Optimal control and analysis of stabilometric tests with step disturbances of human sensory systems

Abstract

Several optimal control problems are considered for a human motion model in the case of stabilometric tests when the posture of a person changes under a step disturbance. Such a situation is observed in the case of a galvanic vestibular stimulation or a vibration stimulation of the proprioceptors of shin muscles. Stabilometric tests with visual step disturbance are widespread in Russia. A characteristic feature of center of pressure (COP) trajectories for these tests is the presence of swings and overshoots. The test results are compared with the solutions of optimal control problems devoted to the repositioning of an inverted pendulum by a coupling torque. A speed-of-response problem and an optimal stabilization problem with a quadratic quality criterion are considered. The solutions to these optimum problems are compared with the results of stabilometric tests, which allows one to state a hypothesis on the sources of the above effects.