• Title/Summary/Keyword: weight system

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Study on Gravitational Torque Estimation and Compensation in Electrically Driven Satellite Antenna System (전기식으로 구동하는 위성안테나 시스템의 중력토크 추정 및 보상에 관한 연구)

  • Kim, Gwang Tae
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.10
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    • pp.789-796
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    • 2016
  • The weight of an antenna system pointing satellite on the mobile platform is restricted by the weight limit of the mobile platform. The maximum power of the actuator driving the antenna system is thus limited because a high power actuator needs a heavier weight. Thus, a drive system is designed to have a low torque requirement by reducing the gravitational torque depending on gravity or acceleration of the mobile platform, including vibration, shock, and accelerated motion. To reduce the gravitational torque, the mathematical model of the gravitational torque is preferentially obtained. However, the method to directly estimate the mathematical model in an antenna system has not previously been reported. In this paper, a method is proposed to estimate the gravitational torque as a mathematical model in the antenna system. Additionally, a method is also proposed to calculate the optimal weight of the balancing weight to compensate for the gravitational torque.

Quality Evaluation by Root Weight Distribution in White Ginseng Package (근중 분포에 의한 포장된 백삼의 품질평가)

  • Park, Hoon;Kim, Young-Hee;Yang, Cha-Bum
    • Journal of Ginseng Research
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    • v.17 no.3
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    • pp.219-223
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    • 1993
  • Assessment of root weight grade system for the numeral definition in Korea ginseng was tried by investigation of 13 boxes of the 15-root-grade of 4-year-old white ginseng as a model. In this case satisfaction to theoretical value was 58% in root weight and 50% in root number. The coefficient of variation (CV) was high (35%) for individual root weight in package. The CV of tap root weight 1 among package is low (7.1%) even though there was no significant correlation between tap root weight : and lateral root weight among roots. The mean percentage of tap root to root weight in each package ranged 61 to 74% with CV range of 16.5 to 33.2%. The CV was not much different between 1st and 2nd lateral root weight and the means was above 60%. Strict practice of numeral definition of root weight grade system will be prerequisite for chemical standardization of Korea ginseng.

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A Study on the Estimation of Cargo Weight for Container Crane System (컨테이너 크레인 시스템의 하물중량 추정에 관한 연구)

  • 김환성;박흥수;김상봉
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10a
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    • pp.175-180
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    • 1998
  • In container crane system, the variation of cargo weight have effect on the travelling and sway control of load. For precise travelling and/or anti-sway control of crane system, the cargo weight should be measured and considered with control algorithm. But, and added attachment for measuring the cargo weight put restraint upon the control freedom for travelling and anti-sway. In this paper, we propose an estimation method for cargo weight in container crane system by using observation technique. First of all, we model the container crane system as a bilinear system and transform this model into linear system with external disturbance model. Second, we propose a generalized type - disturbance estimation observer and set a disturbance model, where, the cargo weight is related with the sway of load, and the sway is represented as a periodic external disturbance. Lastly, by using simulation we verify that the proposed algorithm of disturbance estimation observer is effective to estimate the cargo weight, and it will be used with anti-sway control algorithm.

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Image Processing Algorithm for Weight Estimation of Dairy Cattle (젖소 체중추정을 위한 영상처리 알고리즘)

  • Seo, Kwang-Wook;Kim, Hyeon-Tae;Lee, Dae-Weon;Yoon, Yong-Cheol;Choi, Dong-Yoon
    • Journal of Biosystems Engineering
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    • v.36 no.1
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    • pp.48-57
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    • 2011
  • The computer vision system was designed and constructed to measure the weight of a dairy cattle. Its development involved the functions of image capture, image preprocessing, image algorithm, and control integrated into one program. The experiments were conducted with the model dairy cattle and the real dairy cattle by two ways. First experiment with the model dairy cattle was conducted by using the indoor vision experimental system, which was built to measure the model dairy cattle in the laboratory. Second experiment with real dairy cattle was conducted by using the outdoor vision experimental system, which was built for measuring 229 heads of cows in the cattle facilities. This vision system proved to a reliable system by conducting their performance test with 15 heads of real cow in the cattle facilities. Indirect weight measuring with four methods were conducted by using the image processing system, which was the same system for measuring of body parameters. Error value of transform equation using chest girth was 30%. This error was seen as the cause of accumulated error by manually measurement. So it was not appropriate to estimate cow weight by using the transform equation, which was calculated from pixel values of the chest girth. Measurement of cow weight by multiple regression equation from top and side view images has relatively less error value, 5%. When cow weight was measured indirectly by image surface area from the pixel of top and side view images, maximum error value was 11.7%. When measured cow weight by image volume, maximum error weight was 57 kg. Generally, weight error was within 30 kg but maximum error 10.7%. Volume transform method, out of 4 measuring weight methods, was minimum error weight 21.8 kg.

An Evaluation of the Tolerance of the Static Characteristics for Light Weight Torpedoes (경어뢰의 정특성 허용오차 산정)

  • 나영인
    • Journal of the Korea Institute of Military Science and Technology
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    • v.5 no.2
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    • pp.149-158
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    • 2002
  • Static Characteristics of the system, such as weight, center of gravity etc., are inspected and regulated through the whole design process of a light weight torpedo system, and the nominal condition of the characteristics is prescribed for standardization of manufacturing and fabrication. It is possible that a real system or assembled system has different static characteristics from that of the nominal condition. It is required to evaluate the tolerance of the static characteristics within which the performance of the system should not be contaminated by the static characteristics. In this paper, an evaluation method of the tolerance is described for light weight torpedo systems. The method is to check on the performance and related critical parameters of light weight torpedoes. The checking items are composed of general conditions of underwater mobile systems such as stability and dynamic sensitivity and specified performance requirements for light weight torpedoes.

