A Flow Automatic Detective System Of Rectangular Channel Based On The3-Dot Method

Our country goes short of water resources,but also is a great country in the aspact of agriculture simultaneously.The irrational use of Irrigation water is the main reason of a huge loss of agricultural water resources,the innovation of traditional flow-measure equipments and means is imperative.The flow-measure of open channel plays an important role in agricultural production,which is directly related to the utilization of irrigation water and the level of irrigation management.The application of several current flow-measure devices are often subject to their own inadequacies and conditions of using constraints such as high cost,high technical requirements for the installation,poor anti-interference performance and so on.To solve the problems above and to consider the characteristic of current domestic water distribution channels are widely used by rectangular cross-section,the issue researches and designs a flow automatic detective system of rectangular channel based on the3-dot method.The system adopts the classic "3-dot method" in hydrologic test industry to calculate the flow rate,and then to figure out the accurate flow value according to the relationship between the flow velocity and volume flow.The collecting board of the system is placed in the channel to acquire water pressure signal,and then to transmit the signal to the controlling board,the operate of the signal and the real-time display of the display module are all controlled by the controlling board.The design includes the following contents:(1)Aiming at the characteristic of the domestic and overseas distribution channels and the problems exist in other flow measurement devices,a flow detective system based on the3-dot method’s proposed,which provides a convenience for the real-time display of flow.(2)The part of hardware circuit’s designed,including the signal acquisition circuit,A/D conversion circuit,the SCM circuit,the power circuit and so forth.(3)The part of software’s wrote by the compiler Keil uVision2and Visual Basic language,including the software of the host computer’s running,the lower computer’s running and the communication between the both sides.(4)The commissioning of the system’s hardware and software and related tests and data analysis’re completed,which verify that the system could real-time detective the flow of open channel.(5)The improvement program of the system’s proposed.The design combines flow measurement technology with sensor technology and automatic control technology organically.Using flow automatic detective system of rectangular channel based on the3-dot method to operate flow for real-time detection reduces the human and material resources,the impact of the external environment is small and it’s easy to install and maintain,it also has a certain reference value for the future development of flow testing industry of open channel.