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On Active Surge Control of Compression Systems via Characteristic Linearization and Model Nonlinearity Cancellation Simamora, Yohannes S.M.; Tjokronegoro, Harijono A.; Leksono, Edi
Journal of Engineering and Technological Sciences Vol 46, No 3 (2014)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1139.257 KB) | DOI: 10.5614/j.eng.technol.sci.2014.46.3.8

Abstract

A simple approach of active surge control of compression systems is presented. Specifically, nonlinear components of the pressure ratio and rotating speed states of the Moore-Greitzer model are transferred into the input vectors. Subsequently, the compressor characteristic is linearized into two modes, which describe the stable region and the unstable region respectively. As a result, the system’s state and input matrices both appear linear, to which linear realization and analysis are applicable. A linear quadratic regulator plus integrator is then chosen as closed-loop controller. By simulation it was shown that the modified model and characteristics can describe surge behavior, while the closed-loop controller can stabilize the system in the unstable operating region. The last-mentioned was achieved when massflow was 5.38 per cent less than the surge point.
Compensation of time-varying clock-offset in a LBL navigation Yohannes S. M. Simamora; Harijono A. Tjokronegoro; Edi Leksono; Irsan S. Brodjonegoro
Bulletin of Electrical Engineering and Informatics Vol 9, No 4: August 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5316.737 KB) | DOI: 10.11591/eei.v9i4.1996

Abstract

This paper presents compensation of the clock-offset in a long baseline (LBL)navigation. It departs from the existing literature mainly in dealing with a time-varyingclock-offset, i.e. the clock-rate drifts over the time. Specifically, the clock-offsetdynamics are introduced to the ToFs as an autoregressive filter.Subsequently,interactions among the now biased ToFs and the kinematics of an autonomousunderwater vehicle (AUV)–the navigation subject–are represented in a state-spaceform. Implementing the so-called graphic approach, minimum sensor requirementfor this system’s observability is then explicated. Finally, a standard discrete Kalmanfilter is deployed as the state estimator. By simulation, it is demonstrated that theestimator manages to compensate the offset and to provide localization with less than1 m accuracy
On Active Surge Control of Compression Systems via Characteristic Linearization and Model Nonlinearity Cancellation Yohannes S.M. Simamora; Harijono A. Tjokronegoro; Edi Leksono
Journal of Engineering and Technological Sciences Vol. 46 No. 3 (2014)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2014.46.3.8

Abstract

A simple approach of active surge control of compression systems is presented. Specifically, nonlinear components of the pressure ratio and rotating speed states of the Moore-Greitzer model are transferred into the input vectors. Subsequently, the compressor characteristic is linearized into two modes, which describe the stable region and the unstable region respectively. As a result, the system's state and input matrices both appear linear, to which linear realization and analysis are applicable. A linear quadratic regulator plus integrator is then chosen as closed-loop controller. By simulation it was shown that the modified model and characteristics can describe surge behavior, while the closed-loop controller can stabilize the system in the unstable operating region. The last-mentioned was achieved when massflow was 5.38 per cent less than the surge point.
Kaji Terap Tanaman Akumulator Limbah Timbal (Pb) di Desa Mangunsaren, Kabupaten Tegal Maulana Teguh Perdana; Titiek Deasy; Budi Santoso; Mohammad Samsul Bakhri; Muhammad Nursyams Hilmi; Yuli Nurasri; Yohannes S.M. Simamora; Kawi Boedisetio
Jurnal Pengabdian Masyarakat Bangsa Vol. 1 No. 4 (2023): Juni
Publisher : Amirul Bangun Bangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59837/jpmba.v1i4.71

Abstract

Sejumlah industri kecil menengah (IKM) di Desa Mangunsaren, Kecamatan Tarub, Kabupaen Tegal, bergerak dalam bidang penyepuhan logam. Berdasarkan pengamatan, pengolahan limbah industri tersebut belum dikelola dengan baik. Hal ini dikhawatirkan akan berpotensi mencemari lingkungan di sekitarnya dengan logam berat seperti timbal (Pb). Sinyalemen ini diperkuat dengan hasil pengujian terhadap beberapa titik terutama di sekitar IKM penyepuhan logam. Tampak bahwa kandungan Pb pada kisaran 11,58 hingga 462,07 ppm. Di sisi lain, pada literatur diperlihatkan bahwa gelagah (saccharum spontaneum) merupakan tanaman akumulator Pb. Berdasarkan  pengetahuan ini, dilakukan inisiasi penanaman gelagah pada titik-titik yang tercemari Pb di Desa Mangunsaren.  Kegiatan kaji terap ini mendapat dukungan dari IKM, Pemerintah Kabupaten Tegal, Karang Taruna Desa Mangunsaren, Penyuluh Pertanian Kecamatan Tarub, Karang Taruna Kabupaten Tegal, Pemerintah Desa Mangunsaren, dan Dinas Lingungan Hidup Kabupaten Tegal. Dukungan ini berupa penyediaan lahan penanaman, penyediaan bibit, hingga partisipasi dalam kegiatan penananaman. Hasil pokok kegiatan ini adalah ketersediaan titik-titik uji yang dapat diamati tiga bulan berikutnya untuk mengukur selisih tingkat pencemaran Pb sebelum dan sesudah penanaman gelagah.
Revisiting Trilateration Method Based on Time-of-Flight Measurements for Navigation Simamora, Yohannes S.M.; Rachmach, Nahdia Fadilatur; Rizqon, Muhammad Yaasir; Suseno, Kheri Agus; Hilmi, Muhammad Nursyams
Jurnal Riset Multidisiplin dan Inovasi Teknologi Том 2 № 01 (2024): Jurnal Riset Multidisiplin dan Inovasi Teknologi
Publisher : PT. Riset Press International

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59653/jimat.v2i01.432

Abstract

This paper revisits trilateration in three-dimensional positioning. Specifically, range between a positioning target and the reference points through time-of-flight (ToF) measurements. In a ToF, range is yielded by multiplying the time required by a wave to travel between two points and its propagation speed. Position of the target can be then estimated once the number of references are adequate, i.e. at least three for two-dimensional positioning and four for three-dimensional one. In this paper, the positioning is considered for navigation where the target moves following a trajectory whilst the ToFs take place in a certain period. The target position at the time is computed based on the ToFs through least square estimation. Through a numerical simulation, it is shown that the trilateration can track a target’s trajectory despite the decreasing performance at the end of the course.