Pantograph/Catenary Contact Force Control

Abstract

In this paper, a new continuum-based pantograph/catenary model based on the absolute nodal coordinate formulation (ANCF) is proposed and used to develop an effective method to control the contact force which arises from the pantograph/catenary interaction. In the proposed new model, only one ANCF gradient vector is used in the formulation of the pantograph/catenary contact conditions, thereby allowing for using the proposed approach for both fully parameterized and gradient deficient ANCF finite elements. A three-dimensional multibody system (MBS) model of a pantograph mounted on a train is developed using a nonlinear augmented MBS formulation. In order to take into account the catenary large deformation, ANCF finite elements are used. The contact between the pantograph and the catenary system is ensured using a sliding joint constraint whereas the contact between the rail vehicle wheels and the train track is modelled using an elastic contact formulation. In addition to the use of the new MBS approach to model the pantograph/catenary interaction, the contact force between the pantograph and the catenary is computed using a simpler lumped parameter model which describes the pan-head and the plunger subsystem dynamics. In order to reduce the standard deviation of the contact force without affecting its mean value, a control actuator is used between the pan-head and the plunger. To this end, three types of control laws for the control action are designed to improve the contact quality both in the transient phase and in the steady state phase of the pantograph/catenary interaction. The first control law proposed features a feedback structure whereas the second and the third control strategies employ a feedback plus feed-forward architecture. In order to demonstrate the effectiveness of the proposed method, the results of a set of numerical simulations with and without the controllers are presented.

Modal Coupling in Presence of Dry Friction

“…The research of the authors is finalized with the development of new methods for performing accurate analytic modeling [26][27][28][29][30], numerical parameter identification using experimental data [31][32][33][34][35], finite element analysis in the presence of dry friction [36][37][38][39][40][41][42][43][44][45] and control optimization for dynamic models of retrofitted mechanical systems [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. The main theories that describe the squeal phenomenon ascribe the increase of vibration amplitudes to the stick-slip mechanism or to the geometrical instability of the brake assembly.…”

Development and implementation of a control system for a retrofitted CNC machine by using Arduino

“…Therefore, the main research efforts of the authors are devoted to the development of new methods for performing accurate analytic modelling [31][32][33][34][35], numerical parameter identification using experimental data [36][37][38][39][40], and optimal control optimization for dynamic models of multibody mechanical systems [41][42][43][44][45][46]. In particular, this paper is focused on the development of a control scheme by using the Arduino platform in order to convert a machine for performing simple manufacturing operations.…”

Obstacle Avoidance System for Unmanned Ground Vehicles by Using Ultrasonic Sensors

“…Furthermore, the use of low-cost electronic components does not affect the possibility to obtain good models by means of identification techniques [20][21][22][23][24]. The identification of models and very detailed multi-body models, created by using 3D CAD models [25][26][27][28][29][30][31], are the starting point for designing optimal control laws [32][33][34][35][36][37][38][39][40][41][42]. Most multi-body simulation software considers systems made up of rigid bodies, but it is possible to study the behavior of flexible multi-body systems by using ANCFtechniques [43][44][45][46].…”