scholarly journals Generalized Majority Voter Design Method for N-Modular Redundant Systems Used in Mission- and Safety-Critical Applications

Computers ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 10 ◽  
Author(s):  
Jaytrilok Choudhary ◽  
Padmanabhan Balasubramanian ◽  
Danny Varghese ◽  
Dhirendra Singh ◽  
Douglas Maskell
Keyword(s):  
Design Method ◽  
Majority Voting ◽  
Normal Operation ◽  
Majority Logic ◽  
Simultaneous Production ◽  
Safety Critical ◽  
Majority Voter ◽  
Logic Equation ◽  
Modular Redundancy ◽  
Common Logic

Mission- and safety-critical circuits and systems employ redundancy in their designs to overcome any faults or failures of constituent circuits and systems during the normal operation. In this aspect, the N-modular redundancy (NMR) is widely used. An NMR system is comprised of N identical systems, the corresponding outputs of which are majority voted to generate the system outputs. To perform majority voting, a majority voter is required, and the sizes of majority voters tend to vary depending on an NMR system. Majority voters corresponding to NMR systems are physically realized by enumerating the majority input clauses corresponding to an NMR system and then synthesizing the majority logic equation. The issue is that the number of majority input clauses corresponding to an NMR system is governed by a mathematical combination, the complexity of which increases substantially with increases in the level of redundancy. In this context, the design of a majority voter of any size corresponding to an NMR specification based on a new, generalized design approach is described. The proposed approach is inherently hierarchical and progressive since any NMR majority voter can be constructed from an (N − 2)MR majority voter along with additional logic corresponding to the two extra inputs. Further, the proposed approach paves the way for simultaneous production of the NMR system outputs corresponding to different degrees of redundancy, which is not intrinsic to the existing methods. This feature is additionally useful for any sharing of common logic with diverse degrees of redundancy in appropriate portions of an NMR implementation.

scholarly journals Quasi Delay Insensitive Majority Voters for Triple Modular Redundancy Applications

2019 ◽  
Vol 9 (24) ◽  
pp. 5400 ◽  
Author(s):  
Padmanabhan Balasubramanian ◽  
Douglas L. Maskell ◽  
Nikos E. Mastorakis
Keyword(s):  
Oxide Semiconductor ◽  
Normal Operation ◽  
Synthesis Methods ◽  
Correct Operation ◽  
Triple Modular Redundancy ◽  
Majority Voter ◽  
Function Modules ◽  
Function Module ◽  
Modular Redundancy ◽  
Design Style

Mission- and safety-critical applications tend to incorporate triple modular redundancy (TMR) in their hardware implementation to reliably withstand the fault or failure of any one of the function modules during normal operation, and the function module may be a circuit or a system. In a TMR implementation, two identical copies of a function module are used in addition to the original function module, and the correct operation of at least two function modules is required. In TMR, the corresponding primary outputs of the three function modules are combined using majority voters, which determine the actual primary outputs based on the Boolean majority. Hence, the majority voter is an important component that is useful for conveying the correct operation of a TMR implementation. In the existing literature, many designs of three-input majority voters for TMR have been discussed. However, most of these correspond to the synchronous design style and just one corresponds to the bundled-data asynchronous design style, which is not delay insensitive and hence non-robust. To our knowledge, a robust delay insensitive design of the three-input majority voter has not been considered. In this context, this article presents the designs of robust quasi delay insensitive (QDI) three-input majority voters based on QDI logic synthesis methods, and analyzes which majority voters are preferable in terms of speed, power, and area. We implement example QDI TMR circuits using a QDI full adder as the function module and QDI majority voters using 32/28 nm complementary metal oxide semiconductor (CMOS) technology. The QDI TMR implementations use the delay insensitive dual rail code for data encoding, and four-phase return-to-zero and four-phase return-to-one handshake protocols for data communication.

scholarly journals Asynchronous quasi delay insensitive majority voters corresponding to quintuple modular redundancy for mission/safety-critical applications

PLoS ONE ◽  
2020 ◽  
Vol 15 (9) ◽  
pp. e0239395
Author(s):  
P. Balasubramanian ◽  
N. E. Mastorakis
Keyword(s):  
Data Communication ◽  
Cmos Process ◽  
Electronic Circuits ◽  
Asynchronous Design ◽  
Multiple Faults ◽  
Safety Critical ◽  
Majority Voter ◽  
Modular Redundancy ◽  
Power And Energy ◽  
Design Style

