Kinematics And Dynamics Analysis Of Non-singular Two-way Plow Turning Mechanism

Mechanized tillage and soil preparation technology are a fundamental part of mechanized farmland operation technology,and it is also the most energy consuming project in field mechanization.At present,the common tilling machines are the moldboard and disc plough.The moldboard plough is the most widely used farming machinery in agricultural production.Most moldboard plows can only plough in one direction,and after that,a closed ridge is formed.The appearance of two-way plough can solve the problem with no ridge.The turnover mechanism is the key part of the reversible plow,and there are some problems,such as poor reliability,unstable working position and singular configuration.In this paper,a novel type of singularity-free kinematically redundant turnover mechanism is designed for the above problems,and its kinematics and dynamics are analyzed.Turnover mechanism is the core component of reversible two-way plow.How to avoid or exceed the singular position is a problem which must be solved in the process of designing and applying this mechanism.Firstly,based on mechanism and machine theory,a novel type of singularity-free kinematical redundant turnover mechanism with two degrees of freedom is proposed and introduced into design of two-way plow.Secondly,the position and velocity equations of this mechanism are established according to geometric constraints,and the Jacobian matrices including input and output are derived.Taking the determinant of the input and output Jacobian matrices as identification,singularities of all introduced variants are analyzed when the plow realizes turnover motion with singularity-free capability.Based on the transfer matrix of force and Jacobian matrix of velocity,the force transmissibility performance,stiffness performance and payload performance of the mechanism are analyzed,and effects of link lengths to these performances are summarized.Conclusions obtained in this paper can provide a theoretical basis for the design of heavy-duty turnover plow.Based on the kinematical analysis,the force of each component is analyzed,and its ideal dynamic model is established.Then,based on the ideal dynamic model,the dynamic model considering the joint friction is established.Finally,the above-mentioned systems have been calculated numerically by MATLAB software.The kinematical redundant turnover mechanism is virtually simulated in Solid Works.By contrast with the simulation results and the test results,the correctness of the model is verified.Based on the optimization of the turning mechanism,the 3D models of all parts and components are established,then the prototype manufacturing and test are going on.And the electro-hydraulic proportional technology is applied to control the hydraulic cylinder.Finally,the experimental results are output and compared with the theoretical values.The results show that there is a certain error between the theoretical value and the experimental value,but the relative error is within 15 percent.It proves that the scheme of turnover mechanism is practicable.