In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...

The optimal design of human lower limb prostheses, in particular of knee devices, is fundamental in order to restore the lost functionality and aesthetic aspect of the amputee’s locomotion. Among all knee devices, the four-bar linkage is still the most widespread mechanism, since, despite its simplicity, it allows the prosthesis to be sufficiently stable and, at the same time, to replicate the ...

Four-bar linkage mechanisms are of interest for many specialists in the academia and industry. However, it is one of the mechanisms that is highly nonlinear and exhibits complex behavior. Therefore, it is difficult to model and control their dynamic responses. In this paper, various control schemes are explored and tested on the four-bar mechanism to investigate the dynamical performance under ...

A spherical parallel manipulator (also called an orientational parallel manipulator or rotational parallel manipulator) refers to a threedegree-of-freedom (3-DoF) parallel manipulator in which the moving platform undergoes a 3-DoF spherical motion or rotates about a fixed point. In this paper, we propose a new method for the type synthesis of non-overconstrained (isostatic) spherical parallel m...