Power Management to Meet Thermal Safe Power in Fault-Tolerant Embedded Systems

10.36227/techrxiv.14703192 ◽

2021 ◽

Author(s):

Mohsen Ansari ◽

Sina Yari-Karin ◽

Sepideh Safari ◽

Alireza Ejlali

Keyword(s):

Embedded Systems ◽

Power Management ◽

Thermal Management ◽

Fault Tolerant ◽

Thermal Design ◽

Time Constraints ◽

Power Constraint ◽

Dynamic Thermal Management ◽

The Core ◽

Design Power

Thermal Design Power (TDP) as the chip-level power constraint for a specific chip has been exploited in fault-tolerant embedded systems. TDP, as the chip-level power constraint of the system, could be either pessimistic or thermally unsafe. Employing TDP as a pessimistic constraint can increase the rate of missing real-time constraints because of triggering Dynamic Thermal Management (DTM) more frequently. If TDP as a chip-level power constraint is not a pessimistic constraint, TDP can be thermally unsafe and can lead to thermal violations. Employing Thermal Safe Power (TSP) as the core-level power constraint, which is defined as a function of the number of simultaneously operating cores, can result in improving the efficiency and the schedulability. This comment improves the efficiency and the schedulability rate of one of the proposed methods in the literature by employing TSP.

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Peak Power Management to Meet Thermal Design Power in Fault-Tolerant Embedded Systems

IEEE Transactions on Parallel and Distributed Systems ◽

10.1109/tpds.2018.2858816 ◽

2019 ◽

Vol 30 (1) ◽

pp. 161-173 ◽

Cited By ~ 12

Author(s):

Mohsen Ansari ◽

Sepideh Safari ◽

Amir Yeganeh-Khaksar ◽

Mohammad Salehi ◽

Alireza Ejlali

Keyword(s):

Embedded Systems ◽

Power Management ◽

Peak Power ◽

Fault Tolerant ◽

Thermal Design ◽

Design Power

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Thermal Design for Six Sigma of an Imaging Device with Dynamic Thermal Management

2018 24rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) ◽

10.1109/therminic.2018.8593324 ◽

2018 ◽

Cited By ~ 1

Author(s):

Wendy Luiten

Keyword(s):

Thermal Management ◽

Six Sigma ◽

Thermal Design ◽

Imaging Device ◽

Dynamic Thermal Management ◽

Design For Six Sigma

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Dynamic thermal management for networked embedded systems under harsh ambient temperature variation

Proceedings of the 16th ACM/IEEE international symposium on Low power electronics and design - ISLPED '10 ◽

10.1145/1840845.1840905 ◽

2010 ◽

Cited By ~ 2

Author(s):

Sangyoung Park ◽

Jian-Jia Chen ◽

Donghwa Shin ◽

Younghyun Kim ◽

Chia-Lin Yang ◽

...

Keyword(s):

Embedded Systems ◽

Ambient Temperature ◽

Temperature Variation ◽

Thermal Management ◽

Dynamic Thermal Management ◽

Networked Embedded Systems

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A Novel Rail-Network Hardware Simulator for Embedded System Programming

Electronics ◽

10.3390/electronics10010013 ◽

2020 ◽

Vol 10 (1) ◽

pp. 13

Author(s):

Balaji M ◽

Chandrasekaran M ◽

Vaithiyanathan Dhandapani

Keyword(s):

Embedded Systems ◽

Embedded System ◽

Real Time ◽

Learning Outcomes ◽

Real World ◽

Time Constraints ◽

Network Simulator ◽

Practical Applications ◽

Rail Network ◽

Knowledge Enhancement

A Novel Rail-Network Hardware with simulation facilities is presented in this paper. The hardware is designed to facilitate the learning of application-oriented, logical, real-time programming in an embedded system environment. The platform enables the creation of multiple unique programming scenarios with variability in complexity without any hardware changes. Prior experimental hardware comes with static programming facilities that focus the students’ learning on hardware features and programming basics, leaving them ill-equipped to take up practical applications with more real-time constraints. This hardware complements and completes their learning to help them program real-world embedded systems. The hardware uses LEDs to simulate the movement of trains in a network. The network has train stations, intersections and parking slots where the train movements can be controlled by using a 16-bit Renesas RL78/G13 microcontroller. Additionally, simulating facilities are provided to enable the students to navigate the trains by manual controls using switches and indicators. This helps them get an easy understanding of train navigation functions before taking up programming. The students start with simple tasks and gradually progress to more complicated ones with real-time constraints, on their own. During training, students’ learning outcomes are evaluated by obtaining their feedback and conducting a test at the end to measure their knowledge acquisition during the training. Students’ Knowledge Enhancement Index is originated to measure the knowledge acquired by the students. It is observed that 87% of students have successfully enhanced their knowledge undergoing training with this rail-network simulator.

