Design Of Agricultural Exoskeleton Mechanism And Study On Static Instability Condition

With the rapid development of robotics,mechanical design,modern manufacturing technology,and computer simulation,exoskeleton robots based on human body imitating have made greater breakthroughs and more extensive applications.The exoskeleton robot can simulate the skeletal structure and joint motion of the human body.Under the control of the drive system,the exoskeleton robot can provide help and support to the wearer,and can also protect the human body.In this paper,after analyzing the current domestic helper-type lower extremity exoskeleton robots,according to the needs of the wearers in agricultural labor,a tailored agricultural lower extremity exoskeleton robot is designed.The agency has a good biomimetic nature,can assist labor writers in all kinds of environments and terrain to carry out work,help labor authors to give support when carrying out fruit picking,and reduce the labor intensity of labor writers.The content of this study is based on several key technologies for the exoskeleton of the lower extremity of agriculture.The following research was conducted on the wear coordination,human-robot coordination,static support control,and static support instability conditions of the designed organization.(1)In view of the general design principles of human bionics,this paper analyzes the lower limb joints,bones and joint movement angles of the human body,combines the needs of the wearer's agricultural posture and the need for assistance,and then designs a suitable lower limb for agricultural work.The skeletal robot mechanism was modeled by the three-dimensional software UG.The hip,knee,and ankle joints of the lower extremity exoskeleton were all innovatively designed.(2)In order to provide a theoretical basis for the study of control strategies,this paper analyzes the kinematics of lower extremity exoskeleton based on the spin theory and the Paden-Kahan sub-problems,including positive kinematic analysis and inverse kinematic analysis.Inverse kinematics solve equations,and use Matlab simulation software to verify the algorithm.(3)In order to verify the assistedness and synergy of the exoskeleton established,the model designed in UG was introduced into ADAMS for analysis.The hip joint,knee joint and ankle joint were analyzed for walking movement,and the joint angle comparison analysis chart was obtained.The exoskeleton was synergistic;weight simulation of theexoskeleton of the lower extremity was performed,and a comparison chart of the joint torque was obtained to verify the assistive performance of the exoskeleton.(4)Analyze the static instability condition of the exoskeleton when the wearer's half picking posture,establish a balance equation of the lower limb exoskeleton based on the spiral theory,and derive the Jacobian matrix and the singularity of the mechanism.Discriminating the matrix,analyzing the condition of the static instability of the mechanism under the condition of static support locking,and giving the formula calculation proof.