Hadha Afrisal
King's College London, Informatics, Graduate Student
- Hadha Afrisal is a graduate of Master of Science in Robotics from King's College London. He is currently working as a... moreHadha Afrisal is a graduate of Master of Science in Robotics from King's College London. He is currently working as a Research Assistant in the Research Group for Electrical Power and Mechatronics, Indonesian Institute of Sciences (LIPI).edit
Penyearah merupakan rangkaian yang digunakan sebagai konversi tegangan arus AC menjadi tegangan arus searah. Dari segi pengendaliannya, penyearah terbagi menjadi penyearah terkontrol dan tak terkontrol. Pengaturan tegangan masukannya... more
Penyearah merupakan rangkaian yang digunakan sebagai konversi tegangan arus AC menjadi tegangan arus searah. Dari segi pengendaliannya, penyearah terbagi menjadi penyearah terkontrol dan tak terkontrol. Pengaturan tegangan masukannya melalui modul TRIAC dimmer sebagai pengganti variac. Seiring dengan perkembangan elektronika daya, pengaturan tegangan dapat dilakukan dengan suatu peralatan elektronika daya. Penggunaan peralatan elektronika daya yang lebih murah dan praktis dapat menggantikan penggunaan variac yang lebih mahal. Pada penelitian ini akan dijelaskan mengenai pengaturan tegangan AC – AC terkontrol menggunakan TRIAC BTA-41600B yang terintregasi pada modul TRIAC dimmer. Setelah tergangan dapat divariasi, lalu tegangan AC satu fasa disearahkan menggunakan penyearah gelombang penuh menggunakan dioda bridge MB3510W, kapasitor 330µF dan 470µF difungsikan sebagai filter untuk mengurangi ripple pada tegangan keluaran sumber arus searah. Prinsip kerja dari rangkaian filter ini be...
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Panel surya dapat mengubah energi surya menjadi energi listrik dengan keluaran tegangan arus searah. Hal ini menyebabkan perlu dirancangnya inverter yang dapat mengubah tegangan DC menjadi AC. Inverter dilengkapi dengan transformator... more
Panel surya dapat mengubah energi surya menjadi energi listrik dengan keluaran tegangan arus searah. Hal ini menyebabkan perlu dirancangnya inverter yang dapat mengubah tegangan DC menjadi AC. Inverter dilengkapi dengan transformator step-up untuk menaikan tegangan hingga mencapai 220 VAC. Pemicuan sinyal menggunakan mikrokontroler Arduino Nano untuk menghasilkan sinyal SPWM. Dalam Tugas Akhir ini dilakukan pengujian dengan memvariasikan nilai frekuensi dari 40 Hz – 60 Hz dan melihat pengaruh pada tegangan keluaran, arus keluaran, dan efisiensi . Pada pengujian didapatkan nilai tegangan rata-rata pada lampu LED 12 Watt sebesar 187,422 V dan lampu pijar 100 Watt sebesar 172,367. Pengujian dengan variasi beban kipas angin 35 Watt memiliki nilai tegangan rata-rata sebesar 221,6 V. Berdasarkan pengujian tersebut didapatkan efisiensi rata-rata dengan variasi frekuensi pada keluaran inverter saat dibebani lampu LED 12 Watt sebesar 77,41% dan saat dibebani lampu pijar 100 Watt sebes...
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Penggunaan tegangan tinggi tidak hanya untuk keperluan transmisi, tetapi juga dapat digunakan sebagai pemaanfaatan untuk pembuatan perangkap serangga penggangu bahkan berbahaya dengan cara Short Circuit tegangan tinggi dengan tingkat... more
Penggunaan tegangan tinggi tidak hanya untuk keperluan transmisi, tetapi juga dapat digunakan sebagai pemaanfaatan untuk pembuatan perangkap serangga penggangu bahkan berbahaya dengan cara Short Circuit tegangan tinggi dengan tingkat keamanan yang tinggi. Studi tentang tegangan tinggi yang dimanfaatkan untuk membunuh serangga penggangu sering memberi para insinyur wawasan yang berharga untuk meningkatkan keandalan jangka panjang dari peralatan tegangan tinggi tersebut. Pada umumnya, tegangan tinggi dibangkitkan menggunakan pembangkit tegangan tinggi konvensional yang berukuran besar. Oleh karena itu, diperlukan rangkaian yang lebih sederhana untuk membangkitkan tegangan tinggi, salah satunya menggunakan konverter flyback. Konverter flyback merupakan konverter direct curent to direct current (DC-DC) yang memiliki isolasi di antara masukan dan keluarannya. Komponen utama dari konverter flyback adalah trafo step up dan komponen pensaklaran. Pada Penelitian ini dirancang jendela perangk...
