SkyEye模拟器的LCD及TouchScreen模拟模块的设计、实现与验证

本文首先描述了开放源码的嵌入或硬件仿真环境SkyEye的总体架构,然后对SkyEye模拟器的LCD及TouchScreen模拟模块的设计、实现与验证过程进行了深入的阐述,并且分析比较了LCD模拟的不同实现方式。开源嵌入式GUI系统—MiniGUI和Linux 操作系统在SkyEye 模拟器上的成功运行说明了SkyEye 模拟器的LCD及TouchScreen模拟模块的设计实现是正确和可靠的。     

基于树莓派的能耗数据采集网关设计

设计了一种基于树莓派、Linux操作系统和MD5与AES加密的能耗数据采集网关.该网关系统支持对建筑用电量、用水量、用气量等能耗数据的采集并通过因特网将采集到的能耗数据上传至监测平台,为能耗数据统计分析和规划提供数据基础.该系统具备Web服务、数据采集与解析、数据加密与传输和数据存储等功能.该系统已经成功应用到工业现场,结果表明该网关工作稳定可靠,能够完成实时采集与传输建筑能耗数据的任务.     

嵌入式系统软硬件协同模拟验证环境设计与实现

介绍了一个嵌入式系统软硬件协同模拟验证环境，该环境以指令集模拟器和事件驱动硬件模拟器为基本框架，并由总线调度模型和总线界面模型提供软硬件模拟交互界面。重点讨论该环境中软硬件模拟器之间的接口设计与实现方法，最后给出一个嵌入式系统协同验证的应用实例。     

基于SkyEye对UART模拟的实现

利用仿真技术模拟嵌入式硬件系统的真实运行情况,有助于提高嵌入式系统的教学效果。文章采用开放源码的嵌入式硬件仿真环境SkyEye实现对UART的仿真,论述了SkyEye的总体结构,详细阐述了SkyEye模拟器的UART模拟模块的设计与实现方法。嵌入式操作系统μC/OS-Ⅱ在SkyEye上的成功移植与UART的测试,验证了SkyEye模拟器的UART模拟模块的设计是正确的。     

嵌入式系统节能自动调节技术仿真研究

研究嵌入式系统的节能问题.针对工业控制中嵌入式系统的应用广泛,应用的环境复杂,大中小型的系统功耗不断的提高,急需降低系统的能量消耗的问题.为了有效地降低功耗,提出了基于平衡点算法的降低嵌入式系统能耗的方法.利用工业控制系统工作的时候频率调节和工作电压测量技术,计算出系统功耗最低的时候,电压和频率的平衡点,使得系统在平衡点状态下工作.进而达到降低能耗的目的.实验表明.利用调节算法,能够有效降低以 ARM7 为主的 CMOS 工业控制中嵌入式系统的功耗,对工业系统取得较好的效果,为设计提供了依据.     

基于CC-NUMA系统模拟器的并行程序性能分析

针对CC－NUMA并行系统的特点,本文描述了模拟器－AMY的设计与实现。该模拟器运行在x86PC机上的Linux操作系统环境下,采用多项优化技术,能够较精确地统计并行程序的时间开销和CC－NUMA并行系统的各项参数,具有执行速度快、精度高和内存开销小等特点。在AMY模拟器环境下,通过对几个典型的并行测试程序的模拟执行,文章给出了统计的模拟结果,分析了并行测试程序的执行行为和开销,最后得出了在CC－NUMA并行系统中对并行程序进行性能优化的有益的指导原则。     

单处理器多外设实时系统全局能耗优化算法研究

在电池供电的实时嵌入式系统中,能耗是系统设计的一个重要研究问题.动态电压调度和动态电源管理是两种重要的节能技术.前者是动态改变处理器电压/频率,降低处理器能耗;而后者是动态调整片外设备的工作模式,减少片外设备能耗.目前只有少量研究把这两种技术综合在一起.本文研究支持这两种技术的嵌入式全系统实时任务节能调度问题.针对连续和离散处理器频率模型,论文分别提出高效的算法,通过计算系统运行的能耗最小处理器最优频率和设备最优空闲时间,来实现全系统综合节能的目的.实验模拟表明本文算法大大优于其他算法.     