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Wide range continuously tunable and fast thermal switching based on compressible graphene composite foams

Nature Communications ◽

10.1038/s41467-021-25083-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Tingting Du ◽

Zixin Xiong ◽

Luis Delgado ◽

Weizhi Liao ◽

Joseph Peoples ◽

...

Keyword(s):

Thermal Management ◽

Dynamic Control ◽

Operating Conditions ◽

Dynamic Thermal Management ◽

Graphene Composite ◽

Continuous Tuning ◽

Composite Foams ◽

Wide Range ◽

Thermal Switches ◽

Thermal Switching

AbstractThermal switches have gained intense interest recently for enabling dynamic thermal management of electronic devices and batteries that need to function at dramatically varied ambient or operating conditions. However, current approaches have limitations such as the lack of continuous tunability, low switching ratio, low speed, and not being scalable. Here, a continuously tunable, wide-range, and fast thermal switching approach is proposed and demonstrated using compressible graphene composite foams. Large (~8x) continuous tuning of the thermal resistance is achieved from the uncompressed to the fully compressed state. Environmental chamber experiments show that our variable thermal resistor can precisely stabilize the operating temperature of a heat generating device while the ambient temperature varies continuously by ~10 °C or the heat generation rate varies by a factor of 2.7. This thermal device is promising for dynamic control of operating temperatures in battery thermal management, space conditioning, vehicle thermal comfort, and thermal energy storage.

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Perimeter Cooling Unit and Localized Row-Based Cooling Unit Transient Air Flow Effects Modeling and Characterization in Data Centers

Volume 8B: Heat Transfer and Thermal Engineering ◽

10.1115/imece2015-51012 ◽

2015 ◽

Author(s):

Tianyi Gao ◽

James Geer ◽

Bahgat G. Sammakia ◽

Russell Tipton ◽

Mark Seymour

Keyword(s):

Thermal Management ◽

Data Center ◽

Data Centers ◽

Cooling System ◽

Air Flow ◽

Cooling Systems ◽

Dynamic Thermal Management ◽

Hybrid Cooling ◽

Cooling Unit ◽

Cooling Air

Cooling power constitutes a large portion of the total electrical power consumption in data centers. Approximately 25%∼40% of the electricity used within a production data center is consumed by the cooling system. Improving the cooling energy efficiency has attracted a great deal of research attention. Many strategies have been proposed for cutting the data center energy costs. One of the effective strategies for increasing the cooling efficiency is using dynamic thermal management. Another effective strategy is placing cooling devices (heat exchangers) closer to the source of heat. This is the basic design principle of many hybrid cooling systems and liquid cooling systems for data centers. Dynamic thermal management of data centers is a huge challenge, due to the fact that data centers are operated under complex dynamic conditions, even during normal operating conditions. In addition, hybrid cooling systems for data centers introduce additional localized cooling devices, such as in row cooling units and overhead coolers, which significantly increase the complexity of dynamic thermal management. Therefore, it is of paramount importance to characterize the dynamic responses of data centers under variations from different cooling units, such as cooling air flow rate variations. In this study, a detailed computational analysis of an in row cooler based hybrid cooled data center is conducted using a commercially available computational fluid dynamics (CFD) code. A representative CFD model for a raised floor data center with cold aisle-hot aisle arrangement fashion is developed. The hybrid cooling system is designed using perimeter CRAH units and localized in row cooling units. The CRAH unit supplies centralized cooling air to the under floor plenum, and the cooling air enters the cold aisle through perforated tiles. The in row cooling unit is located on the raised floor between the server racks. It supplies the cooling air directly to the cold aisle, and intakes hot air from the back of the racks (hot aisle). Therefore, two different cooling air sources are supplied to the cold aisle, but the ways they are delivered to the cold aisle are different. Several modeling cases are designed to study the transient effects of variations in the flow rates of the two cooling air sources. The server power and the cooling air flow variation combination scenarios are also modeled and studied. The detailed impacts of each modeling case on the rack inlet air temperature and cold aisle air flow distribution are studied. The results presented in this work provide an understanding of the effects of air flow variations on the thermal performance of data centers. The results and corresponding analysis is used for improving the running efficiency of this type of raised floor hybrid data centers using CRAH and IRC units.

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