A method developed at the Laboratory of Process Automation (LPA), Saarland University, for compensating complex hysteretic actuator and sensor characteristics in open loop control is based on the so-called modified Prandtl-Ishlinskii method. Within the scope of the EU-funded project MESEMA (contract AST3-CT-2003-502915) the algorithm for the inverse filter was implemented in a FPGA and a digital circuit was developed, which can compensate two hysteretic actuator characteristics independently

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... simultaneously in open loop control, or one inverse filter can be integrated in a closed control loop, i.e. the second channel can be used for the feedback implementation. This board is easily extendable to several channels, since the FPGA works below its full capacity and other control algorithms could be implemented. The signal digitising occurs with 14 bit resolution and sampling frequency of 2.5 MHz. The overall signal run time of the compensator is 1 µs .