I present Searle’s theory of intentionality and defend it against some objections. I then significantly extend his theory by exposing and incorporating an ambiguity in the question as to what an intentional state is about as between a subjective and an objective reading of the question. Searle implicitly relies on this ambiguity while applying his theory to a solution to the problem of substitution in propositional attitudes, but his failure to explicitly accommodate the ambiguity undermines his solution. My extension of his theory succeeds. I also indicate how the new theory can be deployed to resolve other outstanding problems.

This paper addresses the swing-free transport of simply suspended objects which cannot be grasped by robot manipulators, and therefore, must be carried by a hook or a similar device attached to the manipulator endpoint. Two methods are presented to stop the suspended object in a swing-free state at the end of a move/gross motion; (1) limiting transportation time, thus stopping the manipulator at the instant when the object completes one or more full cycle(s), and (2) adjusting traveling time of each section of a three-piece continuous trajectory provided that a given transportation time is unchanged. A hydraulically actuated robot manipulator carrying a compound pendulum was employed as an experimental system to test the methods. Simulation and experimental results are presented to demonstrate the feasibility of both methods. It is concluded that while limiting transportation time is not a preferred way to eliminate swing at the end of the move as it depends on the period of oscillation of the suspended object, the latter is a more practical and applicable method and is valid for moves of any length. The results reveal that by properly planning the acceleration of the transporting device, a robot manipulator or a similar device such as a crane, a swing-free stop is obtainable. The proposed approaches are simple and easy to implement.