基于QEMU的AARCH64平台仿真技术的研究

在嵌入式软件开发过程中，通常可以使用仿真技术模拟目标硬件平台，进行软件运行环境的仿真。通过仿真器对目标硬件的CPU、内存和输入/输出（I/O）设备等进行仿真，支持用户可以在不具备硬件条件的情况下，尽快地开展嵌入式软件的开发工作。研究了基于开源的虚拟操作系统模拟器（QEMU）仿真器平台，选取了目前嵌入式领域常用的国产飞腾2000嵌入式处理器作为仿真目标，以验证仿真AARCH64平台QEMU虚拟机的可行性，方便用户开展嵌入式软件的开发。     

数据仓库在城市公共建筑能耗管理中的应用

当前众多城市公共建筑能耗监测系统中已收集了大量的建筑能耗数据。针对这些数据源存在的各自独立而且分散,不能够提供全局的数据分析环境,不能够有效支持建筑能耗的评估与建筑节能的研究等问题,提出将数据仓库技术应用于城市公共建筑能耗监管系统的解决方法。通过对建筑能耗监测系统的研究,以及对建筑能耗管理的应用需求的调研,建立城市级公共建筑能耗数据仓库的多维数据模型,对主题设计、指标设计和维度模型设计进行了探讨,并在实验阶段已成功构建了某高校公共建筑能耗数据仓库的实例。实验结果表明,该方法能够有效地为建筑能耗的管理与决策提供良好的数据分析环境。     

线性加速比并行实时任务的节能研究

节能设计是嵌入式实时系统中一个重要的研究方向.目前的研究大多采用串行任务模型,很少关注并行任务.文中研究了在离散工作模式与实时约束下,多核平台下的线性加速比并行实时任务的能耗最小化问题.文中假设所有处理器核都支持DVS技术且加速比是线性的,在此条件下,文中首先给出一个定理证明了当各任务执行在系统全部核上时系统能耗最小.然后,将问题建模为一个0-1整数线性规划,利用最早截止期优先算法确定任务调度,并给出了两个高效的节能算法确定各任务的工作频率.文中最后通过大量的模拟实验,证明提出的算法的效果显著,可以达到几乎与最优解相同的节能效果.     

SEProf: A high-level software energy profiling tool for an embedded processor enabling power management functions

Energy efficiency has become one of the most important design issues for embedded systems. To examine the power consumption of an embedded system, an energy profiling tool is highly demanded. Although a number of energy profiling tools have been proposed, they are not directly applicable to the embedded processors with power management functions that are widely utilized in battery-operated embedded systems to reduce power consumption. Hence, this study presents a high-level energy profiling tool, called SEProf, that estimates the energy consumption of an embedded system running multithread software and a multitasking operating system (OS) that supports power management functions. This study implements the proposed SEProf in Linux 2.6.19 and evaluates its performance on an ARM11 MPCore processor. Experimental results demonstrate that the proposed tool can provide accurate energy profiling results with a low profiling overhead.     

基于故障注入的嵌入式软件安全性测试框架及实现

为确保安全关键软件能够稳定工作,需要把验证其中的安全保障措施有效性纳入到测试工作范围,其关键问题和难点是如何在被测软件运行过程中动态模拟其安全保障措施针对的异常状态。为此提出一种辅以故障注入的嵌入式软件安全性测试框架,并给出了实现过程。该框架的核心组件是利用设备建模语言DML和控制脚本构建的运行态故障注入软仿真环境,实验证明可用于单粒子效应等异常环境状态的动态仿真,进而实现对软件的安全性测试。     

嵌入式系统软硬件协同验证中软件验证方法

随着集成电路及计算机技术的发展,嵌入式系统设计变得越来越复杂．复杂的嵌入式系统设计,通常采用验证的手段检验系统设计的正确性,硬件验证通常是在硬件设计描述的基础上建立用于模拟硬件功能的硬件模拟器;软件验证常用的方法是建立处理器功能模型(指令集模拟器ISS),逐条解释嵌入式软件在目标机器上的执行过程,产生模拟输出,驱动外围电路(即硬件设计)．指令集模拟器从底层时序关系模拟嵌入式软件在目标CPU上运行过程．对于复杂嵌入式系统设计,ISS模拟速度通常成为协同模拟瓶颈．基于RTOS的嵌入式软件快速验证方法可以有效地提高软件模拟速度,扩展RTOS功能,适应协同模拟需要,建立硬件模拟驱动,实现软件和硬件模拟器通信连接和协同模拟同步控制．基于RTOS的嵌入式软件验证方法以编译代码模型为基础,从系统行为级验证嵌入式软件功能,验证速度快．在实际应用中,该方法和ISS验证相结合,能够实现更有效、更快速的嵌入式系统协同验证．最后以几个典型硬件设计为基础,编写相应的控制软件,进行软硬件协同验证实验,实验结果数据说明该验证方法实用、有效、快速．     

Gini Coefficient-based Task Allocation for Multi-robot Systems With Limited Energy Resources

Nowadays, robots generally have a variety of capabilities, which often form a coalition replacing human to work in dangerous environment, such as rescue, exploration, etc. In these operating conditions, the energy supply of robots usually cannot be guaranteed. If the energy resources of some robots are consumed too fast, the number of the future tasks of the coalition will be affected. This paper will develop a novel task allocation method based on Gini coefficient to make full use of limited energy resources of multi-robot system to maximize the number of tasks. At the same time, considering resources consumption, we incorporate the market-based allocation mechanism into our Gini coefficient-based method and propose a hybrid method, which can flexibly optimize the task completion number and the resource consumption according to the application contexts. Experiments show that the multi-robot system with limited energy resources can accomplish more tasks by the proposed Gini coefficient-based method, and the hybrid method can be dynamically adaptive to changes of the work environment and realize the dual optimization goals.      