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Pembangkitan energi terbarukan seperti energi surya, menghasilkan energi listrik dengan tegangan yang fluktuatif. Dengan demikian diperlukan sistem konverter untuk meningkatkan efisiensi pada sistem panel surya. Konverter dengan topologi... more
Pembangkitan energi terbarukan seperti energi surya, menghasilkan energi listrik dengan tegangan yang fluktuatif. Dengan demikian diperlukan sistem konverter untuk meningkatkan efisiensi pada sistem panel surya. Konverter dengan topologi buck-boost sisipan yang dirancang akan mengatur arah aliran daya masuk (charging) dan arah keluar (discharging) baterai. Pada Tugas Akhir ini berfokus pada perancangan Konverter DC-DC Dua Arah Sisipan Online yang berfungsi menghubungkan antara media penyimpanan dan DC Bus serta memperhalus arus keluaran dengan pergeseran fasa pada sinyal PWM-nya sebesar 180°. Fitur pergeseran fasa diatur menggunakan sistem minimum ATMEGA328P. Konverter DC-DC Dua Arah Sisipan ini terdapat juga fungsi pemantauan online. Fitur online monitoring yang dirancang akan menampilkan nilai tegangan DC Bus dan tegangan baterai, sedangkan fitur controlling online memungkinkan pengguna untuk mengubah mode konverter dari buck ke boost atau sebaliknya secara manual. Hasil Pengujian...
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Penyebaran virus korona terjadi dari manusia ke manusia melalui droplet dan udara, kontak fisik atau jarak dekat manusia ke manusia merupakan penyebab utama penularan virus korona meskipun dengan penggunaan alat perlindungan diri (APD),... more
Penyebaran virus korona terjadi dari manusia ke manusia melalui droplet dan udara, kontak fisik atau jarak dekat manusia ke manusia merupakan penyebab utama penularan virus korona meskipun dengan penggunaan alat perlindungan diri (APD), ini dibutktikan dengan meninggalnya lebih dari 1400 tenaga medis karena terpapar COVID-19 per tanggal Juli 2021 di Indonesia. Penelitian ini dirancang robot manipulator 4 DOF (RPRR) dengan sistem ROS menggunakan penggerak motor stepper Nema 17 serta dengan sistem pengendalian inverse kinematics dan trajectory planning dengan fungsi sigmoid yang bekerja pada joint space. Untuk mengurangi osilasi pada pergerakan robot ditambah kontrol proporsional dengan nilai KP=10 yang dihasilkan dengan metode trial and error. Robot dirancang untuk memindahkan tabung reaksi. Dari hasil rancangan robot yang dibangun robot dapat melakukan pergerakan dengan presisi ditunjukan dengan pengujian kinematika balik dengan galat rata-rata pada sumbu x sebesar 0,62 mm, pada su...
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Pandemi COVID-19 menyerang seluruh penduduk dunia. Pandemi COVID-19 juga menyebabkan banyaknya kematian tenaga medis di Indonesia dan dunia. Solusi yang dapat diterapkan untuk mengurangi jumlah tenaga medis yang terpapar virus SARS-CoV-2... more
Pandemi COVID-19 menyerang seluruh penduduk dunia. Pandemi COVID-19 juga menyebabkan banyaknya kematian tenaga medis di Indonesia dan dunia. Solusi yang dapat diterapkan untuk mengurangi jumlah tenaga medis yang terpapar virus SARS-CoV-2 adalah dengan menerapkan robot yang dapat membantu tenaga medis dalam bekerja. Robot harus bisa bergerak dari tempat satu ke tempat yang lain dan bisa membawa perlengkapan yang diperlukan seperti obat-obatan, alat medis, dll. Robot differential drive menggunakan 2 roda yang digerakkan oleh penggerak terpisah sebagai penggerak utama. Mobile robot membutuhkan path planning yang optimal dalam melakukan navigasi dari suatu koordinat ke koordinat lain. Dalam tugas akhir ini penulis merancang sistem navigasi robot tipe differential drive dengan menerapkan algoritma A*. Hasil pengujian menunjukkan data nilai galat maksimum adalah 0.073 meter atau 7.3 cm terjadi pada detik 138.8. Nilai rata-rata galat absolut robot dalam bernavigasi sebesar 0.017 meter atau...
