This dissertation deals with the design and optimization of a direct drive positioning system with air bearing. It is a question of a prototype positioning system with very accurate positioning and low system damping. Based on the similary laws of electrical machines, the design guidelines for maximum axis accleration are deduced. The scientific fundamentals for the systematic design and the closed loop performance are presented. For a high qualitiy position loop, a speed and a position information is necessary.The complete system is modelized in a digital controller. The controlled system is modelled and simplified on account of the application for dynamic positioning systems. The direct drive are investigated concerning the nonlinear influences like delay time, saturation and quantisation of the position sensor. Traditional position closed loop system has cascaded speed and position loop with classic controller (P,PI,PID). But for high dynamic and stiffness at all frequencies it is nessesary to realize a state space controller. The position is given by the sensor and is derivated to obtain the speed. For high bandwith position loop, it is necessary to add an observer.In addition to the closed loop performance further economical factors like costs, maintnance or duration of life are investigated. In future the direct drive will present a serious alternative to other drives also from the economical point of view. Linear motors offer smooth direct linear force. They have distinct advantages over rotary motors. Linear motors can reach very high accelerations and speeds. The investigation shows a great potential for direct drives.

Calculation of Harmonics of Rectifiers with the Computer

The rigid coupling between the electric motor and the fulcrum shaft of the Electromechanical Positioning System EMPS has been replaced by an elastic clutch. Also new is, that masses can be assembled on the sledge of the EMPS. The setting of the task for our diploma was to improve solutions of the last project (FS1997/1) and to realize new controllers for the System.

Refinement of the positioning set-point generator

The velocity-control of the previous project has been carried out with a PI-controller. The integrator of the controller didn't stop integrating and the control variable exceeded the limit.We now found a possibility to get rid of this problem with an anti-reset-windup circuit.Positioning-control with elastic coupling

The system combined with the elastic clutch had a super-elevation at a certain frequency in the bode-diagram. For this case a new controller had to be designed.We carried out a PI-controller for velocity with a notch-prefilter and designed a state-controller with a reduced observer to estimate the not measurable states.

Automatic controller-adaptation

Because the sledge of the linear axis now can be loaded with masses, it is necessary to invoke an adaptation to the controller. All controller-parameters of are optimally adjusted in every operating point.For this we designed a process for a dynamic load-measurement. It sets the moment of inertia of the mass when accelerating.Additionally we carried out an adaptive controller, which adapts his parameters with Fuzzycontrol. The parameters of the second notch-filter we realized, are also adapted with Fuzzycontrol.

Emergency stopping device

For the protection of the system we embeded an emergency stopping device, which slows down the sledge with the maximum moment of inertia when passing the end position switch and the comes to a stop. This is necessary, because the ABB servo positioner does not provide such guard when in moment of inertia control ope