| Hydrological information is an important basis for the decision-making of flood control,drought relief and disaster relief departments.At present,the collection,transmission and imaging technology of automatic hydrological cable system in China is relatively backward,and the measuring accuracy and efficiency are relatively low.In this paper,a new fully automatic hydrological cable channel ultrasonic sounding system is designed.By analyzing the advantages and disadvantages of hydrological automatic measurement technologies at home and abroad,the overall structure,core technology,hardware circuit and system software of hydrological cable ultrasonic sounding system are designed.The design scheme is developed into corresponding equipment and tested in laboratory,pond and hydrological station.The main design content are as follows:(1)The sounding system is composed of outdoor depth sounder,indoor wireless data transmission terminal and client software system.The key technologies such as temperature sensor,depth sensor,remote transmission,storage and imaging of the sounding system are designed.The temperature sensor adopts the real-time automatic temperature compensation equipment to realize the real-time temperature compensation of ultrasonic velocity.Pressure sensor is used to measure the depth of the lead fish.Using bluetooth and wireless radio to transmit data,realize wireless remote transmission control;The analog signal printed on the recording paper is displayed by digital image and can be stored to realize the display and storage of echo signal.(2)The hardware circuit design is the core of the ultrasonic sounding system,which respectively designs the power supply system,human-computer interaction hardware circuit,hydroacoustic signal processing circuit,transmission circuit and receiving circuit.The power supply system USES htc4006-4 charging management and outputs the charging state through the CHG pin.The discharge loop provides input to digital power supply and analog power supply respectively.The MSP430F5438 A is used as the main control center.The hydroacoustic signal processing circuit adopts the fixed point DSP chip of TMS320F2812 measurement and control application as the processing core board.The transmitting circuit is isolated by the light coupler.The OC door pushes TTL and the rear push-pull amplifies.The receiving circuit mainly includes front stage amplifier,controllable gain amplifier,network filter,detection circuit and output stage circuit.Its receiving circuit module is hd-max double-frequency echo sounder hf receiving board,the maximum total gain is designed to be 120 dB,the gain control range is 56dB~120dB,and the minimum detection signal amplitude is 5mV.(3)The software of the sounding system is designed.The recognition software of underwater reflected signals adopts underwater tracking technology.It is assumed that the change of the secondary depth is + /-10%.It is designed to open a time gate from 10% times T to 10% times T before the last correct echo time,and the echo within the time gate is the correct echo.The processing of ultrasonic echo sounder using ultrasonic characteristics reflected in different media,the ultrasonic transducer installed on fish lead level wing,vertical to the bottom side of launch ultrasonic wave in the water,bottom reflection wave calculation launch starting time and received the end of the time,calculate the unilateral depth,through pressure liquid level sensor measured the distance of the transducer and the surface of the water.In this paper,a complete set of hydrological cableway ultrasonic sounding system to conduct a comprehensive design and field test,and realized the real-time measuring temperature,real-time of ultrasonic sound velocity correction,wireless transmission is rapid,stable signal width,high efficiency and automation in the whole process of the imaging technology can accurately identify the channel section,late for automatic hydrological cableway ultrasonic sounding system transition and application to provide the basis. |
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