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Sektor perikanan Indonesia memegang peranan penting untuk menunjang perekonomian Indonesia. Salah satunya sektor ikan hias seperti ikan Koi. Cuaca yang tidak mendukung dapat mengurangi kualitas ikan Koi itu sendiri. Maka dari itu, penulis... more
Sektor perikanan Indonesia memegang peranan penting untuk menunjang perekonomian Indonesia. Salah satunya sektor ikan hias seperti ikan Koi. Cuaca yang tidak mendukung dapat mengurangi kualitas ikan Koi itu sendiri. Maka dari itu, penulis merancang sistem kontrol dan monitoring kualitas air kolam ikan Koi berbasis Internet of Things (IoT) menggunakan web server Thingspeak. Metode kontrol yang digunakan pada sistem control suhu adalah PI-Gain Scheduling dan kontrol ON-OFF pada sistem kontrol oksigen terlarut. Kontrol PI-Gain Scheduling pada sistem kontrol suhu mengendalikan tegangan pada pemanas air 100W dengan tiga tingkat penjadwalan, yaitu e > 3; 1,5 < e ≤ 3, dan 0 < e ≤ 1,5. Metode tuning parameter yang digunakan pada sistem kontrol suhu adalah metode Ziegler-Nichols II. Kontrol ON-OFF pada sistem kontrol DO (dissolved oxygen) mengendalikan aerator 12W. Dari hasil pengujian yang telah dilakukan, dapat disimpulkan bahwa suhu air dan tingkat DO dapat terjaga dengan cukup o...
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Sektor perikanan Indonesia memegang peranan penting untuk menunjang perekonomian Indonesia. Salah satunya sektor ikan hias seperti ikan Koi. Cuaca yang tidak mendukung dapat mengurangi kualitas ikan Koi itu sendiri. Maka dari itu, penulis... more
Sektor perikanan Indonesia memegang peranan penting untuk menunjang perekonomian Indonesia. Salah satunya sektor ikan hias seperti ikan Koi. Cuaca yang tidak mendukung dapat mengurangi kualitas ikan Koi itu sendiri. Maka dari itu, penulis merancang sistem kontrol dan monitoring kualitas air kolam ikan Koi berbasis Internet of Things (IoT) menggunakan web server Thingspeak. Metode kontrol yang digunakan pada sistem control suhu adalah PI-Gain Scheduling dan kontrol ON-OFF pada sistem kontrol oksigen terlarut. Kontrol PI-Gain Scheduling pada sistem kontrol suhu mengendalikan tegangan pada pemanas air 100W dengan tiga tingkat penjadwalan, yaitu e > 3; 1,5 < e ≤ 3, dan 0 < e ≤ 1,5. Metode tuning parameter yang digunakan pada sistem kontrol suhu adalah metode Ziegler-Nichols II. Kontrol ON-OFF pada sistem kontrol DO (dissolved oxygen) mengendalikan aerator 12W. Dari hasil pengujian yang telah dilakukan, dapat disimpulkan bahwa suhu air dan tingkat DO dapat terjaga dengan cukup o...
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This paper presents a trajectory planning method with obstacle avoidance strategy of 3 DoF parallel link robotic arm to perform the task of autonomous test tube handling. For implementation in real-world environment such as in the process... more
This paper presents a trajectory planning method with obstacle avoidance strategy of 3 DoF parallel link robotic arm to perform the task of autonomous test tube handling. For implementation in real-world environment such as in the process of material handling within healthcare setting, robotic arm frequently needs to deal with obstacles come up on its way of finishing its task. Hence to maintain a smooth actuation and a safer manipulation point-to-point from a start to a goal position, a method of trajectory planning with obstacle avoidance is required. In this paper, the method of cubic polynomials trajectory generation with distance calculation for obstacle avoidance has been performed. The result of our experiments shows that our proposed method is successfully demonstrated with a high degree of accuracy and precision in our research setup. The average position error of trajectory tracking is not more than 0.43 cm during the experiment with obstacle, and 0.35 cm during the experiment without obstacle.
