199 research outputs found
On Crossley's contribution to the development of graph based algorithms for the analysis of mechanisms and gear trains
This paper celebrates a particular branch of Crossley's early work dedicated to Mechanism Science, which deals with a rigorous introduction of Graph Theory to the study of some fundamental and intrinsic properties of kinematic chains and mechanisms. Although such idea gave its main outcome in Type and Number Synthesis (which has been much better and extensively described in another paper of the present special issue) some other intriguing side effects appeared, later in Mechanism Science, which yielded several results, and are still in the center of research and industrial world interest, such as, to name but a few, the automatic generation of the equations governing kinematic, static force and dynamic analysis of mechanisms and geared trains, the power flow analysis, the computation of the efficiency and, finally, the never fully explored structure-to-function mapping, which the present contribution points out to be still a challenge in the field
Control and virtual reality simulation of tendon driven mechanisms
In this paper the authors present a control strategy for tendon driven mechanisms. The aim
of the control system is to find the correct torques which the motors have to exert to make the end
effector describe a specific trajectory. In robotic assemblies this problem is often solved with closed
loop algorithm, but here a simpler method, based on a open loop strategy, is developed. The difficulties
in the actuation are in keeping the belt tight during all working conditions. So an innovative solution
of this problem is presented here. This methodology can be easily applied in real time monitoring or
very fast operations. For this reason several virtual reality simulations, developed using codes written
in Virtual Reality Markup Language, are also presented. This approach is very efficient because it
requires a very low cpu computation time, small size files, and the manipulator can be easily put into
different simulated scenarios
- …