Workspace Modeling and Analysis for Dexterous Hands

Abstract

The workspace is a fundamental feature for a dexterous hand to grasping plan, motion control, and mechanical design. Although the graphic, numerical, or analytical methods are valid to generate the workspace of dexterous hands, but there exist several defects for these methods to describe the workspace characteristics, such as forms, boundaries, volumes, and intersection workspaces. We propose a combined modeling approach to visualize and analyze the workspace of YWZ dexterous hand, which has¯ve¯ngers, 20 degrees of freedom (Dofs). The proposed approach is also¯t for similar dexterous hands to generate their precise workspaces. After a brief mechanism introduction of YWZ dexterous hand, a displacement equation of its index¯nger is deduced to calculate the¯ngertip positions in three-dimension (3D) Euclidean space. Then, a two-dimension (2D) boundary¯gure enclosing the°exion-extension motion¯eld of the¯nger is drawn by the displacement equation. Taking this boundary¯gure as a sketch in a CAD modeling environment, we further model a vivid 3D¯nger workspace, which is relative with the abduction-adduction motion of the¯nger. Besides, we generate the whole workspace of YWZ dexterous hand and analyze its volumes and intersection workspaces. The kinematic simulations and physical prototype experimentations are carried out to validate this approach can construct perfect workspace of dexterous hands. Compared with the Monte Carlo method, the form and boundary of the 3D¯nger workspace generated by our proposed approach have more accurate, integrated, vivid, and intuitional.

A Parametric Modelling Method for Dexterous Finger Reachable Workspaces

“…Compared with UGS NX, these tests prove that this prototype software can accurately, automatically and quickly model a 3D reachable workspace of the dexterous finger. For the parametric design of the whole dexterous hand, this prototype software can be improved in the future to model each finger-reachable workspace, calculate its reachable workspace volume and analyse the finger-intersection workspace, which is an important feature to evaluate the mechanical design, grasping range and manipulation dexterity of dexterous hands [20].…”

“…This process is difficult for mechanical designers, who have to master not only the computing software, such as Matlab, C ++, but also the 3D modelling software. Third, the designer needs to cost for much extra time in operating these pieces of software to obtain the 3D workspace with low interactive efficiency [20]. Instead, as pointed out in Ref.…”