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Inertial navigation systems is used to determine the attitude estimation and bearing navigation of a quadrotor. The design implemented in this research uses IMU (Inertial Measurement Unit) and GPS (Global Positioning System) sensor. The... more
Inertial navigation systems is used to determine the attitude estimation and bearing navigation of a quadrotor. The design implemented in this research uses IMU (Inertial Measurement Unit) and GPS (Global Positioning System) sensor. The attitude estimates are obtained from a complementary filter by combining the measurements from the IMU sensor. Bearing navigation can determine the quadrotor's rotation by calculating the the difference between the actual value of the quadrotor and the given setpoint Longitude-Latitude value. By this research, the average error of GPS sensor is 3,86 m, average error of compass is 3, 4°, average error of attitude estimation is roll: 23,63 °pitch: 16,67°, and yaw: 14,88°. bearing angle and yaw rotation direction calculations performed by the system are correct.
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Research Interests: Engineering, Computer Science, Materials Science, Technology, Design, and 11 moreBiologically Inspired Robotics, Stiffness, Fabrication, Shape Memory Alloy, Science Technology, Soft Robotics, Sma, Mechanism in Biology, Active Layer, Automation Control Systems, and Computer Science Information Systems
This research paper presents experimental analysis of global-local path planning strategy using Dijkstra algorithm and Follow the Carrot method implemented in differential drive mobile robot for indoor delivery mechanism. Experiment... more
This research paper presents experimental analysis of global-local path planning strategy using Dijkstra algorithm and Follow the Carrot method implemented in differential drive mobile robot for indoor delivery mechanism. Experiment results show that Dijkstra algorithm performed an accurate, precise, and high stability of path planning strategy in supporting our indoor robot navigation. Experimental analysis has been performed to measure maximum positioning error, maneuverability of mobile robot, and accuracy of path tracking algorithm. Our research findings show that the more complicated the map in between the initial position and final position, the measured error rate has increased linearly. With a medium level of mobile robot's speed, which is set to 0.12 m/s, the measured maximum positioning error during path tracking process is 7.5 cm and the average positioning error is 2.5 cm. In terms of maneuverability, our mobile robot has demonstrated capability of coping with a sharp U-turn and eventually can correct its relative position to the targeted path.
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Robotics is a technology that grows rapidly in this 4.0 Industrial Revolution. Robotics application in the medical field refers to the high demand from the medical world for robotics technology, where on that is also needed is to handle a... more
Robotics is a technology that grows rapidly in this 4.0 Industrial Revolution. Robotics application in the medical field refers to the high demand from the medical world for robotics technology, where on that is also needed is to handle a test tube for laboratory use. Trajectory planning on an arm manipulator with 3 Degrees of Freedom (DOF) and parallel link mechanism is a method that will be designed in this paper with the aim of moving a test tube from a test tube rack to another rack. The test will be carried out by giving 8 coordinate points as a position reference of the trajectory planning movement. As for the test results, the average error on the x-axis, y-axis, and z-axis are 1.04 cm, 0.73 cm, and 0.8 cm respectively. So, it can be concluded that the average position error between the reference position and actual position while the arm manipulator executes the trajectory is 0.85 cm.
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Thirty-three years has passed since the first utilization of laparoscopic technology in surgery, yet the deployment of robots in endovascular catheterization process is currently still in its infancy. Following up some reviews by other... more
Thirty-three years has passed since the first utilization of laparoscopic technology in surgery, yet the deployment of robots in endovascular catheterization process is currently still in its infancy. Following up some reviews by other researchers, this paper elaborates trends in robotic-assisted endovascular catheterization through literature study of published articles since the last 4 years, direct observation of on going minimally invasive endovascular intervention surgery, and discussions with an interventional cardiologist. Some important facts have been identified such as, some commercial robots have been used In Vitro, and magnetic resonance compatible slave robots as well as methods for physician skill evaluation are under development. The existing issues include miniaturization of flexible robots, side contact force sensing device for catheters, and stable haptic feedback in master robot. Some examples of interesting topics for future research are more stable and robust haptic feedback, structure and mechanism of catheter, intra-cardiac sensors, estimation methods of catheter tip states (position, angle and contact force), modeling and control methods, image sensing technology which does not yield radiation exposure yet more economically affordable, and simulator with skill assessment algorithm.
