Driver mechanism with two degree of freedom (MP 2-DK) is a robotic device that can be used for various applications such as turret drive system, gutling gun, launcher, radar antennas, and communications satellite antennas. The precision and the speed of a MP 2-DK are determined by its control system. The calculation inverse angle due to interference in six degree of freedom is necessary to control a MP 2 DK. This paper analyses three calculation methods of inverse angle which are iteration method using Jacobian matrix, reduction of matrix equations using positioning geometry, and an analytical derivation using a rotation matrix. The simulation results of the three methods showed that the first and the third methods could visually demonstrate three rotational disturbances, whereas the second method could only demonstrate the pitch and yaw (PY) disturbances. The third method required less processing time than the first and the second methods. The best method based on this research was the method of rotation matrix.

Makalah ini membahas tentang desain sistem kendali motor DC brushless menggunakan microcontroller ATMega 16 untuk diimplementasikan pada independent 4-Wheel drives pada platform Mobil Robot LIPI versi 2 (REV-11). Sistem kendali yang dibuat terdiri dari 2 bagian yaitu modul kendali motor DC brushless dan kendali supervisor yang berfungsi untuk mengoordinasi perintah ke modul-modul kendali motor. Untuk mengendalikan platform REV-11, kendali supervisory mengirimkan data referensi berupa kecepatan dan arah pada modul kendali motor sebagai referensi untuk mengendalikan kecepatan dan arah dari masing-masing aktuator pada platform REV-11. Dari hasil pengujian disimpulkan bahwa sistem kendali yang didesain sudah mampu berfungsi dengan baik untuk mengkoordinasi dan mengendalikan kecepatan dan arah gerak motor aktuator platform REV-11.

Rotary car parking system (RCPS) is one of the effective parking models used in the metropolitan area because the mechanical parking system is designed vertically to conserve the land usage. This paper discussed the implementation of fuzzy logic with the Sugeno Inference Model on the RCPS miniature control system. The research started with kinematics analysis and a mathematical model was derived to determine the slot position and optimal power requirements for each condition. Furthermore, the Fuzzy Inference model used was the Sugeno Model, taking into account two variables: distance and angle. These two variables were selected because in the designed miniature RCPS there will be rotational changes of rotation and rotation in turn. Variable distance was divided into four clusters, such as Zero, Near, Medium and Far. While the angle variables were divided into four clusters as well, such as Zero, Small, Medium, and Big. The test results on a miniature RCPS consisting of six parking slots showed that fuzzy based control provided better results when compared to conventional systems. Step response on the control system without fuzzy control showed the rise time value of 0.58 seconds, peak time of 0.85 seconds, settling time of 0.89, percentage overshoot of 0.20%, and steady state error of 4.14%. While the fuzzy control system provided the rise time value of 0.54 seconds, settling time of 0.83 seconds, steady state error of 2.32%, with no overshoot.

The manufacturing technology has developed rapidly, especially those intended to improve the precision. Consequently, increasing precision requires greater technical capabilities in the field of measurement. A prototype of a 3-axis CNC milling machine has been designed and developed in the Research Centre for Electrical Power and Mechatronics, Indonesian Institute of Sciences (RCEPM-LIPI). The CNC milling machine is driven by a 0.4 kW servo motor with a spindle rotation of 12,000 rpm. This study aims to measure the precision of the CNC milling machine by carrying out the measurement process. It is expected that the CNC milling machine will be able toperform in an optimum precision during the manufacturing process. Accuracy level testing is done by measuring the deviations on the three axes namely X-axis, Y-axis, and Z-axis, as well as the flatness using a dial indicator and parallel plates. The measurement results show the deviation on the X-axis by 0.033 mm, the Y-axis by 0.102 mm, the Z-axis by 0.063 mm, and the flatness of the table by 0.096 mm, respectively. It is confirmed that the deviation value is within the tolerance standard limits set by ISO 2768 standard. However, the calibration is required for this CNC milling machine to achieve more accurate precision. Furthermore, the design improvement of CNC milling machine and the application of information technology in accordance with Industry 4.0 concept will enhance the precision and realibility.

Tujuan dari penelitian ini untuk menentukan kondisi perairan sungai kapuas tempat budidaya karamba jaring apung berdasarkan parameter kelimpahan jenis jenis perifitondi sungai kapuas kota pontianak. Metode yang digunakan dalam penelitian ini yaitu metode survey dengan pengambilan sampel di beberapa titik di perairan sungai kapuas. Jenis–jenis perifiton yang terdapat di perairan Sungai Kapuas selama penelitian adalah terdapat 20 jenis perifiton dari 7 kelas yaitu Bacillariophyceae, Cyanophyceae, Chlorophyceae, Choraphyeeae, Protozoa, Myxophyceae dan Rotifera. Kelas Chlorophceae paling banyak jenisnya di perairan sungai kapuas. Nilai Kelimpahan perifiton selama penelitian berkisar 2800 – 12413 sel/cm2. Kelimpahan perifiton yang paling tinggi terdapatdi stasiun I dengan rerata kelimpahan 12.413 sel/ cm2. Berdasarkan pengamatan nilai rata-rata indeks keanekaragaman untuk perifiton berfluktuatif pada setiap stasiun di sungai kapuas dengan kisaran rata-rata  1,869 - 3,322, hasil perhitungan diperoleh  rata-rata indeks keanekaragaman perifiton berada pada kisaran sedang. Nilai indeks dominansi jenis (C) yang diperoleh selama penelitian di perairan sungai kapuas berkisar antara 0,006 - 0,014. Berdasarkan perhitungan kelimpahan perifiton, indeks keanekaragaman jenis (H’) dan indeks dominasi jenis (C) dapat disimpulkan bahwa kelimpahan tergolong tinggi, keanekaragaman jenis pada kisaran sedang dan tidak ada spesies yang mendominasi perairan sungai kapuas. Hasil dari pengukuran kualitas air secara umum masih mendukung kehidupan organism termasuk perifiton.