Kinematics and experiments of a life-sized masticatory robot for characterizing food texture

A life-sized masticatory robot, which is intended to chew foods in a human way while the food properties are evaluated, of a 6RSS parallel mechanism is discussed in this paper. A robotic mechanism is proposed, and its kinematic parameters are defined according to the biomechanical findings and measurements of the human masticatory system. For a given mandibular trajectory to be tracked, the closed-form solution to inverse kinematics of the robot is found for joint actuations, whereas differential kinematics is derived in Jacobian matrices. Major features of the robot, including the motion control system, are presented. Experimental results for free chewing, soft-food chewing, and hard-food chewing are given where the foods are simulated by foam and hard objects, and crank actuations and driving torques (an indication of muscular activities) required are compared for the chewing of different foods.