Young-Hak Chang

Development of steering control system for autonomous vehicle using array magnetic sensors

In this paper, development of steering control system for autonomous vehicle using array magnetic sensors of the magnetic guidance based is described. The Steering system is operated following on magnetic marker position of on the roadway. For experimental test, steering system is designed and operation test is realized.

Position Sensing System for Magnet Based Autonomous Vehicle and Robot Using 1-Dimensional Magnetic Field Sensor Array

In this paper, a position sensing system for magnet based autonomous vehicle and robot using 1-diemnsional magnetic field sensor array was described. In advanced vehicle and robot control, position sensing is an important task for the identification of their locations, such as the lateral position within a trajectory. The magnet based autonomous vehicle and robot was identified position using magnetic materials. In the magnetic sensing system, the Earth field is a disturbance. It should be estimated a real-time. And, the memory space should be reduced in implementation. To solve the above problems, this paper proposes the magnetic field sensor array system included a vertical component of magnetic field, a linear region of the sensor output, method of position determination using a simple equation with a microcontroller. The proposal is verified practicability for magnetic position sensing system by the experimental results

Embedded Switched-Inductor Z-Source Inverters

In this paper, a ripple input current embedded switched-inductor Z-source inverter (rESL-ZSI) and a continuous input current embedded switched-inductor Z-source inverter (cESL-ZSI) are proposed by inserting two dc sources into the switched-inductor cells. The proposed inverters provide a high boost voltage inversion ability, a lower voltage stress across the active switching devices, a continuous input current and a reduced voltage stress on the capacitors. In addition, they can suppress the startup inrush current, which otherwise might destroy the devices. This paper presents the operating principles, analysis, and simulation results, and compares them to the conventional switched-inductor Z-source inverter. In order to verify the performance of the proposed converters, a laboratory prototype was constructed with 60 Vdc input to test both configurations.

A Study on Design of 50kW PMSG for Micro-grid Application

In this paper, the 50kW aerogenerator which is applicable to the microgrid was designed and analyzed by using commercial simulation program Maxwell 2D. Particularly, the suggested PMSG to reduce the cogging torque introduced the offset and skew concept. The suggested optimal value of offset and skew was decided by 2mm and 60 degree of electric angle. The simulation results of the PMSG when load operation condition showed the average harmonic distortion 1.3%, voltage 322.41V, current 94.95A, and iron loss 9.73W, eddy current loss 73.68W, copper loss 3.52kW. The capacity of aerogenerator calculated 61.56kW, and the suggested design process can be applied to higher capacity generator.

A Study on Optimization Design of Off-grid Hybrid Power Generation System

The majority of electric power in the domestic manned islands with off-grid power system is supplied by the diesel generators. However, in the case of off-grid islands the fuel cost is more expensive to inland areas and difficult to transport them to islands. So the development of renewable energy system using natural resource have been recently introduced. But renewable energy that depend on the natural environment, it is necessary to organized the hybrid system with existing diesel engine because the energy is difficult to maintain stable electric power. This paper presents the results of a feasibility study of hybrid system with energy storage system such as wind, solar, battery and diesel engine. The study included off-grid island as the Seogeochado islands located in Jeolanamdo Province. And, the paper proposed a optimal capacity of hybrid system configuration to maintain carbon free with minimum investment cost. the analysis of economic adaptability performed by HOMER program.

A Study on non-linear trajectory shaped apparatus applied solar tracking device

In this paper, 1-axis tracking mechanism of solar-cell panel, which is able to rotate from -90 degree to +90 degree for maintaining always perpendicular between solar-cell panel and sun, was analyzed. This paper propose the non-linear shaped guidance and analyze mathematical formulation of non-linear shape. This analysis shows that it is able to identify the non-linear shaped guidance. Especially, even though the length of rotating link have changed, the non-linear shaped guidance could be confirm with proper size. As effectiveness of this result, 10% efficiency rising is estimated compared to the conventional 1-axis tracking mechanism and also optimal non-linear shaped guidance can be suggested for various size of solar-cell panel. Therefore the flexible mass-production is possible for various size of non-linear shaped guidance.

A Study on Design of Control Device on Small Wind Generator Using 2-Level Boost Converter

The small wind generator with existing mechanical control system has a frequent failure and malfunction, and its maintenance is difficult. In this paper, an electric control method using a boost converter for small wind generator was suggested. The suggested 2-level boost converter control device was manufactured and its experimental operation were conducted on a wind generator with 200 [W] capacity. As a result of experimental device, the control by a boost converter was executed at the point that the output voltage of a wind generator became 36 [V] so it could be identified that the output voltage of a wind generator diminished and then it became 0 [V] after 5 [sec]. Besides, in case of applying the method suggested in this paper to a small wind power generation facility for street lights, it is expected to reduce its maintenance by preventing a frequent failure of a generator and to improve its utilization rate.

The study on prediction of power generation of offshore wind farm of western and southern coast utilizing offshore buoy meteorological observations data

Given the massive early investment needed for the construction of large offshore wind farms, the ROI (return of investment), which can guarantee sufficient profitability, should be secured in advance. The highest priority in terms of determining profitability is to estimate the power production volume of an offshore wind farm based on surveyed wind resources. The maritime measurement of wind resources in Korea has only been performed at one point in the water off the coast of Wido. And the measurements released by the Korea Meteorological Administration were used, as there are no available long-term measurements for other areas. This paper suggested some analysis results that have been collected using a 4[m] tall meteorological-purpose buoy facility installed at the West Coast. The measured wind speeds were corrected at a height of 80[m], which is the average hub height of wind power generators. In addition, an offshore wind farm consisting of 34 3[MW] wind power generators were designed using WindPRO in order to estimate annual power production capacity and utilization rates. The provided average wind speed was 4.92[m/s], and a wind speed of 6.66 [m/s] was obtained by correcting the average wind speed at a height of 80[m]. The power generation capacity and utilization rates of a 100[MW] offshore wind farm, designed using WindPRO based on the corrected data, were estimated to be 294,313.9[MWh] and 32.9[%], respectively. As power production using tidal currents was envisaged to be possible due to the average depth of the water at which an offshore wind farm is to be located was found to be 34[m], it was thought that the design of a hybrid wind farm combining wind power with tidal current power would prop up the economic feasibility of the farm.

Cancellation of background field using magnetic compass sensor for magnetometer based autonomous vehicle

In this paper, a cancellation method of background field using a magnetic compass sensor is proposed for a magnetometer based autonomous vehicle. The magnetic fields from sample magnets are first measured to determine the characteristics of the field patterns as the basis for detection and position identification. The properties of the earths magnetic field on the recognition of magnet field patterns are discussed. Also presented in the paper is a discussion of a position sensing system with a cancellation of the earths field. The position sensing technique was implemented in the guidance of autonomous vehicle. By the experiment, it is verified that the proposed cancellation method of background field can be useful for an autonomous vehicle.

Platform Design of Caterpillar Typed Electrical Vehicle

In this paper, a platform design of caterpillar typed electrical vehicle is proposed. Nowadays, there have been many researches on mobile robots in the various ways. Many different fields such as military, exploration, agricultural assistance and disaster relief have applied the mobile robot. Design condition of stable angle, upset angle is reflect to caterpillar typed electrical vehicle. To experiment, developed a caterpillar typed electrical vehicle and design a driving controller. Developed caterpillar typed electrical vehicle is tested about operating and driving. Test environment is consisted of driving on flatland and climbing 15 degree and outdoor 40 degree slope. It is confirmed that developed tracked electric vehicular robot can driving and climbing.