Electronic circuits and systems employed in mission- and safety-critical applications such as space, aerospace, nuclear plants etc. tend to suffer from multiple faults due to radiation and other harsh external phenomena. To overcome single or multiple faults from affecting electronic circuits and systems, progressive module redundancy (PMR) has been suggested as a potential solution that recommends the use of different levels of redundancy for the vulnerable portions of a circuit or system depending upon their criticality. According to PMR, triple modular redundancy (TMR) can be used where a single fault is likely to occur and should be masked, and quintuple modular redundancy (QMR) can be used where double faults are likely to occur and should be masked. In this article, we present asynchronous QDI majority voter designs for QMR and state which are preferable from cycle time (i.e., speed), area, power, and energy perspectives. Towards this, we implemented example QMR circuits in a robust QDI asynchronous design style by employing a delay insensitive dual rail code for data encoding and adopting four-phase handshake protocols for data communication. Based on physical implementations using a 32/28nm CMOS process, we find that our proposed QMR majority voter achieves improved optimization in speed and energy.

scholarly journals A Novel Scheme for Fault Tolerant Computing

2021 ◽  
Vol 3 (1) ◽  
pp. 17-23
Author(s):  
Pramode Ranjan Bhattacharjee ◽  
Keyword(s):  
Fault Tolerant ◽  
Present Scheme ◽  
Triple Modular Redundancy ◽  
Test Input ◽  
Digital Network ◽  
Additional Control ◽  
Majority Voter ◽  
Modular Redundancy ◽  
Primary Output

A novel scheme for ensuring reliability in the operation of a combinational digital network has been offered in this paper. This has been achieved by making use of three copies of the same digital network along with two additional sub-networks, one of which consists of three additional control inputs, which can also be used as additional observable outputs. If both the said two sub-networks are fault free, then the primary output of the network in the present scheme will always give fault-free responses even if a fault (single or multiple) occurs in one of the three copies of the digital network under consideration. Unlike the Triple Modular Redundancy (TMR) scheme, the present scheme does not require any majority voter circuit. Furthermore, unlike the TMR scheme, the additional sub-networks in the present scheme can be tested off-line by predefined test input patterns.

Optimal Design Method of Fins in Automotive Oil Cooler Based on the Thermal-Hydraulic Performances

2012 ◽  
Vol 490-495 ◽  
pp. 2381-2385
Author(s):  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Neural Networks ◽  
Optimal Design ◽  
Heat Exchangers ◽  
Flow Resistance ◽  
Design Method ◽  
Normal Operation ◽  
Oil Cooler ◽  
Optimal Design Method ◽  
Simulation Results

The excellent thermal-hydraulic performances of oil cooler are the strong guaranty for automotives’ normal operation. In this study, the thermal-hydraulic performances of compact oil cooler units with different fin size parameters are numerical simulated. According to simulation results, combined with neural networks method, the optimal fin size parameters are determined. Based on this, the effects of different fin arrange layouts on performances are also studied, and optimal layouts for different requirements for flow resistance and heat transfer performances are put forward. This optimal design method can play a guidance role for the designer and manufacturer of heat exchangers.

scholarly journals An Engineering Approach to Storage and Access in High Priority Scenarios

2019 ◽  
Vol 63 (1) ◽  
pp. 1349-1353
Author(s):  
FNU Varun Ananthasivan Srikrishnan ◽  
Richard T. Stone ◽  
Cong Xu
Keyword(s):  
Human Factors ◽  
Human Performance ◽  
Normal Operation ◽  
Aviation Industry ◽  
Critical Systems ◽  
Safety Critical ◽  
Work Spaces ◽  
Storage Room ◽  
Before And After ◽  
Time Critical

Over the past few years, an extensive amount of research has been done in the field of Human Factors. Applications range from the design of day-to-day products like cell phones to the design and development of safety-critical systems like flight displays. The highly critical aviation industry has shown time and again the importance of human-centered approach in developing systems for the safety of those operating it and the passengers. Similarly, other safety-critical industries like law enforcement have been seen to incorporate human factors in the design of weapons and exoskeletons aimed at adapting to humans and making their unit stronger. Many manufacturing firms have begun to see the importance of proper work postures for their employees to avoid musculoskeletal disorders and the financial and regulatory implications of not following proper work ethics that take care of employees’ health. Further, many organizations have started to consider team dynamics in their operations understanding the importance of healthy interaction among the employees and between employees and the management. However, there are a very few references to any studies or organizational practices that draw a connection between human performance and human-centric re-design of work places, with most designs being limited to work desks and activity-based working (ABW) work spaces. This paper focuses on the organizational engineering of storage spaces to enable easy location and retrieval of equipment, thus supporting the time-critical nature of operations at a miscellaneous storage room at the Story County Sheriff’s Office. Experiments were carried out using two familiar scenarios both before and after the redesign of the storage room. A significant improvement in the performance of the operator was observed after the redesign, as could be seen by the reduction in time taken to identify and retrieve equipment and the qualitative survey that was obtained at the end of the experiment. The wasted time was translated to a cost and the newly designed storage design saved a significant amount of money spent on actions that precluded efficient accomplishment of tasks, something that could have been used by the Sheriff’s office to purchase equipment for normal operation of the office. The results suggested such interventions in different sectors that have similar high-priority operations. The results of the study indicates that there is a need for the industry to extend research towards this field that we name “organization engineering”.

