A min-max problem of optimal actuator placement for lifting
Summary The paper addresses the following problem: for a three-bar lifting linkage, find the locations of the two ends of the actuated link so as to minimize the maximum value of the force seen by the actuator over a specified range of arm angular positions. A simple analytical solution to this min-max problem is given, showing that the optimal locations are with the actuated link perpendicular either to the fixed link or to the lifting arm, when the arm is in a horizontal position. The method can be used to optimize the actuation of robots, doors, platforms, landing gears, etc., and allows to account for actuator length constraints. It can be extended also to Stewart's platform-type spatial manipulators.
On the Maximum and Minimum Velocities and the Accelerations in Four-Link Mechanisms

 A method of analysis has been developed for obtaining (a) geometrical criteria for an extreme value of the angular velocity ratio of one link relative to another in a four-bar mechanism; (b) a direct method of determining the angular acceleration of the follower link of a four-bar mechanism, and maximum values of this acceleration in certain special cases. The results have been applied to a slider-crank mechanism.
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