Penggunaan system penentuan dan kawalan adalah subsistem yang penting dalam penerokaan misi angkasa. Untuk memperoleh ketepatan menunjuk arah, penggerak system kawalan memainkan peranan yang penting. Untuk satelit bersaiz kecil, roda tindak balas adlah paling disyorkan oleh kerana mekanikal dan prestasinya. Kajian telah dilakukan pada konfigurasi dan pelaksanaan roda tindak balas ke dalam sistem kawalan atitud. Perisian MATLAB Simulink telah digunakan bagi membina sistem kawalan atitud untuk roda tindak balas. Kajian mendalam telah dilakukan bagi lebih memahami dalam bidang ini. Terdapat beberapa jenis konfigurasi roda tindak balas iaitu konfigurasi tiga roda tindak balas, pyramid dan tetrahedral. Dalm kajian ini, penggunaan empat roda tindak balas difokuskan. Penggunaan empat roda tindak balas memberikan kelebihan kepada sitem kawalan atitud. Dalam usaha untuk melaksanakan sistem kawalan atitud, semua parameter dan formula seperti parameter orbit, rujukan atitud, kesalahan atitud, pengawal, pengedaran matrix roda tindak balas, kinematik dan dinamik telah dikaji. Penggunaan kaedah kawalan terbitan berkadar (PD control) telah digunakan di dalam kajian ini. Dalam proses penalaan kawalan terbitan berkadar, frekunsi semulajadi dan nisbah redman telah divariasikan unrtuk mendapat sistem respon yang baik. Daripada hasil simulasi, graf telah diperolehi. Analisis dan pemerhatian keatas masa menetap kelajuaan sudut satelit, tork dihasilkan bersama tiga paksi satelit dan tork roda tindak balas. Masa menetap ialah masa yang diperlukan untuk sesuatu parameter mencapai keadaan stabil. Kegagalan satu daripada empat roda tindak balas telah dianalisis. Daripada keputusan simulasi, kegagalan satu daripada empat roda tindak balas memberi kesan kepada sistem. Ia deperhatikan bahawa masa menetap meningkat. Oleh itu, parameter yang ditetapkan mengambil masa yang lama untuk mancapai nilai sifar atau untuk mencapai atitud yang dikahendaki.
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The use of determination and control systems is among the crucial subsystem in the exploration space missions. To better pointing accuracy, the actuator of the attitude control plays an important role. For small satellites, reaction wheel was the most preferred due to its mechanical and performance. The study conducted on the configuration and implementation of reaction wheels by design and simulate an attitude control system using. The software to design and create an attitude control system for the reaction wheel was using MATLAB Simulink software. A further study on reaction wheel configuration have been done to be more understanding in this field. There are several types of reaction wheel configurations namely three-wheel configuration, pyramid configuration and tetrahedral configurations. In this study, the use of four response wheel is focus on. The use of four reaction wheels gives a beneficial to the attitude control system. To implement an attitude control system, all the parameter and mathematical equation namely orbit parameter, attitude reference, attitude error equation, controller, reaction wheel matrix distribution, kinematic equation and dynamic equation were studied. The Proportional Derivative control (PD) control method was used in this studies. In the process of tuning the PD controller, the natural frequency and damping ratio were varied to get fine response system. From the simulation results, graphs were obtained. Analysis and observations over the fixed time velocity of the satellite angle, the torque is generated along the three axes of the satellite and the torque of the reaction wheel. Setting time is the time required for a parameter to reach a stable state. The failure of one of the four reaction wheels was analyzed. From the simulation results, the failure of one of the four reaction wheels affects the system. It is observed that the settling time increases. Therefore, the set parameters take a long time to reach the value of zero or to achieve the desired attitude.
Satellite attitude performance of reaction wheel based controlled small satellite / Muhammad Aliff Ashraf Abdullah