• 제목/요약/키워드: length control

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The Design of Path Length Controller in Ring Laser Gyroscope for Attitude Control in the LEO satellite (저궤도 위성 자세제어 센서 RLG 피에조 구동기 설계)

  • Kim, Eui-Chan;Lee, Heung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.9
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    • pp.1584-1588
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    • 2008
  • The Ring Laser Gyroscope makes use of the Sagnac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. The Low Earth Orbit satellite for observatory use require the high accuracy Gyro to control and determine the altitude because of the need of payload pointing accuracy. In this paper, The theory of the Path Length Control is explained. The electrical design of Path Length Controller is described. The Design for Path Length Controller is composed of the demodulator, integrator, phase shifter, high voltage amplifier. We apply the circuit to 28cm square ring laser gyro and get the test results.

Automating the visual classification of metal cores

  • Park, In-Gyu;Song, Kyung-Ho;Ha, Tae-Joong
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.945-950
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    • 1990
  • An automatic visual classification system is introduced which provides for measuring the length and diameter of coilform cores and dividing them into 5 different classed in terms of how far their length be from the desired length. This task is fully automated by controlling two STEP motors and by using image processing techniques. The classification procedure is broken into three logical parts, First, cores in the form of randomly stacked bundle are lined up one by one so as to be well captured by a camera. The second part involves capturing core image. Then, it enters the measuring process. Finally, this machine would retain all the information relating to the length. According to the final result, cores are sent to the corresponding bin. This considerably simplifies the selecting task and facilitates a greatly improved reliablity in precision. The average classifying capability is about 2 pieces per second.

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Stabilization and trajectory control of the flexible manipulator with time-varying arm length

  • Park, Chang-Yong;Ono, Toshiro;Sung, Yulwan
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.20-23
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    • 1996
  • This paper deals with the flexible manipulator with rotational and translational degrees of freedom, which has an arm of time-varying length with the prismatic joint. The tracking control problem of the flexible manipulator is considered. First we design the controller of the 2-type robust servo system based on the finite horizon optimal control theory for the trajectory planned as a discontinuous velocity. Next, to reduce the tracking error, we use the method of the dynamic programming and of modifying the reference trajectory in time coordinate. The simulation results show that the dynamic modeling is adequate and that the asymptotic stabilization of the flexible manipulator is preserved in spite of nonlinear terms. The PTP control error has been reduced to zero completely, and the trajectory tracking errors are reduced sufficiently by the proposed control method.

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A study on the calculation method for the number of vehicles in queue to determine the fire ventilation capacity in road tunnels - forced on the effect of queue length (도로터널의 제연용량 산정을 위한 정체차량대수 산정기법에 관한 연구 - 정체길이를 중심으로)

  • Yoo, Yong-Ho;Kim, Hyo-Gyu;Ryu, Ji-Oh
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.1
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    • pp.41-52
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    • 2016
  • When the queue length of congestion vehicles in tunnel fire is extended beyond tunnel length, the capacity of smoke control system needs to be increased in line with ventilation resistance. However, the vehicle queue length is not defined, so a rational equation is necessary in current fire prevention guideline. This study is intended to propose an equation to calculate the queue length considering the number of vehicles in queue in tunnel fire and evaluate the applicability by tunnel length as well. When it comes to normal tunnel, it is necessary to compare the vehicle queue length with tunnel length up to the length of 1,200 m in a bid to avoid applying the vehicle queue length excessively in case of fire. As a result of evaluation of applicability to model a tunnel, saving the number of jet fan for smoke control appeared to be effective. Besides, quantitative approach to explain the vehicle queue length through the relationship between the percentage of large vehicles and tunnel length was presented. Consequently, when the queue length of the congestion vehicles exceeds the tunnel length in determining the capacity of smoke control system in case of fire, the number of vehicles beyond the tunnel length needs to be excluded from estimating the ventilation resistance by vehicles.

