• Title/Summary/Keyword: Sun sensor

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The Design of Sun Sensor and the Construction of Control Algorithm for Digital Sun Seeker Control System (디지털 향태양 제어장치를 위한 Sun Sensor 설계 및 제어 알고리즘 구성)

  • 박진양;고명삼
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.4
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    • pp.590-596
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    • 1987
  • In this paper, it was studied on the design of a sun sensor which is able to sense the declinations of an azimuth angle and a zenith angle for a digital sun seeker control system so that it will seek the sun accurately. And, it was considered the construction of digital controllable algorithms through experiments. Peculiar design method of the sun sensor is that sensor box was constructed with three square silicon solar cells and that the three cells were mounted unsymmetrical forming the

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A Solar Cell Based Coarse Sun Sensor for a Small LEO Satellite Attitude Determination

  • Zahran, Mohamed;Aly, Mohamed
    • Journal of Power Electronics
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    • v.9 no.4
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    • pp.631-642
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    • 2009
  • The sun is a useful reference direction because of its brightness relative to other astronomical objects and its relatively small apparent radius as viewed by spacecrafts near the Earth. Most satellites use solar power as a source of energy, and so need to make sure that solar panels are oriented correctly with respect to the sun. Also, some satellites have sensitive instruments that must not be exposed to direct sunlight. For all these reasons, sun sensors are important components in spacecraft attitude determination and control systems. To minimize components and structural mass, some components have multiple purposes. The solar cells will provide power and also be used as coarse sun sensors. A coarse Sun sensor is a low-cost attitude determination sensor suitable for a wide range of space missions. The sensor measures the sun angle in two orthogonal axes. The Sun sensor measures the sun angle in both azimuth and elevation. This paper presents the development of a model to determine the attitude of a small cube-shaped satellite in space relative to the sun's direction. This sensor helps small cube-shaped Pico satellites to perform accurate attitude determination without requiring additional hardware.

Analysis of Sun Tracking Performance of Various Types of Sun Tracking System used in Parabolic Dish Type Solar Thermal Power Plant (접시형 태양열 발전시스템에서 사용하는 여러 가지 형태의 태양추적시스템의 태양추적성능 분석)

  • Seo, Dong-Hyeok;Park, Young-Chil
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.4
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    • pp.388-396
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    • 2011
  • Sun tracking system is the most important subsystem in parabolic dish type solar thermal power plant, since it determines the amount of thermal energy to be collected, thus affects the efficiency of solar thermal power plant most significantly. Various types of sun tracking systems are currently used. Among them, use of photo sensors to located the sun(which is called sensor type) and use of astronomical algorithm to compute the sun position(which is called program type) are two of the mostly used methods. Recently some uses CCD sensor, like CCD camera, which is called image processing type sun tracking system. This work is concerned with the analysis of sun tracking performance of various types of sun tracking systems currently used in the parabolic dish type solar thermal power plant. We first developed a sun tracking error measurement system. Then, we evaluate the performance of five different types of sun tracking systems, sensor type, program type, hybrid type(use of sensor and computed sun position simultaneously), tracking error compensated program type and image processing type. Experimentally obtained data shows that the tracking error compensated program type sun tracking system is very effective and could provide a good sun tracking performance. Also the data obtained shows that the performance of sensor type sun tracking system is being affected by the cloud significantly, while the performance of a program type sun tracking system is being affected by the sun tracking system's mechanical and installation errors very much. Finally image processing type sun tracking system can provide accurate sun tracking performance, but costs more and requires more computational time.

An intelligent sun tracker with self sensor diagonosis system (자기 센서진단기능을 가진 지능형 태양추적장치)

  • 최현석;현웅근
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.452-456
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    • 2002
  • The sensor based control system has some sensor fault while operating in the field. In this paper, a sensor fault detection and reconstruction system for a sun tracking controller has been researched by using polynomial regression and principle component analysis approach. The developed sun tracking system controls tow actuators with sensor based mechanism as on-line control and sun orbit information as off-line control, alternatively. To show the validity of the developed system, several experiments were illustrated.

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Design of Sun Tracker System for Solar Power Generation (태양광 발전을 위한 태양추적시스템 설계)

  • An, Jun-Sik;Heo, Nam-Euk;Kim, Il-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.330-332
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    • 2006
  • In this paper, sun tracking system using Sun position sensor is proposed, the sun tracking system designed as which raises the efficiency of solar power generation. It design the structure being simple and it develops the system which is economical efficiency. It develops the hazard technique such as location tracking method of the sun which uses the sensor and to use the motor solar cell module movement. The Sun tracking system makes the drive in order to do with one axis and to use the sensor and to know in order to put out, the location of the sun and it makes. To make the solar location tracking sensor where the structure is simple it used two solar cells.

