Egi Muhammad Idris Hidayat

Design and implementation of density sensor with flow rate as disturbance

In distillation process, density sensor that can overcome the flow rate is very important. This paper represents design and implementation of density sensor with flow rate as a disturbance. The fluid density experiments were carried out using several mixtures of alcohol and water that flew in various percentages. In this design, the density of the fluid is affected by the distance, the height displacement of the hydrometer is measured by the ultrasonic, and the ultrasonic oscillations are ± 1.5 mm which was caused by echo characteristics of the ultrasonic sensor. The problem has been solved with pulse-echo mode with 500 sampling data and 1 ms of sampling time, hence the ultrasonic reading is steady. When the height displacement is greater, the alcohol concentration in the water is higher. The correlation between the height displacements to concentration is non-linear. Various methods of relation model from a distance to concentration have been shown and compared. The best model was acquired by using power equation with a Root-Mean-Square-Error (RMSE), and the result was 2.945. The volume flow rate characteristic has been studied and considered in order to eliminate disruption to concentration readings. The Linear model approach was applied to avoid the influence of the volume flow rate with Root-Mean-Square-Error (RMSE), and the result was 1.095. Minimum flow rate is 0.2 L/m, and maximum flow rate is 0.75 L/m.

Design of a modular, compact, long endurance autonomous underwater vehicle with gliding capabilities for research purpose operations

The consideration of long-term autonomous instrumentation for ocean research applications is now trying to be answered by developing The concept of the Underwater glider. Combining the capabilities of AUV (self-propelled vehicle), which is very good in maneuverability, and underwater glider with their long endurance platform promising advantageous feature. In order to gain some amount of space for carrying many different subsystems, the capacity of payload must be reduced. In addition, there is some additional drag and interference in the optimum cruise efficiency that may cause by external appendages, payload and navigation systems such wings, propeller, etc. Continuing with this concept, prototype of an underwater glider has been designed and built to prove its feasibility and capabilities in real scale to be used for various offshore research. Experiment at the pool of a depth of 5 meters has shown a good result with full functionality of ballast and buoyancy engine. The combination of both systems proves that propelled vehicle forward in a pool as well as open sea.

Modelling, identification, and simulation of autonomous underwater glider in longitudinal plane for control purpose

In this paper a mathematical model of a class of autonomous underwater glider in longitudinal motion plane is presented. The obtained model is a six degree-of-freedom nonlinear model derived based on the kinematic and hydrodynamic principals of the system. The model is further separated into three parts describing the buoyancy, pitch, and glide motion and later linearized. Parameter of the model is identified and validated using experimental data from lab test.

Comparison of prediction methods for moving objects in 3D coordinates using Kalman Filter and Least Square

This paper proposed for comparison of two methods used to predict the trajectory of a moving object in 3D fields using Kalman Filter and Levenberg-Marquardt Least Squares. The Kalman Filter needs dynamic model of the object to predict trajectory, different from The Levenberg-Marquardt method requires previous movements of the object, and the system can determine the next move, to perform this experiment a simulation of the motion was created that an object moving in 3D fields using MATLAB, the movement is also added random noise using normal probability to give real effect, where in fact, there are noise sensors that affect the performance of a system. An experiment proposed to test the speed of each method achieving convergent, and the endurance of each method to receive noise.

Comparison of Indonesian speaker recognition using Vector Quantization and Hidden Markov Model for unclear pronunciation problem

This paper presents a comparison of two classifier methods based on accuracy level in Indonesian speaker recognition for unclear pronunciation problem in a word, simple sentences, and complete sentences. The first method is Vector Quantization (VQ) based on distortion distance and the second method is Hidden Markov Model (HMM) based on the probability value of the data is observed. Based on the experiments, It can be concluded that HMM method have better accuracy than VQ method especially for pronunciation of simple sentences.

Design and implementation of walking pattern and trajectory compensator of NAO humanoid robot

Humanoid robot is a dynamic robot which can walk with two legs like a human. Many researchers are interested in this class of robot due to its flexibility in reaching a variety of terrain and also its similarity to humans. The main problem often faced by developers is the motion control system which is rather nontrivial. Having 25 DOF with only two legs, it is difficult to model the robot movement that achievesstatic and dynamic balance. To facilitate the developer, there needs to be a model that can be used as a foundation for the development of robot motion system. This model allows us to obtain the information which needed in the formation of the robot posture. Information such as joint position, position of the center of mass, ZMP position, support polygon and load torque of each joint can affect the balance of the formed posture. In addition, with the establishment of some proper posture, it is possible to determine several sequential postures that generate a walking pattern. The walking pattern enablesthe humanoid robot to move to another place. However, in reality, this robot movement often has a shifting trajectory from the target location due to various reasons. A Neuro-Fuzzy system has been designed and implemented to compensate error in trajectory tracking. This system processes the trajectory shift by fuzzy logic (linguistic) combined with learning algorithms that allows the system to change its own structures to produce better control output. Smaller shift on trajectory is achieved as the number of learning iteration increases.

Hardware-In-the-Loop Simulation of UAV hexacopter for Chemical Hazard monitoring mission

Field trial is a very critical stage and high risk in UAV development cycle. HILS is a computer-assisted simulation techniques used in the development and testing of complex embedded real-time systems. HILS has the ability to simulate UAV flight characteristics, sensor modeling, and modeling of actuators while communicating in real time with flight control hardware. HILS aims to test the reliability of UAV flight control hardware, integration test of Chemical monitoring systems, and tuning the control parameters. Advantages of using HILS are lower the development costs, improve safety, and streamline the development process. HILS provides development process without using actual UAV platform, but by using a mathematical equation to represent the UAV platform that will be used. HILS implement control system on Pixhawk then the output actuators used as model input. Hexacopter model will produce the attitude and position of hexacopter modeled as sensors model. The output of sensors model will be the input for computing the next control command of Pixhawk. HILS can be used to test the integration of UAV platform with Chemical sensor module to ensure Chemical monitoring missions can run well on the real situation.