Estiko Rijanto

Analysis of Inverse Angle Method for Controlling Two Degree of Freedom Manipulator

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.

Battery state of charge estimation by using a combination of Coulomb Counting and dynamic model with adjusted gain

Majority of electric vehicles depend on batteries that require a Battery Management System (BMS). Increasing accuracy of State of charge (SoC) estimation was crucial. The uncomplicated method for SoC estimation is Coulomb Counting (CC), however it has drawback in information of previous SoC initial value and tolerate with error propagation. Dynamic model equipped with integral controller can increase accuracy of the CC method. In this paper adjusted gain of the integral controller is proposed to further improve performance of SOC estimation. The Li-ion battery was modelled using first order RC battery model. Least square method is used to determine parameter of battery model. The simulation results show that the combination of CC and dynamic model with fixed integral gain could increase accuracy of the CC algorithm approximately to 87%, and the mixed algorithm with adjusted integral gain could further increase it to around 89%.

SOC estimation for Li-ion battery using optimum RLS method based on genetic algorithm

Battery state of charge (SOC) has to be estimated properly in order to build a good battery management system (BMS) for electric vehicles. A Lithium battery dynamics has nonlinearity element and time varying parameter values. The speed of parameter change is different to each parameter. This paper proposes a new method of SOC estimation based on recursive least square (RLS) algorithm with multiple fixed forgetting factors whose optimum values are determined using Genetic Algorithm (GA). Open circuit voltage (OCV) is treated as parameter to be estimated together with internal resistance. Computer scripts of battery model, RLS, and GA have been built and numerical simulation has been conducted. Urban Dynamometer Driving Schedule (UDDS) was used as the input data. The results show that the combination algorithm between multiple fixed fogetting factor RLS (MFFF-RLS) and GA provides better performance than single fixed forgeting factor RLS (SFFF-RLS) as well as RLS without forgetting factor in estimating terminal voltage, OCV, SOC, and internal resistance of the Lithium battery. The multiple objective optimization can be solved using the built GA computer code giving peformance index of 1.09∗10−6 for SFFF-RLS and 2.11∗10−7 for MFFF-RLS. It can be concluded that the proposed algorithm works satisfcatory.

Trends in robot assisted endovascular catheterization technology: A review

Thirty-three years has passed since the first utilization of laparoscopic technology in surgery, yet the deployment of robots in endovascular catheterization process is currently still in its infancy. Following up some reviews by other researchers, this paper elaborates trends in robotic-assisted endovascular catheterization through literature study of published articles since the last 4 years, direct observation of on going minimally invasive endovascular intervention surgery, and discussions with an interventional cardiologist. Some important facts have been identified such as, some commercial robots have been used In Vitro, and magnetic resonance compatible slave robots as well as methods for physician skill evaluation are under development. The existing issues include miniaturization of flexible robots, side contact force sensing device for catheters, and stable haptic feedback in master robot. Some examples of interesting topics for future research are more stable and robust haptic feedback, structure and mechanism of catheter, intra-cardiac sensors, estimation methods of catheter tip states (position, angle and contact force), modeling and control methods, image sensing technology which does not yield radiation exposure yet more economically affordable, and simulator with skill assessment algorithm.

Client Server System for MiroSot Robot Soccer

Robot Soccer has become increasingly popular over the last decade as a platform for education and entertainment. By FIRA rule, each team has a camera, a computer, and some robots and in every game there will be two pieces of camera, 2 computers, and some robots. The camera used is different for each team, so the team with a better camera would have a better chance of winning than a team that has a crappy camera. For education and training that system is too expensive. To promote robotic soccer research, we need a low cost robot and multi system of vision and a communication device. A client server system for Mirosot by this method it only required a single camera and a single frame grabber card for vision system. From the experiment result it was obtained that data delivery travel time from the server to the client is less than 1 millisecond.

Grammatical Evolution Algorithm for Position Prediction of the Ball in Robot-Soccer Goal Keeper Optimization

Position prediction of the ball that approaches to the goal is necessary for a goalkeeper robot. In this paper, grammatical evolution is used for prediction. Grammatical evolution will be tested on grammar with linear characteristic. Data used in this research was taken from the Y-axis coordinate of the Ball and divide into 3 Home area. The research focuses on two conditions of the ball: straight movement and bouncing off the wall. From the results of this study, it was obtained three functions which can be used to predict position of the ball in goal area. The smallest mean of fitness value is 1.24729 for straight movement and 2.64366 for bouncing off the wall conditions.

Single phase boost inverter using hybrid modelling approach

Boost inverters provide the ac voltage from lower dc voltage source without additional transistor switches compared to the conventional inverters. Some control shave already been proposed to control boost inverters, but most control methods are based on small signal analysis and nonlinear models which make computation complicated and require fine tuning. In this paper, the authors propose a control scheme based on the hybridmodel. The method does not require complicated mathematical formulas and allows easier tuning. The simulation results show that the boost inverter can achieve a good performance using this control approach.

RLS with optimum multiple adaptive forgetting factors for SoC and SoH estimation of Li-Ion battery

Recursive least square (RLS) with a single forgetting factor has been commonly used for parameter and state estimation of dynamical systems. In many applications such as robotics, electric vehicles, renewable energy systems, and smart-grid, accurate battery state of charge (SOC) and state of health (SOH) estimation is essential for the safe and efficient operation. To this end, the challenge lies in identifying and parameterization the temporal behavior of Lithium-Ion batteries, because their response is nonlinear and time-varying. This paper proposes a new RLS algorithm with optimum multiple adaptive forgetting factors (MAFFs) for SOC and SOH estimation of Li-ion batteries. Particle swarm intelligence is employed for identifying the system parameters. The performance of the optimum MAFF-RLS algorithm is compared to RLS with multiple fixed forgetting factors (MFFFs). Performance evaluation is carried out using the Urban Dynamometer Driving Schedule (UDDS). The simulation results indicate the better performance of MAFF-RLS algorithm compared to MFFF-RLS algorithm in terms of mean square error of SOC and internal resistance.

Recent results of robotics R & D in the Indonesian Institute of Sciences: Mobile robot, articulated robot, pan tilt mechanism, and object recognition

This paper outlines recent results of robotics research and development (R & D) in the Indonesian Institute of Sciences (LIPI). Research prototypes of mobile robot equipped with articulated robot and pan tilt mechanism (PTM) for remote controlled weapon systems (RCWS) have been developed. R & D has been carried out concerning mechanical structure, kinematics, dynamics, motion control, trajectory planning, object recognition, and data communication. Some important results are reported including trajectory planning of mobile robot which minimizes energy consumption, positioning control, PTM stabilization using Inertial Measurement Unit (IMU), and object recognition using Scale Invariant Feature Transform (SIFT). Presently conducted R & D activities are also presented including control of Brushless DC motor (BLDC) and 32 bit data communication method through 8 bit ports between microcontrollers in the RCWS. From the experiment results it can be concluded that PWM reference signal is not suitable for directly replacing analog speed reference signal of the BLDC motor. Experiment results proved that the developed method of 32 bit data transmission through 8 bit ports functions well without error or data loss.