Manipulator Cable with Constant StressA manipulator or mechanical arm involves an upper and a lower arm, with a variable angle between them. Cables used to transmit motion and force from the upper to the lower arms pass over a pulley at the joint or elbow. A pulley, axially fixed with respect to the joint, imposes a change in length of the cable as the angle between the arms varies. Manipulation design requires a cable of constant length during this variation; this constant length may be achieved by guiding the center of the pulley along the proper path. Acceptable solutions were obtained in terms of variables such as the lengths of each arm, the radius of the pulley, and the angle between the arms. In one design the pulley center is moved along a straight line with respect to the lower arm, while in the other solution the pulley center is moved along a circular arc with respect to the upper arn. Practical and economical mechanisms based on these solutions were investigated for use in manipulator design. |
Common terms and phrases
180 degrees 45 degrees 565 Transfer 90°0 Data missing A₁ addition ARGONNE NATIONAL LABORATORY Arm Center Line bending stress C-Eq cable length cable of constant cable or tape Cables and Tapes change in length circular arc constant length cot a)²+Y² cota Data missing Data Data missing TABLE Diff 11 ELECTRONIC MANIPULATOR equation four-bar linkage graphical solution JK and MN L₁/R L₂ L2 MN L₂-Y L₂/R length due load due LOOP-FLOW DIAGRAM lower arm manipulator design mechanical cable mechanical manipulators missing Data missing MN L2 moved the pulley O₁ Operation Codes Parameter Set 15 Parameter Set 21 Particular Solution Pitch Line Tangent prescribed path problem Pulley Center Moving pulley diameter Radians relationship single link Switch Table XXVII Trans to Beg Transfer To 586 Ultimate Load upper arm variation X-Y cot a)² Y cot a)² y²]² Ymax ΜΝ ρ μ