Modeling of Human-Robot Physical Interaction for Case of Mobile Self-Balanced Robot

This article solves the problem of making a mathematical model of a self-balanced robot moving together with am operator person. The operator is placed directly on the robot's bearing platform which commands the robot's movement using the change of the center of mass position of the operator's body. Such way of control can be considered a result of a physical interaction of the operator with the robot's structure. The advantage of this method is that the operator's hands are free and aren't occupied with robot driving. Moreover, the way of control by changing the center of masses' position can be used in autonomous robots moving without the human interference. To build the mathematical model of this particular human-robot physical interaction system, the kinematic scheme was utilized involving the two-unit backward pendulum with the slowed-down hinge between the units. The change of a center of the system mass position is effected by the change of the angular position of the top unit in relation to the lower one. Basing on the Lagrange equations for the kinetic energy of a system in the generalized coordinates the mathematical model in the form of two nonlinear differential equations of the second order was built. The angular provision of the top unit is included in these equations in the form of a parameter. An eligibility test of this model, using the mathematical MatLab package, confirmed its adequacy to a real process of the physical human-robot interaction for the case of the operator's interaction with the mobile self-balanced platform.