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An experimental study of the control of the operating modes of the plate feeder based on a frequency-controlled electric drive in the mining industry has been carried out. The graphs of measurements of the electrical parameters of the... more
An experimental study of the control of the operating modes of the plate feeder based on a frequency-controlled electric drive in the mining industry has been carried out. The graphs of measurements of the electrical parameters of the electric drive supplied from the frequency converter of the plastic feeder, instantaneous values of harmonic composition of voltage and current up to 50 harmonics, as well as changes in current and voltage harmonics over a period of 30 minutes were obtained. Measurement of oscillograms of voltage and current of each phase in operating mode and the moment of turning off and turning on the electric motor of the plastic feeder. The issues of control of starting modes of the plate feeder from frequency-controlled electric drives are considered. It has been determined that frequency start-up with the linear control law for the frequency of the plate feeder as a function of time and technological parameters are the most acceptable condition for starting modes.
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A healthy and comfortable habitation in coastal areas is one of the requirements for establishing a modern society in the increasing number of water and air pollutions. On the one hand, high humidity and temperature levels reduce the... more
A healthy and comfortable habitation in coastal areas is one of the requirements for establishing a modern society in the increasing number of water and air pollutions. On the one hand, high humidity and temperature levels reduce the convenience of settlements in coastal areas. This condition is even worsened in many houses, which are built with poor air circulation. On the other hand, when the house’s windows are opened to allow airflow, many insects such as mosquitoes will enter the room. Mosquitoes are carriers of many diseases in Indonesia, such as dengue fever, malaria, chikungunya and many more. For solving this problem, this paper proposes a solution by designing insect trap of windows connected to a DC high voltage source to exterminate mosquitoes. The source of electricity is obtained from PLN 220 Volt. The voltage from PLN is boosted to reach 3240 Volts. Our prototype has been demonstrated to exterminate a swarm of mosquitoes. When mosquitoes pass through the window trap, ...
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This research aims to develop a quadrotor control system for maintaining its position and balance from disturbance while hovering. A fast and reliable control technique is required to respond to high maneuverability and high non-linearity... more
This research aims to develop a quadrotor control system for maintaining its position and balance from disturbance while hovering. A fast and reliable control technique is required to respond to high maneuverability and high non-linearity of six degrees of freedom system. Hence, this research focuses on designing a Self-Tuning Fuzzy-PD control system for quadrotor’s attitude. The designed control system utilizes input data from the Inertial Navigation System (INS). Then the quadrotor’s attitude is controlled by passing the PWM signal to the flight controller APM 2.6. The result shows that the average absolute error for the roll, pitch, and yaw angles are relatively small, as mentioned consecutively 2.0790, 2.2660, and 1.5280, while the maximum absolute errors are 6.3140, 6.7220, and 3.820.
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Pada mobile robot yang memiliki sensor utama hanya berupa kamera, estimasi posisi robot relatif terhadap landmark-landmark visual dapat dilakukan dengan menggunakan pendekatan multiple view geometry. Hal tersebut berguna bagi robot untuk... more
Pada mobile robot yang memiliki sensor utama hanya berupa kamera, estimasi posisi robot relatif terhadap landmark-landmark visual dapat dilakukan dengan menggunakan pendekatan multiple view geometry. Hal tersebut berguna bagi robot untuk bernavigasi serta melakukan localization dan mapping secara bersamaan. Penelitian ini bertujuan untuk merancang dan mensimulasikan algoritma estimasi posisi yang merupakan langkah awal pada monocular SLAM (Simultaneous Localization and Mapping) 2-dimensi. Penelitian akan membahas tentang fungsi kamera sebagai sensor posisi untuk mobile robot dengan menitikberatkan diskusi pada transformasi citra dengan menggunakan model kamera pinhole dengan parameter intrinsik dan ekstrinsiknya. Berdasarkan hasil pengujian, estimasi pose dan posisi terhadap citra papan catur (checkerboard) berhasil memetakan jarak dan sudut dengan cukup akurat dan dengan error estimasi yang cukup kecil, yakni 2,9 mm untuk estimasi jarak, dan 0.3° untuk estimasi sudut. Simulasi algo...
