Publication

Abstract : A lot of applications require controlling the orientation of an object and this can be achieved using mechanical input devices or mechanisms with electronic sensors. It is desired that these mechanisms are balanced, such that they retain their orientation even after the user has stopped using it. This can be achieved using active or passive balancing techniques. A passively balanced mechanical input device utilizes springs or/ placement of optimum masses at appropriate distances such that the overall forces and moments acting on the mechanism are balanced. As the configuration of the links change according to the user's input, the mechanism should be designed such that the overall centre of mass remains constant. In this paper, a novel 3-R Orientation Sensing Mechanism (3-ROSM) is presented, which consists of three moving links and one fixed link. The characteristic feature of this mechanism is that the three axes of the links are intersecting as found in various gimbal linkage systems. The balancing is carried out using counterweights placed on linkages on the moving links. The end result is a mechanism that can be used as a hand operated balanced mechanism (HOBM) in applications such as tele-surgery; control of a CCTV camera mounted on a gimbal mechanism, etc., which utilize master-slave robotics as a principle. The proposed mechanism has been modelled and simulated for dynamic analyses in a CAD software and found to be suitable for passive balancing.