Abstract For artificially simulating rainfall with variable intensity in laboratory, a linear relation between the simulated rainfall intensity and the frequency of flow rate, and that between the frequency and the regulating voltage of electric actuator were established through analyzing the performance parameters of the actuator; subsequently, an automatic control system for such a simulation was designed based on the flow rate regulation of water supply. An automatic control algorithm with variable timestep was proposed based on the LabVIEW language and then applied into gradation control on the water supply in the artificial rainfall system by analyzing the performance parameters of signal acquisition equipment and the voltagemechanical sensitivity of electric actuator. The voltagemechanical sensitivity of electric actuator was 0.2 mm/V, and the minimum control accuracies of frequency of water supply flow rate and rainfall intensity were 7 Hz and 0.053 mm/min, respectively. The experimental results indicated that the relative error between the rainfall intensity achieved and the designed one is less than 4%; the fidelity and the stability of simulated rainfall intensity is above 0.98; the spatial homogeneity coefficient of rainfall intensity is above 0.97; the linear correlation coefficient of rainfall intensity is above 0.75.
Zhou-Qi,CEN Guo-Ping,ZHANG Liang et al. Design and test of automatic control system of artificially simulating rainfall with variable intensity[J]. Journal of Drainage and Irrigation Machinery Engin, 2012, 30(4): 473-478.
Sousa Júnior S F, Siqueira E Q. Development and calibration of a rainfall simulator for urban hydrology research[C]∥12th International Conference on Urban Drainage. Porto Alegre, Brazil:[s.n.], 2011:18.
Shane Courtney Porter B S.The use of a rainfall simulaor for brush control reseach on the edwards plateau region of texas［D］. Texas:Texas A＆M University,2005.
Wischmeier W H,Smith D D.Comparison of rainfall energy and soil erosion parameters from a rainfall simulator and natural rain［D］.Columbia:University of MissouriColumbia,2007.
Williams J D, Wilkins D E, McCool D K, et al.The pacific northwest rainfall simulator:A research tool for the interior northwest［C］∥1996 Columbia Basin Agricultural Research Annual Report. Columbia,USA:［s.n.］,1996:37-40.
Zhou Yue,Wang Jie,Hu Shaowei.Designing and calibration of Kust03-1 rainfall simulating system[J].Journal of Kunming University of Science and Technology: Science and Technology,2008,33(2):81-85.(in Chinese)
Xie Yun,Lin Xiaojuan,Liu Yingna, et al.Calibration of simulated rainfall intensity and its spatial distribution for trough rainfall simulator[J].Bulletin of Soil and Water Conservation,2008,28(4):1-6.(in Chinese)
Shi Weidong,Zhang Desheng,Lang Tao, et al. Development of pump performance test system based on LabVIEW[J].Drainage and Irrigation Machinery,2007,25(3):38-41.(in Chinese)
Bowman B T, Brunke R R, Reynolds W D, et al. Rainfall simulator-grid lysimeter system for solute transport studies using, large, intact soil blocks[J]. Journal of Environmental Quality,1994,23(4):815-822.
Pall R, Dickinson W T,Beals D,et al.Development and calibration of a rainfall simulator[J].Canadian Agricultural Engineering,1983,25(2):181-187.
Sangüesa1 Claudia, Arumí José, Pizarro1 Roberto, et al.A rainfall simulator for the in situ study of superficial runoff and soil erosion[J].Chilean Journal of Agriculture Research,2010,70(1):178-182.