Weight Estimation of the Sea Cucumber (Stichopus japonicas) using Vision-based Volume Measurement

  • Lee, Donggil;Kim, Seonghoon;Park, Miseon;Yang, Yongsu
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.2154-2161
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    • 2014
  • Growth analysis and selection of sea cucumbers (Stichopus japonicas) is typically performed through length or weight measurements. However, because sea cucumbers continuously change shape depending on the external environment, weight measurement has been the preferred approach. Weight measurements require extensive time and labor, moreover it is often difficult to accurately weigh sea cucumbers because of their wet surface. The present study measured sea cucumber features, including the body length, width, and thickness, by using a vision system and regression analysis to generate $R^2$ values that were used to develop a weight estimation algorithm. The $R^2$ value between the actual volume and weight of the sea cucumbers was 0.999, which was relatively high. Evaluation of the performance of this algorithm using cross-validation showed that the root mean square error and worst-case prediction error were 1.434 g and ${\pm}5.879g$, respectively. In addition, the present study confirmed that the proposed weight estimation algorithm and single slide rail device for weight measurement can measure weights at approximately 4,500 sea cucumbers per hour.

Development and Application of Coating Weight Control Technology

  • Park, Jin-Hyoung
    • Corrosion Science and Technology
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    • v.9 no.4
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    • pp.159-163
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    • 2010
  • Precise coating weight control is very important issue on quality and minimizing operating costs on continuous galvanizing line. These days, many steel making companies are having a new understanding of cost importance by rise raw material prices and customer's requirement for cost reduction. Dongbu steel also meets these situations and decided to develop the technologies. Dongbu Steel developed Integrated coating weight control system jointly with Objective Control Ltd. and installed 2CGL and 4CGL. Several technological functions were developed and realized to achieve true hands-off operation and maximum cost benefit by combining model-based preset and dynamic prediction models. We also installed it on 1 CGL on April, 2008. This paper will present the interface, functions and application result of the integrated coating weight control system including Zn saving and coating weight uniformity.

An Image Processing System for Measuring the Weight of A Dairy Cattle (젖소 체중측정을 위한 영상처리 시스템)

  • 이대원;김현태
    • Journal of Animal Environmental Science
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    • v.7 no.3
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    • pp.183-190
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    • 2001
  • The objective of this research was to design and construct an image processing system to measure easily and accurately cow's weight. The image processing system was built for a dairy cattle to be measured and estimated it's weight using camera and personal computer. The pixel numbers, which was derived from the image processing system, were counted to estimate the weight of a dairy cattle. They were utilized various was for finding the relationships between pixel numbers and it's real weight. Based on the results of this research the following conclusions were made: 1. It's weight could be estimated by using pixel numbers, which was captured from top and side cameras to measure it. The correlations with tea-view pixel numbers, side-view pixel numbers, superficial area pixel numbers and the volume pixel numbers were 0.909, 0.939, 0.944 and 0.965. 2. 50 cattle was used to execute an experiment with the image processing system, but average errors were big to make out the good relationship between cow's weight and pixel numbers. In order measure accurately a cattle weight, cattle weight, cattle groups would be divided by the age of cattle and further study should be carried out to be based on the results of this research. 3. The average time it took to perform the image processing to be measure it was 10 seconds, but it took 10 minutes for cattle to enter for measuring it's weight into the weighting system.

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Mass Standards Calibration through Internet (인터넷을 이용한 표준분동 교정 활용)

  • 이우갑;정진완;김광표
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1109-1112
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    • 2003
  • Information technology has enabled mass standards calibration to be performed through internet. For this, an automatic weight handler was manufactured. During the operation the images of weight operation and the system are provided via the measurement system and a web server. The measurement system consists of a balance, a weight handler, instruments for environment measurement and a PC. The weight handler automatically loads and unloads weights on and from the weighing pan. The weight handler allows 6 series weights to be operated for weight calibration of 100-50-20-20-10-10 gram series weight. This capability could be used for "remote training" for series weight calibration.

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Development of a Load Measurement System for Vehicles using Tire Pressure System Technology (타이어 공기압 시스템 기술을 사용한 차량의 적재중량 측정 시스템 개발)

  • Park, Jae-Hyun;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.33-39
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    • 2020
  • In this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires. The proposed technique consists of four processes: noise correction by load and vibration, gas flow correction, data mixer and weight conversion. Noise correction by load and vibration eliminates noise that increases the tire's internal pressure due to external shocks and vibrations produced by the vehicle while it is in motion. In the gas flow correction process, the noise of the internal pressure of the tire is increased due to the temperature rise of the ground with respect to the data obtained through the noise correction process due to the load and vibration. In the data mixer process, the load and pressure on the tolerances the empty, median and the full load are classified according to the change in pressure of the tire that is delivered perpendicular to the tire in the event of cargo. In the weight conversion process, weight is expressed by weight through weight conversion algorithms using noise correction results by load and vibration and gas flow correction. The weight conversion algorithm calculates the weight conversion factor, which is the slope of the linear function with respect to the load and pressure change, and converts the weight. In order to evaluate the accuracy of the loading weight measurement system of the vehicle using the tire pneumatic system technique proposed in this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires.. Noise correction results by load and vibration and gas flow data correction results showed reliable results. In addition, repeated weight precision test showed better weight accuracy than the standard value of 90% of domestic companies.