scholarly journals Modeling and simulation of FPGA-based redundant digital systems

2020 ◽  
Vol 11 (1) ◽  
pp. 73-79
Author(s):  
Csaba Szász
Keyword(s):  
Operation Mode ◽  
Majority Voting ◽  
Digital Systems ◽  
Gate Arrays ◽  
Reliability Level ◽  
Initial Assumption ◽  
Wide Range ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Modular Redundancy

AbstractReliability is one of the most important criteria that characterize last generation digital systems. In a wide range of applications the required reliability level is achieved by using hardware redundant configurations. Perhaps their most common form is the triple modular redundancy (TMR) based on a majority voting structure. Researchers that use this strategy make a major assumption: in fault-free operation mode the outputs of these digital systems match in all. This paper proves that synchronization and matching in all the outputs of such systems is not such a trivial problem. In this endeavor FPGA-based (Field Programmable Gate Arrays) redundant topologies are considered for study and experiments. Upon these structures specially conceived redundant models have been developed and simulated. The results outline that synchronization of complex digital systems is a difficult engineering undertaking and any initial assumption should be managed with the adequate circumspection.

Study on design method of embedded adaptive safety critical middleware

2009 ◽  
Vol 28 (11) ◽  
pp. 2919-2921
Author(s):  
Yi ZHANG ◽  
Wan-dong CAI ◽  
Yue WANG
Keyword(s):  
Design Method ◽  
Safety Critical

scholarly journals Dual-modular-redundancy and dual-level error-interception based triple-node-upset tolerant latch designs for safety-critical applications

2021 ◽  
Vol 111 ◽  
pp. 105034
Author(s):  
Aibin Yan ◽  
Zhihui He ◽  
Jun Zhou ◽  
Jie Cui ◽  
Tianming Ni ◽  
...  
Keyword(s):  
Safety Critical ◽  
Modular Redundancy

scholarly journals N-version programming approach with implicit safety guarantee for complex dynamic system stabilization applications

2020 ◽  
pp. 002029401988747
Author(s):  
Nadir Subasi ◽  
Ufuk Guner ◽  
Ilker Ustoglu
Keyword(s):  
Essential Element ◽  
Majority Voting ◽  
Programming Approach ◽  
Critical Systems ◽  
Software Safety ◽  
Critical System ◽  
Iso 26262 ◽  
Safety Standards ◽  
Safety Critical ◽  
Iec 61508

Safety-critical systems are widely used in many sectors to prevent fatal accidents and prevent loss of life, damage of property, or deterioration of the environment. Implementation of software safety standards as part of the development of safety-critical software is generally considered an essential element of any safety program. Therefore, it has become more critical to produce highly reliable software to meet the safety requirements established by functional safety standards, such as IEC 61508, ISO 26262, and EN 50128. IEC 61508 supports well-known safety mechanisms such as design diversity like N-version (multi-version) programming. N-version (multi-version) programming is a method where multiple functionally equivalent programs are independently developed from the same software specifications. N-version (multi-version) programming is particularly an effective approach to increase the quality of software in a safety-critical system. In this paper, one of the well-known and widely used algorithms in the field of N-version (multi-version) programming, the majority voting algorithm, has been modified with an online stability checker where the decisions of the voter are judged against the stability of the underlying system. The plant where all the theoretical results are implemented is a tilt-rotor system with the proposed N-version (multi-version) programming–based controller. The experimental results show that the modified majority voter-based N-version (multi-version) programming controller provides more reliable control of the plant.

System Design for Large-Scale Water Control Based on PLC

2013 ◽  
Vol 846-847 ◽  
pp. 176-179
Author(s):  
Xin Hui Yang
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
System Design ◽  
Large Scale ◽  
Design Method ◽  
Control Process ◽  
Normal Operation ◽  
Water Control ◽  
Actual Control

Traditional algorithms for large-scale water control system need to realize control according to mathematical model which makes the parameters setting difficult. At the same time, certain defects in the control effects reduce the safety and the reliability of the system, thus it is hardly to satisfy the normal operation of the water control system. In order to avoid the defects in traditional algorithms, this paper proposes a design method for large-scale water control system bases on PLC and applies it in the actual control process. The results show that the proposed algorithm can effectively improve the accuracy of the large-scale water control system.

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