Study On The Identification Of Soil Grades And Best Penetrating Angle Based On Digging Resistance

Hydraulic excavator plays an important role in the area of engineering machinery for its multiple functions and wide applications. In face of the sustainable development of the modern agriculture, hydraulic excavator, a kind of agricultural machinery, has become an effective way of improving agricultural production efficiency and reducing labor intensity for its modernization and intelligentization. Therefore, this subject starts from improving the operation efficiency of excavator, aiming to realize the purpose of the automated identification of the best penetrating angle and soil grade. The experiment result is evaluated finally by analyzing and modeling the digging resistance and working device and then taking the model as theoretical foundation to experiment with different kinds of soils.This research studies on recognition of soil grade and excavator’s best penetrating angle by combining soil mechanics, theoretical mechanics, kinematics, dynamics and programmatic support etc. Research involves following parts:The development of research on mechanic modeling of soil digging and cutting is surveyed firstly, and then the necessity of research on soil mechanics is indicated, finally, the key point and difficult point in modeling are introduced.According to the analysis of soil inner structure, the vital elements of soil collapsing force is obtained; Combined with practical engineering application, ranking the grade of soil according to difficulty of soil digging; By using soil mechanics to put detailed analysis on the soil shear stress, soil resistance model is given; By using kinematics and theoretical mechanics to build the soil-tool interaction model, digging resistance model of bucket is obtained; Combined with soil resistance model and digging resistance model, the final soil grade recognition model is obtained.The excavator working device is connected with robotics, kinematics is used to set kinematic model of working device; Forward kinematics results are applied to feedback current bucket tip’s pose (position and posture), inverse kinematics is used to accomplish trajectory automatic control; The research analyzes all feasibilities of digging strategies and locates digging strategies that fit automatic control, convenient for automation of soil grade recognition.At last, the theoretical model is tested, and experiment results indicate that after adding soil grade identification model and automatic digging strategies, the excavator has commendable automatic recognition results of soil grade and the best penetrating angle. The accuracy of soil grade recognition is above 95%, the best penetrating angle of clay is about 19.6o to 24.73o, the best penetrating angle of coarse sand is about 21.26o to 29.08o, the best penetrating angle of cobble is about 30.99o to 37.63o.