外文翻譯--用于監(jiān)測(cè)和控制溫室氣候的zigbee無線網(wǎng)絡(luò)的使用（英文）

1、International Journal of Engineering and Advanced Technology (IJEAT) ISSN: 2249 – 8958, Volume-2, Issue-1, October 2012 35 ? Abstract: The increasing demands for crop production and quality have significantly increased t

2、he utilization of high quality and productivity green houses. Modern greenhouses are nowadays having great sizes and they are equipped with sophisticated monitoring and controlled actuation systems to assure maximum

3、productivity and provide value-added quality. Increases in greenhouse sizes has increased the demand in increasing the monitoring points in order to provide real-time precise measurement of some important parameters a

4、nd hence to avoid unnecessary exposure to unhealthy ambient conditions. The increase of monitoring points is certainly leads to increase the complexity of managing and maintaining them efficiently. The aim of this

5、 paper is to present a novel wireless sensor network based ZigBee technology for monitoring and controlling greenhouse climate. The system consists of a number of local stations and a central station. The local station

6、s are used to measure the environmental parameters and to control the operation of controlled actuators to maintain climate parameters at predefined set points. For each local station a PIC Microcontroller is used t

7、o store the instant values of the environmental parameters, send them to the central station and receive the control signals that are required for the operation of the actuators. The communication between the local st

8、ations and the central station is achieved via ZigBee wireless modules. Index Terms— Greenhouse monitoring and control, Wireless network, ZigBee. I. INTRODUCTION The increased demand for high quality products, the incr

9、eased concern about food security, and the impact of climate changes are some of the factors that have contributed to the rapid development of the greenhouse industry in the past four decades across the world [1]. In

10、general greenhouses are structures that are designed to provide a climate-controlled environment for plants that are not in season to be cultivated indoors where a controlled environment can mean a higher survi

11、val rate. The target of the commercial purpose greenhouses, like in any other business, is to maximize profit, which depends directly on the yield grown. It is well known that, plant species perform their best while

12、being in the most suitable environment through maintaining the temperature, light and humidity at the optimal level for photosynthesis. Beside the commercial purpose greenhouses, there are a number of facilities for p

13、erforming experiments related to plant growth research, where a high degree of the climate control is needed, too. Consequently, greenhouse climate control requires real-time precise measurement of some important par

14、ameters in order to avoid unnecessary exposure to unhealthy ambient conditions [2]. Computerized environmental control systems were found to be the most reliable solution in providing the ability to Manuscript receiv

15、ed on October, 2012 Ibrahim Al-Adwan, Assistant Professor Department of Mechatronics Engineering Faculty of Engineering Technology Al-Balqa` Applied University Amman 11134- Jordan, India. Munaf S. N. Al-D., Assistant

16、Professor Department of Electrical Engineering Faculty of Engineering Tafila Technical University, India. integrate the control of all systems involved in manipulating the growing environment, thus improving the crop d

17、evelopment and reducing the production costs [3]. Nowadays there are numerous greenhouse environmental control systems presented on the market, offering as much or as little of the control as may be feasible. In the pa

18、st generation of greenhouses it was enough to have one cabled measurement point in the middle to provide the information to the greenhouse automation system. The system itself was usually simple without opportunities

19、 to control locally heating, lights, ventilation or some other activities, which was affecting the greenhouse interior climate [2]. In modern greenhouses, facilities are required to provide several options to make loc

20、al adjustments to the artificial climate and other greenhouse support systems easier and more reliable. Moreover, with the increase of greenhouses size, more measurement data is also needed to make this kind of the s

21、ystems work properly. Increased number of measurement points should not dramatically increase the automation system cost. It should also be possible to easily change the location of the measurement points according to

22、 the particular needs, which depend on the specific plant, on the possible changes in the external weather or greenhouse structure and on the plant placement in the greenhouse [4]. Wireless sensor network (WSN) can f

23、orm a useful part of the automation system architecture in modern greenhouses. Wireless communication can be used to collect the measurements and to communicate between the centralized control unit and the actuators l

24、ocated at the different parts of the greenhouse. Compared to the cabled systems, the installation of WSN is fast, cheap and easy. Moreover, it is easy to relocate the measurement points when needed by just moving sen

25、sor nodes from one location to another within a communication range of the coordinator device. Furthermore, if the greenhouse flora is high and dense the small and light weight nodes can even be hanged up to the plant

26、s’ branches. WSN maintenance is also relatively cheap and easy. The only additional costs occur when the sensor nodes run out of batteries and the batteries need to be charged or replaced, but the lifespan of the bat

27、tery can be several years if an efficient power saving algorithm is applied [5-8]. As an open and global standard for WSN, ZigBee shows advantages on low-cost, low power consumption and self-forming. The current rese

28、arches of ZigBee wireless sensor network on industrial automation, electronic products, smart buildings and medical care were presented and, as an explorative application of ZigBee wireless sensor network in protected

