Rotorcraft Pilot Impedance from Inverse Dynamics-Based Biomechanical Model

The involuntary interaction of the pilot with a vehicle is often an undesired consequence of the biomechanical properties of the human body and its relation with the layout of the man-machine interface. This work discusses how muscular activation patterns affect the variability of the equivalent impedance of helicopter pilots. A multibody model is used to compute the joint torques associated to a prescribed pilot task, which are then transformed into corresponding 'optimal' muscular activation patterns. Equivalent pilot impedance is obtained by consistently linearizing the constitutive model of the muscles about the reference activation. The effect on equivalent impedance of non-optimal activation, resulting from the addition of Torque-Less Activation Modes to the optimal activation, is evaluated and discussed.