嵌入式系统源程序级软件能耗建模与分析

针对嵌入式系统能耗对各种嵌入式设备工作时长的影响,本文从系统指令级到源程序级的软件能耗考虑,首先通过分析设备源程序级语句的相关特征,基于源程序语句的指令能耗,提出一种针对源程序级的能耗模型,然后基于模型分析对五个经典算法的源程序中不同类别语句进行能耗优化,最后分别对五组经典算法优化前后的能耗比较。实验表明,本模型使得优化后的源程序能耗降低了9.46%-50.29%,达到了降低嵌入式系统软件能耗的目的。     

功耗仿真器HMSim的I/O接口功耗仿真模块设计与实现

在目前全球倡导“低碳经济”的背景下,嵌入式软件功耗已成为嵌入式系统设计的重要瓶颈,利用仿真技术实现嵌入式软件功耗的度量与实验是一种重要的开发手段。HMSim是一个高精度的指令级嵌入式软件功耗仿真器,介绍了HMSim的总体设计以及指令集仿真器结构,详细设计UART和LCD控制器等I/O接口的功能仿真模型,提出一种I/O接口功耗统计方法,最后通过运行基于μC/OS-II RTOS的应用程序,验证HMSim I/O接口功耗仿真模块的设计实现正确性。     

嵌入式系统软件模拟器设计

利用软/硬件协同设计的方法，将嵌入式系统设计采用软件模拟系统环境来开发，通过对CPU行为、内存、中断控制器和操作系统等模块的设计，把硬件系统设计和软件系统仿真相结合。是目前嵌入式系统设计的全新的方法。通过实例对软件模拟器进行验证，表明了这种方法的可行性和可靠性，为嵌入式系统的开发提供软件系统仿真的经验。     

Energy-aware disk scheduling for soft real-time I/O requests

In this work, we develop energy-aware disk scheduling algorithm for soft real-time I/O. Energy consumption is one of the major factors which bar the adoption of hard disk in mobile environment. Heat dissipation of large scale storage system also calls for an energy-aware scheduling technique to further increase the storage density. The basic idea in this work is to properly determine the I/O burst size so that device can be in standby mode between consecutive I/O bursts and that it can satisfy the soft real-time requirement. We develop an elaborate model which incorporates the energy consumption characteristics, overhead of mode transition in determining the appropriate I/O burst size and the respective disk operating schedule. Efficacy of energy-aware disk scheduling algorithm greatly relies on not only disk scheduling algorithm itself but also various operating system and device firmware related concerns. It is crucial that the various operating system level and device level features need to be properly addressed within disk scheduling framework. Our energy-aware disk scheduling algorithm successfully addresses a number of outstanding issues. First, we examine the effect of OS and hard disk firmware level prefetch policy and incorporate its effect in our disk scheduling framework. Second, our energy aware scheduling framework can allocate a certain fraction of disk bandwidth to handle sporadically arriving non real-time I/O’s. Third, we examine the relationship between lock granularity of the buffer management and energy consumption. We develop a prototype software with energy-aware scheduling algorithm. In our experiment, proposed algorithm can reduce the energy consumption to one fourth if we use energy-aware disk scheduling algorithm. However, energy-aware disk scheduling algorithm increases buffer requirement significantly, e.g., from 4 to 140 KByte. We carefully argue that the buffer overhead is still justifiable given the cost of DRAM chip and importance of energy management in modern mobile devices. The result of our work not only provides the energy efficient scheduling algorithm but also provides an important guideline in capacity planning of future energy efficient mobile devices. This paper is funded by KOSEF through Statistical Research Paper for Complex System at Seoul National University.     

Dynamic aggregated building electricity load modeling and simulation

In order to support the growing interest in demand response modeling and analysis, there is a need for physical-based building load models. This work presents a new approach for simulating electrical power flow in buildings. The new approach handles the power flow capacity shortage in existing building simulation programs, which have been used for the past few decades by building energy communities. The suggested approach represents the building as a group of electrical networks, organized in hierarchical levels. On the top level, the user defines key parameters such as rated power and power factor of existing loads. The power cables are modeled by their equivalent PI model. Accurate simulation models are developed for solving the building network equations where building loads are integrated into building network. Smart meters are implemented at different locations for power quality and energy auditing. Two case studies of residential and commercial buildings are investigated to prove the capability of the introduced approach. A comparison with EnergyPlus, as verified building energy software, is introduced to prove the ability of the proposed Matlab-based model to evaluate the annual energy consumption of the building. All results show the accuracy and ability of the proposed approach for simulating the electrical power flow of the building and can be integrated with renewable and storage energy.