The Relationships among Trunk Control Ability, Dynamic Balance and Gait in Stroke Patients (뇌졸중 환자의 체간조절 능력과 동적균형 및 보행과의 상관관계)

  • Chung, Eun-Jeong;Lee, Jong-Soo;Kim, Seong-Sik;Lee, Byoung-Hee
    • The Journal of Korean Medicine
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    • v.33 no.1
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    • pp.148-159
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    • 2012
  • Objectives: This study investigated the correlation among Postural Assessment Scale for Stroke (PASS), Timed "Up and Go" Test (TUG) and gait (velocity, cadence, step-length, stride-length and single-limb support). Methods: The 70 subjects were assessed on trunk control measured with the use of the PASS, dynamic balance (TUG) and gait function (by GAITRite). The data were analyzed using Pearson product correlation. Results: The PASS total scores were significantly correlated with PASS-M, PASS-C, and PASS-T (r =.80 ~ .88 p<.01). All items of the PASS were significantly correlated with TUG (r = -.63 ~ -.81 p<.01), velocity (r = .44~.58 p<.01), cadence (r =.38 ~.51. p<.01), affected side step length (r = .44 ~.56 p<.01) and affected side stride length (r = .45 ~.59 p<.01). But affected side single-limb support was lowly correlated with PASS-M, PASS-C, PASS-T and PASS-total (r = .25~.36 p<.05). Conclusions: Measures of trunk control were significantly related with values of dynamic balance and gait. Based on these results, trunk control is an essential core component of balance and gait. Trunk control training programs after stroke should be developed and emphasized.

The Effects of Repetitive Transcranial Magnetic Stimulation Integrated Mirror Therapy on the Gait of Chronic Stroke Patients

  • Cha, Hyun-Gyu;Kim, Myoung-Kwon
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.133-137
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    • 2015
  • This study was conducted to determine the effects of repetitive transcranial magnetic stimulation (rTMS) integrated mirror therapy on the gait of post-stroke patients. Thirty patients who were six months post-stroke were assigned to either the experimental group (n = 15) or the control group (n = 15). Stroke patients in the experimental group underwent rTMS and mirror therapy for the lower limbs, while those in the control group underwent rTMS and sham therapy. Participants in both groups received therapy five days per week for four weeks. A significant difference in post-training gains for the single support phase, step length, stride length and velocity was observed between the experimental group and the control group (p < 0.05). The experimental group showed a significant increment in the single support phase, step length, stride length, swing phase, velocity, cadence, double support phase and step width as compared to pre-intervention (p < 0.05). The control group showed a significant increment in step length, velocity, cadence and step width compared to preintervention (p < 0.05). Further investigation of the availability and feasibility of rTMS integrated mirror therapy for post-stroke patients as a therapeutic approach for gait rehabilitation is warranted.

A multivariable controller design of 6 DOF motion simulator (6자유도 운동재현기의 다변수 제어기 설계)

  • 이호영;강지윤;이교일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.449-454
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    • 1994
  • The Stewart Platform is one example of a motion simulator which generater 6DOF motion in space by six actuators in parallel. The presented control methrol of 6DOF motion simulator is generally classified into two types, one is SISO and the other is MIMO control type. The SISO control can't compensate for external load variation and different dynamic behavior of 6DOF motion, trerefore this type don's control motion precisely. On the other hand, the MIMO control compensates for a interference of 6DOF motion because MIMO controller is designed with 6DOF motion simulator synamics. But MIMO control of motion simulator has a complexity of 6DOF displacement feedback, because in oder to obtain feedback value we must solve the forward kinematics using measurement of cylinder length or design a state estimator, unless measurement of 6DOF displacement is possible. In this paper, a multivariable controller using H .inf. optimal control theory is designed to consider a interference of 6DOF motion and to obtain robust,precise control of system. Also in order to solve the mentioned problem of MIMO control, this paper presents a modified MIMO control model which control 6DOF motion by using feedback of measurement od cylinder length.

