in Moran Hill, Pyongyang, where magpies
and crows flew a lot, was selected, and the area was
divided in half and a total of two our bird repellers
were installed at 20m height of pine trees in a
position to monitor each area.
There are 28 pine trees and 520 m2 of pond in the
area of the open area, while the rest are lawn areas.
Depending on the distance from the camera (50
m, 100 m, and 200 m), a red flag was placed at both
ends of the zone to make the distance visible on the
screen.
The experiment was conducted from October
2019 to August 2023 throughout the spring to
winter, during which 31,308 birds (21,142 magpies,
8046 crows, and 120 others) were observed to
invade the area.
In addition, bird infestation was observed from 5
to 19 a.m. and almost no other time.
And the experiment was carried out by changing the
laser color from blue, red and green every day.
6.2 Classification result
For the results of deep learning, an evaluation of the
bird classification performance was performed.
. For 10308 magpies and crows, positive (False
Positive Rate) and negative (False Negative Rate)
sampling rates were calculated.
Here, the positive sample rate is the rate
estimated by fitting a moving object with no
magpies or crows, and the negative sample rate is
the rate estimated by not being magpies or crows for
a moving object.
In our study, FPR = 3.8% and FNR = 1.2% were
calculated.
6.3 Effective rate by Laser color and attack
distance
Experiments were carried out to evaluate the
response of laser color and distance from 5 a.m. to
19 p.m. when the attack mode was changed to red,
green and blue in the laser control unit according to
the laser color and distance, with bird infestations
such as magpies and crows being the most frequent.
If a bird subjected to laser attack evades the
invasive area within 3 s, it is considered to have an
attack effect, or it is considered to have no attack
effect if not.
For the total number of birds measured, the
percentage of the number of birds that had an attack
effect was evaluated as responsive.
The distance-dependent flags were estimated to
be 50 m distance when the invading bird were near
40-75 m, 100 m distance when near 75 m to 150 m,
and 200 m distance from 150 m to 200 m.
The total measured data were calculated by
arithmetic averaging because the magpies and crows
were similar in responsiveness and the illuminance
varied with time over the seasons.
The figures below show the reactivity of the
algae at distances of 50 m, 100 m and 200 m,
respectively (Fig. 4, Fig. 5, Fig. 6).
Fig 4: Response effect rate according to the laser
color (50m)
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Fig 5: Response effect rate according to the laser
color (100m)
Fig 6: Response effect rate according to the laser
color (200m)
Graph shows that the reactivity with Laser Color
depends on the illuminance.
It can be seen that the response of the bird is the
lowest, especially at noon, when the illuminance is
greatest, and the response is large in the morning
and evening when the illuminance is relatively
small.
It can also be seen that the green laser has a
relatively large bird repelling effect and a low
reactivity with distance.
6.4 Shirking Time of bird
We measured the time it took for a bird to start to
run out of surprise from the time it was perceived by
the camera to enter the survey area.
The magpies or crows flew in astonishment as
soon as a circular beam of light appeared, as the
laser beam descended into the field of the intrusion
area.
With the ranging accuracy of the laser beam
generator and the slight movement of the bird, the
effect is different, but the evacuation time is
estimated to be about 0.5 s to 3 s.
This was attributed to the inability of the bird to
perform its desired behavior in the descending
position.
7. Conclusion
Considering the bird classification performance and
reactivity, the bird repelling rate of the system is
estimated to be 93% in the morning and evening and
7% in the day time within the distance 200 m region
when using a 1000 mW green laser.
And the prevention area of one bird repeller is
estimated at about 2000 m2 in daylight and 25 000
m2 in morning and evening.
The operating time of the laser beam generator
and the camera control panel is about 5 to 7 seconds
per cycle starting the attack and returning to its
position, and the operating time of the day is equal
to the operating time per cycle multiplied by the
number of birds detected.
It can be seen that the service life is much longer
and the compliance of the algae is as small as that of
the scanning laser algae detector.
Intelligent laser bird repeller using PTZ cameras
and Caffe frameworks have high bird repellent
effect due to their long service life, large area of
protection, and prompt repelling of bird infestations,
and can be widely used in farms, aquaculture farms,
orchards, airports, etc.
Acknowledgement:
We would like to thank Mr. Kwanghwi Kim, who
taught us about the need for bird control and pushed
us into this research.
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Contribution of Individual Authors to the
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All authors have contributed equally to the creation
on this paper.
Sources of Funding for Research Presented in a
Scientific Article or Scientific Article Itself
No funding was received for conducting this study.
Conflict of Interest
The authors have no conflict of interest to declare.
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