29、 agriculture overcoming the limits of wire connection, its applied design for greenhouse management was proposed by introducing both the hardware and software architectures. II. GREENHOUSE CONTROL SYSTEM The control

30、system for the greenhouse includes the following components: - Data acquisition of the environmental parameters through sensors; The Use of ZigBee Wireless Network for Monitoring and Controlling Greenhouse Climate Ibrahi

31、m Al-Adwan, Munaf S. N. Al-D International Journal of Engineering and Advanced Technology (IJEAT) ISSN: 2249 – 8958, Volume-2, Issue-1, October 2012 37 B. Actuation System An actuator is a piece of equipment that produce

32、s movement when given a signal. Actuators are used in the computer control of an environment, industrial automation and in robotics or, more generally, actuators are the machines used for output in control application

33、s. For the situation in a computer controlled greenhouse, the actuators receive their control signal from the microcontroller to control the inside climate variables of the greenhouse. The designed system includes th

34、e following actuators: - A ventilation fan, its speed determines the exchange between inside and outside air, thus causing natural ventilation. - Heating system consists of a number of heaters distributed along the gre

35、enhouse. - Thermal/shade screen, which is picked up or extended along the roof of the greenhouse. In the first case, it prevents the loss of heat acquired during the day (for cold months). Whereas, as shade screen, it

36、protects the crop from excess of solar radiation and reduces the increasing temperature (for hot months). - Evaporative cooling system consists of an exhaust fan at one end of the greenhouse and a pump circulating wate

37、r through and over a cellulose pad installed at the opposite end. When the fan operates, negative pressure is created inside, causing external air to be drawn through the wetted pad. Evaporation results from contact

38、between water and air, getting a lower inside temperature in the greenhouse. - Irrigation system, water is pumped through polyethylene tubes to apply drip irrigation. - Artificial lighting lamps, apply light radiation o

39、ver plants to lengthen the photoperiod. III. COMPARISON BETWEEN WIRELESS SENSOR NETWORK STANDARDS A wireless sensor network (WSN) is a computer network consisting of spatially distributed autonomous devices using sensor

40、s to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. The development of wireless sensor networks was originall

41、y motivated by military applications such as battlefield surveillance [5]. During the last decade wireless sensor networks are utilized in many civilian applications, including environment and habitat monitoring, hea

42、lthcare applications, home automation, and traffic control. Several standards are currently either ratified or under development by organizations. Standards are used far less in WSNs than in other computing systems wh

43、ich make most systems incapable of direct communication between different systems. The predominant standards commonly used in WSN communications are: 1- Wi-Fi 2- Bluetooth 3- ZigBee All the above mentioned technolo

44、gies work at similar RF frequencies, and their applications sometimes overlap [6]. In the current study, we chose the following five main factors of greenhouse networks to compare: cost, data rate, number of nodes, cu

45、rrent consumption and battery life. From cost point of view, ZigBee chip is US$ 1 or less, the lowest; Wi-Fi and Bluetooth chips are $ 4 and $ 3, respectively. The overall system cost can be significantly reduced by the

46、 employment of ZigBee chip. Regarding data rate, ZigBee is 250 kbps, while Wi-Fi and Bluetooth are 54 Mbps and 1~2 Mbps, respectively. Despite the lowest data rate, ZigBee is sufficient for a greenhouse. Generally, dat

47、a traffic in a greenhouse is low—usually small messages such as the change of temperature or a command from the controller to an actuator. And also, low data rate helps to prolong the battery life. As it is well known

48、, the capacity of network is determined by the number of nodes, and ZigBee has up to 254 nodes, the largest among the three. It meets the application demand of more and more sensors and actuators in a greenhouse. The p

49、ower and current consumption, ZigBee has the lowest current consumption, 30 mA, while Wi-Fi, 350 mA, and Bluetooth, 65~170 mA. It also greatly helps to prolong the battery life. Finally the battery life of a ZigBee chi

50、p has the longest battery life, a few months or even years. As a whole, ZigBee technology offers long battery life, small size, high reliability, automatic or semi-automatic installation, and, particularly, a low system

51、 cost. Therefore, it is a better choice for greenhouse monitoring and control than other wireless protocols [7-8]. IV. APPLICATION OF ZIGBEE WIRELESS SENSOR NETWORKS IN GREENHOUSE CLIMATE ZigBee based wireless network

52、s have three types of topologies namely: star topology, peer-to-peer topology and cluster tree topology [9]. The first topology is called Personal Area Network (PAN). The central station plays the role of the network

53、coordinator and it is responsible for establishing the communication between it and the local units. Each local unit chooses a PAN identifier, which is not currently used by any other station within the radio sphere o

54、f influence. This allows each star network to operate independently. Figure (4) shows the actual distribution of the local stations within the greenhouse. Figure 4: Location of ZigBee Wireless sensor Stations. In this

55、 paper, we established the network according to the star topology. As shown in figure 5, once the central station is activated for the first time, it establishes its own network and becomes the network coordinator. The