Comparison of different control approaches aiming at enhancing the comfort of a railway vehicle

Abstract

In the last years magneto-rheological dampers have been successfully used to realize semi-active suspension systems for automotive applications. Due to their dimension flexibility and the wide range of forces they can exert, these devices can be used even for railway applications, such as in the present work. This paper is focused on the design, evaluation and comparison of different control strategies for semi-active suspension system on the secondary suspension stage of an high speed train. In particular, the classical simulation of mechanical impedance, also known as "skyhook damper", and a "sliding mode" control exploiting the gradient projection method in order to cope with linear constraints on the forces, have been compared to a traditional passive suspension system. In order to test the proposed control strategies and to simplify the control gain refinement, a multi-body model of the railway vehicle have been built by means of Matlab/Simulink TM . Moreover, in order to fairly compare the different control strategies, a performance index has been defined, which is based on the comfort test that is usually done on real trains.

Design and testing of an innovative electro-hydraulic actuator for a semi-active differential

“…High bandwidth and precision: the response time of semi active MR actuators is often measurable in terms of milliseconds reaching control bandwidth that is very difficult to be achieved by conventional mechanical actuators. 13,14 A relative low energy consumption: energy consumption is often limited to few Watts needed to feed solenoids that produce the magnetic flux through the fluid. 15 However, despite the interesting properties of MR fluids, the adoption of conventional clutches with a proper actuation system still maintains great industrial interest, mainly for three reasons: a wider range of regulated clamping torques and operating conditions compared to MR fluids; lower costs in comparison to MR solutions; high reliability compared to some known stability issues of MR fluids due to aging or excessive thermo-mechanical loads.…”

Design and testing of a pulley and cable actuator for large ball valves

“…18 Moreover, the authors have specific experiences on this field, mostly derived from experimental activities on hydraulic active suspensions for a railway pantograph 19,20 and from the design of hydraulic semi-active suspension systems of railway vehicles. 21…”

“…18 Moreover, the authors have specific experiences on this field, mostly derived from experimental activities on hydraulic active suspensions for a railway pantograph 19,20 and from the design of hydraulic semi-active suspension systems of railway vehicles. 21 The tested positioner has a quite slow dynamical response (valve opening time is about 10-12 s), so a high dynamical response that should be granted by controlling pressure in both chambers 22 of the hydraulic actuator of the rig does not represent a primary aim. In addition, the rig hydraulic cylinder has to be controlled in order to work as a hydraulic brake.…”

Non-fragile multi-objective static output feedback control of vehicle active suspension with time-delay

“…linear optimal control, [2] linear and nonlinear skyhook damping control, [3] sliding mode control of active suspension system for a high-speed pantograph, [4][5][6][7] etc. In particular, H ∞ , H 2 , L 2 -L ∞ (or generalised H 2 , i.e.…”