is desired/feedforward assistive torque,
	is control-oriented assistive elevation torque by the high-level controller,
	is human limb estimated model,
	is robot’s desired strength variable, which is positive for assistive and negative for resistive control between 0 and ,
	is smooth curve of the human elevation torque between the dead zone and the threshold torque,
	is wearable robot actuator model, the result of the rotor inertia and the viscous damping,
	is the positive threshold torque,
	is the positive dead zone torque,
	is actuator joint angle,
	is actuator joint angular velocity that is calculated with the derivative of the joint angle,
	is actuator joint angular acceleration that is calculated with the derivative of the joint angular velocity,
	is the gear ratio,
	is moment of inertia of the motor rotor around the elevation joint,
	is rotator viscous friction coefficient,
	is combined mass of the exoskeleton elevation mechanism, housing, and fixture of the motor,
	is gravitational acceleration, and
	is distance of mass center from the rotational joint.