Bawab, S, Kinzel, GL & Waldron, KJ 1996, 'Rectified Synthesis of Six-Bar Mechanisms With Well-Defined Transmission Angles for Four-Position Motion Generation', Journal of Mechanical Design, vol. 118, no. 3, pp. 377-383.
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This paper describes a rectified synthesis method where a rigid body of a six-bar linkage with well-defined transmission angles is guided to pass through four precision positions. The procedure includes the elimination of circuit, branch, and order defects. This is achieved by decomposing the six-bar mechanism into groups of vector pairs called dyads and groups of three vectors called triads. The algebraic method of synthesis can be applied to rectify those chains. Although these defects can be eliminated, it has been a challenging task in the past. The procedure has been implemented for a Watt I crank-driven six-bar linkage in the interactive synthesis package RECSYN.
Furukawa, T, Rye, DC, Dissanayake, MWMG & Barratt, AJ 1996, 'Automated polishing of an unknown three-dimensional surface', Robotics and Computer-Integrated Manufacturing, vol. 12, no. 3, pp. 261-270.
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Sreenivasan, SV & Waldron, KJ 1996, 'Displacement Analysis of an Actively Articulated Wheeled Vehicle Configuration With Extensions to Motion Planning on Uneven Terrain', Journal of Mechanical Design, vol. 118, no. 2, pp. 312-317.
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This manuscript presents a displacement analysis of actively articulated wheeled vehicles on uneven terrain. These vehicles are distinct from traditional wheeled systems since they have the ability to actively adapt to variations in the terrain and they can actively influence the forces at the wheel-terrain contact locations. They also possess special mobility capabilities such as obstacle climbing and self-recovery from an over-turn failure. The problem of solving for the configuration of these vehicles on uneven terrain has been addressed in detail. The displacement analysis leads to multiple solutions due to the inherent nonlinearity in the position kinematic equations. Geometric reasoning has been used to identify the particular configuration that represents the “correct” vehicle geometry on the terrain. Applications of the displacement analysis algorithms to vehicle planning on uneven terrain have been discussed. An obstacle climbing maneuver of a three-module actively articulated wheeled vehicle has been described.
Sreenivasan, SV, Waldron, KJ & Mukherjee, S 1996, 'Globally Optimal Force Allocation in Active Mechanisms With Four Frictional Contacts', Journal of Mechanical Design, vol. 118, no. 3, pp. 353-359.
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Mechanisms interacting with their environments that possess complete contact force controllability such as multifingered hands and walking vehicles are considered in this article. In these systems, the redundancy in actuation can be used to optimize the force distribution characteristics. The resulting optimization problems can be highly nonlinear. Here, the redundancy in actuation is characterized using geometric reasoning which leads to simplifications in the formulation of the optimization problems. Next, advanced polynomial continuation techniques are adapted to solve for the global optimum of an important nonlinear optimization problem for the case of four frictional contacts. The algorithms developed here are not suited for real-time implementation. However, these algorithms can be used in off-line force planning, and they can be used to develop look-up tables for certain applications. The outputs of these algorithms can also be used as a baseline to evaluate the effectiveness of sub-optimal schemes.
Waldron, KJ & Sreenivasan, SV 1996, 'A Study of the Solvability of the Position Problem for Multi-Circuit Mechanisms by Way of Example of the Double Butterfly Linkage', Journal of Mechanical Design, vol. 118, no. 3, pp. 390-395.
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It is frequently forgotten that the common methods of position analysis of planar linkages, which are based on dyadic decomposition, are not general. This is true regardless of whether a graphical or analytical approach is used. It is demonstrated in this paper that relatively simple linkages can give rise to problems that cannot be addressed by dyadic decomposition methods, and that solution of these problems can be far more complex.