Position Control of a Three Degree of Freedom Gyroscope using Optimal Control

In this paper, a 3 DOF gyrscope position control have been designed and controlled using optimal control theory. An input torque has been given to the first axis and the angular position of the second axis have been analyzed while the third axis are kept free from rotation. The system mathematical model is controllable and observable. Linear Quadratic Integral (LQI) and Linear Quadratic State Feedback Regulator (LQRY) controllers have been used to improve the performance of the system. Comparison of the system with the proposed controllers for tracking a desired step and random angular position have been done using Matlab/Simulink Toolbox and a promising results has been analyzed

Gyroscope Sebagai Alternatif Pengganti Katir Pada Kapal Berbentuk Slender

Kapal penangkap ikan di Indonesia, masih banyak yang dilengkapi katir untuk meningkatkan stabilitas kapal, terutama pada kapal-kapal berbentuk ramping atau slender.  Akan tetapi keberadaan katir juga memiliki risiko, terutama saat kapal-kapal tersebut hendak berlabuh di suatu tempat pendaratan. Hal ini terjadi karena antar katir saling bersinggungan dan dapat mengakibatkan patahnya katir atau bahkan hingga membalikkan kapal. Saat ini perkembangan teknologi di bidang perkapalan sudah semakin maju. Salah satunya dengan ditemukannya marine gyrostabilizer yaitu perangkat yang memanfaatkan prinsip kerja gyroscope dalam menjaga olah gerak kapal yang disebabkan gangguan gaya eksternal. Sehingga muncul suatu pemikiran untuk memanfaatkan teknologi marine gyrostabilizer sebagai pengganti katir pada kapal berbentuk slender. Penelitian ini bertujuan untuk merancang gyrostabilizer dan posisi penempatannya di atas model kapal berbentuk slender. Penelitian ini dilakukan secara eksperimental dengan menggunakan model kapal berbentuk ramping atau slender dengan dimensi utama LOA (65cm), LPP (58,19cm), B (16cm), D (8,5cm), d (3,1cm) dan ton displacement 0,00141 ton (1,41 kg). Eksperimen dilakukan untuk mendapatkan data berupa performa gerakan rolling kapal yang dilengkapi dengan gyroscope dan tanpa gyroscope, sehingga dapat diperoleh performa dan pengaruh keberadaan gyroscope dalam mempertahankan stabilitas kapal berbentuk slender. Berdasarkan hasil penelitian diperoleh bahwa nilai profil gerakan rolling pada perlakuan model kapal yang dilengkapi dengan gyroscope lebih baik dibandingkan perlakuan pada model kapal yang tidak dilengkapi gyroscope dan performa penggunaan prototype gyroscope memiliki kemampuan meredam rolling model kapal slender sebesar 68,45

Roll motion compensation by active marine gyrostabiliser

Unmanned Surface Vehicle (USV) has been gaining more marine applications nowadays. However, the USV is vulnerable to excessive rolling motions induced by water waves, and this phenomenon may cause significant downtime to the operations of USV and engender detrimental effects to the on-board instrument and sensors. Active control system had been proposed to compensate the rolling stability issue but most of the proposed devices were expensive. This paper developed a gyrostabiliser on USV model to compensate the excessive rolling motion. Gyrostabiliser consists of rotor, gimbal and spinning axes, which commonly used for measuring or maintaining orientations and angular velocities. The gyrostabiliser was mounted vertically inside the USV model. Experiments were conducted to obtain the ideal gains of gyrostabiliser’s controller, to investigate the differences between active- and passive-gyrostabiliser, and to identify the induced pitch effect of the vertical gyrostabiliser to the USV model. The roll angle of the USV was measured by gyro sensor, whereas the precession motor and flywheel motor were controlled by a non-encoder Direct-Current (DC) motor. A proportional controller of the gyrostabiliser was implemented through Arduino Integrated Development Environment (IDE) to ensure optimal performance of gyrostabiliser in precession speed and direction control. The results showed that both active- and passive-gyrostabiliser managed to mitigate the roll angle of USV from +/- 15° back to less than 1° and reached steady state within 2.32 seconds and 2.60 seconds, respectively. The active gyrostabiliser had advantage to return to zero precession angle while the passive gyrostabiliser accumulated 30° precession angle in the experiment. The induced pitch angle by the gyrostabiliser had been found in an insignificant magnitude for the case study. The outcomes of this paper lead to an alternative for improving the robustness of USV in rolling reduction. 

Roll motion compensation by active marine gyrostabiliser

922-929Unmanned Surface Vehicle (USV) has been gaining more marine applications nowadays. However, the USV is vulnerable to excessive rolling motions induced by water waves, and this phenomenon may cause significant downtime to the operations of USV and engender detrimental effects to the on-board instrument and sensors. Active control system had been proposed to compensate the rolling stability issue but most of the proposed devices were expensive. This paper developed a gyrostabiliser on USV model to compensate the excessive rolling motion. Gyrostabiliser consists of rotor, gimbal and spinning axes, which commonly used for measuring or maintaining orientations and angular velocities. The gyrostabiliser was mounted vertically inside the USV model. Experiments were conducted to obtain the ideal gains of gyrostabiliser’s controller, to investigate the differences between active- and passive-gyrostabiliser, and to identify the induced pitch effect of the vertical gyrostabiliser to the USV model. The roll angle of the USV was measured by gyro sensor, whereas the precession motor and flywheel motor were controlled by a non-encoder Direct-Current (DC) motor. A proportional controller of the gyrostabiliser was implemented through Arduino Integrated Development Environment (IDE) to ensure optimal performance of gyrostabiliser in precession speed and direction control. The results showed that both active- and passive-gyrostabiliser managed to mitigate the roll angle of USV from +/- 15° back to less than 1° and reached steady state within 2.32 seconds and 2.60 seconds, respectively. The active gyrostabiliser had advantage to return to zero precession angle while the passive gyrostabiliser accumulated 30° precession angle in the experiment. The induced pitch angle by the gyrostabiliser had been found in an insignificant magnitude for the case study. The outcomes of this paper lead to an alternative for improving the robustness of USV in rolling reduction