Abstract: An automatic multi-point water quality monitoring system integrated with a sensor cleaning device was designed to solve the problem of the high cost of on-line monitoring of water quality sensors in aquaculture and the influence of surface algae and fouling on sensor detection accuracy. In considering of the gradual change of water quality parameters in aquaculture, a kind of multi-sink water quality sampling tank including clean water tanks was designed by adopting a sensor time-sharing multiplexing scheme, with which the water samples needing to be monitored online are transferred to the corresponding sampling tanks; the multi-point water quality cycle monitoring is realized by switching sensor modules controlled by a three-axis moving platform; and the sensor can be cleaned and maintained through the cleaning brush set in the cleaning water tank. PLC is preferred as the main controller to control the actuators, solenoid valves, water pumps, three-axis moving platforms and other executable devices. The on-site human-computer interaction is realized through the MCGS touch screen, the data exchange between which and the PLC is realized through the RS232 bus so as to realize the equipment status monitoring and the real-time display, storage and historical information statistics of test data. The results showed that the system was stable and reliable, the operation interface was normal, and the system can effectively improve the adhesion of algae and microorganisms on the sensor through the combination of clean water immersion, water flow rinsing and flexible wiping with sponges.

Key words: multi-point water quality monitoring, MCGS configuration, Sensor cleaning and maintenance

摘要： 针对目前水产养殖中在线监测水质传感器成本高，传感器表面藻类及污垢附着影响检测精度的问题，设计集成传感器清洁装置的全自动多点水质监测系统。考虑水产养殖中水质参数缓变特点，采用传感器分时复用方案，设计包括清洁水槽在内的多水槽水质采样箱，将需要在线监测的水样输送到对应采样水槽，由三轴移动平台控制传感器模块切换实现多点水质循环监测，在清洁水槽中设置清洁毛刷等实现传感器的清洁维护。系统采用PLC为主控制器，完成对传感器、电磁阀、水泵、三轴移动平台等可执行装置的控制。现场人机交互选用MCGS触摸屏，PLC与触摸屏之间通过RS232总线通讯交换数据，实现设备状态监控与测试数据的实时显示、储存、历史信息统计。研究表明，系统运行稳定可靠，操作界面正常，使用清水浸泡、水流冲洗、海绵柔性擦拭相结合的清洗方式，可有效地缓解传感器上藻类及微生物的附着问题，实现水质传感器的自动清洁维护。

关键词: 多点水质监测, MCGS组态, 传感器清洁维护