Design And Research Of Test Bench For Spray Technology

In order to increase food production, people used an excessive amount of chemical fertilizers and pesticides, and low utilization rate of the traditional application equipment. About80%of the pesticide directly into the environment, resulted into a lot of waste and serious environmental pollution, and residues pesticide of vegetables exceeded the standard bringed serious harm to people’s health. In order to improve the spray technology, designed of spray test bench mainly studied on the nozzle flow, spray painting, homogeneity and the optimal combination of uniformity of spray. This paper focused on the function of spray test bench, designed the electrical system, and completed the relevant research.This paper firstly designed of the test scheme of the spray uniformity of spray test bench, and then designed the system. According to the function requirements of test bench, This paper designed of the MCU control circuit of spray test bench. The32bit ARM controller LM3S1138was used as the core microcontroller of the spray test bench hardware systems design. The design concluded interface circuit of proximity sensors, the relay driver circuit, sampling circuit, and serial communications circuit. Then the application software of MCU was programmed according to the design requirement of the hardware, in order to achieve the various functions of the hardware circuit. Applications software included the location detection module, the AD sampling module, the serial communication module, LCD display module. Combination of the function of the spray test bench and designed software and hardware, designed the electrical control system of the spray test bench. The system included the parts of the liquid pump and the air pump, the drive parts of the spray boom up and down and the spray rack moving, the test tube rack rotary, and the liquid level detection. Combined with the functions of MCU and the spray test bench main function, and designed the PC software. The PC software used the graphical programming language of LabVIEW to design the serial port with the MCU communication, visual interface and automatically generated an Excel table and stored the data.The drive section of up and down of spray test bench was used to control the high of spray, in order to measure the uniformity of spraying at the different altitudes, and obtain the optimal combination of parameters of different nozzle types. The driven part of movement realized to replace of the nozzle. After the starting of the liquid pump, the spray liquid from the tank formed high pressure fluid to the nozzle and started spray. The liquid along a set of flow into different test tubes, after the set time, the time relay started the rotating electrical work, and rotated the test tube be filled with liquid to the vertical position. Then the proximity sensors send the signal to the MCU, and started the detection motor.The detection motor driven the ultrasonic sensor installed on the detection device, and run together along the detected track. When the ultrasonic sensor reached above the test tube, the signal from the proximity switch triggered the MCU sampling, detected the liquid level of the test tube. When the ultrasonic sensor run to the next test tube, the proximity switch triggered again, sampling, until all the test-tube was detected, stop to run. When dumping button was pressed, the detection motor returned to its original position, and waited for the next detection. The liquid level data which was detected by MCU was send to the PC and generated charts and stored in the Excel table.According to the system debugging, the test bench was expected to the function, and accomplished the spray experiment of a single nozzle and the dual nozzles. The test bench can measure the flow and spray painting of single nozzle, and the spray uniformity of double spray nozzle.