Estiyanti Ekawati

Quadrotor position control based on model identification and proportional-derivative algorithm

In this paper, position control for a quadrotor in outdoor environment is designed and is validated by experiment. The quadrotor used in the experiment is equipped by accelerometers which are used by an internal controller to maintain its velocity in the global coordinate, and a global position system (GPS) for location determination. A proportional derivative (PD) controller, utilizing feedback of the data location from the GPS, is used to control the motion of quadrotor, reaching a final position from an initial position. Identification of motion model is conducted to determine proper parameters for the controller. The experiments show that the quadrotor can achieve the final positions with acceptable errors in the presence of noise in the GPS measurement and disturbance caused by the wind in outdoor environment.

Development of mechanical coupling for piezoelectric energy harvester adapted to low-frequency vibration

Piezoelectric cantilever is widely use as energy harvester from vibration source. Common of the problem is how to tune the natural frequency of piezoelectric in order to generate maximum ouput power. This work was proposed alternative scheme of mechanical coupling for tune the vibration input into natural frequency of piezoelectric, that consist of cantilever beam and permanent magnet. On the experiment, correlation with the lenght of cantilever beam and the output power are evaluated. Based on experiment, the maximum ouput power could be reached when the length of cantilever beam is twice of the length of the piezoelectric dimension.

Design and implementation of biodiesel washing automation system with set of sensors and programmable logic controller device

Biodiesel washing is part of a biodiesel production process that aims to remove impurities contained in biodiesel. In this research, the process of biodiesel washing was conducted at a liquid separation mini plant using mechanical stirring method. A capacitive sensor was utilized to detect interface which is used in the separation between the two liquids, biodiesel and water. This sensor acts as a substitute for the operator who does visual observation in liquid separation. The temperature and the level of water and mixture in the mixing tank to make the process run optimally was also constantly controlled. The process of washing or purification was carried out with 3 times iteration. Programmable logic controller (PLC) was used as a controller device that serves to detect the sensor readings and operate the pumps and valves in this biodiesel washing process. The water mixing process was tested by mixing water temperature ranging from 70°C to 75°C with 25°C water for 2 times to get the water temperature of ± 55°C. The capacitive sensor module was able to differentiate water from biodiesel. The module produced 58.2 - 84.5 kHz voltage signal when detecting water and 84.5 - 98.8 kHz voltage signal when detecting biodiesel in static condition. The time delay for the transfer from water discharge valve to biodiesel discharge valve is 12 seconds. The overall, biodiesel washing automation system can be operated in ± 18 minutes duration for one washing cycle (excluding the duration of the water heating).

Modelling of Mechanical Coupling for Piezoelectric Energy Harvester Adapted to Low-Frequency Vibration

In our previous work, we have developed a mechanical coupling for energy harvester from vibration source. This energy harvester uses piezoelectric with additional cantilever beam and permanent magnets. Our work proposed alternative scheme of mechanical coupling for tune the vibration input into resonant frequency of piezoelectric. Based on the experiment, correlation between the length of cantilever beam and the output power also evaluated. In this paper, we try to modelling our work into mathematical model and apply it to some case study. For example application, we apply our energy harvester system to generate electrical energy to enlighten the street. The human footsteps can be used as vibration source to generate electrical energy.

Process and controller configuration of high purity binary distillation columns in the purification stage of petrochemical plant

This paper reports the systematic selection of process and controller configurations of four distillation columns operated at purification stage in an olefin petrochemical plant. These columns were demethanizer, deethanizer, depropanizer #1 and depropanizer #2 columns, which separated ethane (C2H6) and propane (C3H8) from methane (CH4) and other heavier components (i.e. C4+). The interconnection of these unit processes propagate the noise and cause severe instabilities towards the final unit process. Therefore, the decision about the choice of the process and control configuration is important in order to ensure the process stability. Such a decision includes the pairing of the manipulated and the controlled variables, the control rules and the inclusion of surge tanks to buffer the disturbances that caused the mentioned instabilities. In particular, the assessment selected three out of six control pairings available for distillation columns. A Proportional — Integral (PI) controller was utilized for all control pairs, and tuned by the Ziegler-Nichols method. In addition, two surge tanks were added as buffers between the demethanizer, the deethanizer and the depropanizer columns. This approach yields the process configuration that was capable of absorbing the disturbance, ensuring a 98–99% product purity and keeping a bias under 2%.

The development of swarm control on quadrotor with visual localization and proportional-integral velocity controller

This paper presents the design and implementation of Boid algorithm with proportional — integral controller to control the velocity of quadrotor which uses a camera-based localization method. The algorithm consists of three rules: cohesion, separation, and alignment in order to mimic the behavior of groups of animals such as bird colonies. The control action was applied to achieve a reference velocity and the controller parameters were obtained using Ziegler-Nichols tuning method. The localization method utilized sixteen combinations of cyan, magenta, yellow, and black color markers. These markers provide coordinate information for the quadrotor.

Speed bump with piezoelectric cantilever system as electrical energy harvester

Speed bump is one common tool to reduce the speed of oncoming vehicles in Indonesia, either in residential road or in main highways. Due to its nature of being run over by oncoming vehicles, speed bumps have a great potential to harvest the mechanical energy at each run. In order to do so, this study equipped a speed bump with spring module, cantilever with piezoelectric module, and electrical energy converter circuit. This paper reports the modifications of our preceding design. These include the modifications of the size of the speed bump to comply with government regulation, the spring characteristics, the cantilever knocking mechanism and the mechanical coupling system. The prototype test by running a motorcar back and forth over the speed bump system produces energy up to 68.82 mJ.

Model predictive control of combined renewable energy sources

This paper proposes strategy to maximize the use of renewable energy on islanded grid. Photovoltaic will be used as main electricity source to supply home load. Lack of electricity will be supplied by picohydro power plant (PHPP). Deficit of electricity supply is utilized as set point reference by a controller implementing model predictive control (MPC) to regulate the flow control valve which feed water to PHPP turbine generator. A comparison of results between PI and MPC is presented. The method is verified using simulation result.

Temperature and humidity characteristic of cassava fermentation process: A preliminary study for air controlled treatment for cassava fermentation process

Fermentation food is known as one of traditional food processing method. This method is used in several countries. In Indonesia, fermented food that made by cassava is very famous in West Java area known as peuyeum or tape. Further aim of study is to control fermentation environment so that tape can be fermented at all area where cassava can be cultivated in Indonesia with better product and consistent quality. As preliminary research, temperature and humidity measurement is reported in this paper before control system is built to understand fermentation process.