Soft robotics

This thesis is encompasses the design, construction, control and testing of an improvement upon the novel soft robotic Jennifish platform. The advancement of this platform includes the addition of light and depth sensors as well increasing the separation of tentacle groups from two to three sets. The final vehicle model consists nine PneuNetstyle actuators divided into three groups of three, molded around a machined Delrin pressure vessel. With a 12V submersible impellor pump connected to each actuator grouping, propulsion is created by the filling and emptying of these tentacles with surrounding ambient water. The Jellyfish2.0 is capable of omnidirectional lateral movement as well as upward driven motion. The vehicle also has a temperature sensor and IMU as did the previous of this platform. Qualitative free-swimming testing was conducted, recorded and analyzed as well as quantitative inline load cell testing, to create a benchmark for comparison with other jellyfish like robots.

Traditional robots are made from hard materials like hard plastic or metal and consist of
regular rigid mechanical parts. Using those parts has some limitations, like limited
dexterity and lack of flexibility. Some of these limitations could be avoided through using
a compliant material, because it has higher flexibility and dexterity. It is also safer to be in
direct contact with humans. This thesis studies soft pneumatic manipulators (SPMs) that
move in multi degrees of freedom (MDOF), which makes them able to perform various
functions. The study will include designing, fabricating, and testing three different SPMs
with different taper angles -- 0^0, 1^0, and 2^0 -- to measure the effect of varying this geometry
on the achievable force by the end effector and the range of bending and elongation. Every
single SPM consists of three soft pneumatic chambers to reach unlimited points on its
workspace through implementing bending and elongating movements. There are a lot of
applications for this kind of soft actuators, like rehabilitation, underwater utilizes, and
robots for surgery and rescues. Most soft pneumatic actuators provide one kind of movement, for bending, twisting, or elongating. Combining more than one kind of
movement in one soft pneumatic actuator provides considerable contributions to the body
of research. The SPMs were controlled and tested to evaluate the achieved force and two
kinds of movement, bending and elongating range. The results of each module has been
compared with the others to determine which actuator has the best performance. Then a
force controller was created to maintain the desired force that was achieved by the end
effector. The results indicated that the optimal angle of the SPM was 2^0.