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Effect of Day Length on the Growth of Plug Seedlings and Bulbing after Planting in Onion (Allium cepa L.) (양파 공정육묘시 일장조건이 묘 생육 및 정식 후 구 비대에 미치는 영향)

  • 서전규
    • Journal of Bio-Environment Control
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    • v.12 no.2
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    • pp.101-105
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    • 2003
  • This experiment was conducted to find out the effect of day length on the production of high quality plug seedlings in onion (Allium cepa L.). Two cultivars, ‘Changnyongdaego’ and‘Wolryun’, were grown to seedlings in 200-cell plug trays under 11.5, 12.5, 13.5 hours and natural day length. These seedlings were transplanted to the pot (16 cm In diameter) and grown under 16 hours day length. Number of leaves and neck diameter showed better growth in the longer than shorter day length treatments, but plant height old sheath length were retarded in the longer day length treatments. Growth such as no. of leaves, neck diameter, plant height and sheath length increased with the passage of day, but plant height and neck diameter decreased by treatment over 20 days with 13.5 hours day length. Bulbing and bulb size of onion after transplanting were enhanced in the seedlings cultured under longer day lengths. From the above results, treatment of long day length during seedling culture in plug tray can control the overgrowth and produce high quality plug seedlings.

Step Length Estimation Algorithm for Firefighter using Linear Calibration (선형 보정을 이용한 구난요원의 보폭 추정 알고리즘)

  • Lee, Min Su;Ju, Ho Jin;Park, Chan Gook;Heo, Moonbeom
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.7
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    • pp.640-645
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    • 2013
  • This paper presents a step length estimation algorithm for Pedestrian Dead Reckoning using linear calibrated ZUPT (zero velocity update) with a foot mounted IMU. The IMU consists of 3 axis accelerometer, gyro and magnetometer. Attitude of IMU is estimated using an inertial navigation algorithm. To increase accuracy of step length estimation algorithm, we propose a stance detection algorithm and an enhanced ZUPT. The enhanced ZUPT calculates firefighter's step length considering velocity error caused by sensor bias during one step. This algorithm also works efficiently at various motions, such as crawling, sideways and stair stepping. Through experiments, the step length estimation performance of the proposed algorithm is verified.

Effect of Hwalhyulsungjang-san and KC101 Composed of Oriental Medicinal Stuffs on Physical Development in Growing Rats (활혈성장산과 KC101이 흰쥐의 성장발육에 미치는 영향)

  • 박승만;한찬규
    • The Journal of Korean Medicine
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    • v.24 no.1
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    • pp.1-8
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    • 2003
  • Purpose : Nowadays, there are many studies of growth retardation treatment by oriental medical therapy. This study was performed to evaluate the effect of Hwalhyulsungjang-san (Huoxuechengzhang-san) and KC101 on physical development in growth, Methods : 60 young (3 weeks old) male rats, whose mean weight was $46.8{\pm}0,7g$, were divided into 5 groups : groups A, B, C, and D were fed an experimental diet containing respectively Hwalhyulsungjang-san 2.5%, Hwalhyulsungjang-san 7.5%, KC101 5.0%, and KC101 10.0%, and the other group were fed an AIN-diet containing neither Hwalhyulsungjang-san nor KC101 as a control. Study of each group used 2 rats and was repeated in 6 times. Body weight, daily weight gain, dietary intake, body length, femur length, backbone length and serum concentration of IGF-I and hemoglobin were measured. Result : 1. Body weight and daily weight gain of group D (KC101 10%) were highest; dietary intake of group D was also increased by 13% over the control group. 2. Average body length of group D was increased to 1.69cm, which was 3.2% over the control group. Backbone length of group D was also increased 4% compared to control group. 3. Serum concentration of IGF-I of group D increased 17% compared to control group. 4. Serum concentration of hemoglobin of group B (Hwalhyulsungjang-san 7.5%) increased 8% compared to control group. Conclusion : This study showed that Hwalhyulsungjang-san and KC101 composed of oriental medicinal stuffs have effect on physical development in growing rats. There were not any statistical meaning compared to control group, but this study suggests that intake of these compounds from a young age may lead to increase physical development in growth.

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