Catur Atmaji
Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Bulaksumur, Yogyakarta, Indonesia 55281

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SISTEM KENDALI GIMBAL 2-SUMBU SEBAGAI TEMPAT KAMERA PADA QUADROTOR MENGGUNAKAN PID FUZZY Haris, M Saiful; Dharmawan, Andi; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 7, No 2 (2017): October
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1035.641 KB) | DOI: 10.22146/ijeis.24220

Abstract

The function of camera gimbal control system that use in this research is to serves with the angle changes that occur due quadrotor maneuver. The PID control with tuning classical method has weakness, which is the PID variable not independently adjust to the environment, thus proposed using PID fuzzy control.Gimbal camera used in this study has a mechanical design with two joint (pitch and roll) and the BLDC motor as actuator. The angle changes that occur in the pitch and roll axis will be a feedback system. Then, fuzzy logic will tune the PID variable based on that feedback.Results of testing the system on 2-axis gimbal camera shows the PID fuzzy control generates better response in parameter risetime, overshoot, and settlingtime compared with PID control. Error input value range of [-30° 30°] and delta error of [-10° 10°] on the pitch and roll axes. The range of the output value for the pitch axis is, Kp at [40.2 46.2], Ki at [10.7 20.7], and Kd of [0.05 to 0.15]. The range of the output value for the roll axis is, Kp at [6.4 16.4], Ki at [17.3 to 27.3], and Kd at [0.08 0.16]. Speed response speed of pitch axis is 0.12 second and the roll axis is 1.07 seconds.
PENGARUH LATAR BELAKANG WARNA PADA OBJEK GAMBAR TERHADAP HASIL EKSTRAKSI SINYAL EEG Atmaji, Catur; Perwira, Zandy Yudha
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 7, No 2 (2017): October
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (674.868 KB) | DOI: 10.22146/ijeis.22893

Abstract

In this study, observation on the differences in features quality of EEG records as a result of training on subjects has been made. The features of EEG records were extracted using two different methods, the root mean square which is acquired from the range between 0.5 and 5 seconds and the average of power spectrum estimation from the frequency range between 20 and 40Hz. All of the data consists of a 4-channel recording and produce good quality classification on artificial neural network, with each of which generates training data accuracy over 90%. However, different results are occured when the trained system is tested on other test data. The test results show that the two systems which are trained using training data with object with color background produce higher accuracy than the other two systems which are trained using training data with object without background color, 63.98% and 60.22% compared to 59.68% and 56.45% accuracy respectively. From the use of the features on the artificial neural network classification system, it can be concluded that the training system using EEG data records derived from the visualization of object with color background produces better features than the visualization of object without color background.
IMPLEMENTASI KALMAN FILTER PADA KENDALI ROKET EDF Pamungkas, Wisnu; Sumbodo, Bakhtiar Alldino Ardi; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 7, No 1 (2017): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (508.622 KB) | DOI: 10.22146/ijeis.15436

Abstract

EDF (electric ducted fan) rocket is a flying object shapes like bullet with electric ducted fan motor as the booster. This rocket fly autonomously by utilizing accelerometer, gyroscop, and magnetometer sensor to determine the attitude of the rocket against the earth?s gravitational and magnetic field of the earth. In controlling the rocket required a control system capable of controlling a rocket with sensor data that has been processed into the value of the attitude that has been filtered.In this study, designed a filter that will be implemented on the microcontroller rocket. The filters are Kalman filter is implemented while the control used is the control proportional integral derivative (PID) with Ziegler-Nichols tuning method.The result of this research is an implementation of kalman filter to EDF rocket control system. Based on the experiment that has been done, control system using a Kalman filter has a standard deviation value against the value of linear regression on a roll attitude of 2.73, a pitch of 3.03, and yaw of 6.96 degrees. While the standard deviation of the ideal value on a roll attitude of 3.43, a pitch of 2.92 and yaw of 5.21 degrees.
DETERMINATION OF CONSECUTIVE REACTION RATE CONSTANTS BETWEEN GLYCINE AND ISOLEUCINE WITH O-PHTHALDIALDEHYDE AND 2-MERCAPTOETHANOL FROM SINGLE EXPERIMENT DATA Falah, Iip Izul; Triyono, Triyono; Atmaji, Catur
Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.21414

Abstract

Kinetics study of chemical reaction is important in producing optimum product, designing a reactor, analyzing a compound, and many other purposes. This work presents the result of study of consecutive pseudo first order reaction between glycine and isoleucine with o-phthaldialdehyde and 2-mercaptoethanol in borate buffer solution at pH=9.0. Continuous detection was used to follow the change of fluorescence intensity of formed isoindole during the reaction. Although concentrations of initial compound and its derivative were not known; by using iteration method, the reaction constants could be determined with high precision from single experiment data. Result of the work showed that reaction rate constants k1 and k2 for consecutive reaction of glycine with excess of o-phthaldialdehyde and 2-mercaptoethanol were 18.75x10-3 and 26.70x10-5 s-1, respectively; whereas for isoleucine were 6.06x10-3 and 12.59x10-5 s-1, respectively.
RANCANG BANGUN PURWARUPA PENERIMA PAKET APRS BERBASIS RASPBERRY PI 2 UNTUK STASIUN BUMI Putra, Agfianto Eko; Nugroho, Unggul Adhi; Ardi Sumbada, Bakhtiar Alldino; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 9, No 1 (2019): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1153.792 KB) | DOI: 10.22146/ijeis.44299

