Design And Bionic Performance Research Of Jaw Movement Robot

A robot that simulates the jaw movements is a kind of device which can not only imitate the human chewing behavior, but also reproduce human chewing trajectory and force. And the jaw movement robot in biologically faithful fashion has found many applications in such as dentistry, food science and biomechanics. This subject comprehensive research on the bionic mechanism principle of human mandible system, then we propose a novel jaw movement robot which correspond with the biomechanical characteristics of mandible system, and the proposal is significant in supplying a robotic instrument to other fields such as materials wear tests of artificial teeth, evaluation of food texture properties and food chewing dynamics, stress distribution in mandible, etc.To achieve the high bio-imitability requirements, this paper according to the biomechanical properties of mandible muscles, such as unsymmetrical distribution, force with different direction and the joints in maxillary and mandible is non-coplanar, while using the mechanical bionic principles, a novel robot that simulates the jaw movements is built based on the6-PSS parallel mechanism. First, comprehensive consideration of the high bio-imitability and mechanism design feasibility requirements, and derived the insertion point position in maxillary and mandible. Then for the mandible platform need to meet demand of multidisciplinary experimental study under different force, this paper make the finite element analysis for the mandible platform. In order to convenient for effective analysis of mandible bionic performance, the reference points on mandible platform were determined.According to the characteristics of the parallel mechanism, analyze the inverse displacement and inverse kinematic by analytical method, and get the non-linear relationship between pose transformation of lower mandible and the movement of slider along the guide rail in the branch chain. Afterwards, consideration of constraint conditions such as spherical vice corner, slider stroke and leg intervention, and then determine the workspace boundary of jaw movement robot by numerical method. As the junction in maxillary and mandible is non-coplanar, it may lead to complicated singularity configuration problem. Based on the deduced Jacobean matrix, the flexibility ratio and manipulability is used to analyze and evaluate the motion performance in the workspace and nearby the district of singularity configuration. Based on the designed structural parameters, the virtual prototype of jaw movement robot was built in ADAMS, and proceeds with the simulation experiment in various postures such as irregular bite, bite, left chewing, normal opening and closing, right chewing. The results show that the jaw movement parallel mechanism can truly reproduce the movement environment of mandible, and the mechanism has well bionic performance. Finally, the robot prototype model was designed, and then this paper presents the parameters of main components, so laid foundation for the actual prototype.