  This paper presents a passive control method for multiple degrees of freedom
in a soft pneumatic robot through the combination of flow resistor tubes with
series inflatable actuators. We designed and developed these 3D printed
resistors based on the pressure drop principle of multiple capillary orifices,
which allows a passive control of its sequential activation from a single
source of pressure. Our design fits in standard tube connectors, making it easy
to adopt it on any other type of actuator with pneumatic inlets. We present its
characterization of pressure drop and evaluation of the activation sequence for
series and parallel circuits of actuators. Moreover, we present an application
for the assistance of postural transition from lying to sitting. We embedded it
in a wearable garment robot-suit designed for infants with cerebral palsy.
Then, we performed the test with a dummy baby for emulating the upper-body
motion control. The results show a sequential motion control of the sitting and
lying transitions validating the proposed system for flow control and its
application on the robot-suit.
