One of the major problems of robotics and especially legged machines is the need for high force/torque to weight and high power to weight ratios of the actuators combined with relative low actuation rate. Aiming to develop such lightweight actuators, the multibody mechanics group started studying pneumatic artificial muscles in 1995.
Pleated Pneumatic Artificial Muscle (PPAM).
Pneumatic artificial muscles are contractile devices operated by pressurized air. When inflated, they bulge, shorten and thereby generate a contraction force. The force depends on the applied pressure and on the muscle’s length, ranging from an extremely high value at maximum length, i.e. zero contraction, to zero at minimum length or maximum contraction. Because of the one-way force a paired or antagonistic set-up is needed in order to generate a restoring force or movement. The PAM developed by the group is characterized by its pleated shape, allowing bulging to happen free of material deformation and friction. Its non-linear force-length relation is directly proportional to the applied pressure. Energy losses are reduced to a strict minimum.
More information about the pleated pneumatic artificial muscle can be found here.
Second Generation Pleated Pneumatic Artificial Muscle and Its Robotic Applications
Authors: VERRELST Bjorn, VAN HAM Ronald, VANDERBORGHT Bram, LEFEBER Dirk, DAERDEN Frank, VAN DAMME Michael
Reference: Advanced Robotics, Volume 20 No. 7, 2006, pp. 783-805
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