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Place recognition algorithm based-on visual sensor is crucial to be developed especially for an application of indoor robot navigation in which a Ground Positioning System (GPS) is not reliable to be utilized. This research compares the... more
Place recognition algorithm based-on visual sensor is crucial to be developed especially for an application of indoor robot navigation in which a Ground Positioning System (GPS) is not reliable to be utilized. This research compares the approach of place recognition of using learned-features from a model of Convolutional Neural Network (CNN) against conventional methods, such as Bag of Words (BoW) with SIFT features and Histogram of Oriented Uniform Patterns (HOUP) with its Local Binary Patterns (LBP). This research finding shows that the performance of our approach of using learned-features with transfer learning method from pre-trained CNN AlexNet is better than the conventional methods based-on handcrafted-features such as BoW and HOUP.
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Penelitian ini bertujuan mengembangkan robot humanoid untuk permainan sepakbola secara otomatis. Robot humanoid yang dikembangkan tersusun atas 20 sendi yang digerakkan dengan motor servo dynamixel berjenis AX-12 (bagian tubuh atas) dan... more
Penelitian ini bertujuan mengembangkan robot humanoid untuk permainan sepakbola secara otomatis. Robot humanoid yang dikembangkan tersusun atas 20 sendi yang digerakkan dengan motor servo dynamixel berjenis AX-12 (bagian tubuh atas) dan RX-24 (bagian tubuh bawah), serta dikontrol menggunakan board servo-controller CM-700 (ATMega2561). Robot humanoid memiliki tinggi 44 cm serta dilengkapi dengan sistem keseimbangan menggunakan sensor gyro LPR530 dan akselerometer KXM52-1050. Untuk mengenali objek dan bernavigasi secara otomatis, robot humanoid menggunakan sistem sensor visual berbasiskan kamera CMOS dengan board CMUCAM (LPC2106). Pengujian menunjukkan bahwa robot humanoid pemain bola yang dikembangkan mampu berjalan dengan kecepatan rata-rata 14.37 cm/detik dan memiliki kecepatan maksimal 20 cm/detik. Robot humanoid yang dikembangkan mampu bermain bola secara otomatis: yakni mampu mendeteksi keberadaan bola, mendeteksi lokasi gawang, serta menendang bola ke arah gawang dan mencetak gol.
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In this paper we propose a deep neural network based algorithm for indoor place recognition. It uses transfer learning to retrain VGG-F, a pretrained convolutional neural network to classify places on images acquired by a humanoid robot.... more
In this paper we propose a deep neural network based algorithm for indoor place recognition. It uses transfer learning to retrain VGG-F, a pretrained convolutional neural network to classify places on images acquired by a humanoid robot. The network has been trained as well as evaluated on a dataset consisting of 8000 images, which were recorded in sixteen rooms. The dataset is freely accessed from our website. We demonstrated experimentally that the proposed algorithm considerably outperforms BoW algorithms, which are frequently used in loop-closure. It also outperforms an algorithm in which features extracted by FC-6 layer of the VGG-F are classified by a linear SVM.
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This paper proposes multi-battery design of battery management control using bus communication method based on loop shaping. The experiment of proposed method shows that the capacity dynamics of battery has been improved. The multiple of... more
This paper proposes multi-battery design of battery management control using bus communication method based on loop shaping. The experiment of proposed method shows that the capacity dynamics of battery has been improved. The multiple of battery control system is implemented in electric vehicle's model, and we modify the origin control system using bus communication method auto tuning based on loop shaping. The result of modified control system using bus method based on loop shaping is shown in the implementation design response of battery management that the cost and reliability are improved. Moreover, this method could maintain the error steady state to be zero.
