• 제목/요약/키워드: local control

검색결과 3,855건 처리시간 0.034초

Design of Sliding Mode Fuzzy-Model-Based Controller Using Genetic Algorithms

  • Chang, Wook
    • 한국지능시스템학회논문지
    • /
    • 제11권7호
    • /
    • pp.615-620
    • /
    • 2001
  • This paper addresses the design of sliding model fuzzy-model-based controller using genetic algorithms. In general, the construction of fuzzy logic controllers has difficulties for the lack of systematic design procedure. To release this difficulties, the sliding model fuzzy-model-based controllers was presented by authors. In this proposed method, the fuzzy model, which represents the local dynamic behavior of the given nonlinear system, is utilized to construct the controller. The overall controller consists of the local compensators which compensate the local dynamic linear model and the feed-forward controller which is designed via sliding mode control theory. Although, the stability and the performance is guaranteed by the proposed method, some design parameters have to be chosen by the designer manually. This problem can be solved by using genetic algorithms. The proposed method tunes the parameters of the controller, by which the reasonable accuracy and the control effort is achieved. The validity and the efficiency of the proposed method are verified through simulations.

  • PDF

지역적 CPs 특성에 기반한 고해상도영상의 자동기하보정 (Automatic Registration of High Resolution Satellite Images using Local Properties of Control Points)

  • 한유경;변영기;한동엽;김용일
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2010년 춘계학술발표회 논문집
    • /
    • pp.221-224
    • /
    • 2010
  • When the image registration methods which were generally used to the low medium resolution satellite images is applied to the high spatial resolution images, some matching errors or limitations might be occurred because of the local distortions in the images. This paper, therefore, proposed the automatic image-to-image registration of high resolution satellite images using local properties of control points to improve the registration result.

  • PDF

Industrial Process Monitoring and Fault Diagnosis Based on Temporal Attention Augmented Deep Network

  • Mu, Ke;Luo, Lin;Wang, Qiao;Mao, Fushun
    • Journal of Information Processing Systems
    • /
    • 제17권2호
    • /
    • pp.242-252
    • /
    • 2021
  • Following the intuition that the local information in time instances is hardly incorporated into the posterior sequence in long short-term memory (LSTM), this paper proposes an attention augmented mechanism for fault diagnosis of the complex chemical process data. Unlike conventional fault diagnosis and classification methods, an attention mechanism layer architecture is introduced to detect and focus on local temporal information. The augmented deep network results preserve each local instance's importance and contribution and allow the interpretable feature representation and classification simultaneously. The comprehensive comparative analyses demonstrate that the developed model has a high-quality fault classification rate of 95.49%, on average. The results are comparable to those obtained using various other techniques for the Tennessee Eastman benchmark process.

Comparative evaluation of photobiomodulation therapy at 660 and 810 nm wavelengths on the soft tissue local anesthesia reversal in pediatric dentistry: an in-vivo study

  • Ankita Annu;Sujatha Paranna;Anil T. Patil;Sandhyarani B.;Adhithi Prakash;Renuka Rajesh Bhurke
    • Journal of Dental Anesthesia and Pain Medicine
    • /
    • 제23권4호
    • /
    • pp.229-236
    • /
    • 2023
  • Background: Local anesthesia has been reliably used to control pain during dental procedures and is important in pediatric dentistry. However, children occasionally complain of prolonged numbness after dental treatment, leading to several problems. Studies conducted to reverse the effect of local anesthesia using phentolamine mesylate and photobiomodulation therapy (PBM) are encouraging but limited. PBM is a type of light therapy that utilizes visible and near-infrared non-ionizing electromagnetic spectral light sources. Hence, this study used this modality to compare the reversal of local anesthesia at two different wavelengths. This study compared the effect of PBM at 660 and 810 nm wavelengths on the reversal of soft tissue local anesthesia using a diode LASER in pediatric dentistry. Method: Informed consent and assent were obtained, and the participants were then divided randomly into three groups of 20 children each: control group-without LASER irradiation, LASER irradiation at 660 nm, and LASER irradiation at 810 nm. Sixty children aged 4-8 years with deciduous mandibular molars indicated for pulp therapy were administered an inferior alveolar nerve block. After 45 min of injection, a duration that was similar to the approximate duration of treatment, they were exposed to 660- and 810-nm LASER irradiation according to their groups until reversal of local anesthesia was achieved. The control group did not undergo LASER irradiation. The reversal of the soft tissue local anesthetic effect was evaluated using palpation and pin prick tests every 15 min, and the LASER irradiation cycle continued until reversal of the soft tissue local anesthesia was achieved. Results: A significant reduction of 55.5 min (27.6%) in the mean soft tissue local anesthesia reversal time was observed after the application of 810 nm wavelength PBM and 69 min (34.7%) after 660 nm wavelength LASER irradiation. Conclusion: PBM with a 660 nm wavelength was more effective in reducing the mean soft tissue local anesthesia reversal duration, and thus can be used as a reversal agent for soft tissue local anesthesia in pediatric dentistry.

