| Along with the advancing of industrialization and urbanization,our country’s soil resources are facing new situations and challenges both in terms of quantity and quality.This requires us to improve our understanding of the status and importance of soil,to analyze soil properties,to reasonably utilize soil resource.In order to make a better study of the soil,it is necessary to conduct various tests in the laboratory,such as rock and soil bulk density test.The accuracy and authenticity of the experiment determines the accuracy and authenticity of our cognition of soil.The biggest factor that affects the accuracy and authenticity of the experiment is the quality of the soil sample.Therefore,based on the experimental steps of artificial ring-knife soil sampling and combined with automatic control technology,this paper develops a ring-knife soil sampler used in laboratory.Firstly,this paper introduces the research of various soil samplers at home and abroad,Mainly Introduce the research status of ring-knife soil sampler used in laboratory.The stress change when the pipe shoe enters the soil is calculated Through the calculation of soil mechanics.Based on the experimental steps of artificial and combined with automatic control technology,the ring-knife soil sampler’s soil sampling mechanism,cutting transportation mechanism,soil sample cleaning structure and other mechanisms,and complete three-dimensional modeling are designed.Then,the control system of ring-knife soil sampler is built,the hardware of the control system is selected,the power supply and control circuit are designed and the construction of the electric control circuit is completed.According to the actual situation,the working process of the machine is determined,the G code program is written,and the manual control and automatic control of the machine is designed.After completing the construction of the whole machine model,the dynamic model of the whole machine is established in RecurDyn,and the kinematics analysis of the whole machine is carried out in RecurDyn according to the set workflow.The motion posture of the whole machine,the motion curves of X,y,Z linear module and electric push rod are analyzed.,this provides the reference for the subsequent cosimulation.Afterwards,a co-simulation was carried out in RecurDyn and EDEM software,the force of the wire knife when cutting the soil is analyzed.It is found that the maximum force is 20.15 N,and it shows a single wave-like fluctuation as entering the soil sample.The displacement and force of the Z linear module during the soil sampling process are analyzed,it is found that the maximum force is 297.161N;the displacement and force of the electric push rod are analyzed,it is found that the maximum value is 421.57 N.After the analysis,the reason why the force of the Z linear module is less than electric push rod is the existence of the tube shoe.After completing the simulation analysis,the experimental prototype was assembled,and soil sampling verification was carried out in the laboratory of the Geological Bureau.After comparing the samples taken by machine and artificial soil,it is found that the relative error between its’ mass and the soil bulk density are less than 5%.The machine can roughly simulate artificial soil sampling and can basically meet the requirements for soil sampling.Through the installation of acceleration sensors and experimental verification of machine motion,the accuracy and stability of the linear module and the electric push rod can meet the design requirements.The ring cutter borrower designed in this paper is a borrowing and sampling device with my country’s independent intellectual property rights.It provides an effective tool for soil science research,and has important engineering practical value and good application prospects for promoting soil research and utilization. |
