温室环境控制无线传感器网络的服务质量管理

针对基于无线传感器网络构建的温室环境控制系统，为了减少无线网络固有的时变传输延时、丢包、网络拥塞等现象对控制性能的影响，该文从提高网络服务质量（quality of service，QoS）的角度出发，提出一种基于Takagi-Sugeno模糊控制器的QoS管理策略。该QoS管理策略以截止期错失率作为QoS性能评价指标，针对传感器节点和执行器节点之间的数据传输，通过动态调整传感器节点的采样周期，使截止期错失率维持在设定水平，从而提高网络QoS。初步试验表明了该QoS管理策略的合理性、有效性和实用性。该QoS管理策略可以广泛应用于温室、农田、苗圃等区域。该研究为提高无线传感器网络在设施农业中的应用水平做出了有益探索。

Quality of service management in wireless sensor networks for greenhouse environmental control

In order to reduce the impact of inherent network time-varying delay, packet loss, network congestion and other phenomena on control performance of the greenhouse environmental control system based on wireless sensor networks, the QoS management strategy based on Takagi-Sugeno fuzzy logic controller were proposed from the perspective of improving quality of service (QoS). The basic idea of the proposed QoS management strategy is to use deadline miss ratio as the evaluating index of the QoS and to adapt the sampling period of each sensor nodes by means of feedback control technology at run time so that the deadline miss ratio associated with the real-time data transmission from the sensor nodes to the actuator nodes is maintained at a pre-determined desired level and the required QoS can be achieved. Preliminary experimentations indicate the rationality, effectiveness and practicability of the proposed QoS management strategy. It can be effectively applied to the greenhouse, the field cropland, and the nursery garden, etc. This research contributes to the exploration on how to improve the application level of wireless sensor networks in facility agriculture.