A Robust Control of Contact Force of Pantograph-Catenary for The High-Speed Train Nassim MOKRANI and Ahmed RACHID ∗ Abstract In this paper, a simplified model to three degree of freedom (3-DOF) of the pantograph-catenary (PAC) system is represented. A robust control of contact force between the pantograph and the cate- nary for the high-speed trains using the fuzzy slid- ing mode controller and the additional compen- sator is presented. A PID outer loop in the con- trol law is use then the gains of the sliding term and PID term are tuned on-line by a fuzzy system. The result of the simulation is fit for the actual phe- nomenon. Thus, the method of this paper is valid. 1. INTRODUCTION One of the main problems in high-speed train transportation systems is the control of the contact force between the catenary and the pantograph col- lector end. The force exerted by the pantograph on the contact wire oscillates a lot, such oscillations can originate electric arcs that damage the mechan- ical structure and reduce the system performance [1]. The contact wire is an elastic system which can be characterized from a static perspective by its stiffness and from a dynamic one by its frequency. In addition, by design, it contains non- linearities that make the modeling difficult. The pantograph is an articulated system, also non-linear, which has its own dynamics and can be modeled more or less finely. Studies on the interac- ∗ Laboratoire des Technologies Innovantes (LTI), Universit de Picardie Jules Verne, 7 rue moulin neuf, 80000 Amiens, France. Phone:0033-322-804-221; email:rachid@u-picardie.fr tion between the pantograph and the catenary [2, 3] have shown that the variation of the contact force is primarily caused by the variation of the elasticity along the reach, and the waves propagation in the catenary’s contact wire (console and return arm). When the pantograph slides under the cate- nary, the change in stiffness causes a periodic ex- citation which leads to the vibration of the pan- tograph and to fluctuations in the contact force. Moreover, as the pantograph head slides along the contact wire of the catenary, it causes an increase in wave’s propagation along the contact wire. This wave’s propagation affects the contact force and also the pantograph movement. To provide an- swers on the dynamic behavior of the system, an improved model; more general compared to the one proposed in [4, 5, 6], was designed. The task of regulating the contact force to a pre-specified constant value of about 100N in the presence of model uncertain-ties and external dis- turbances is suggested. Different approaches have been followed in order to cope with this prob- lem, such as, for instance, Optimal control strategy, [7, 8, 9, 10], H control method [11], fuzzy-sliding mode control [12, 13], Variable Structure Control (VSC) with Sliding Modes (SM) [4, 14, 15]. A Sliding Mode Fuzzy Controller (SMFC) inherits the robustness property of Sliding Mode Control and Interpolation property of Fuzzy Logic Control, so that the non-linear switching curve can be approximated and the robustness can be main- tained. Sliding mode control is known for its ro- bustness to the external disturbance and system modeling error [16]. In Sliding Mode Fuzzy Con- troller each fuzzy rule output function is exactly a sliding mode controller, the slope of the slid- ing mode controller in each rule is determined by the approximate slope of the nonlinear switch-ing 2013 European Control Conference (ECC) July 17-19, 2013, Zürich, Switzerland. 978-3-952-41734-8/©2013 EUCA 4568