— In past research on the control of pneumatic
actuators, typically proportional servo valves have been used for
achieving high-performance control of the mass flow rate. In this
brief, we instead use fast-switching ON/OFF valves due to their
distinct advantages in terms of low cost and small size. Accurate
control of pneumatic actuators with ON/OFF solenoid valves
is a challenge since the system dynamics is both discrete
input and highly nonlinear. In this brief, we apply a hybrid
control algorithm to a pneumatic actuator with ON/OFF valves.
Such a control approach is developed for choosing the best
control vector at each sample time to track the reference state
(i.e., desired force) in the inner force control loop within a
bilateral teleoperation system. Experimental results show that
good teleoperation transparency is achieved despite all the
obstacles such as discrete input and nonlinear behavior of the
pneumatic-actuated teleoperation system.
Index Terms— Bilateral control, haptic teleoperation,
hybrid control, ON/OFF solenoid valve, pneumatic actuators,
transparency