在研究傳統(tǒng)家用燃氣報警器的基礎上，以ZigBee協(xié)議為平臺，構建mesh網狀網絡實現網絡化的智能語音報警系統(tǒng)。由于傳感器本身的溫度和實際環(huán)境溫度的影響，傳感器標定后采用軟件補償方法。為了減少系統(tǒng)費用，前端節(jié)點采用半功能節(jié)點設備，路由器和協(xié)調器采用全功能節(jié)點設備，構建mesh網絡所形成的家庭內部報警系統(tǒng)，通過通用的電話接口連接到外部的公用電話網絡，啟動語音模塊進行報警。實驗結果表明，在2.4 GHz頻率下傳輸，有墻等障礙物的情況下，節(jié)點的傳輸距離大約為35 m，能夠滿足家庭需要，且系統(tǒng)工作穩(wěn)定，但在功耗方面仍需進一步改善。 Abstract: On the basis of studying traditional household gas alarm system, this paper proposed the platform for the ZigBee protocol，and constructed mesh network to achieve network-based intelligent voice alarm system. Because of the sensor temperature and the actual environment temperature, this system design used software compensation after calibrating sensor. In order to reduce system cost, semi-functional node devices were used as front-end node, however, full-function devices were used as routers and coordinator，constructed alarm system within the family by building mesh network，connected to the external public telephone network through the common telephone interface, started the voice alarm module. The results indicate that nodes transmit about 35m in the distance in case of walls and other Obstacles by 2.4GHz frequency transmission, this is able to meet family needs and work steadily, but still needs further improvement in power consumption.
標簽： ZigBee 無線智能 家 報警系統(tǒng)
上傳時間： 2013-10-30
上傳用戶：swaylong
This discussion will attempt to outline some truths and common misconceptions about digital audio watermarking. It will survey the intrinsic Obstacles that such technology is required to overcome, shedding light on its performance criteria, compromises and limitations. While doing so, it will also survey a few common types of applications, hopefully leading to a clear understanding as to the appropriateness of such technology and its expertise within multimedia content protection.
標簽： misconceptions discussion attempt digital
上傳時間： 2016-07-18
上傳用戶：520
Optimal Manipulator Path Planning with Obstacles using Disjunctive Programming
標簽： Manipulator Disjunctive Programming Obstacles Planning Optimal using Path with 機械臂
上傳時間： 2016-04-28
上傳用戶：yanghanjiang
The objective of this book is to allow the reader to predict the received signal power produced by a particular radio transmitter. The first two chapters examine propagation in free space for point-to-point and point-to-area transmission, respectively. This is combined with a dis- cussion regarding the characteristics of antennas for various purposes. In chapter 3, the effect of Obstacles, whether buildings or mountains, is discussed and analytical methods, whereby the strength of a signal is the shadow of an obstacle can be predicted, are presented.
標簽： Propagation Essentials Radio Wave of
上傳時間： 2020-05-27
上傳用戶：shancjb
Ultra-wideband (UWB) technology enables high data-rate short-range communica- tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds, over a wide spectrum of frequencies, while keeping power consumption at low lev- els. This low power operation results in a less-interfering co-existence with other existed communication technologies (e.g., UNII bands). In addition to carrying a huge amount of data over a distance of up to 230 feet at very low power (less than 0.5mW), the UWB signal has the ability to penetrate through the doors and other Obstacles that tend to reflect signals at more limited bandwidths and higher power densities.
標簽： Silicon-Based Front-Ends RF
上傳時間： 2020-06-01
上傳用戶：shancjb
