scholarly journals Design, Simulation and Optimization of an Electrical Drive-Train

Vehicles ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 390-405
Author(s):  
Sven Schumacher ◽  
Stefan Schmid ◽  
Philipp Wieser ◽  
Ralf Stetter ◽  
Markus Till
Keyword(s):  
High Performance ◽  
Drive Train ◽  
Optimization Approach ◽  
Electrical Drive ◽  
Simulation And Optimization ◽  
Design Engineers ◽  
Main Requirement ◽  
Product Models ◽  
Holistic Concept ◽  
Physical Phenomena

Today, design engineers engaged in the development of a high-performance electrical drive-train are challenged by the multitude of possible topological choices and numerous mutually interconnected physical phenomena. Development teams around the globe struggle with this challenge; usually they employ several tools for simulation and topology optimization and transfer multiple versions of their product models in a mainly manual process. The research presented in this paper aims to explore a holistic possibility to realize a sensible analysis-synthesis cycle that takes into consideration current developments in design, simulation and optimization processes. This kind of process can enhance the transparency of design decisions, can reduce the risk of design and process flaws and can support the approach toward a holistic optimum. The investigation starts with the development of the topological concept of the drive-train and continues over the interconnected simulation of several decisive properties of the drive-train. Obviously, these properties concern several domains (mechanical, electrical, thermal and the control domain). The optimization of the drive-train takes into consideration the main requirement—in the investigated example, which is a formula student drive-train—the lap time. The result is a holistic concept for a design, simulation and optimization approach that considers topological variety, interconnected multi-domain simulation and a continuous connection to the decisive requirements.

Assessment of Arterial Signal Timings Based on Various Operational Policies and Optimization Tools

2021 ◽  
pp. 036119812110111
Author(s):  
Suhaib Al Shayeb ◽  
Nemanja Dobrota ◽  
Aleksandar Stevanovic ◽  
Nikola Mitrovic
Keyword(s):  
Travel Time ◽  
Heavy Traffic ◽  
Future Research ◽  
Signal Timing ◽  
Highway Capacity ◽  
Average Delay ◽  
Highway Capacity Manual ◽  
Simulation And Optimization ◽  
Fort Lauderdale ◽  
Design Engineers

Traffic simulation and optimization tools are classified, according to their practical applicability, into two main categories: theoretical and practical. The performance of the optimized signal timing derived by any tool is influenced by how calculations are executed in the particular tool. Highway Capacity Software (HCS) and Vistro implement the procedures defined in the Highway Capacity Manual, thus they are essentially utilized by traffic operations and design engineers. Considering its capability of timing diagram drafting and travel time collection studies, Tru-Traffic is more commonly used by practitioners. All these programs have different built-in objective function(s) to develop optimized signal plans for intersections. In this study, the performance of the optimal signal timing plans developed by HCS, Tru-Traffic, and Vistro are evaluated and compared by using the microsimulation software Vissim. A real-world urban arterial with 20 intersections and heavy traffic in Fort Lauderdale, Florida served as the testbed. To eliminate any bias in the comparisons, all experiments were performed under identical geometric and traffic conditions, coded in each tool. The evaluation of the optimized plans was conducted based on average delay, number of stops, performance index, travel time, and percentage of arrivals on green. Results indicated that although timings developed in HCS reduced delay, they drastically increased number of stops. Tru-Traffic signal timings, when only offsets are optimized, performed better than timings developed by all of the other tools. Finally, Vistro increased arrivals on green, but it also increased delay. Optimized signal plans were transferred manually from optimization tools to Vissim. Therefore, future research should find methods for automatically transferring optimized plans to Vissim.

BISWSRBS: A Winograd-based CNN Accelerator with a Fine-grained Regular Sparsity Pattern and Mixed Precision Quantization

2021 ◽  
Vol 14 (4) ◽  
pp. 1-28
Author(s):  
Tao Yang ◽  
Zhezhi He ◽  
Tengchuan Kou ◽  
Qingzheng Li ◽  
Qi Han ◽  
...  
Keyword(s):  
High Performance ◽  
State Of The Art ◽  
The State ◽  
Optimization Approach ◽  
Quantization Scheme ◽  
Model Accuracy ◽  
Sparsity Pattern ◽  
Computing Platform ◽  
Energy Efficiency Improvement ◽  
Mixed Precision

