Marc Dahan

A Historical Review of the Evolution of the Theory on Balancing of Mechanisms

This work deals with the historical aspects of the origins and the evolution of the balancing theory of mechanisms, the researchers and the countries where work has been conducted on this problem, the fundamental results obtained in the course of this century and the aspects in this evolution that are considered to be the most significant.

Development of a Mechatronical Device to Measure Plantar Pressure for Medical Prevention of Gait Issues

A medically helpful mechatronical device for natural gait analysis is proposed. This consists of an instrumented shoe equipped with eight force sensors. The instantaneous plantar pressures are recorded by a personal digital assistant (PDA) belted on the patient hips. This article describes this original concept and the first results of its use

Representation of tolerances using fuzzy Logic

Geometric parts of mechanical assembly are not manufactured precisely. Two uncertainty measures are especially interested for the defects representation: the distribution of the uncertainties that one piece can be manufactured at dimension X, and the likelihood that the assembly respects the functional constraints. This paper deals with the use of fuzzy logic for the representation of tolerances. This new method is an extension of the worst case and statistical kinematic analysis. It simplifies the equations of maximum likelihood which generally uses complex Gaussian distribution and is an easy understood representation of uncertainties. We treat the case of connecting rod — crank assembly as an example.

Experimental Analysis of a Translator Based on a Wohlhart Mechanism

The aim of this paper is to present a theoretical and experimental analysis of 6R-translator based on Wohlhart 6R overconstrained mechanism. The variable distance between the fixed plane and the platform of the 6R-translator is obtained using a theoretical approach and then validated experimentally.Copyright

Design of Spatial Fixed-Sequence Manipulator for Precise and Approximate Reproduction of Gripper Predetermined Positions

The synthesis of manipulation systems by the predetermined positions of the gripper is one problem of the most actual in modem robotics. One of the methods used to solve this problem is the creating one degree-of-freedom actuators with open kinematic chain allowing for either a precise reproduction of a limited number of gripper predetermined positions or an approximate reproduction of an unlimited number of gripper predetermined positions.

Équilibrage dynamique des mécanismes spatiaux

This paper deals with a new solution suggested for dynamic balancing (shaking force and shaking moment balancing) of spatial mechanisms. The conditions for balancing are formulated by the minimization of the root-mean-square value of the shaking moment. There are considered two cases: mechanism with the input link by constant angular velocity and mechanism with the input link by variable angular velocity. The method is realized by displacement of the axis of rotation of the input link connected with the counterweight. The efficiency of the suggested method is illustrated by numerical example.