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.
Quality of motion and force transmission
Abstract Actual mechanism performance can differ markedly from the performance expected from a theoretically perfect model. A good quality design is one which not only theoretically solves the design problem but actually does so reliably when installed in its applications. This paper summarized work done by the author in developing merit functions which reflect motion and force transmission quality, and in combining these quality merit functions with primary design merit functions to form viable mechanisms design algorithms.
Knocking in an Internal-Combustion Engine
The question remains open of the relation between the phenomena of knocking in the engine and the explosion wave. The solution of this problem is the object of this paper. The tests were conducted on an aircraft engine with a pyrex glass window in the cylinder head. Photographs were then taken of various combinations of fuels and conditions.