Development And Stability Analysis Of The Small-scale Linearly Moved Irrigation System

With the aggravation of contradiction between the shortage of water resources and the social development,vigorously developing water-saving irrigation is a fundamental way to solve the shortage of water in our country today.A new type of small-scale linearly moved irrigation system(LMIS)is designed for solving problems of sprinkler units,poor adaptability,complicated equipment and bulky structure included.In this paper,through theoretical analysis of structure,strength calculation and dynamic modeling and simulation,the self-made LMIS is designed and discussed by the performance of this system in different ramps.Then the hydraulic performance of the sprinkler unit was tested under specific test conditions.The main contents of the research were presented as follows:(1)The key components of the self-made LMIS were designed which made the irrigation machine have some disadvantages like disassembly property,adjustable nozzle installation height and spacing.Through analyzing forces on key components of the sprinkler,the method of enhancing the structural strength was put forward.According to requirements of automatic control,a simple and convenient control method was put forward.(2)By theoretical analysis of the stability on the slope,the factors influencing the climbing ability of LMIS were put forward including wheel track,height of center of mass and adhesion coefficient.The results show that in the longitudinal ramp on the uniform speed,the unit front and rear track distance of 3m,the center of mass height of 3.37 m,the system limit slope angle ?lim is nearly at 26 ° and in the wet soil road adhesion coefficient of 0.5 ~ 0.7 conditions,the maximum slip angle of tlim is 31 °.(3)Multi-body dynamics modeling and simulation of small-scale LMIS were carried out.Thus,a parameterized dynamics simulation model was established for the small-scale LMIS in the software ADAMS.The whole machine model was used to simulate the vehicle through the performance of the 2D horizontal road and the different slope,and the change of the centroid height was monitered by the sensor.The results show that when the maximum climbing angle of the new sprinkler unit is less than or equal to 25 °,the simulation can be completed successfully.When the roll is greater than 25 °,the roll can not work normally.At the same time,the virtual prototype technology is used to simulate and calculate the whole machine,which provides an efficient test method for the future development and popularization of the sprinkler unit.(4)Based on the new type of LMIS,the hydraulic performance tests were carried out under the nozzle in a specific installation height,installation spacing,working pressure.The factors influencing the irrigation volume of the unit were analyzed by single factor analysis of variance and least squares method.Quantitative analysis was carried out among the main factors influencing the irrigation amount.The results show that when the pressure,sprinkler spacing and the height is 0.07 Mpa and 0.14 MPa,3m and 1m respectively,the uniformity coefficient of the combined sprinkler is more than 85%,and the distribution uniformity coefficient nearly at 80%.The probabilities of the influence of the running distance and the working pressure on the irrigation amount are 0.74 and 0.08 respectively,and the probability of the run speed ratio is 8.2e-7.