• Computational Structural Engineering : An International Journal
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• v.1 no.2
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• pp.137-137
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• 2001

The reliability/redundancy of structural system has become a serious concern among engineers and researchers after structural failures in Northridge and Kobe earthquakes. The reliability/redundancy factor, ρ, in current codes considers only member force and floor area and has received much criticism from dissatisfied engineers. Within a reliability framework. the redundancy is investigated for dual systems of primary shear walls and secondary moment frames and steel moment frame systems. Probabilistic performance analyses are carried out baled on nonlinear responses under SAC ground motion. The effects of structural configuration, ductilily capacity, 3-D motion, and uncertainty of demand verses capacity are investigated. Important redundancy-contributing factors are identified and a uniform-risk redundancy factor is developed for design. The result are compared with the p factor and its inconsistency is pointed out.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.639-649
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• 2020

Air data systems measure airspeed, pressure altitude, angle of attack and angle of sideslip. These measurements are essential for operating flight control laws to ensure safe flights. Since the loss or corruption of air data measurements is considered as catastrophic, a high level of operational reliability needs to be achieved for air data systems. In the case of unmanned air vehicles, failure of any of air data sensors is more critical due to the absence of onboard pilot decision aid. This paper presents design of a dual redundancy air data system and the integration process for an unmanned air vehicle. The proposed dual-redundant architecture is based on two independent air data probes and redundancy management by central processing in two independent flight control computers. Starting from unit testing of single air data sensor, details are provided of system level tests used to meet overall requirements. Test results from system integration demonstrate the efficiency of the proposed process.

• Journal of Ocean Engineering and Technology
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• v.29 no.5
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• pp.380-385
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• 2015

In the development of an underwater construction robot, the reliability of the operating system is the most important issue because of its huge maintenance cost, especially in a deep sea application. In this paper, we propose a new redundant architectural design for the hydraulic control system of an underwater construction robot. The proposed architecture consists of dual independent modular redundancy management systems linked with a commercial profibus network. A cold standby redundancy management system consisting of a preprocessing switch circuit is applied to the signal network, and a hot standby redundancy management system is adapted to utilize two main controllers.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.4
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• pp.168-176
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• 2001

In this paper, we develop a dual-duplex system which detects a fault by hardware comparator and switches to hot standby redundancy. This system is designed on the basis of MC68000 and can be used in VMEbus. To improve reliability, the dual-duplex system is designed in dual modular redundancy. The failure rate of electrical element is calculated in MILSPEC-217F, and the system RAMS(Reliability, Availiability, Maintainability and Safety) and MTTF(Mean Time to Failure) are evaluated by Markov modeling method. As the evaluation result shows improved reliability, it can be used as a component hardware for a highly reliable control system.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2606-2609
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• 2004

As computer system has developed, the break down rate of system has been increased. So, engineers have been interested in reliability of system. General method that is used to heighten reliability of system is Redundancy of System by dual switching control. In this paper, we propose DSCM which can give Redundancy structure in existent PC(Microsoft Window 2000 OS) base system. And we experiment redundancy structure that is applied DSCM to currently using train control in IFC(Interface Computer) system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.5
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• pp.349-357
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• 2022

Since the flight control computer of unmanned aerial vehicle (UAV) is a flight critical equipment, it is necessary to ensure reliability and safety from the development step, and a redundancy-based fault management design is required in order to operate normally even a failure occurs. To reduce cost, weight and power consumption, the dual-redundant flight control system design is considered in UAV. However, there are various restrictions on the fault management design. In this paper, we propose the fault detection and isolation designs for the dual-redundant flight control computer to satisfy the safety requirements of an UAV. In addition, the flight control computer developed by applying the fault management design performed functional tests in the integrated test environment, and after performing FMET in the HILS, its reliability was verified through flight tests.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1877-1886
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• 2010

In this paper, we design a redundancy control circuit for 1T-SRAM repair using electrical fuse programming. We propose a dual port eFuse cell to provide high program power to the eFuse and to reduce the read current of the cell by using an external program supply voltage when the supply power is low. The proposed dual port eFuse cell is designed to store its programmed datum into a D-latch automatically in the power-on read mode. The layout area of an address comparison circuit which compares a memory repair address with a memory access address is reduced approximately 19% by using dynamic pseudo NMOS logic instead of CMOS logic. Also, the layout size of the designed redundancy control circuit for 1T-SRAM repair using electrical fuse programming with Dongbu HiTek's $0.11{\mu}m$ mixed signal process is $249.02 {\times}225.04{\mu}m^{2}$.

• Journal of Mechanical Science and Technology
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• v.20 no.11
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• pp.1834-1847
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• 2006

A robust minimum-time control (RMTC) strategy is addressed and it is extended to the dual-stage servo design. Rather than conventional switching type sub-optimal controls, it is a reference following control approach where the predetermined minimum-time trajectory (MTT) is tracked by the perturbation compensator based feedback controller. First, the minimum-time trajectory for a mass-damper system is derived. Then, the perturbation compensator to achieve robust tracking performance in spite of model uncertainty and external disturbance is suggested. The RMTC is also applied to the dual-stage positioner which consists of coarse actuator and fine one. To best utilize the actuation redundancy of the dual-stage mechanism, a null-motion controller to actively regulate the relative motion between the two stages is formulated. The performance of RMTC is validated through simulation and experiment.

• Journal of the Korea Society of Computer and Information
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• v.20 no.10
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• pp.1-5
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• 2015

Based on the dual hardware and software with distributed recovery blocks, the centralized type fault tolerant store management system(SMS) was proposed. As a result of trade off study related to mutiplex hardware system design, dual single board computer(SBC) was adapted. To verify redundancy function of the proposed structure, the prototype SMS and weapon simulator were used. The proposed SMS operated normally without being affected by a primary SBC failure. The switching time from primary SBC to shadow SBC was within 200 ms. The reliability of the proposed SMS was predicted and compared with the non fault tolerant SMS, thereby it was proved that the proposed SMS has a higher reliability than the non fault tolerant system within effective range.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.753-759
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• 2009

As many systems depend on electronics in an intelligent vehicle, concern for fault tolerance is growing rapidly. For example, a car with its braking controlled by electronics and no mechanical linkage from brake pedal to calipers of front tires(brake-by-wire system) should be fault tolerant because a failure can come without any warning and its effect is devastating. In general, fault tolerance is usually designed by placing redundant components that duplicate the functions of the original module. In this way a fault can be isolated, and safe operation is guaranteed by replacing the faulty module with its redundant and normal module within a predefined interval. In order to make in-vehicle network fault tolerant, this paper presents the concept and design methodology of an IEEE 1451 based dual CAN module. In addition, feasibility of the dual CAN network was evaluated by implementing the dual CAN module.