PDAODMRP: An Extended PoolODMRP Based on Passive Data Acknowledgement

  • Cai, Shaobin;Yang, Xiaozong;Wang, Ling
    • Journal of Communications and Networks
    • /
    • 제6권4호
    • /
    • pp.362-375
    • /
    • 2004
  • An ad hoc network is a multi-hop wireless network. Its limited bandwidth and frequently changing topology require that its protocol should be robust, simple, and energy conserving. We have proposed PoolODMRP to reduce its control overhead greatly by its one-hop local route maintenance. However, PoolODMRP still has some shortcomings. In this paper, we propose PDAODMRP (passive data acknowledgement ODMRP) to extend PoolODMRP. Compared with PoolODMRP, PDAODMRP has the following contributions: (1) It knows the status of its downstream forwarding nodes by route information collected from data packets instead of BEACON signal of MAC layer; (2) it max simplifies the route information collected from data packets by pool nodes; (3) it adopts a dynamic local route maintenance to enforce its local route maintenance; (4) it adopts the route evaluation policy of NSMP (neighbor supporting multicast protocol). Compared with PoolODMRP, PDAODMRP has lower control overhead, lower data delivery delay, and lower data overhead.

무인 이동 로봇 위치추정을 위한 초음파 위성 시스템 (USAT(Ultrasonic Satellite System) for the Autonomous Mobile Robots Localization)

  • 이동활;김수용;윤강섭;이만형
    • 제어로봇시스템학회논문지
    • /
    • 제13권10호
    • /
    • pp.956-961
    • /
    • 2007
  • We propose a new distance measurement method and local positioning system for the autonomous mobile robots localization. The distance measurement method is able to measure long-range distances with a high accuracy by using ultrasonic sensors. The time of flight of the ultrasonic waves include various noises is calculated accurately by the proposed period detecting method. The proposed local positioning system is composed of four ultrasonic transmitters and one ultrasonic receiver. The ultrasonic transmitter and receiver are separated but they are synchronized by RF (Radio frequency) signal. The proposed system using ultrasonic waves is represented as USAT(Ultrasonic Satellite System). USAT is able to estimate the position using the least square estimation. The experimental results show that the proposed local positioning system enables to estimate the absolute position precisely.

A Lane Based Obstacle Avoidance Method for Mobile Robot Navigation

  • Ko, Nak-Yong;Reid G. Simmons;Kim, Koung-Suk
    • Journal of Mechanical Science and Technology
    • /
    • 제17권11호
    • /
    • pp.1693-1703
    • /
    • 2003
  • This paper presents a new local obstacle avoidance method for indoor mobile robots. The method uses a new directional approach called the Lane Method. The Lane Method is combined with a velocity space method i.e., the Curvature-Velocity Method to form the Lane-Curvature Method (LCM). The Lane Method divides the work area into lanes, and then chooses the best lane to follow to optimize travel along a desired goal heading. A local heading is then calculated for entering and following the best lane, and CVM uses this local heading to determine the optimal translational and rotational velocities, considering some physical limitations and environmental constraint. By combining both the directional and velocity space methods, LCM yields safe collision-free motion as well as smooth motion taking the physical limitations of the robot motion into account.

거리 형태 히스토그램을 이용한 이동로보트의 장애물 회피 주행 (Obstacle Avoidance Navigation Using Distance Profile Histogram)

  • 김현태;노흥식;조영완;박민용
    • 전자공학회논문지B
    • /
    • 제33B권12호
    • /
    • pp.1-12
    • /
    • 1996
  • A new local path planning algorithm using DPH (distance profile histogram) is suggested in this paper. The proposed method makes a grid type world map using distance values from multiple ultrasonic sensors and genrates local points through which the mobile robot can avoid obstcles safely. The DPH (distance profile historgram) represents geometrical arrangement of obstacles around the robot in the local polar coordinate system which is assumed to be atached to the robot. To control robot's navigation, a three-layered control structure is adopted. The proposed local path planning algorithm is placed on the top level. And a point-to-point translation controller takes the middle level. The bottom level consists of a velcoity servo and sonar driver modules which take charge of driving physical hardwares. The validity of the propsoed method is demonstated through several experiments.

  • PDF

Local stereo matching using combined matching cost and adaptive cost aggregation

  • Zhu, Shiping;Li, Zheng
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제9권1호
    • /
    • pp.224-241
    • /
    • 2015
  • Multiview plus depth (MVD) videos are widely used in free-viewpoint TV systems. The best-known technique to determine depth information is based on stereo vision. In this paper, we propose a novel local stereo matching algorithm which is radiometric invariant. The key idea is to use a combined matching cost of intensity and gradient based similarity measure. In addition, we realize an adaptive cost aggregation scheme by constructing an adaptive support window for each pixel, which can solve the boundary and low texture problems. In the disparity refinement process, we propose a four-step post-processing technique to handle outliers and occlusions. Moreover, we conduct stereo reconstruction tests to verify the performance of the algorithm more intuitively. Experimental results show that the proposed method is effective and robust against local radiometric distortion. It has an average error of 5.93% on the Middlebury benchmark and is compatible to the state-of-art local methods.

Local and Global Isotropy Analysis of Caster Wheeled Omnidirectional Mobile Robot

  • Kim Sung-bok;Moon Byoung-kwon
    • 융합신호처리학회논문지
    • /
    • 제7권1호
    • /
    • pp.38-44
    • /
    • 2006
  • The omnidirectional mobility of a mobile robot may lose significance in motion control, unless the isotropy characteristics of the mechanism is maintained well. This paper investigates the local and global isotropy of an omnidirectional mobile robot with three caster wheels. All possible actuations with different number and combination of rotating and steering joints are considered. First, the kinematic model based on velocity decomposition and the algebraic conditions for the local isotropy are obtained. Second, the geometric conditions for the local isotropy are derived and all isotropic configurations are fully identified. Third, the global isotropy index is examined to determine the optimal parameters in terms of actuation set, characteristic length, and steering link length.

  • PDF