Volume 60, Issue 9 -

A method is presented that allows for the identification of parameters in a linear infinite-dimensional model for the heavy rope using only boundary measurements. The approach relies on an operational representation of the solution of the corresponding boundary value problem. A system of algebraic equations in the parameters is generated by repeated convolution of the measured trajectories. Simulations illustrate the results.

Modern turntable ladders are built as truss structures. Due to the length and limited stiffness of such structures, turntable ladders are susceptible to harmonic oscillations in higher modes. Using the model of an Euler–Bernoulli beam with multiple homogeneous sections, these oscillations can be reconstructed from measurements, and can effectively be damped using the hydraulic actuators. This paper considers parameter identification and active damping control for an IVECO Magirus M60 L, and presents experimental data validating the approach.

In this contribution an approximation approach for linear distributed-parameter port controlled Hamiltonian systems with damping (PCHD systems) is presented that allows for the preservation of the PCHD structure of the original system. Futhermore, it is possible to assure that the stability margin of the approximation satisfies a lower bound that depends on the dissipativity of the infinite-dimensional system operator. The presented approximation method is based on a generalized version of the Petrov-Galerkin approximation and has free parameters that can be used to achieve approximations with matching moments. The results of the paper are demonstrated by approximating a heat conducting system.

Based on the Finite-Element-Method — the most frequently used numeric principle of structural mechanics — and the method of Multi-Body-Dynamics — which serves the modeling of mechanical systems with large deflections — this paper presents the background of the coupling process of both methods. The combination leads to elastic Multi-Body-Dynamics and utilizes usually a Model Order Reduction. For this purpose, diverse techniques are implemented in the in-house software MORPACK that is introduced at the example of the commercial Finite-Element-Program ANSYS and the commercial Multi-Body-Dynamics-Program SIMPACK.

This paper discusses the application of Proper Orthogonal Decomposition (POD) to the model reduction of particle processes in fluid flow. This class of processes is highly relevant for chemical and pharmaceutical industry. As detailed first principle models of such processes tend to be very complicated, reduced models are required for process control and process design. POD is an attractive method to obtain the reduced models, as it is highly flexible, does not require a special structure of the reference model and treats internal and external coordinates in the same manner. The method is presented and illustrated by examples.

In this paper, recursive versions of a subspace identification algorithm for linear parameter-varying systems are presented. In contrast to the original algorithm with block-processing, the recursive approach allows to avoid a simplifying assumption. This can lead to better identification results compared to block-processing. The performance of the algorithms is assessed using a benchmark example from literature.