Two-link robotic robotic arm

Contexts in source publication

Context 1

... two-link robotic arm presented in Fig. 3 is subject to the gravity represented by the vector g, which is equivalent to an acceleration a = −g in the proposed approach. The reference frame in acceleration is noted R = (O, x, y, z). The arm is composed of 3 bodies B 1 , B 2 , and B 3 . The revolute joints J 1 and J 2 , which allow the rotation around x, are actuated with ...

Context 2

... rotation around x, are actuated with torques T 1 and T 2 . B 3 is a point mass representing the end-effector carrying a load, and is rigidly connected to B 2 (no degree of freedom). The characteristics of the rigid bodies are indicated in Table I. The position of the center of gravity (CoG) is the distance of the CoG from the body's left tip (in Fig. 3), normalized by the length of the body. Uncertainties of ±20% have been set on some parameters. The scheduling parameters t 1 = tan( ¯ θ 1 /2) and t 2 = tan( ¯ θ 2 /2) are defined as uncertain parameters in the revolute joints blocks. ...

Context 3

... vectors, wrenches) are evaluated with the routine ulinearize as static input/output transfers in separated SIMULINK files, where the individual static LFT models of each body at equilibrium are assembled (steps 1 and 2). Once the trim conditions are obtained as LFT models, they are re-injected in the linearized models which are assembled as in Fig. 4 (step 3). For readability, it is indicated whether the connections represent a motion vector δm or a wrench δW, but the full nomenclature adopted in previous sections is omitted. The LFT dependencies of the trim conditions are carried by the blocks ∆ of the revolute joints. A damping K d = 0.1 N s rad −1 and a stiffness K p = 0.1 N rad −1 are ...