Andras Bartfai

Budapest University of Technology and Economics · Department of Applied Mechanics

This study presents a time domain simulation and workpiece surface generation framework for broaching operations, carried out with broaching tools of arbitrary geometry by machine tools of general dynamics. First, a three degree of freedom simulation model is formulated by considering an adequately discretized infinitely rigid tool, and a broaching...

This study is interested in the stability of robots in machining. The goal is to improve the dynamic performance of robots using an additional acceleration signal fed back through the conventional built-in proportional-derivative controller provided by the manufacturer. The structure of the robot is modelled with a simple one degree of freedom lump...

In this study, a non-autonomous dynamical system undergoing the simplest possible dynamic stability loss subjected to parameter change is investigated. Firstly, we give the approximate WKB analytical solution for the homogeneous equation, then a novel semi-analytical method is introduced to approximate the particular solution for a given excitation...

This study investigates the lane-keeping control of autonomous vehicles with an emphasis on the digital delayed nature of the system. The vehicle dynamics are represented using a kinematic bicycle model, and a hierarchical lane-keeping controller is introduced with multiple delays in the feedback loop. An extension of the semidiscretization method...

This study investigates the stability of robots in machining. The goal is to improve the dynamic performance of robots using an additional acceleration signal fed back through the conventional built-in proportional-derivative controller provided by the manufacturer. The structure of the robot is modelled with a simple one degree-of-freedom lumped m...

This study gives the derivation of the Hopf bifurcation calculation for neutral delay differential equations using the centre manifold reduction theorem and normal form calculation. The whole concept was inspired by a case study where a robotic arm subjected to nonlinear stiffness with delayed acceleration feedback controller is modelled. Two diffe...

Stability and bifurcation analysis of a non-rigid robotic arm controlled with a time-delayed acceleration feedback loop is addressed in this work. The study aims at revealing the dynamical mechanisms leading to the appearance of limit cycle oscillations existing in the stable region of the trivial solution of the system, which is related to the com...