The mechanical design of a seven-axes manipulator with kinematic isotropy

Abstract

Abstract. Discussed in this paper are the issues underlying the mechanical design of a seven-axes isotropic manipulator. The kinematic design of this manipulator was made based on one main criterion, namely, accuracy. Thus, the main issue determining the underlying architecture, defined by its Hartenberg-Denavit (HD) parameters, was the optimization of its kinematic conditioning. This main criterion led not to one set of HD parameters, but rather to a manifold of these sets, which allowed the incorporation of further requirements, such as structural behavior, workspace considerations and functionality properties. These requirements in turn allowed the determination of the link shapes and the selection of actuators. The detailed mechanical design led to heuristic rules that helped in the decision-making process in defining issues such as link sub-assemblies and motor location along the joint axes.

Combined Structural and Dimensional Synthesis of Serial Robot Manipulators

“…However, in order to avoid the dimensional inhomogeneities of J, the dimensionally homogeneus Jacobian matrixJ (Ranjbaran et al 1995) must be used instead. The LCI is evaluated at the initial (q ini ) and end (q end ) point of the task.…”

Kinematic synthesis of a novel rapid spherical CRS/PU parallel manipulator

“…Other researchers [8][9][10][11] have applied these indices for optimizing the structure of the robot and to achieve other desired objectives, such as dexterity, isotropy, and accurate robot positioning and orientation. Making Jacobian matrix homogeneous has been performed by some researchers [12][13][14][15][16][17][18][19][20]. Ranjbaran et al [12] resolved this inconsistency by defining a Characteristic Length, by which they divided the Jacobian entries that have units of length, thereby producing a new Jacobian that is dimensionally homogeneous.…”

Joint stiffness identification of industrial serial robots

“…Later on, the concept of characteristic length was introduced in [27] and revisited in [28] in order to avoid the random choice of the normalizing length denoted L.…”