• Title/Summary/Keyword: First Order Logic

Search Result 176, Processing Time 0.053 seconds

A Sensorless PMDC Motor Speed Controller with a Logical Overcurrent Protection

  • Guerreiro, M.G.;Foito, D.;Cordeiro, A.
    • Journal of Power Electronics
    • /
    • v.13 no.3
    • /
    • pp.381-389
    • /
    • 2013
  • A method to control the speed or the torque of a permanent-magnet direct current motor is presented. The rotor speed and the external torque estimation are simultaneously provided by appropriate observers. The sensorless control scheme is based on current measurement and switching states of power devices. The observers performances are dependent on the accurate machine parameters knowledge. Sliding mode control approach was adopted for drive control, providing the suitable switching states to the chopper power devices. Despite the predictable chattering, a convenient first order switching function was considered enough to define the sliding surface and to correspond with the desired control specifications and drive performance. The experimental implementation was supported on a single dsPIC and the controller includes a logic overcurrent protection.

Fault Tolerant Control for Distributed Programmable Logic Controller System (분산형 PLC 시스템에서의 고장 허용 제어)

  • Jeong, Young-Mi;Jeong, Seok-Kwon
    • Proceedings of the KIEE Conference
    • /
    • 2003.07d
    • /
    • pp.2197-2199
    • /
    • 2003
  • Most of distributed PLC system is secured reliability of the system by fully duplicated controller. But it costs too much. In this paper, we proposed fault tolerant control using minimum spare controllers. First, the system is modeled using Galois field. Next, we designed additional spare controllers using the parity code of two dimensions. Finally, the algorithm for producing estimated output in remote I/O when the fault occurs was suggested. This method will be applied to an automatic system in order to increase reliability and improve cost performance.

  • PDF

An efficient reliability estimation method for CNTFET-based logic circuits

  • Jahanirad, Hadi;Hosseini, Mostafa
    • ETRI Journal
    • /
    • v.43 no.4
    • /
    • pp.728-745
    • /
    • 2021
  • Carbon nanotube field-effect transistors (CNTFETs) have been widely studied as a promising technology to be included in post-complementary metal-oxide-semiconductor integrated circuits. Despite significant advantages in terms of delay and power dissipation, the fabrication process for CNTFETs is plagued by fault occurrences. Therefore, developing a fast and accurate method for estimating the reliability of CNTFET-based digital circuits was the main goal of this study. In the proposed method, effects related to faults that occur in a gate's transistors are first represented as a probability transfer matrix. Next, the target circuit's graph is traversed in topological order and the reliabilities of the circuit's gates are computed. The accuracy of this method (less than 3% reliability estimation error) was verified through various simulations on the ISCAS 85 benchmark circuits. The proposed method outperforms previous methods in terms of both accuracy and computational complexity.

Pensar la Fraternidad en la Diferencia

  • Jurado, Jenniffer Londono
    • Iberoamérica
    • /
    • v.21 no.1
    • /
    • pp.107-125
    • /
    • 2019
  • How to conceive fraternity in difference? I will hold two premises to answer this question. First: fraternity is an ineradicable element of the Political. Second: the recognition of fraternity in difference is a precondition for the consolidation of fraternal relations in Latin America in the context of coloniality. On the same path, I will show that fraternity must be thought of as difference in order to face the logic of neoliberal life imposed by capitalism in globalization. The articulation of both premises in the political praxis would contribute to the preservation of our life in common; in conditions of dignified existence. The fraters of precariousness and vulnerability are the ones who can re-establish being-with- and being-together.

A study on the ventilation control method of road tunnel for small vehicles (소형차 전용 도로터널의 환기기 제어방안에 대한 연구)

  • Ryu, Ji-Oh;Lee, Hu-Young;Chang, Ji-Don
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.21 no.6
    • /
    • pp.749-762
    • /
    • 2019
  • In recent years, in urban areas, underground of roads are being promoted in order to resolve traffic congestion and to secure green spaces, and due to the low ratio of large vehicles, they are planned or constructed as road tunnels for small cars only. In addition, the tunnels being built in the city is a tendency to be enlarged to play the role of main roads. Accordingly, the capacity of the ventilation system is increasing and various ventilation methods are required, and the importance of maintenance after the completion of the tunnel such as the operating cost of the ventilation system is emphasized. Therefore, the need for optimization of the operation stage for reducing the power consumption of the ventilation system and the study of the ventilation system operation control logic is increasing. In this study, the study on the necessity of the optimization of operation stage and control logic of the ventilation system was carried out to realize the energy-saving operation for the small car only passing through tunnels which is applied of ① jet fan and combination ventilation system (② jet fan + air purifying equipment, ③ jet fan + vertical shaft, ④ jet fan + supply air semi-transverse). As a result of this study, there can be various operating combinations in the case of the combined ventilation system, and even though the amount of ventilation air is the same, the operating power varies greatly according to the operating combinations. It was found that operating the axial fan first rather than the jet fan first operation method has an effect on power saving.

