After Hitler's rise to power, the couple had founded an underground group that helped imperiled Jews, assisted forced laborers, documented and archived Nazi acts of violence, especially in occupied areas in the East, and distributed anti-Hitler pamphlets.
3. Natural control of the assisting force.
Thus, we can generate the appropriate assist force for motion correction.
To employ energy control, the assist force must be synchronized with the operator's force possessing an arbitrary phase difference.
Namely, the assist force can adjust the impedance of the man-machine system, especially in a periodic motion.
We can then describe the assist force as begin{aligned} displaystyle F_s&=kA sin left( omega t + psi right).
We have confirmed that the control method can control operator's movement by adjusting the phase difference of assist force.
Next, we investigate the effects of the power assist and the skill assist through a visual tracking experiment by controlling the phase difference of the synchronized assist force.
The semi-active assist mechanisms use elastic materials as the source of the assist force and as actuators for controlling the elastic force.
On the other hand, (x_{20}) and (tilde{x}_{2}) are parameters to design the assist effect because it is related to the magnitude of assist force.
The operator's force is (F_h = tilde{F}_h sin (omega t)) and the assist force is given by Eq. (7).
