| Bionic chewing robot is a kind of bionic robot which can reappear chewing movement ofthe human mandibular. It is mainly applied to food material detection and texture evaluation,testing and evaluation of denture materials, treatment of mandibular movement disorders andother fields, and also it has abroad application prospect. With the cross integration of bionicsand robotics, bionic chewing robot is developing in the direction of high bionic extent, fastdynamic response and more precise control.In this paper, based on the full investigation and analysis of the development trend ofbionic chewing robot and research status of parallel driving mechanism, taking the realmandibular chewing movement as the simulation object, considering the bigger mandibularsize, smaller chewing space and larger chewing biological force load, this paper proposes a6-PSS parallel bionic chewing robot model.Firstly, this paper described the basic structural shapes and dimensions of the constructed6-PSS parallel bionic chewing robot. And also according to the virtual prototyping technologyestablished the absolute coordinate system and relative coordinate system, in addition solvedinverse position and inverse velocity of the slider by kinematic equations of parallel mechanism,which was building relative foundation for the kinetic analysis.Secondly, analyzed the workspace of6-PSS parallel bionic chewing robot based on thekinematics inverse position solution; combined with the constraints of mechanism movementestablished a calculated mathematical model of the workspace. Through the Matlab programcarried out the workspace in different posture, and displayed them in dimensionality reduction.Then we can solved out the whole workspace of the moving platform in the scope ofmasticatory movement. Taking the calculated mathematical model of workspace as theobjective function, extracted some certain key parameters of6-PSS parallel mechanism asdesign variables, later then, with the constraint limitation of moving platform workspace rangeinclude the mandibular chewing movement and interferences between different links,constructed the maximum of minimum mathematical optimization model based onmulti-objective parameters, completed the optimization design of the mechanism.Finally, made kinetics analysis of the optimized bionic chewing robot; on the basis ofpartial simplification of the mechanism, calculated the inertia tensor of moving platform,solved out the key parts of the kinetic energy and potential energy. Established the dynamicsmodel of the6-PSS parallel chewing mechanism based on Lagrange equation, and solved outthe generalized force of dynamic equations with the help of Matlab symbol function. Then builtvirtual prototype of bionic chewing robot in Adams. According to two basic chewingmovements of the lower incisors cutting food materials and grinding shearing food material,designed out the moving platform to simulate the movement of the mandibular chewing foodby right side. The results of kinematics simulation of typical composite chewing movement inAdams show that this mechanism can truly reproduce the human chewing movement; Kineticssimulation in Adams verified the reliability and validity of the dynamic model, at the same time,the simulation results can be used as the important basis for the evaluation of kinetics performance of6-PSS parallel bionic chewing robot. |
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