Field-programmable Gate Array (FPGA) is a high-performance computing platform for Convolution Neural Networks (CNNs) inference. Winograd algorithm, weight pruning, and quantization are widely adopted to reduce the storage and arithmetic overhead of CNNs on FPGAs. Recent studies strive to prune the weights in the Winograd domain, however, resulting in irregular sparse patterns and leading to low parallelism and reduced utilization of resources. Besides, there are few works to discuss a suitable quantization scheme for Winograd. In this article, we propose a regular sparse pruning pattern in the Winograd-based CNN, namely, Sub-row-balanced Sparsity (SRBS) pattern, to overcome the challenge of the irregular sparse pattern. Then, we develop a two-step hardware co-optimization approach to improve the model accuracy using the SRBS pattern. Based on the pruned model, we implement a mixed precision quantization to further reduce the computational complexity of bit operations. Finally, we design an FPGA accelerator that takes both the advantage of the SRBS pattern to eliminate low-parallelism computation and the irregular memory accesses, as well as the mixed precision quantization to get a layer-wise bit width. Experimental results on VGG16/VGG-nagadomi with CIFAR-10 and ResNet-18/34/50 with ImageNet show up to 11.8×/8.67× and 8.17×/8.31×/10.6× speedup, 12.74×/9.19× and 8.75×/8.81×/11.1× energy efficiency improvement, respectively, compared with the state-of-the-art dense Winograd accelerator [20] with negligible loss of model accuracy. We also show that our design has 4.11× speedup compared with the state-of-the-art sparse Winograd accelerator [19] on VGG16.

scholarly journals Modeling and Controlling the Cooling System of an IC Vehicle

2021 ◽  
pp. 80-85
Author(s):  
C. Mureșan ◽  
◽  
G. Harja
Keyword(s):  
Mathematical Modeling ◽  
Heat Exchangers ◽  
High Performance ◽  
Cooling System ◽  
Control Strategies ◽  
Positive Influence ◽  
Control Algorithms ◽  
Performance Control ◽  
Ic Engines ◽  
Physical Phenomena

The performance and efficiency of internal combustion (IC) engines can be greatly improved by using a high-performance cooling system. This can be achieved by implementing robust control strategies and, also by building the cooling system with high-performance elements. The mechanical execution elements can be replaced with electrically controllable elements such as the pump and the thermostat valve. This will have a positive influence on the degree of controllability of the system. In order to develop high-performance control algorithms, it is necessary to have a model that best reflects the behaviors of the physical system. Thus, this paper presents a mathematical modeling approach for the cooling system using the principles of heat exchangers and the physical phenomena present in them.

scholarly journals Ecological and economic aspects of optimizing the creation and functioning of drainage systems in accordance with modern requirements

2021 ◽  
Vol 285 ◽  
pp. 02009
Author(s):  
Anatoly Rokochinskiy ◽  
Yuri Mazhayskiy ◽  
Pavlo Volk ◽  
Roman Koptyuk ◽  
Lubov Volk ◽  
...  
Keyword(s):  
Water Management ◽  
Land Reclamation ◽  
System Optimization ◽  
Climatic Conditions ◽  
Practical Implementation ◽  
Optimization Approach ◽  
Local Optima ◽  
Drainage Systems ◽  
Simulation And Optimization ◽  
The Creation

Land reclamation is important in the development of agricultural production for unfavorable climatic conditions. This necessitates the improvement of scientific and methodological approaches to the creation and operation of water management and reclamation facilities, including drainage systems, which are adapted to these changes. Approaches to the type and design of drainage systems based on a combination of a modern progressive optimization approach with the traditional water balance method, hydrodynamic and hydraulic methods are presented. Approaches to the systemic optimization of technological and design solutions for the creation and operation of drainage systems have been determined. It seems that the drainage system is a complex natural and technical ecological and economic system. Finding the general optimum in such a system based on the system optimization consists in substantiating local optima for all its main components of heterogeneous elements in the system effect - mode - technology - design in their interconnection. The practical implementation of a complex of predictive-simulation and optimization calculations in projects for new construction, reconstruction and modernization of drainage systems based on the developed scientific, methodological, information and software can be carried out using the appropriate toolkit, which is CAD and modern BIM technologies. The transition to optimization methods will improve the feasibility and overall technical, technological, environmental and economic efficiency of the creation and operation of water management and reclamation facilities in accordance with modern requirements.

