Modeling And Performance Research Of Chewing Movement Robot

The chewing movement robot is a kind of mechanical device which can simulate human masticatory movement and reduce human masticatory force.Its research results have broad application prospects in the fields of Stomatology and food science.In this paper,based on the characteristics of human chewing movement,which can be divided into two stages: chopping and grinding,a kind of low degree of freedom chewing movement robot with 3-UPS/RPP parallel mechanism as the main structure is proposed,and the kinematic performance of the robot is also studied.Firstly,the characteristics of human masticatory motion are analyzed with the help of relevant medical knowledge.A kind of low degree of freedom chewing movement robot with3-UPS/RPP parallel mechanism as the main structure is proposed,and the degree of freedom of this robot is checked based on the formula of degree of freedom.In UG software,the 3D model of chewing movement robot is built,and two working modes of the robot are introduced.The corresponding relationship between the degree of freedom of motion and human chewing action in each mode is described by the fixed coordinate system.Secondly,based on the theory of spatial mechanism,the kinematics model of 3-UPS/RPP less freedom chewing movement robot is constructed.Based on the analysis of the drive and constraint chains,the inverse position solution of 3-UPS/RPP chewing movement robot is presented.Then,based on the results of the inverse position solution,the forward position solution of the robot is calculated.Finally,the velocity analysis of the robot is carried out and the Jacobian matrix of the mechanism is solved,which lays the foundation for the further mechanism performance analysis.Then,based on the inverse position solution model,and considering the constraint conditions of each motion pair in the drive and constraint chains,the workspace of the chewing movement robot is solved by the numerical discrete search method.The calculation results show that the workspace of the mechanism meets the basic needs of simulating human chewing movement.Then,the singularity of the mechanism is analyzed by the Gosselin analysis method.Based on the Jacobian matrix,the evaluation indexes of operability,dexterity and static stiffness are defined,and the motion performance of the mechanism is further analyzed by numerical simulation.At last,the kinematics simulation analysis of the chewing movement robot is carried out in ADAMS software based on the working examples of the two modes of chopping and grinding.The correctness of the kinematics analysis is verified by comparing the simulation results with the theoretical calculation results.Then,based on the kinematic simulation,the dynamic simulation of the mechanism is carried out to further observe the kinematic performance of the mechanism.At the same time,based on the PID control method,the control system of the chewing movement robot is designed,and the effectiveness of the control system is verified bythe joint simulation of Simulink and ADAMS.The results show that the designed robot has three degrees of freedom in the plane,and the robot can complete the two modes of chopping and grinding by changing the working plane,which meets the design requirements of simulating human chewing movement.The research in this paper provides a theoretical basis for the practical application of the design.Compared with the traditional Stewart platform and other 6-DOF mechanisms,the lower-mobility parallel mechanism has the irreplaceable advantages of simple structure,low cost,easy control and so on.In-depth research can provide a new idea for the design and manufacture of the chewing movement robot.