Soft robotic structures might play a major role in
the 4th industrial revolution. Researchers have successfully
demonstrated advantages of soft robotics over traditional
robots made of rigid links and joints in several application
areas including manufacturing, healthcare and surgical
interventions. However, soft robots have limited ability to exert
higher forces when it comes to interaction with the
environment, hence, change their stiffness on demand over a
wide range. One stiffness mechanism embodies tendon-driven
and pneumatic air actuation in an antagonistic way achieving
variable stiffness values. In this paper, we apply a beammechanics-based
model to this type of soft stiffness controllable
robot. This mathematical model takes into account the various
stiffness levels of the soft robotic manipulator as well as
interaction forces with the environment at the tip of the
manipulator. The analytical model is implemented into a
robotic actuation system made of motorised linear rails with
load cells (obtaining applied forces to the tendons) and a
pressure regulator. Here, we present and analyse the
performance and limitations of our model
