Maximum Workspace Research Articles

Kinematic Analysis and Design of Articulated Manipulators with Joint Motion Constraints

For an articulated manipulator with joint rotation constraints, we show that the maximum workspace is not necessarily obtained for equal link lengths but is also determined by the range and mean positions of the joint motions. We present expressions for sectional area, workspace volume, overlap volume and work area in terms of link ratios, mean positions and ranges of joint motion. We present a numerical procedure to obtain the maximum rectangular area that can be embedded in the workspace of an articulated manipulator with joint motion constraints. We demonstrate the use of analytical expressions and the numerical plots in the kinematic design of an articulated manipulator with joint rotation constraints.

Design of a singularity-free articulated arm subassembly

Adding a redundant degree of freedom to the shoulder pointing system complex of an articulated arm subassembly makes it possible to achieve a maximal workspace that is free of singularities. This paper derives a functional constraint between three of the four joints of this new type of arm, achieving a singularity-free workspace encompassing the entire reachable volume between the maximal- and minimal-reach surfaces. The large volume of dexterous workspace is verified by animation of the resulting arm design. Graphical results from the animation are presented comparing the dexterous workspace of this new arm to that of the standard nonredundant articulated arm subassembly found in the Puma manipulator. >

Anesthetic management for carbon dioxide laser surgery of the larynx

Fifty-one patients underwent 71 carbon dioxide laser procedures under general anesthesia for various intralaryngeal pathology. Anesthesia was induced with thiopental sodium, followed by succinylcholine to facilitate endotracheal intubation. For maintenance of anesthesia, 70% nitrous oxide was supplemented with halothane, enflurane or small doses of fentanyl. Succinylcholine, d-tubocurare or pancuronium were used to maintain muscular relaxation of jaw, pharyngeal and laryngeal muscles for a smooth lasing procedure. Small diameter (16-22 Fr.), red rubber, cuffed endotracheal tubes provided maximum working space, facilitated the controlled ventilation and reduced the explosion hazard of the anesthetic gases. Safely eyeglasses were used by all the personnel in the operating room against accidental injury to the cornea by the laser beam. Anesthetic management provided excellent operative conditions with maximum safety to the patient and the personnel in the operating room.