基于云服务接入的温室环境采集终端优化设计

The Optimized Design of the Greenhouse Climate Monitoring Terminal base on Cloud Service Accessing

由于温室环境信息采集需求多样、应用分散设备接入网络困难且为物联网,云服务优先应用领域,使得采用运营商通讯(GSM/GPRS、3G、4G等)的环境数据采集设备在温室生产中应用越来越多,但实际运行过程中依然存在系统能耗高、太阳能温室内充电效率低、铅酸蓄电池供电为主体积大、整体密封性差难以适应高温高湿环境等问题,迫切需要在以上几个方面开展优化设计。开发了低成本、集成度高、低功耗的温室环境感知终端,能够采集常规数字(I2C、1-wire、串口等)、模拟信号传感器(0~5V,4~20m A),灵活选择传感器满足用户对不同监测参数的测量需求并通过GSM/GPRS接入已有的设施农业云服务平台,适合分散,大区域接入、单温室直接网络接入等应用场景。重点在终端能耗管理、防护结构、太阳能供电结构等方面开展优化设计,小功率太阳能电池板采用多角度安装方式,实现延长充电时间超过2h·d^(-1),提高温室内太阳能利用率;将主动通风空气防辐射罩与符合IP67标准防护壳构成一体,适应高温高湿环境,并加速防辐射罩内部与外部气流交换速度,提高温湿度、CO2测量响应速度和精度;低功耗硬件选型配合事件触发唤醒能耗管理模式解决GSM/GPRS通讯能耗问题使终端休眠能耗为44u A,常规应用频率平均功耗达1.1m A,实现无外接供电设备全负荷独立工作近1个月,满足温室环境在线监测需求。该优化设计与应用具有开放性、易用性、低成本、安装便捷等特点,能够提升温室生产监测能力,市场前景广阔。

The environment data acquirement devices with GSM/GPRS, 3 G or 4 G module were used in greenhouse production widely for diverse demands in measuring parameters, hard to link to Internet for distributed and large area application, and needed by IOT and cloud service technology. But these productions had disadvantages of the higher power consumption, low charging efficiency with solar panel inside greenhouse, higher size and weight powered by lead acid battery, and poor seal ability hard to adapt the high temperature and humidity. It is important to carry out the optimization design for these devices. Base on the optimization in energy consumption and distribution, packaged structure, and solar powered structure, a low cost, highly practical, and low power consumption greenhouse climate monitoring terminal was designed in this paper. It provided digital interface for the protocol of I2 C, one-wire, and USART, analog signal acquisition interface for 0-5 V or 4-20 m A output sensors was also provided in this terminal. It could connect several kinds of environment sensors（Air temperature and humility, CO2 concentration, light radiation, soil humility） as user needed. Multi-angle mounted low power solar panels could prolong the charging time more than 2 hours each day in greenhouse. Higher solar energy utilization efficiency was achieved. The active ventilation radiation shield and encapsulated box with the standard of IP67 were used for decreasing the affection of high temperature and humidity in greenhouse. Air sensor and PCB were integrated in radiation shield and encapsulated box. Faster response time and higher accuracy could achieved by the structural optimization design. Low power consumption design methods in hardware and software were applied in this system. It achieved the 44 u A power consumption in sleep mode. Average power consumption was 1.1 m A when measure interval time was 15 minutes, and transmit interval time was 1 hour. It could be used for nearly one month using only Li-on battery. The monitoring terminal was also accessed to the cloud service platform. Through the design and application in greenhouse and cloud platform, there were open, easy-using, low cost and convenient installation characteristics in this terminal, and it could improve the ability of greenhouse climate measurement.