Abstract

The design of Raspberry Pi 2-based APRS packets for UGM earth stations has been designed, which is much cheaper than commercial devices on the market. A TV tuner is used as a signal receiver, the receiver is accessed via a laptop wirelessly. A directed antenna with a controller is used to automatically point to the satellite. The test was carried out by receiving the APRS package emitted by the International Space Station (ISS) satellite and the LAPAN-A2 satellite. The results showed that the tool was able to get the ISS satellite APRS package with a total of 6 packages out of 10 packets emitted. The package received has an average amplitude of 1,200 Hz and 2,200 Hz which is much smaller than the overall audio amplitude. This indicates that there is high noise in the signal. While the APRS package from the LAPAN-A2 satellite has not been successfully obtained.
EVALUATION OF ANNUAL ALLOWABLE CUT (AAC) DETERMINATION OF TEAK FOREST PLANTATIONS IN PERUM PERHUTANI, INDONESIA Rohman, Rohman; Warsito, Sofyan P; Supriyatno, Nunuk; Purwanto, Ris Hadi; Atmaji, Catur
Jurnal Manajemen Hutan Tropika Vol. 20 No. 3 (2014)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (563.229 KB) | DOI: 10.7226/jtfm.20.3.195

Abstract

The degradation of teak forest plantations in Java that are managed by Perum Perhutani (PP) continues to happen, and this is caused by some risk factors such as illegal logging, grazing, forest fire, and encroachment. However, these risk factors have not been considered by PP notably in annual allowable cut (AAC) determination of yield regulation. Therefore, the AAC value could be overestimated. The research was aimed at evaluating the method of AAC determination and proposing an alternative method that considers the risk factors. This research was conducted with a series of data analysis approach from the data on five planning periods. The research result showed that forest damage occurs in varied situations. On average, the rate of deforestation accounted for 0.8% per annum. The calculation of AAC by considering the rate of damage risk in normal condition approximately made up 70.8%. Thus, compared to another method without considering damage risk rate, overestimation constituted 29.2%. In brief, this had an impact on the decline of timber stock. 
PENINGKATAN SKALABILITAS MINI WEATHER STATION PORTABLE BERBASIS INTERNET OF THINGS Putro, Nur Achmad Sulistyo; Atmaji, Catur; Devianto, Kristiawan; Perwira, Zandy Yudha
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 9, No 2 (2019): October
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (596.782 KB) | DOI: 10.22146/ijeis.50377

Abstract

Indonesia is a country that has unique weather that provides not only abundant natural resources but also can causes disasters at any time. To reduce the threat of losses, observing weather elements using a weather station is a solution that can be used. The development of systems related to environmental monitoring and weather stations is not new. However, most research focuses on various innovations in utilization, low cost and power savings. These studies have not touched on the aspect of ease of system development, especially in the concept of adding nodes. Indonesia, as a country with diverse regional topography, needs an integrated weather monitoring system with the concept of centralized data collection to get a complete picture.In this study, a portable mini weather station system was built named Amicagama. This system is built with the concept of high scalability which means the system is designed to be used publicly, with each user able to manage the nodes which are their respective weather stations. Management by each user here means that each user can manage weather data to be submitted, add nodes at a new location, and can delete nodes at a certain location if something unexpected happens.
ANALISIS HASIL PROSES PEMAMPATAN JPEG DENGAN METODE DISCRETE COSINE TRANSFORM Utomo, Adi Prasetio; Putra, Agfianto Eko; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 2, No 1 (2012): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (424.075 KB) | DOI: 10.22146/ijeis.2335