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A Study on the Development of Two Axes Sun Tracking System for the Parabolic Dish Concentrator (Parabolic Dish형 태양열 집열기를 위한 2축 태양추적장치의 개발에 관한 연구)

  • Park, Y.C.;Kang, Y.H.
    • Solar Energy
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    • v.19 no.4
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    • pp.81-91
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    • 1999
  • The work presented here is a design and development of sun tracking system for the parabolic dish concentrator. Parabolic dish concentrator is mounted on azimuth and elevation tracking mechanism, and controlled to track the sun with computed and measured sun positions. Sun tracking mechanism is composed of 1/30000 speed reducer(3 stages) and 400W AC servomotor for each axis. The nominal tracking speed of each axis is ${\pm}0.6^{\circ}/sec$ and the system has a driving range of $340^{\circ}$ in azimuth and of $135^{\circ}$ in elevation. Sun tracking control system consists of sun sensor, wind speed and direction measurement system, AC servomotor position control system and personal computer as a master controller. Sun sensor detects the sun located within ${\pm}50^{\circ}$ measured from the sun sensor normal direction. Computer computes the sun position, sunrise and sunset times and controls the orientation of parabolic dish concentrator through the AC servomotor position control system. It also makes a decision of whether the system should follow the sun or not based on the information collected from sun sensor and wind speed and direction measurement system. The sun tracking system developed in this work is implemented for the experimental work and shows a good sun tracking performance.

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DEVELOPMENT OF ULTRA-LIGHT 2-AXES SUN SENSOR FOR SMALL SATELLITE

  • Kim, Su-Jeoung;Kim, Sun-Ok;Moon, Byoung-Young;Chang, Young-Keun;Oh, Hwa-Suk
    • Journal of Astronomy and Space Sciences
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    • v.22 no.1
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    • pp.47-58
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    • 2005
  • This paper addresses development of the ultra-light analog sun sensors for small satellite applications. The sun sensor is suitable for attitude determination for small satellite because of its small, light, low-cost, and low power consumption characteristics. The sun sensor is designed, manufactured and characteristic-tested with the target requirements of ${\pm}60^{\circ}$ FOV (Field of View) and pointing accuracy of ${\pm}2^{\circ}$. Since the sun sensor has nonlinear characteristics between output measurement voltage and incident angle of sunlight, a higher order calibration equation is required for error correction. The error was calculated by using a polynomial calibration equation that was computed by the least square method obtained from the measured voltages vs. angles characteristics. Finally, the accuracies of 1-axis and 2-axes sun sensors, which consist of 2 detectors, are compared.

A Non-contact Two-Dimensional Position Sensing Device Using Electromagnetic Induction (전자기 유도 방식을 이용한 비접촉식 2차원 위치 센서)

  • Ryu, Young-Kee;Koh, Kuk-Won;Kim, Hak-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.11
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    • pp.1159-1163
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    • 2012
  • In this paper, we would like to introduce two dimensional non-contact position sensor by using an electromagnetic induction based coil system and an algorithm to estimate the position of pointer. The sensor which will introduce in this paper is composed of a pointer including LC resonant circuit and a sensor board to detect the electromagnetic signal from the pointer. Because of the simplicity shape of the line antenna, low cost and free form curved shape of the sensor device is possible. In this research, we proposed a new two dimensional non-contact type electromagnetic sensor system and realized the proposed sensor device. From the experiments, the proposed device can be employed for the two dimensional position sensor.

Monitoring Systems for Embedded Equipment in Ubiquitous Environments

  • Bae, Ji-Hye;Kang, Hee-Kuk;Park, Yoon-Young;Park, Jung-Ho
    • Journal of Information Processing Systems
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    • v.2 no.1
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    • pp.58-65
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    • 2006
  • Accurate and efficient monitoring of dynamically changing environments is one of the most important requirements for ubiquitous network environments. Ubiquitous computing provides intelligent environments which are aware of spatial conditions and can provide timely and useful information to users or devices. Also, the growth of embedded systems and wireless communication technology has made it possible for sensor network environments to develop on a large scale and at low-cost. In this paper, we present the design and implementation of a monitoring system that collects, analyzes, and controls the status information of each sensor, following sensor data extracted from each sensor node. The monitoring system adopts Web technology for the implementation of a simple but efficient user interface that allows an operator to visualize any of the processes, elements, or related information in a convenient graphic form.

Study on the Allocation Method of Sun Sensor Assembly for GEO-KOMPSAT2 (정지궤도복합위성 태양센서 장착방법에 관한 연구)

  • Park, Young-Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.7
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    • pp.551-556
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    • 2018
  • A lot of hardwares are allocated on the satellite to perform the attitude control. Sun sensor is very important hardware to acquire the initial attitude after separation from launcher and to maintain the safety attitude from the satellite anomaly operation. So the allocation of the sun sensor to acquire the field of view and the attitude control design using it, are critical work in the beginning of development. Number of Sun sensor for GEO-KOMPSAT2 is reduced with respect to COMS due to star tracker usage. The additional sun sensor using COMS heritage is considered. In this paper, it is described the analysis and the results on the method for the safety improvement which is to enlarge the field of view and to consider the harness connection of P/R-side of the sun sensor.