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This paper discusses the development of portable fruit sorting and grading machine based on computer vision for small agro-industries. The mechanical system is designed from low cost material in the form of inclined and segmented plane to... more
This paper discusses the development of portable fruit sorting and grading machine based on computer vision for small agro-industries. The mechanical system is designed from low cost material in the form of inclined and segmented plane to substitute the utilization of conveyor belt. In this case, motor servos are used as gate opener and director for the mechanical system. The autonomous system collects video image from a Logitech C920 webcam placed on the top of analysis area, then the image will be analyzed due to the process of computer vision. Firstly, the computer vision algorithm transforms the RGB (Red, Green, and Blue) color space to HSV (Hue, Saturation, and Value) color space of the image to facilitate the processes of color segmentation that are robust to the light intensity fluctuation. To speed up the process, every single frame is classified to 2 ROI (Region of Interest) based on fruit position in queuing and analysis area. Then the system will cluster fruit quality according to the level of maturity and its dimension. In the end, the autonomous system will actuate the servos to move the fruit to a specific bin according to their quality grade. Then the result of fruit analysis data will be displayed on PC's monitor. The system can do the task in 500 ms with precision result.
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— Smart attachment mechanisms are believed to contribute significantly in stiffness control of soft robots. This paper presents a working prototype of an active Velcro based stiffness controllable fastening mechanism inspired from micro... more
— Smart attachment mechanisms are believed to contribute significantly in stiffness control of soft robots. This paper presents a working prototype of an active Velcro based stiffness controllable fastening mechanism inspired from micro active hooks found in some species of plants and animals. In contrast to conventional passive Velcro, this active Velcro mechanism can vary the stiffness level of its hooks to adapt to external forces and to maintain the structure of its supported layer. The active hooks are fabricated using Shape Memory Alloy (SMA) wires which can be actuated using Lenz-Joule heating technique via thermo-electric manipulation. In this paper, we show experimental results for the effects of active SMA Velcro temperature, density and number on the attachment resisting force profile in dynamic displacement. We aim to provide new insights into the novel design approach of using active hook systems to support future implementation of active velcro mechanisms for fabrication of wearable stiffness controllable thin layers.
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—This paper discusses the development of portable fruit sorting and grading machine based on computer vision for small agro-industries. The mechanical system is designed from low cost material in the form of inclined and segmented plane... more
—This paper discusses the development of portable fruit sorting and grading machine based on computer vision for small agro-industries. The mechanical system is designed from low cost material in the form of inclined and segmented plane to substitute the utilization of conveyor belt. In this case, motor servos are used as gate opener and director for the mechanical system. The autonomous system collects video image from a Logitech C920 webcam placed on the top of analysis area, then the image will be analyzed due to the process of computer vision. Firstly, the computer vision algorithm transforms the RGB (Red, Green, and Blue) color space to HSV (Hue, Saturation, and Value) color space of the image to facilitate the processes of color segmentation that are robust to the light intensity fluctuation. To speed up the process, every single frame is classified to 2 ROI (Region of Interest) based on fruit position in queuing and analysis area. Then the system will cluster fruit quality according to the level of maturity and its dimension. In the end, the autonomous system will actuate the servos to move the fruit to a specific bin according to their quality grade. Then the result of fruit analysis data will be displayed on PC's monitor. The system can do the task in 500 ms with precision result. Keywords—portable fruit sorting and grading machine; computer vision; HSV color space; servo-based sorter; low cost mechanical design
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Building strong defense is an utmost importance to win a kid size humanoid robosoccer game nowadays, due to the increasing capability of striker robot in shooting a ball precisely. In order to have a strong defense, the ball anticipation... more
Building strong defense is an utmost importance to win a kid size humanoid robosoccer game nowadays, due to the increasing capability of striker robot in shooting a ball precisely. In order to have a strong defense, the ball anticipation capability of humanoid goalie should be improved. The goalie should be able to respond the coming-ball effectively and quickly so that it can prevent the opponent from scoring goal. There are two types of goalie action to anticipate the coming-ball, they are: (1) jumping or falling to a specific direction to block fast coming-ball, and (2) walking normally to approach the near-distance slow coming-ball then kicking it to the opponent's region. From that problem, the goalie should be able to calculate and predict both the direction and speed of ball movement. To achieve that objective, this paper elucidates a linear regression method to calculate ball speed and direction so that the goalie can understand and capable of doing appropriate action to anticipate ball movement that is rolling to its goal. As the result of experiments, the implemented method can increase the effectiveness of goalie response in preventing opponent from scoring goal. The method is not only robust to noise but also fast enough to support strong defense against powerful shooting or slow dribbling. Its inexpensive computation time provide a real-time execution to endorse spry anticipation of the goalie robot of Alfarobi team.