TY - JOUR AB - AbstractWe consider tracking control for multibody systems which are modeled using holonomic and non-holonomic constraints. Furthermore, the systems may be underactuated and contain kinematic loops and are thus described by a set of differential-algebraic equations that cannot be reformulated as ordinary differential equations in general. We propose a control strategy which combines a feedforward controller based on the servo-constraints approach with a feedback controller based on a recent funnel control design. As an important tool for both approaches, we present a new procedure to derive the internal dynamics of a multibody system. Furthermore, we present a feasible set of coordinates for the internal dynamics avoiding the effort involved with the computation of the Byrnes–Isidori form. The control design is demonstrated by a simulation for a nonlinear non-minimum phase multi-input, multi-output robotic manipulator with kinematic loop. AU - Berger, Thomas AU - Drücker, Svenja AU - Lanza, Lukas Johannes AU - Reis, Timo AU - Seifried, Robert ID - 22206 JF - Nonlinear Dynamics SN - 0924-090X TI - Tracking control for underactuated non-minimum phase multibody systems ER - TY - JOUR AU - Sahai, Tuhin AU - Ziessler, Adrian AU - Klus, Stefan AU - Dellnitz, Michael ID - 16709 JF - Nonlinear Dynamics SN - 0924-090X TI - Continuous relaxations for the traveling salesman problem ER - TY - JOUR AB - In forced systems with cyclic symmetry localization can occur due toparameter uncertainties. Often, Monte-Carlo simulations are used to findregions, where the system response is sensitive to parameteruncertainties. These simulations require a large computation time.Therefore, an approximate method to calculate the envelopes of thefrequency response functions is developed in this paper. An example of anonlinear system with cyclic symmetry is a bladed disk assembly withfriction dampers. Friction dampers can be installed underneath the bladeplatforms of turbine blades. Due to dry friction and the relative motionbetween blades and dampers, energy is dissipated, which results in areduction of blade vibration amplitudes. By optimizing the mass of thefriction dampers, the best damping effects are obtained, which lead toan increase in the reliability of the turbine. In this paper, thecalculated response of a mistuned bladed disk assembly with frictiondampers is discussed. An approximate method is developed to calculatethe envelopes of the corresponding frequency response function forstatistically varying eigenfrequencies of the blades. Regions wherelocalization can occur with a high probability, are calculated by thismethod. AU - Sextro, Walter AU - Popp, Karl AU - Krzyzynski, Tomasz ID - 8924 IS - 1-3 JF - Nonlinear Dynamics KW - bladed disk assembly KW - mistuning KW - sensitivity KW - localization SN - 0924-090X TI - Localization in Nonlinear Mistuned Systems with Cyclic Symmetry VL - 25 ER -