【正文】 nd 100 times. To obtain the final3 node test average as a result of the data analysis. Star work radio frequency munication BER test results as shown in table 1. Experimental analysis of: in a star work for data transmission, the test results significantly worse on a single point to single point transmission mode. This is mainly because, in the transmission process node must exist between the frequency interference and other interference. test System status and hibernation, respectively, using a multimeter to test the gateway node and the power consumption of sensor nodes, the test results listed in Table 2. Conclusion This paper analyzes the IEEE and ZigBee protocol, bined with the general development principles of munication systems and embedded syste ms, protocol on the μC / OSII operating system, select the appropriate hardware and software platform, focusing on software support for the platform, the software design of the overall structure of the munication protocol stack, and ultimately to achieve a pliant with the ZigBee specification car star wireless data acquisition work. The system has the following advantages: ① system easy to install. Wireless interconnection makes the equipment installation location is flexible to meet the requirements of the automation system is installed. It is simply that the power can take equipment. The work system can automatically plete the work configuration. ② scalability. Equipment within the coverage of the vehicle gateway, turn on the device, the node will automatically join the work.③ work selfhealing ability. If the work is a device fails, the vehicle gateway can automatically monitor, issue the mand the device reset and rework. 車載無線傳感器網(wǎng)絡監(jiān)測系統(tǒng)設計 康一梅，趙 磊，胡 江，楊恩博 （就 讀于北京航天航空大學） 摘要： 基于 IEEE 802． 15． 4和 ZigBee標準實現(xiàn)了一個車載無線傳感器網(wǎng)絡監(jiān)測系統(tǒng)。目前，汽車電子設備廣泛采用 16 位或 32 位微處理器進行控制。車載監(jiān)控中心可以向車載網(wǎng)關發(fā)出控制命令，由車載網(wǎng)關將控制命令轉(zhuǎn)換為射頻信號后發(fā)送給車載傳感器節(jié)點。為了提高通信傳輸模塊的智能化水 平，在設計中，它的功能不限于數(shù)據(jù)的實時顯示，所有的數(shù)據(jù)采集由監(jiān)控軟件通過發(fā)送請求信號的方式觸發(fā)。 2． 2 MCl3192 與 MC9S08GB60 的硬件連接 MC13192 與 MC9S08GB60 的硬件連接圖如圖 2 所示。同時， MCU 完成 MC13192 收發(fā)控制和所需要的 MAC 層操作。系統(tǒng)層接口定義了硬件的寄存器映射，這樣 C 語言就能直接訪問硬件寄存器來控制硬件。 通過測試發(fā)現(xiàn)， ZigBee 模塊的能耗要遠遠大于中央處理器和傳感模塊的能耗。 3． 4 主機監(jiān)控軟件的設計 本系統(tǒng)最終目的是將采集到的車載傳感器數(shù)據(jù)實時地傳送到主機，并在主 機 中得到顯示和保存。 ③ 歷史數(shù)據(jù)顯示模塊。 測試方法：網(wǎng)關節(jié)點上電后， 4 個 LED 同時點亮，掃描信道如果搜索到空閑信道后， LED 熄滅并加入空閑信道等待。最后統(tǒng) 計數(shù)據(jù)結(jié)果，就可以知道數(shù)據(jù)的丟包率和誤包率。 結(jié)語 本文分析 E 802． 15． 4 和 ZigBee 協(xié)議，結(jié)合通信系統(tǒng)和嵌入式系統(tǒng)的一般開發(fā)原則，在 μC ／ OSII 操作系統(tǒng)上實現(xiàn) IEEE802． 15． 4 協(xié)議，選擇合適的軟硬件平臺，著重于軟件支撐平臺的構建、軟件總體結(jié)構設計以及通信協(xié)議棧的實現(xiàn)，最終實現(xiàn)了一個符合 ZigBee 規(guī)范的車載星型無線數(shù)據(jù)采集網(wǎng)絡。如果網(wǎng)絡中某個設備出現(xiàn)故障，車載網(wǎng)關能夠自動監(jiān)測到，發(fā)出指令將該設備復位并重新入網(wǎng) 。該車載網(wǎng)絡系統(tǒng)能夠自動完成網(wǎng)絡的配置。星形網(wǎng)射頻通信誤碼率測試結(jié)果如表 1 所列。 4． 2 ZigBee 射頻通信測試 測試設備： ZigBee 節(jié)點 4 個，計算機終端 1 臺。在車載系統(tǒng)運行過程中可能關心某一個車載傳感器節(jié)點的數(shù)值，或者需要對某一個傳感器進行閾值設置，以便待監(jiān)測的環(huán)境出現(xiàn)異常情況可以及時地報 告給系統(tǒng)。這個應用程序包括了 4 個模塊： ① 實時數(shù)據(jù)顯示波形模塊。 圖 4 傳感器節(jié)點主程序流程 3． 3 網(wǎng)關節(jié)點軟件設計 車載網(wǎng)關向下管理傳感器節(jié)點，向上完成和 PC 監(jiān)控中心的交互，需要進行復雜的任務管理和調(diào)度，因此，采用基于 uC／ OS 內(nèi)核的嵌入式操作系統(tǒng)管理整個網(wǎng)關，為應用任務的高效運行提供良好的軟件平臺支撐。協(xié)議層則實現(xiàn)了基于 IEEE 802． 15． 4 的物理層和鏈路層以及基于 ZigBee 的網(wǎng)絡層協(xié)議。因為 SMAC協(xié)議棧編程模型采用層次設計，只有底層的 PHY 和 MAC 程序?qū)优c硬件相關，而網(wǎng)絡層和應用層程序則不受硬件影響。MCU 通過 SPI 口進行 MC13192 的讀寫操作，并把傳感器采集的信號經(jīng)過處理后通過 MC13192 發(fā)射出去。這種功能豐富的雙向 2． 4 GHz 收發(fā)器帶有一個數(shù)據(jù)調(diào)制解調(diào)器，可以在 ZigBee 技術應用中使用。 圖 1 系統(tǒng)結(jié)構總體圖 車載傳感器節(jié)點的生命周期由活躍期和休眠期構成。該采集系統(tǒng)的應用對象由溫度傳感器、油壓傳感器、轉(zhuǎn)速傳感器、速度傳感器、電流 傳感器、壓力傳感器等傳感器子系統(tǒng)所組成。 monitoring system Introduction In order to satisfy the people to car safety, handling and fort requirements, vehicle integrated with more and more electronic system .At present, car electronic equipment is widely used 16 or 32bit microprocessor control. Creating invehicle monitoring system based on IEEE and ZigBee standard for wireless sensor works, designed to achieve a more optimized wireless sensor works, the progressive realization of the work of automotive systems, intelligent and controllable to provide highCar System security. System design In this paper, the existing vehicle system, the data transmission mode is extended to the wireless transmission mode, the realization of a star work data acquisition system. And can place each data acquisition node of the acquired data is transmitted to the gateway, the gateway through the serial port to upload data to the host pute