Retis A robot control example 灾etis Design requirements Consider a mobile robot equipped with: >Modularity:a subsystem must be developed without >two actuated wheels; knowing the details of other subsystems(team work). >two proximity (US)sensors; >Configurability:software must be adapted to different situations (through the use of suitable parameters) >a mobile(pan/tilt)camera; without changing the source code. >a wireless tranceiver. >Portability:minimize code changes when porting the system to different hardware platforms. Goal >Predictability:allow the estimation of maximum delays. >Follow a path based on visual feedback; >Avoid obstacles; >Efficiency:optimize the use of available resources (computation time,memory,energy). >Send complete robot status every 20 ms. 家ets Hierarchical control 安etis Software View periodic task buffer visual-based navigation visual-based obstacle 100ms obstacle navigation avoidance object avoidance object recognition recognition 10 ms visual vehicle visual control vehicle tracking tracking control 20m5 (5ms) feature feature extraction extraction motor control camera pan tilt US1 US2 mot_dx camera pan tilt US1 US2 mot dx mot_sx
计算模型：Turning Machine ALAN TURING 19121954 雅sTMt HOME oF Man Twing 101110L MATHEMATICAL g果niw Adlington Rd. ooo000000000000 01R4 01L3 。1 变迁系统 111 11R5 01L4 01R2 2 SunaMaqpuea -Timing:逻辑步？ 11L1 11 4 。 计算复杂性问题 01R3 R4 一时间复杂度 11L 3 ·Time:metrics
计算模型：Turning Machine • 变迁系统 – Timing：逻辑步？ • 计算复杂性问题 – 时间复杂度 • Time：metrics
The Real-Time Problem:缺乏时间语义！ o Programming languages have no time in their core semantics o Temporal properties are viewed as “non-functional'" o Precise timing is poorly supported by hardware architectures o Operating systems provide timed behavior on a best-effort basis (e.g. using priorities). o Priorities are widely misused in practice
：缺乏时间语义！
中围种学技术大学 嵌入式实时系统设计方法 Embedded Computing Real-Time Computing Embedded Real-Time Systems 李曦lxx@ustc.edu.cn 陈香兰xlanchen@ustc.edu.cn
嵌入式实时系统设计方法 Embedded Computing Real-Time Computing Embedded Real-Time Systems 李曦 llxx@ustc.edu.cn 陈香兰 xlanchen@ustc.edu.cn
Presentation Outline 嵌入式系统概述 一嵌入式系统的定义 -嵌入式系统的特征与指标 -嵌入式系统分类 ·发展方向：CPS 。2 热点应用示例 一汽车电子 ·课程说明 llxx@ustc.edu.cn 10/87
Presentation Outline • 嵌入式系统概述 –嵌入式系统的定义 –嵌入式系统的特征与指标 –嵌入式系统分类 • 发展方向：CPS llxx@ustc.edu.cn 10/87 • 发展方向：CPS • 热点应用示例 –汽车电子 –。。。 • 课程说明