Transesterification process of used cooking oil to biodiesel need heating and mixing of ingredients and catalyst at temperature of 30-65oC and stirring speed of 700 rpm for 60 minutes. This research builds a prototype of biodiesel reactor control system to control those process automatically. The system is built using heater element, LM35DZ temperature sensor, DC motor to drive the stirrer, and rotary encoder sensor. PLC OMRON CP1E NA20DR-A is used as system controller by using PID algorithm. The results of this research shows that this system works well as expected. Test results of motor speed control shows, at 700 rpm set point this system gives stable response at 100 % Proportional band, 1,6 s Integral, and 0,2 derivative PID parameters, the system at this setting gives fast rise time and have small overshoot. Test result of temperature control shows, at 60oC set point this system works well at 1% proportional band, 400 s integral, and 0 s derivative PID parameters, the system at this setting gives fast rise time and stable steady state.

Robot Keseimbangan memiliki dinamika yang cepat, tidak stabil, dan nonlinear sehingga memerlukan pengendali yang sesuai. Robot keseimbangan menggunakan sensor accelerometer untuk mengukur perubahan sudut. Sifat sensor tersebut adalah sangat sensitif dan bernoise sehingga memerlukan metode untuk mengurangi noise tersebut. Pada penelitian ini digunakan pengendali PID karena memiliki respon yang cepat dalam menanggapi perubahan sudut dan mudah untuk diterapkan. Sementara untuk mengurangi noie sensor digunakan metode kalman filter. Hasil pengujian menunjukkan bahwa metode kalman filter mampu untuk mengurangi noise pada sensor accelerometer. Nilai parameter kalman filter sangat mempengaruhi hasil filter sehingga memerlukan penentuan nilai yang tepat. Nilai matriks variasi proses harus lebih besar daripada nilai matriks variasi pengukuran. Nilai parameter Kalman filter yang terbaik adalah matriks variasi proses R = 10 dan matriks variasi pengukuran Q = 0; 01. Pengendali PID dapat menstabilkan robot pada posisi tegak. Nilai parameter terbaik pengendali PID adalah Kp = 20, Ki = 1, dan Kd = 20.

Baterai Lithium Polymer (Li-Po) dipilih sebagai sumber daya robot dikarenakan baterai Li-Po karena memiliki bobot yang ringan dan kapasitas penyimpanan listrik yang besar. Namun untuk mengetahui daya baterai yang digunakan, para pemilik robot harus menghentikan robot kemudian dilakukan pengukuran baterai mengunakan alat ukur. Penelitian ini bertujuan memantau nilai tegangan pada baterai Li-Po yang melalui motor penggerak pada robot sepakbola beroda tanpa menggunakan alat ukur dan hasilnya dapat ditampilkan pada komputer maupun PC secara nirkabel. Percobaan dilakukan menggunakan peralatan sensor tegangan dan modul wifi nodeMCU. Hasil dari penelitian ini sensor tegangan dapat membaca data dan didapat nilai standar deviasi 0,39 dan error rata-rata 0,43 yang menunjukkan bahwa sensor memiliki tingkat akurasi yang tinggi. Sementara untuk proses pemantauan sensor berjalan dengan lancar tanpa ada kendala.

Dieng area is a mountainous area, dieng has land with high fertility levels so that they are increasingly high in the agricultural sector, especially potatoes. During the time, the technology for sorting potato seeds was still manual with humans, so it was less effective. The conveyor here is very useful as this device which will later work with loadcell as a weigher, and this device will be driven using a dc motor then the speed stabilization uses the PID algorithm with trial and error methods and this tool is supported using ultrasonic sensors and two servo sorting. This device works with 1 cycle, namely with 1 command with a value of KP 55, KI 20 and KD 0.001. The conveyor movement is quite stable with an average error value of 0.276 load cell with a standard deviation of 0.211877 with an achievement level of 80%.

Biodiesel is one type of biomass as a renewable energy resource. Biodiesel system is a sequential system that can be controlled with a programmable logic controller (PLC) device. Sequential system problems can be solved by making a state diagram that represents the conditions and transitions of the system. Biodiesel system is represented in a state diagram then converted into a ladder diagram as one of the programming languages of a PLC. The method of converting state diagrams into ladder diagrams is structured programming method used by both levels, beginners and experts in running PLCs. The advantage of this method is reliability in detecting errors in the process. The error can be known clearly and structured by programmers. The design of the human-machine interface (HMI) of the biodiesel system in this study was made on CX One software (CXP and CXD) using a PLC type CP1E. System design made based on a state diagram has been successfully tested. In this design, the required memory is 6.5% of the total memory of the PLC CP1E.