The chief objective of Electric Machinery continues to be to build a strong
foundation in the basic principles of electromechanics and electric Machinery.
Through all of its editions, the emphasis of Electric Machinery has been
on both physical insight and analytical techniques. Mastery of the material covered
will provide both the basis for understanding many real-world electric-Machinery
applications as well as the foundation for proceeding on to more advanced courses in
electric Machinery design and control.
This white paper discusses how market trends, the need for increased productivity, and new legislation have
accelerated the use of safety systems in industrial Machinery. This TÜV-qualified FPGA design methodology is
changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to
market. This allows FPGA users to design their own customized safety controllers and provides a significant
competitive advantage over traditional microcontroller or ASIC-based designs.
Introduction
The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in
cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas
around machines such as fast-moving robots, and distributed control systems in process automation equipment such
as those used in petrochemical plants.
The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of
electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing
safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was
developed in the mid-1980s and has been revised several times to cover the technical advances in various industries.
In addition, derivative standards have been developed for specific markets and applications that prescribe the
particular requirements on functional safety systems in these industry applications. Example applications include
process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC
62304), automotive (ISO 26262), power generation, distribution, and transportation.
圖Figure 1. Local Safety System
嵌入式系統(tǒng)是一種應用范圍非常廣泛的系統(tǒng)。可以說除了桌面計算機和服務器外所有計算設(shè)備都屬于嵌入式系統(tǒng),例如從便攜式音樂播放器到航天飛機上的實時系統(tǒng)控制都屬于嵌入式系統(tǒng)。
大多數(shù)商用的嵌入式系統(tǒng)都設(shè)計成專用任務的低成本的產(chǎn)品。大多數(shù)的嵌入式系統(tǒng)都具有實時性的要求。有些功能需要非常快的主頻,但其他大多數(shù)功能并不需要高速的處理能力。這些系統(tǒng)通過特定的器件和軟件來滿足實時性的要求。
簡單地通過速度和成本來定義嵌入式系統(tǒng)是困難的,但對于大批量的產(chǎn)品而言,成本常常對系統(tǒng)設(shè)計起決定作用。通常,一個嵌入式系統(tǒng)的很多部分相對系統(tǒng)主要功能來說需要較低的性能,因此嵌入式系統(tǒng)和通用PC相比,能夠使用一個滿足輔助功能的合適的CPU,從而簡化了系統(tǒng)設(shè)計,降低了成本。例如,數(shù)字電視的機頂盒需要處理每秒以百萬兆位計的連續(xù)數(shù)據(jù),但這些數(shù)據(jù)處理大部分是由定制的硬件來實現(xiàn)的,如解析、管理和編解碼多個頻道的數(shù)字影像。
對于大批量生產(chǎn)的嵌入式系統(tǒng),如便攜式音樂播放器或手機等,降低成本就成為最主要的問題。這些系統(tǒng)通常只具有幾個芯片:一個高度集成的CPU,一個定制的芯片用于控制其他所有的功能,還有一個存儲芯片。在這種設(shè)計中,每部分都設(shè)計成使用最小的系統(tǒng)功耗。
對于小批量的嵌入式應用,為了降低開發(fā)成本,常常使用PC體系結(jié)構(gòu),通過限制程序的執(zhí)行時間或用一個實時操作系統(tǒng)來替換原先的操作系統(tǒng)。在這種情況下,可以使用一個或多個高性能的CPU來替換特殊用途的硬件。
嵌入式系統(tǒng)的軟件通常運行在有限的硬件資源上:沒有硬盤、操作系統(tǒng)、鍵盤或屏幕。軟件一般都沒有文件系統(tǒng),如果有的話,也會采用Flash驅(qū)動器。如果有人機交互接口的話,也是一個小鍵盤或液晶顯示器。硬件是計算機的物理部分,和存儲在硬件中的計算機軟件程序和數(shù)據(jù)區(qū)分開來。
嵌入到機械中的嵌入式系統(tǒng)需要長期無故障連續(xù)運行,因此它的軟件需要比PC中的軟件更加仔細地開發(fā)和更加嚴格地測試。
那么,到底什么是嵌入式系統(tǒng)呢?
