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Subsurface imaging is challenging; it is difficult to detect objects visually. In this research, a novel non-contact photoacoustic (PA) imaging system was developed to detect subsurface objects. The Rosencwaig-Gersho (RG) model was successfully employed to capture microobject images covered by rough paint. The experiments were conducted using a copper ring with a 1-mm diameter fully coated by rough paint with an average thickness of 2.3 μm. The resulting PA images exhibited up to 72% consistency despite the rough paint; the shapes of the objects were clearly recognized before and after coating. To conduct the experiment, simulations and image acquisitions were arranged. Then, the system capability to produce tomographic images was improved by adjusting the thermal diffusion lengths, and subsurface object images were successfully acquired at depths of 2.0, 2.6, 9.8, and 52 μm. The detailed composition of image slices displayed the structure profile of subsurface objects appropriately.

Navigasi merupakan salah satu kendala utama dalam perancangan robot otomatis. Metode kontrol berbasis PID yang popular dipakai menemui sejumah kendala pada sistem yang tidak pasti dan nonlinier. Keunggulan logika fuzzy sebagai metode kontrol dibandingkan kontroler konvensional adalah fleksibilitas dan kemudahan perancangan untuk sistem yang kompleks. Pada penerapan metode kontrol logika fuzzy, robot dirancang agar mampu bernavigasi secara otomatis dan dapat menelusuri peta lapangan pengujian dengan segala kondisi serta variasi secara efektif dan efisien. Peta lapangan yang digunakan sebagai pengujian adalah peta lapangan yang digunakan dalam Trinity College Fire-Fighting Home Robot (TCFFHR) Contest 2016. Untuk perangkat pemroses robot memakai mikrokontroller tipe ATMega128. Robot ini memakai sensor Sonar Range Finder (SRF) sebagai sensor utama serta menggunakan sensor infrared dan sensor garis. Dari hasil pengujian robot yang menggunakan metode kontrol fuzzy mampu bernavigasi dengan rasio kontak per putaran yang lebih baik dibandingkan metode kontrol Propotional-Derivative dan sangat efektif dalam menghadapi berbagai situasi lingkungan yang terjadi ketika bernavigasi.

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A ball and beam trainer kit based on microcontroller was developed for teaching control system course for the sophomore students. This specially-purposed kit consists of a ball located on a beam with a fixed axle at one of its end. At the other end, a servomotor was employed to control the position of the ball by adjusting the rotation angle of the servomotor. Seven predetermined positions were set to 10, 20, 30, 40, 50, 60, and 70