Multivariable control of transmitted vibrations to the seat model of the human body

- A realistic 5DOF model of human body in seating mode, under excitation, is considered.
- Design of multivariable active control strategy for suppression of undesirable vibrations.
- Using advanced mathematical tools, dynamic system is decomposed into two parts.
- Five output variables are controlled at desired values by manipulation of three control inputs.
- Controller acts efficiently in vibrations' suppression under various resonance conditions.

Advanced control techniques are required for the vibrations suppression of the seated human body in different places like automotive and public transportation lines. In this paper, an active multivariable control strategy is applied to a seated human body model and results are simulated and examined via MATLAB. Dynamic equations of the model are derived using Lagrange method and they are linearized around the equilibrium point of the system. After assessing the deficiencies of the previous models and control strategies proposed for the human body, an active control method is presented based on pole placement analysis. This control strategy is designed for a realistic model of the human body with 5 degrees of freedom (5DOF) and in the presence of road excitations. In the proposed multivariable control system, human body movements in five directions (as the five outputs) are controlled via manipulation of the forces in vertical and horizontal directions and a moment about y-axis (as the three inputs). For the simulation purposes, it is assumed that these control inputs are provided by actuators (e.g., piezo-electrics). Dynamic behavior of the system is evaluated around its natural frequencies and the effectiveness of the proposed active multivariable control is investigated. It is observed that under various resonance conditions, the controller acts efficiently in vibrations suppression.