• Journal of the Korean Society for Railway
• /
• v.9 no.6 s.37
• /
• pp.725-731
• /
• 2006

Hot Standby sparing system detecting faults by using software, and being tolerant any faults by using Hardware Redundancy is difficult to perform quantitative reliability prediction and to detect real time faults. Therefore, this paper designs Hot Standby sparing system using hardware basis self checking logic in order to overcome this problem. It also performs failure mode analysis of Hot Standby sparing system with designed self checking logic by using FMEA (Failure Mode Effect Analysis), and identifies reliability assessment of the controller designed by quantifying the numbers of failure development by using FTA (Fault Tree Analysis)

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2006.11a
• /
• pp.331-334
• /
• 2006

This paper deals with the ways how the AUV is composed of sub-modules to be fault-tolerant during the mission. The emergency situations can be classified into several parts according to the zones where the situations take place - sensor zone, actuator zone, interpreter zone, and communication zone. This paper explains how each element of emergency situation is detected, contained and treated, and as a result, introduce the modular structured AUV controller for the autonomous cruising.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.7
• /
• pp.661-667
• /
• 2010

This paper presents a failure diagnosis and accommodation strategy which is capable of tolerating faulty actuators of a submersible vehicle. The proposed method is mainly based on a sliding mode control technique. The primary ideas include a performance index to describe the effectiveness of actuators, and a controller reconfiguration strategy using the actuator effectiveness index. The actuator effectiveness proposed in this work is defined as the relationship between the sliding surface and the controlled system behavior. The resulting actuator effectiveness is then used in reconfiguring the controller in order to counteract for the deteriorated control performance in the presence of a faulty actuator. The effectiveness of the proposed method is demonstrated by means of numerical simulations with a submersible vehicle.

• Proceedings of the KIEE Conference
• /
• 2000.11b
• /
• pp.280-283
• /
• 2000

In this paper, a fault tolerant control problem is considered for a class of nonlinear system formulated in a gain scheduling form with LMI-based H-inf control technique Key benefits of this proposed scheme are demonstrated in the simulation of an electromagnetic suspension system with actuator and/or sensor failures, and the method is compared with the convensional state-feedback and output-feedback controller. It is clearly observed that the proposed control scheme shows an improved output performance in comparision with convensional methods.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.3-9
• /
• 2008

Recently, the plant industries are being activated and plant control systems use various technologies. Because the optimized design for the plants is very important for the reducing of operation and maintenance costs, automatic control systems become more important. Plant control systems consist of the master controller, the plant networks, the programming environment for engineering, monitoring software and the field devices. The control systems should have reliability, availability and safety. Modular architecture of hardware and software makes flexible configuration of the control systems. Each component should have diagnostic functions. It follows industrial standards and makes open systems. Open systems increase accessibility against the data which is distributed in the plants. The controllers including processor and communication modules use the up-to-date technology. They have real time and fault tolerant function by duplicating processors or networks. It also enables to make the distributed control systems. The distributed architecture makes more scalable main control system. Automatic control systems can be operated with better performance. In this paper, we analyzed the requirements of the seawater desalination plants and made some consideration facts for developing the optimized controller. Also we described the design concept of the main controller, which consists of several modules. We should validate and complement the design for the reliability and better performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.4
• /
• pp.101-110
• /
• 2004

Flight and Qualification Models of Single Board Computer (SBC), called On-Board Computer (OBC), for HAUSAT-l picosatellite, which is scheduled to launch on September, 2004 by Russian "Dnepr" launch vehicle, have been developed. The OBC of HAUSAT-1 has been designed with some improved features compared to other picosatellites. A multifunctional controller and up-to-date SPI (Serial Peripheral Interface) and 1-Wire interface are implemented to simplify the harness routing and to minimize the mass and size of OBC. The improved fault-tolerant architecture design methodology is incorporated in the HAUSAT-1 OBC to protect against space radiation environment. The functions of the OBC were fully tested and verified by the Electrical Test Bed (ETB) model. This paper is also addressing the environmental test results, such as random vibration and thermal vacuum tests.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.6
• /
• pp.689-694
• /
• 2014

An SPLC (Safety Programmable Logic Controller) must be designed to meet the highest safety standards, IEEE 1E, and should guarantee a level of fault-tolerance and high-reliability that ensures complete error-free operation. In order to satisfy these criteria, I/O modules, communication modules, processor modules and bus modules of the SPLC have been configured in triple or dual modular redundancy. The redundant modules receive the same data to determine the final data by the voting logic. Currently, the processor of each rx module performs the voting by deciding on the final data. It is the intent of this paper to prove the improvement on the current system, and develop a voting system for multiple data on a system bus level. The new system bus protocol is implemented based on a TCN-MVB that is a deterministic network consisting of a master-slave structure. The test result shows that the suggested system is better than the present system in view of its high utilization and improved performance of data exchange and voting.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.4
• /
• pp.105-111
• /
• 2003

Qualification Model of On-board Computer (OBC) for KAISTSAT-4 was developed. The OBC of KAISTASAT-4 has some improved features compared with that of KAISTSAT-3: To reduce weight and size of OBC many logics are implemented by FPGAs, and a network controller is included in OBC to access the satellite network with high speed. Also, the developed OBC has an improved tolerance against SEUs and faults. The OBC was fully tested under simulated space environment with no errors.

• Bulletin of the Korean Space Science Society
• /
• 2004.10b
• /
• pp.293-295
• /
• 2004

The Engineering Model of on-board computer was developed and tested completely with other sub-systems for STSAT-2. We designed the on-board computer of STSAT-2 which has some improved features compared with that of STSAT-l. A remarkable change is that the on-board computer has a structure of centeralized network communication without a Network Controller of the STSAT-l. That is, the on-board computer directly manages a satellite network. In addition, as many logics are implemented by Field Programmable Gate Array, so we can reduce the weight and size of on-board computer. Also, the developed on-board computer has more improved tolerance against Single Event Upsets and faults than that of the STSAT-l.

• Proceedings of the KIEE Conference
• /
• 1987.07a
• /
• pp.216-220
• /
• 1987

A graphic display and operator console system is developed for monitoring the operation of power plant. It has multiprocessor structure using VME bus and common memory. The graphic monitoring system is applied to fault tolerant control system for enhancing reliability of boiler analog controller. As a result, it displays all the operating date as color graphic images with 14 pages. Moreover, it can transfer the operator commands to the other micro-processors through common memory.