The Optimization Study Of The Cassava Harvest Machinery Uprooted Velocity Model

The main way of cassava root harvesting machinery is digging-elevating harvester, it is adaptability to a variety of soil and root growth,and not easy to damage the cassava root, low power consumption, but to build the optimum velocity model of uprooted is the key of harvesting, and it can improve the efficiency of uprooted and reduce the loss of roots. Also, there is no report about the velocity model of uprooted. So, there is great significance for researching and optimizing on the velocity model of uprooted.In this paper, based on the methods of Lagrange and SPH(Smoothed particle hydrodynamics) coupling algorithm, designed method of experiment, we built the dynamics simulation model of soil-cassava root system and the mathematical model of mechanical uprooted velocity model coefficients and harvest qualities. Reversed the red clay soil parameters of cassava planted in Guangxi, And studied the influence law and mechanism in uprooted time,roots maximum effective stress, the maximum pull force and the uncleanness for the theory of uprooted and the coefficients of A, B, C, D, E, F in the uprooted velocity model. Contemporary, we optimized the coefficients of A, B, C, D, E, F used genetic algorithm and got the optimum mechanical uprooted velocity model which can be applied to red clay soil. The simulation results showed that the soil-cassava root system dynamic simulation model had a high degree of accuracy and the coefficients of A, B, C, D, E, F had great influence on uprooted time, roots maximum effective stress, the maximum pull force and the uncleanness. The optimum combination coefficients in velocity model is A=0.056, B=0.521, C=0.048, D=0.086, E=38.506, F=1.165.Under the condition of this optimal combination, the uprooted time is1.02s, roots maximum effective stress is2.56MPa, the uncleanness is0.034, the maximum pull force is1091.64N.