1 Introduction - On the sector of metrology the analysis of finest surface structures can be considered as one of the
basic tools for the development of high-tech products such as micromechanical systems. Therefore accuracies of
measurement in the range of few nanometres are concrete demands concerning the specification of positioning and
measurement devices. One possibility to optimise high precision positioning systems is to acquire, to evaluate and at
last to compensate all environmental parameters that may have a negative influence. Regarding the development of
the nanopositioning and nanomeasuring machine (NPMM) at the Technical University of Ilmenau the temperature is
one of the main parameters in terms of a disturbance variable that has to be controlled. A variation of the
environmental temperature as well as a variation of the temperature inside the mechanical structure of the NPMM can
effect large errors of measurement. The use of Lorentz-actuators for the ability to perform positioning with high
resolution on the one hand leads to a high heat input into the complete system on the other hand. To solve that
Problem the matter of this work is the realisation, integration and controlling of a unit for the compensation of variable
loads in order to release the drive units of the vertical positioning direction of the NPMM an so to reduce the heat input.
- 2 Realisation - The Lorentz-actuators of the NPMM's z-stage can be considered as an intrasystem heat source that
reaches a value of thermal dissipation loss of up to two digits. The therefore responsible supply current can be
minimised by reducing the variable loads acting on the actuators. The compensation of those loads is realised by
integrable functional modules that are able to perform a PC-controlled dosage of the needed compensation force. By
using a special experimental rig the operating parameters of an existing prototype of such a unit are acquired and
compared with model data. The following process of integration bases on the established parameters. - 3 Summary -
The compensating forces of one unit for compensation of loads can be dosed with an accuracy of 1% within the range
of 2.5 N to 4.75 N. Furthermore a reduction of at least 96.7% of the load acting on all Lorentz-actuators of the NPMM's
z-stage can be achieved. It is possible to integrate four units for compensation of loads without any change of the
mechanical structure of the NPMM's x- and y-stage. The development of new software tools with MATLAB allows the
control of the four units via RS232.