Werner Neddermeyer

A Robot Arithmetic Processor Concept for Cartesian Closed-Loop Control with Prescribed Dynamics

Abstract The hardware implementation of a cartesian closed-loop control scheme will be presented which allows to define the dynamic behaviour of each degree of freedom of the cartesian coordinate system in a prescribed sense. The control system at joint level is designed by multivariate design methods with an additional feedforward component using the concept of inverse dynamics. To achieve high accuracy for cartesian motions quasi-continuous control mode with cartesian sampling periods of not greater than 5 ms is aimed at. A special purpose processor for calculation of kinematic and dynamic terns is designed and integrated into a multiprocessor architecture. This implementation concept with Robot Arithmetic Processor provides the necessary computational power and allows real-time cartesian closed-loop control which is also essential for cartesian sensory control tasks.

Self-Tuning Cross-Profile Control for a Paper Machine

Abstract The paper discusses a self tuning control algorithm for a multivariable plant applied to a grammage cross profile control of a paper machine. The plant model represents the steady-state couplings as well as the dynamics behaviour of the system. The control algorithm handles special situations including the case where the numper of measurments is not equal to the numper of actuators and the case where special actuators are locked. The whole identification algorithm with a specical filter and an estimation of the required measurment accuary for a succesful identification of the steady-state couplings will be discussed. The paper shows how to proof the stability of the control system including the cases of locked actuators and identification errors. Finally, the whole conrol system is verified by in house simulations and at a real plant. The obtained control results are discussed.

CAD of the Horowitz/Sidi-Design for Feedback Systems with Large Plant Parameter Uncertainty

Abstract I. M. Horowitz and M. Sidi (1972) presented a design procedure which guarantees quantitative demands on disturbance rejection and suppression of plant variation using the minimum controller gain just necessary for this effect. This paper describes an interactive, computer-aided implementation of this design procedure, which has proved to be very effective. The plant variations are handled by some expansions of a method from L. Longdon and D. J. East (1979), the controller design by a parameter optimization method using a vectorial performance criterion in an interactive manner.

3D-NaMiS, ein Navigationssystem für den minimal invasiven Eingriff

Das Navigationssystem 3D-NaMiS ist eine Entwicklung fur minimal invasive Eingriffe wie beispielsweise die periradikulare Therapie (PRT). Praoperativ wird der Patient in einer Modalitat untersucht und gleichzeitig wird die Hautoberflache von einem Multikamerasystem observiert. Der eigentliche Eingriff kann anschliesend in einer normalen Operationsumgebung erfolgen. Dabei sind oberhalb des Operationstisches Kameras befestigt, die wiederum die Hautoberflache des Patienten und das Operationsinstrument beobachten. Aus den 3D-Informationen der Modalitat und den Oberflachendaten aus der Operationsumgebung wird die relative Lage des Patienten zu den Schichtbildern der Modalitat berechnet. Mittels eines Visualisierungssystems wird dem Mediziner die aktuelle Lage seines Instruments in dem Volumenmodell der Modalitat dargestellt.

Application of a Multivariable Robust Controller Design Method to Hard-Coal Preparation

Abstract The paper describes an application of a robust controller design method for calculating the parameters of a controller for a multivariable hard-coal preparation process. The parameters are optimized via a sequential design method in the frequency domain, being based on a combination of the Horowitz/Sidi design (1972), Maynes (1973) sequential design and Steinhauser/Kreisselrooiers (1979) vector performance criterion method. The design was carried out using a relatively sophisticated CAD-program. The paper shows how the parameters are calculated with this CAD-method and discusses the simulated control results. The simulation is compared with the measured results at the plant after implementation of the designed controller on a process computer AEG 80/30 with a real time software control package ARSI * .

COMPUTER AIDED CONTROLLER DESIGN FOR A MULTIAXIAL SERVOHYDRAULIC VIBRATION TEST BENCH WITH LARGE PARAMETER UNCERTAINTIES

Abstract In 1973 I. Horowitz and M. Sidi have given a method for quantitative design by cascaded control of processes with large parameter uncertainties. This paper indicates the necessary modifications in case of bandwidth limitations and the differences in the results, which can be reached in such a case. As an example the design of a car test bench - which motivated the investigations -is discussed.