Abstract

AbstrakJPEG merupakan standar kompresi digital yang dikembangkan oleh Group Joints Photograpic Experts yang menggunakan kombinasi DCT dan pengkodean Huffman untuk mengkompresi suatu citra digital.[1]. Pemampatan JPEG merupakan algoritme pemampatan secara lossy. [2]. JPEG bekerja dengan mengubah gambar spasial dan merepresentasikan ke dalam pemetaan frekuensi. Salah satu metode dalam pemampatan JPEG yang dapat digunakan adalah metode DCT (Discrete Cosine Transform), dengan memisahkan antara informasi frekuensi yang rendah dan tinggi dari sebuah gambar.[3]            File yang digunakan adalah gambar grayscale dengan format bitmap, memiliki ukuran 26,422 bytes, resolusi 176x144 piksel.  Gambar diproses sesuai standar pemampatan JPEG, dianalisis hasil pemampatan berdasarkan variasi yang dilakukan pada tahapan block image transformation dan DCT quantization. Pengukuran kualitas gambar hasil pemampatan dilakukan secara subjektif melalui pandangan visual mata manusia dan secara objektif dengan parameter nilai PSNR dan rasio pemampatan            Dari penelitian dapat disimpulkan bahwa nilai PSNR dan rasio pemampatan gambar dapat digunakan sebagai parameter untuk mengukur kualitas gambar dan dapat diketahui penggunaan macroblock serta nilai step kuantisasi yang tepat untuk mendapatkan hasil optimal dalam pemampatan gambar grayscale. Kata kunci?JPEG,DCT,pemampatan JPEG, gamabr grauscale, PSNR, rasio pemampatan  Abstract JPEG is a digital compression standard developed by the Group of Experts Photograpic Joints using a combination of DCT and Huffman coding to compress a digital image.[1]. JPEG compression is a lossy compression algorithm. [2]. JPEG works by converting the spatial images and to represent frequency mapping.One of the methods in JPEG compression that can be used is a DCT method (Discrete Cosine Transform), with a separate low frequency information and high of an image. High frequency information will be selected to be eliminated which related to image compression and measurement quality of the image.[3]Files used are grayscale images with a bitmap format, has a size of 26.422 bytes, 176x144 pixel resolution. Image processed according to standard JPEG compression, the compression results are analyzed based on variations performed on block image  transformationandquantization. Measurement of quality of image compression is done subjectively through visual view of the human eye and objectively with the parameter value of PSNR and compression ratio.From the study it can be concluded that the value of PSNR and compression ratio of an image can be used as a parameter to measure the image quality and can be detected using macroblock  and value of quantization step which the right to obtain optimal results in compression of grayscale images Keywords?JPEG, DCT, JPEG compression, grayscale images, PSNR, compression ratio
ANALISIS PERBEDAAN POLA SINYAL EEG BERDASARKAN JENIS KELAMIN YANG BERBEDA SAAT NUMERICAL STROOP TASK Dimas, Riswandha Latu; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 8, No 1 (2018): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (596.135 KB) | DOI: 10.22146/ijeis.34383

Abstract

Cognitive process show how brain work from stimulus reception until stimuls reaction. With electroencephalogram (EEG) device, cognate process can be observerd in brain signal or EEG signal form. In cognitive process different kind of stimulus could affect generated brain signal. Also, given interference in cognitive prcess could affect brain signal. In this research, conducted observation whether gender difference has effect in cognitive process. Numerical stroop task with three kinds of conditions (congruence, incongruence, and neutral) are used as reference in signal observation process which is generated when the cognitive process in difference genders are done. The resulting EEG signal then conducted three kinds of analysis that is ERP analysis, reaction time, and energy analysis. The result of ERP analysis show both subject class have difference in response time that indicated with P3 peak time. On average, respons time in female (kongruent = 623,34 ms; inkongruent = 645,18 ms ; neutral = 614,91 ms)subject class is faster than male (kongruent = 709,67 ms; inkongruent = 745,00 ms; neutral =715,37 ms) subject class. Energy analysis show when numerical stroop task takes place, left side of the brain (51,36%) and cetral side of the brain (50,65%) more dominant than others parts of the brain.
ANALISIS PERKIRAAN TDOA MENGGUNAKAN ALGORITMA LMS ADAPTIF PADA PELACAKAN PAUS LODAN Permana, Andriyan; Putra, Agfianto Eko; Atmaji, Catur
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 5, No 1 (2015): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (775.479 KB) | DOI: 10.22146/ijeis.7149

Abstract

Research on TDOA estimation in sperm whale tracking has been done [1] that uses the Teager - Kaiser operator in improving accuracy the TDOA estimation using adaptive LMS algorithm on sperm whale tracking. However, further researches on the right convergence factor (?) (fast and accurate) in TDOA estimation using adaptive LMS algorithms for sperm whale tracking have not been performed. Will be analyzed the TDOA estimation using adaptive LMS algorithm in sperm whale tracking with the variation of ?. As a reference to determine the right value of ?, the results of sperm whale tracking[2] is used.TDOA estimation using Adaptive LMS algorithm was first published by Benesty [3]. The approach taken is based on estimation of the impulse responses from source to receivers. In the adaptive LMS algorithm function updates the coefficient with ? as adaptation step. TDOA values obtained from the difference between the two impulse responses.From the results, values changing of ? affect the speed of TDOA estimation using the LMS adaptive algorithm. However, the wrong value of ? is lead to inaccurate sperm whale tracking results. The best value of ? for TDOA estimation using the LMS adaptive algorithm for sperm whale tracking is 0.01.