The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid s...The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.展开更多
The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of...The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of one bionic spine and four pneumatic artificial muscles(PAMs).The coordinated movement of the bionic flexible body and the leg mechanism can achieve pivot turning gait.First,the pivot turning gait planning of quadruped robot was analyzed,and the coordinated movement sequence chart of pivot turning was presented.Then the kinematics modeling of leg side swing and body bending for pivot turning was derived,which should meet the condition of the coordinated movement between bionic flexible body and leg mechanism.The PAM experiment was conducted to analyze its contraction characteristic.The study on pivot turning of the quadruped robot will lay a theoretical foundation for the further research on dynamic walking stability of the quadruped robot in unstructured environment.展开更多
Aiming at the problem of incomplete stem removal in the process of Gentian root and stem separation,a roller-type Gentian stem removal device was designed.Based on the mechanical characteristics of Gentian stems and t...Aiming at the problem of incomplete stem removal in the process of Gentian root and stem separation,a roller-type Gentian stem removal device was designed.Based on the mechanical characteristics of Gentian stems and the force analysis of the extraction process,the operating conditions for the complete removal of Gentian stems were determined.When the tensile force exerted by the stem-pulling rollers on the Gentian stems is less than the tensile force of the Gentian stems and greater than the maximum tensile force required for the Gentian stems to be removed at the stem bases,the complete removal of Gentian stems from the stem base can be realized.The bionic design method is used to construct the bionic flexible surface structure of the stem-pulling rollers by taking the tree frog toe pad as the bionic prototype and investigating its flexible surface microstructure and friction-enhancing characteristics.EDEM simulation software is used to establish the contact model between the bionic flexible stem-pulling rollers and Gentian stems,and the optimal structural parameters of the bionic flexible surface are determined through simulation tests.The optimal working parameters of the bionic flexible roller are determined through test rig tests.The experimental results showed that when the diameter of the hexagonal prism of the bionic surface was 5.67 mm,the spacing of adjacent hexagonal prisms was 2.62 mm,and the height of the hexagonal prism was 3.21 mm,the bionic flexible stem-pulling rollers exerted a maximum tensile force of 30.23 N,and the Gentian stems were not broken.When the speed of the rollers was 195 r/min,the spacing between stem-pulling rollers was 3.0 mm,and the height of the rollers clamping position was 250 mm,the maximum tensile force required for Gentian stem removal was 13.88 N,and the net removal rate reached 94.35%.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51375289)Shanghai Municipal Natural Science Foundation of China(Grant No.13ZR1415500)Innovation Fund of Shanghai Education Commission(Grant No.13YZ020)
文摘The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.
基金Supported by the National Natural Science Foundation of China(No.51375289)Shanghai Municipal National Natural Science Foundation of China(No.13ZR1415500)the Innovation Fund of Shanghai Education Commission(No.13YZ020)
文摘The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of one bionic spine and four pneumatic artificial muscles(PAMs).The coordinated movement of the bionic flexible body and the leg mechanism can achieve pivot turning gait.First,the pivot turning gait planning of quadruped robot was analyzed,and the coordinated movement sequence chart of pivot turning was presented.Then the kinematics modeling of leg side swing and body bending for pivot turning was derived,which should meet the condition of the coordinated movement between bionic flexible body and leg mechanism.The PAM experiment was conducted to analyze its contraction characteristic.The study on pivot turning of the quadruped robot will lay a theoretical foundation for the further research on dynamic walking stability of the quadruped robot in unstructured environment.
基金support of the Basic Scientific Research Program of the Education Department of Liaoning Province(Grant No.LJKMZ20220998)the National Natural Science Foundation of China(Grant No.52275264).
文摘Aiming at the problem of incomplete stem removal in the process of Gentian root and stem separation,a roller-type Gentian stem removal device was designed.Based on the mechanical characteristics of Gentian stems and the force analysis of the extraction process,the operating conditions for the complete removal of Gentian stems were determined.When the tensile force exerted by the stem-pulling rollers on the Gentian stems is less than the tensile force of the Gentian stems and greater than the maximum tensile force required for the Gentian stems to be removed at the stem bases,the complete removal of Gentian stems from the stem base can be realized.The bionic design method is used to construct the bionic flexible surface structure of the stem-pulling rollers by taking the tree frog toe pad as the bionic prototype and investigating its flexible surface microstructure and friction-enhancing characteristics.EDEM simulation software is used to establish the contact model between the bionic flexible stem-pulling rollers and Gentian stems,and the optimal structural parameters of the bionic flexible surface are determined through simulation tests.The optimal working parameters of the bionic flexible roller are determined through test rig tests.The experimental results showed that when the diameter of the hexagonal prism of the bionic surface was 5.67 mm,the spacing of adjacent hexagonal prisms was 2.62 mm,and the height of the hexagonal prism was 3.21 mm,the bionic flexible stem-pulling rollers exerted a maximum tensile force of 30.23 N,and the Gentian stems were not broken.When the speed of the rollers was 195 r/min,the spacing between stem-pulling rollers was 3.0 mm,and the height of the rollers clamping position was 250 mm,the maximum tensile force required for Gentian stem removal was 13.88 N,and the net removal rate reached 94.35%.
