Research On Chewing Platform Mechanism And Its Control System For Food Detection

Mastication platform is an application product integrateing multi-disciplinary technology such as mechanisms,kinematics,control engineering,software engineering,which can approximate simulate oral occlusion and chewing behavior,and has been widely used in dentistry,biomechanics,especially food science.Combined with the insertion of human jaw muscles at the insertion point of the mandible,a chewing platform mechanism is proposed in this paper,which can realize the function of occlusion and mastication.Compared with previous mastication robot,this mechanism regards the chewing behavior as the relative movement of maxilla and mandible.They are driven independently and cooperate with each other to accomplish the function of chewing together.To improve the bionic performance of occlusal function,two PUS branched chains were used to simulate the masseter muscle in mandible to drive the mandibular rotating platform bilaterally.Considering the maximum masticatory force of teeth,and the force of the mechanism during the operation,the specific model parameters of some crucial elements are given.To verify the mechanical strength,the statics simulation for the crucial components of the mechanism was performed through the Workbench software.It is verified that the deformation and stress-strain parameters of the material selected by the mechanism are within a reasonable range under the condition of maximum masticatory force.The relationship between the motion position of the screw table and the mandibular mounting plate is deduced,and the installation height of the limit switch of the maximum opening of the mandible is obtained.Subsequently,combined with the characteristics of the mechanism and the motion function to be achieved,the overall control scheme is proposed,and the hardware selection is analyzed in detail.The resistance-pressure curve of pressure sensor is fitted by MATLAB.The software implementation of multi-channel data acquisition based on DMA transmission is designed,and the data frame format based on serial communication mode is given.A stepping motor control scheme with adjustable speed and pulse number control is designed.Based on this,the control strategy of the mechanism in the occlusion and chewing motion mode according to the specified chewing force is given.And on the basis of this,combined with gyroscope,proximity switch and etc,the control strategy of the mechanism under different motion modes such as occlusion and chewing is given.Then,the requirement analysis of the upper computer software development for the chewing platform mechanism is carried out.The overall framework of the functions of the upper computer is given on this basis,then,the crucial technologies involved in the development process are introduced.Finally,the functions of user login,user management,serial communication connection,multi-channel data acquisition and display,data verification,data conversion and data preservation,and etc are realized.Eventually,a comprehensive test of the chewing platform prototype was carried out.The verification showed that the prototype operation was basically correct,and the error between the chewing force and the set value was small.