A decision making framework model for the selection of a RP using hybrid multiple attribute decision making techniques (3차원 조형장비 선정을 위한 복합 다요소 의사결정 구조 모델 개발에 관한 연구)

  • Byun, Hong-Seok
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.7 no.3
    • /
    • pp.87-95
    • /
    • 2008
  • The purpose of this study is to provide a decision support to select an appropriate rapid prototyping(RP) machine that suits the application of a part. Selection factors include concept model, form/fit/functional model, pattern model for molding, material property, build time and part cost that greatly affect the performance of RP machines. However, the selection of a RP is not an easy decision because they are uncertain and vague. For this reason, the aim of this research is to propose hybrid multiple attribute decision making approaches to effectively evaluate RP machines. In addition, because subjective considerations are relevant to selection decision, a fuzzy logic approach is adopted. The proposed selection procedure consists of several steps. First, we identify RP machines that the users consider. After constructing the evaluation criteria, we calculate the weights of the criteria by applying the fuzzy Analytic Hierarchy Process(AHP) method. Finally, we construct the fuzzy Technique of Order Preference by Similarity to Ideal Solution(TOPSIS) method to achieve the ranking order of all machines providing the decision information for the selection of RP machines.

  • PDF

The Linear Discrepancy of a Fuzzy Poset

  • Cheong, Min-Seok;Chae, Gab-Byung;Kim, Sang-Mok
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.11 no.1
    • /
    • pp.59-64
    • /
    • 2011
  • In 2001, the notion of a fuzzy poset defined on a set X via a triplet (L, G, I) of functions with domain X ${\times}$ X and range [0, 1] satisfying a special condition L+G+I = 1 is introduced by J. Negger and Hee Sik Kim, where L is the 'less than' function, G is the 'greater than' function, and I is the 'incomparable to' function. Using this approach, we are able to define a special class of fuzzy posets, and define the 'skeleton' of a fuzzy poset in view of major relation. In this sense, we define the linear discrepancy of a fuzzy poset of size n as the minimum value of all maximum of I(x, y)${\mid}$f(x)-f(y)${\mid}$ for f ${\in}$ F and x, y ${\in}$ X with I(x, y) > $\frac{1}{2}$, where F is the set of all injective order-preserving maps from the fuzzy poset to the set of positive integers. We first show that the definition is well-defined. Then, it is shown that the optimality appears at the same injective order-preserving maps in both cases of a fuzzy poset and its skeleton if the linear discrepancy of a skeleton of a fuzzy poset is 1.

Simulation Tool Development for Dynamic Tracked Tensioning System in Tracked Vehicles (궤도차량의 동적 궤도장력 조절시스템을 위한 시뮬레이션 툴 구축)

  • 김일민;김민철;임훈기;허건수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2002.04a
    • /
    • pp.76-81
    • /
    • 2002
  • The characteristics of the track are important concerning the mobility of tracked vehicles. It can be represented in terms of the track tension and maintaining the track tension adequately guarantees the stable and improved driving of the tracked vehicles. The track tension must be known in order to be controlled and it needs to be estimated in real-time because it is difficult to be measured. The tension around idler and sprocket can be controlled by the frizzy logic control system base on the estimated values. Dynamic Track Tensioning System(DTTS) which is estimating and controlling the track tension. In this paper, simulation tool is developed in order to apply the DTTS to real battle tanks. To construct the simulation tool, the Modeling the tracked vehicle, constructing estimation system, and designing controller should be achieved first and then all subsystem should be organized in one. The simulation tool make the RecurDyn model of tracked vehicle, which is plant model, and the control system exchange their data simultaneously. Simulation with many kinds of driving conditions and road conditions is carried out and the results are interpreted. The interpretation provides necessary information to apply the DTTS to real battle tanks.

  • PDF

Design and Performance Evaluation of Tactile Device Using MR Fluid (MR 유체를 이용한 촉감구현장치의 설계 및 성능 평가)

  • Kim, Jin-Kyu;Oh, Jong-Seok;Lee, Snag-Rock;Han, Young-Min;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.22 no.12
    • /
    • pp.1220-1226
    • /
    • 2012
  • This paper proposes a novel type of tactile device utilizing magnetorheological(MR) fluid which can be applicable for haptic master of minimally invasive surgery(MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field(or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

Design and Performance Evaluation of Tactile Device Using MR Fluid (MR 유체를 이용한 촉감구현장치의 설계 및 성능 평가)

  • Kim, Jin-Kyu;Oh, Jong-Seok;Han, Young-Min;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2012.10a
    • /
    • pp.415-420
    • /
    • 2012
  • This paper proposes a novel type of tactile device utilizing magnetorheological (MR) fluid which can be applicable for haptic master of minimally invasive surgery (MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field (or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

  • PDF