Decoding the Equations: Understanding the Gripping Mechanism of Soft Robots

[ramadhankd]

Hello everyone,
So I'm trying to design a gripping system using a soft robot. I try to read a journal that explains about the gripping mechanism of the soft robot to measure the forces exerted by the soft robot to the object. The thing is, I got lost to several equations because I didn't find any relevance to any other respective equations that I know. The first is the moment equation (equation 6), second is the balances of linear and angular momenta (is this equilibrium equation?? equation 7), and the third is the total energy equation (equation 11, especially for the first term/strain energy).
Also, the journal seems to add a new coordinate system of E1 and E2, but I don't seem to understand the direction of them, and the difference in direction between E1 and E2 to X and Y.
Can someone help me understand this?
Thank you..:)

 

[Tom.G]

Just from a brief reading of the first four pages:
E₁ and E_2[ appear to be the normal to the surface of the work piece where the manipulator (gripper) contacts the work piece.