根據(jù)IEEE(國際電氣和電子工程師協(xié)會)的定義,嵌入式系統(tǒng)是“控制、監(jiān)視或者輔助設(shè)備、機器和車間運行的裝置”(原文為devices used to control,monitor,or assist the operation of equipment,Machinery or plants)。這主要是從應用上加以定義的,從中可以看出嵌入式系統(tǒng)是軟件和硬件的綜合體,還可以涵蓋機械等附屬裝置。
目前國內(nèi)一個普遍被認同的定義是:以應用為中心、以計算機技術(shù)為基礎(chǔ),軟件 硬件可裁剪,適應應用系統(tǒng)對功能、可靠性、成本、體積、功耗嚴格要求的專用計算機系統(tǒng)。
可以這樣認為,嵌入式系統(tǒng)是一種專用的計算機系統(tǒng),作為裝置或設(shè)備的一部分。通常,嵌入式系統(tǒng)是一個控制程序存儲在ROM中的嵌入式處理器控制板。事實上,所有帶有數(shù)字接口的設(shè)備,如手表、微波爐、錄像機、汽車等,都使用嵌入式系統(tǒng),有些嵌入式系統(tǒng)還包含操作系統(tǒng),但大多數(shù)嵌入式系統(tǒng)都是由單個程序?qū)崿F(xiàn)整個控制邏輯。
本書是按照人事部、信息產(chǎn)業(yè)部全國計算機技術(shù)與軟件專業(yè)技術(shù)資格(水平)考試要求編寫,內(nèi)容緊扣《嵌入式系統(tǒng)設(shè)計考試大鋼》。全書共六章,分別對嵌入式系統(tǒng)基礎(chǔ)知識、嵌入式微處理器與接口設(shè)計、嵌入式軟件與操作系統(tǒng)、嵌入式軟件程序設(shè)計、嵌入式系統(tǒng)設(shè)計與維護等知識進行了詳細的講解。最后介紹了一個典型的嵌入式系統(tǒng)設(shè)計案例。
本書內(nèi)容豐富,結(jié)構(gòu)合理,概念清晰。既可作為全國計算機技術(shù)與軟件專業(yè)技術(shù)資格(水平)考試中嵌入式系統(tǒng)設(shè)計師級別的考試用書,供有關(guān)考生學習使用,也可作為本科生嵌入式系統(tǒng)相關(guān)課程教材或培訓書使用。
This white paper discusses how market trends, the need for increased productivity, and new legislation have
accelerated the use of safety systems in industrial Machinery. This TÜV-qualified FPGA design methodology is
changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to
market. This allows FPGA users to design their own customized safety controllers and provides a significant
competitive advantage over traditional microcontroller or ASIC-based designs.
Introduction
The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in
cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas
around machines such as fast-moving robots, and distributed control systems in process automation equipment such
as those used in petrochemical plants.
The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of
electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing
safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was
developed in the mid-1980s and has been revised several times to cover the technical advances in various industries.
In addition, derivative standards have been developed for specific markets and applications that prescribe the
particular requirements on functional safety systems in these industry applications. Example applications include
process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC
62304), automotive (ISO 26262), power generation, distribution, and transportation.
圖Figure 1. Local Safety System
The ICA/BSS algorithms are pure mathematical formulas, powerful, but rather mechanical procedures: There is not very much left for the user to do after the Machinery has been optimally implemented. The successful and efficient use of the ICALAB strongly depends on a priori knowledge, common sense and appropriate use of the preprocessing and postprocessing tools. In other words, it is preprocessing of data and postprocessing of models where expertise is truly ne
Commercially available active noise control headphones rely on fixed analog controllers to drive "anti-noise" loudspeakers. Our design uses an adaptive controller to optimally cancel unwanted acoustic noise. This headphone would be particularly useful for workers who operate or work near heavy Machinery and engines because the noise is selectively eliminated. Desired sounds, such as speech and warning signals, are left to be heard clearly. The adaptive control algorithm is implemented on a Texas Instruments (TI™ )
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TMS320C30GEL digital signal processor (DSP), which drives a Sony CD550 headphone/microphone system. Our experiments indicate that adaptive noise control results in a dramatic improvement in performance over fixed noise control. This improvement is due to the availability of high-performance programmable DSPs and the self-optimizing and tracking
capabilities of the adaptive controller in response to the surrounding noise.