Modeling and simulation of the dynamic response of a generic mechanical linkage for control application under the consideration of nonlinearities imposed by friction

Abstract

The present work deals with the dynamics of a generic mechanical linkage that is an integral part of many mechanical systems which require manual or automated control. It is necessary to include the dynamics of the control linkage in the model while modeling a system with such control for obtaining realistic dynamic behavior of the overall system. A typical application of the control linkages is to move an inertia element in a controlled manner, while keeping the motion as smooth as possible. Presence of inertia and elasticity in the form of a spring makes such system a second-order system, with a tendency to undergo oscillatory motion during such controlled motion. Presence of friction further introduces irregularities and nonlinearities in the motion of the target inertia element. Under these conditions, the trajectory of the controlling force has to be optimized to achieve smooth controlled motion. The present paper deals with these issues, by using a pedal-operated lever arrangement used in applications requiring controlled release or controlled engagement in mechanical systems. The computer tool used for simulation is MATLAB. The dynamic behavior of the system is assessed on the basis of total settling time of the target mass, computation time, time period of oscillation of the target mass, maximum amplitude, and amplitude decay. The present study can be useful in design of actuators and mechatronic systems involving similar dynamics.