Abstract and Concrete Data Type Optimizations at the UML and C/C++ Level for Dynamic Embedded Software

2010 ◽  
pp. 55-83
Author(s):  
Christos Baloukas ◽  
Marijn Temmerman ◽  
Anne Keller ◽  
Stylianos Mamagkakis ◽  
Francky Catthoor ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Embedded System ◽  
High Performance ◽  
Real Life ◽  
Holistic Approach ◽  
Embedded Software ◽  
Data Types ◽  
Design Engineers ◽  
Implementation Level ◽  
Abstraction Levels

An embedded system is a special-purpose system that performs predefined tasks, usually with very specific requirements. Since the system is dedicated to a specific task, design engineers can optimize it by exploiting very specialized knowledge, deriving an optimally customized system. Low energy consumption and high performance are both valid optimization targets to increase the value and mobility of the final system. Traditionally, conceptual embedded software models are built irrespectively of the underlying hardware platform, whereas embedded-system specialists typically start their optimization crusade from the executable code. This practice results in suboptimal implementations on the embedded platform because at the source-code level not all the inefficiencies introduced at the modelling level can be removed. In this book chapter, we describe both novel UML transformations at the modelling level and C/C++ transformations at the software implementation level. The transformations at both design abstraction levels target the data types of dynamic embedded software applications and provide optimizations guided by the relevant cost factors. Using a real life case study, we show how our transformations result in significant improvement in memory footprint, performance and energy consumption with respect to the initial implementation. Moreover, thanks to our holistic approach, we are able to identify new and non-trivial solutions that could hardly be found with the traditional design methods.

scholarly journals Log Analysis-Based Resource and Execution Time Improvement in HPC: A Case Study

2020 ◽  
Vol 10 (7) ◽  
pp. 2634
Author(s):  
JunWeon Yoon ◽  
TaeYoung Hong ◽  
ChanYeol Park ◽  
Seo-Young Noh ◽  
HeonChang Yu
Keyword(s):  
Execution Time ◽  
High Performance ◽  
Large Scale ◽  
Experimental Result ◽  
Optimization Approach ◽  
Root Cause ◽  
Large Systems ◽  
Job Scheduler ◽  
Performance Computing

High-performance computing (HPC) uses many distributed computing resources to solve large computational science problems through parallel computation. Such an approach can reduce overall job execution time and increase the capacity of solving large-scale and complex problems. In the supercomputer, the job scheduler, the HPC’s flagship tool, is responsible for distributing and managing the resources of large systems. In this paper, we analyze the execution log of the job scheduler for a certain period of time and propose an optimization approach to reduce the idle time of jobs. In our experiment, it has been found that the main root cause of delayed job is highly related to resource waiting. The execution time of the entire job is affected and significantly delayed due to the increase in idle resources that must be ready when submitting the large-scale job. The backfilling algorithm can optimize the inefficiency of these idle resources and help to reduce the execution time of the job. Therefore, we propose the backfilling algorithm, which can be applied to the supercomputer. This experimental result shows that the overall execution time is reduced.

An Accurate Linearization of Electromagnetic Force of Heteropolar Magnetic Bearings With Redundant Structures

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Cheng Xin ◽  
Cheng Baixin ◽  
Liu Han ◽  
Allen G. M
Keyword(s):  
Current Distribution ◽  
Electromagnetic Force ◽  
High Performance ◽  
Fault Tolerant ◽  
Taylor Series Expansion ◽  
Magnetic Bearings ◽  
Optimization Approach ◽  
Rotor Position ◽  
Distribution Matrix ◽  
Emf Model

Abstract Fault tolerance is one of the practical and effective approaches to improve the reliability of magnetic bearings. The linearization of the electromagnetic force (EMF) from the redundant structures is the crucial basis of the design of a fault-tolerant controller. In this paper, we propose an accurate linearization approach for the heteropolar magnetic bearings with redundant structures by solving the Taylor series expansion equation of the current distribution matrix (W) in the nonequilibrium position and introducing a set of displacement compensation matrices to establish a unified accurate EMF model including the controlled current and rotor position. The proposed approach can effectively decrease the EMF error between the actual physical model and the linearized model compared with the existing methods for the consideration of the rotor position. Moreover, the solutions of the current distribution matrix and the relevant optimization approach have been presented on the basis of the proposed approach to help to design a high-performance fault-tolerant controller in the entire rotor displacement range. The numerical results demonstrated the noticeable accuracy advantages of the proposed EMF model.

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